The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools Search this Thread
Old November 23, 2018, 01:21 PM   #51
hounddawg
Senior Member
 
Join Date: March 1, 2009
Posts: 2,268
I can see where a wildcatter might find it useful with the right test barrel setup but other than that I don't see any benefit for the average shooter/reloader. Also from the comments in this thread the data it provides would be questionable at best. Erroneous data could be worse than no data when using it to find maximum safe pressures in my opinion. A false sense of security has led to many an accident
__________________
“How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek
hounddawg is offline  
Old November 23, 2018, 02:10 PM   #52
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
Do you really understand it? How would it benefit a Wildcat user and no one else?
Savvy_Jack is offline  
Old November 23, 2018, 03:03 PM   #53
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Anyone interested in the Pressure Trace instrument should read this article:https://www.shootingsoftware.com/ftp/Instrumenting%20your%20rifle.pdf. It will get your feet wet on what is and isn't possible to determine about pressures.

Jack,

First, housekeeping (and I am hoping this solves other people's problems in this area):

HOW TO MAKE A WORKING LINK (Windows)

Go to a page you want to link to in your browser and select and copy the content of the address bar at the top. Alternately, go to a working link, as to a YouTube video link, and right-click on it and from the flyout menu select to copy the link location. Back in the composition window you are trying to put the link into, you can paste the link text in and then select it and then click on the globe and infinity icon at the top of the composition window. This the place to place your link. It has "http://" already there for someone typing a link in manually. Delete that or select it so it will be overwritten, then paste your original link, still in your clipboard, into that and then click on "OK". DO NOT paste the text into your composition window and later copy it from your composition window, as the system sometimes truncates that text version. Also, you can skip the first step of pasting the link as text if you instead want to have other text in your composition contain the link. For example, you could write "You can see what I am describing on this video" and then select the words "this video" and then click on the link icon and paste in your URL. This will make the words "this video" turn into blue highlighting and clicking on them will then take you to the video.


On 44-40 pressures, SAAMI barrels have minimum chambers and nominal bore dimensions. To mimic one, you have to get a barrel blank made to their bore cross-sectional area dimensions and then chamber it with a special reamer ground to produce the SAAMI minimum chamber diameters and not run it in past half a thousandth beyond what produces SAAMI minimum headspace. That's ±¼ of a thousandth, which can take some skill to do. Standard reamers are commonly made a little wider so they can be resharpened without losing dimensional precision. I don't know if you followed these practices with your test barrel or not, but as Denton Bramwell points out in the article I linked to, most chambers made with standard reamers can expect to produce lower numbers.

SAAMI test barrels are fired with the cartridge manipulated to ensure the powder has fallen back over the flash hole. They are not tapped against anything to do this, as that packs the powder which can lower its burn rate a little. They want worst case highest pressure, so they just turn the case around to let the powder fall back to the rear, then load it carefully so as to avoid shifting the powder position. If you don't do that, you will get lower numbers than they do.

For rifle cartridges, SAAMI expects no more than 4% standard deviation in pressure. If your readings produce a higher SD than that, you are probably using a sample too small to be relied on to produce a good SD number. SAAMI uses ten rounds. Our own board member, Statshooter, who is a professor of statistics, says 30 rounds are needed. Denton Bramwell feels 15 rounds give him what he needs to know. So, why does SAAMI just use 10? They accept the SD results produced by 10 can be off on the high side by two standard errors (about another 2.5%), so they have a second number in addition to the MAP called the Maximum Probable Lot Mean, or MPLM, that allows the next sample of 10 from the same lot could produce a standard deviation that was different by that much. So, while the MAP is 11,000 psi, they allow they might get an average as high as 11,300 psi from another random sample of 10 from the same lot, and that is acceptable. They have a still higher number, called the Maximum Probable Sample Mean (MPSM) that allows that bullet bonding with the case and other factors can produce an increase in pressure as a lot of ammunition ages, and for the 44-40 that number is 11,700 psi. So, in effect, they are saying 11,700 psi is the safe limit, but, wait, there's more: All those numbers, the MAP, the MPLM, and the MPSM are averages produced by 10 round samples. The individual rounds making up that average will go above and below that average. SAAMI controls that by allowing what they call the Maximum Extreme Variation (MEV) which is the maximum spread between pressure readings for any of the 10 rounds in any sample taken at any time in the life of the lot. For the 44-40, the MEV is 2300 psi (this has to be calculated per the standard's instructions; it is not in a table). Theoretically, you could have aged loads centered on 11,700 psi whose 10 shots had one round as high as 13770 psi that would still be acceptable to SAAMI (though it is extremely improbable as it requires all 9 other shots to be exactly 11,470 psi). Mostly, though, you don't see individual rounds more than about ten percent above the MAP.

Even with all of that care, the fact is the absolute pressures are not exactly knowable. SAAMI reference cartridges are made in lots that are sent around to member's test facilities every two years to watch for reading changes. The members use SAAMI standard calibration methods (see the SAAMI standard) and report their results for both pressure and velocity from SAAMI standard test barrels. Interestingly, these vary more than the SAAMI standard deviation limit. The old 1992 standard gave an example for each method firing the same lots of reference loads, and the copper crushers, using targe tables for calibration, produced over 23% difference in average pressure for 10 shots among 9 labs. The transducers, using hydraulic pressure for calibration, produced over 11% difference in 10-shot averages among 7 labs. The reported results for each set of tests from each lab were, in turn, averaged and the final average was declared to be the pressure value that reference lot produced. This way, in effect, the reference lot pressure in the example was evaluated by looking at 90 and 70 total sample shots for the crusher and transducer, respectively. It compensates for average measurement calibration and operation errors, combined, to give a practical expected correct reading.

That approach may seem a bit tenuous, but understand the objective is to get everyone producing ammunition to the same standard, even if its absolute accuracy is not perfect. When a manufacturer wants to load a million rounds in a particular chambering, he buys a sample of a current lot of reference ammunition for that chambering and fires it in his own test equipment and compares his results to its agreed-upon rated pressure. This gives him a calibration factor for correcting his equipment's output to match the average output produced by the rest of the test labs that measured the lot. In the end, he doesn't load to the raw pressure readings his equipment provides, but to pressure readings corrected by what the reference load told him was his equipment's error factor.

So, if you wanted to compare your strain gauge results to commercial equipment, you would ideally get some SAAMI reference ammunition to calibrate to. Unfortunately, reference ammunition is only sold to ammunition makers or others who can show a real need to have it. Otherwise, I think, they fear a run on it would occur that could interfere with the industry.

One thing you could do is ask Buffalo Bore if they use the SAAMI reference ammunition and, assuming they do, you could probably ask them what their calibrated reading was for their most recent lot. You would still have to condition it in the same temperature it was conditioned and tested in by Buffalo Bore and handle the cartridges to keep powder to the rear, but you could get a correction factor to multiply your strain gauge factor by through shooting it and claim to match their pressure fairly closely. That sort of secondary standard approach is probably as close to absolute as amateur equipment can be made to be.

I notice all Hodgdon's psi-rated loads for the 44-40 exceed the SAAMI MAP, while their CUP-rated loads (in their pistol section) do not. Makes me wonder if someone confused the digits? It's still below the CIP's pressures, but those are measured on a different style of transducer (a channel transducer).

Regarding CUP ratings in manuals, while the correlation between CUP and psi is too poor for reliably converting one unit to the other over a range of chamberings, within a single chambering the conversion by the ratio of the CUP and psi maps within the SAAMI system is going to be close enough for practical work. That is, 11000 psi divided by 13000 CUP is 0.846 psi/CUP for the 44-40, so you can take the CUP numbers in the Lyman Manual and multiply them by 0.846 to get a reasonable expectation of psi. Conversely, dividing psi by that same number will come close to CUP.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 23, 2018, 03:17 PM   #54
hounddawg
Senior Member
 
Join Date: March 1, 2009
Posts: 2,268
Quote:
Do you really understand it? How would it benefit a Wildcat user and no one else?
I only care about three things when I develop a load
  • saftey - are there pressure signs
  • accuracy - does it group well
  • precision - does it group well at all ranges consistently

reloading manuals combined with online resources and a visual inspection of fired cases tell me all I need to know on the first, the second only needs my Mark1 Mod 1 eyeballs and glasses, the third uses the eyes also and a chrono to see if the velocities are flat. I fail to see how a piece of equipment that gives me a number representing pressure which may or may not be accurate would help.

Now can you explain why I need one when I have been getting great groups at all ranges without one and how it would improve my life in any way?
__________________
“How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek
hounddawg is offline  
Old November 23, 2018, 04:08 PM   #55
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
Awesome Unclenick...thanks a bunch!!! It took you a good bit of time to write that and I appreciate it more than you know. Thanks as well for clarifying the testing standards I have been pushing in and out of my brain from the SAAMI website. https://saami.org/wp-content/uploads...-SAAMI_CFR.pdf

Last edited by Savvy_Jack; November 23, 2018 at 04:27 PM.
Savvy_Jack is offline  
Old November 23, 2018, 04:13 PM   #56
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Cartridge pressure instrumentation's main value lies is in producing loads for shooting across multiple platforms, so if you are developing loads for guns that includes some antiques, as Savvy Jack is, or loads for sale, as Buffalo Bore is, then it is of value. Otherwise, knowing a peak pressure is mainly for comparative purposes. Out of two equally performing loads (on targets), the one with higher peak pressure will wear your throat out faster, for example. Of more concern to me is identifying bullet and powder combinations that produce a reflected secondary spike from blowing unburned powder and gas into the base of a bullet that can't get out of the way in time. It happens when the powder is too slow for the bullet weight and the bullet scoots forward expanding the volume behind it faster than the powder starts out making gas. Example of a normal trace and one with the bullet rear-ending phenomenon are below. While I can sort of guess what combinations to stay away from, this is the only way to prove it. That said, neither the comparison nor the collision indication requires absolute accuracy of the pressure reading; just that the loads be fired in the same gun with the same strain gauge.

Reproduced with verbal permission from Jim Ristowe at RSI.

Normal trace:




Powder too slow for the bullet weight. The collisions here can ring barrels and Texas gunsmith Charlie Sisk has been able to repeatedly blow muzzles off 338's with them.




Jack,

Glad to help. I thought maybe that last conversion would be useful to you.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 23, 2018, 07:45 PM   #57
hounddawg
Senior Member
 
Join Date: March 1, 2009
Posts: 2,268
Thanks Uncle Nick, that pretty much answered my question. For the type of loading I do I would see no benefits since I use book loads in modern rifles

can always find out something new here, gotta love it
__________________
“How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek
hounddawg is offline  
Old November 23, 2018, 08:39 PM   #58
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Some book loads will kick up the spikes, too. The problem is that to let handloaders use as many powders as possible, hoping to include what they have on hand, they include some that are really too slow. Watch out for combinations of high charge weight with a low maximum load pressure. If you stick to the powders that have the highest listed maximum pressures in Hodgdon or Lyman loads, you are working with the most consistent burners and those or the faster powders (lighter maximum charge weights) are unlikely to produce the problem with the bullet weight listed.

One of the funny things is that because the pressure spike doesn't actually occur in the chamber, but in a very short space right behind the bullet part way down the tube, copper crushers and transducers don't see them. The strain gauge picks them up because the event expands the steel above it and that spreads out along the barrel until it reaches the strain gauge and expands the steel under it. So even when a commercial loader builds such a load, as Winchester did in that second plot, above, they are unaware of it using SAAMI standard gear.

Hornady now uses strain gauges, so they should see them and for that reason I expect the loads in their current databook to be OK, making it another place you can check if a powder is OK to use with a bullet weight.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 23, 2018, 09:45 PM   #59
stagpanther
Senior Member
 
Join Date: March 2, 2014
Posts: 5,645
Hey unclenick--thanks for the clarifications--I remember those traces from Jim's site-- as I recall he used a 30 06 trace from a very well known manufacturer as the example for the secondary spike recorded. Since the gauge is intended to measure material expansion at the chamber proximity--is it fair to say that the pressure spike might be significantly higher than what the trace indicates? In the dim recesses of my scrambled mind I also recall having a discussion with Jim about a "P pulse" wave phenomenon upon ignition--a pulse wave that goes down the barrel to the muzzle and back again to the chamber as the bullet leaves the chamber.

It's been a while since I've hooked up my system--I've been trying to get ready for hunting and also spending (too) much time trying to figure out the 224 valk thing.I need to review and refresh my memory.

I once had a powder that had sat on my shelf for a while (and was actually already a pretty old lot when purchased on-line) produce pressure warning signs in the handloads I had fired that were well within charge weights listed in the reload manual. I erroneously assumed that in general when a powder degrades --among other things the powder efficacy degrades. I called the powder manufacturer about this--and was told for the particular powder I was using that in fact that energy yield could go up upon ignition as a result of degradation for the particular powder.
__________________
I screw things up--so you don't have to.
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!

Last edited by stagpanther; November 23, 2018 at 10:19 PM.
stagpanther is online now  
Old November 23, 2018, 10:14 PM   #60
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
I have heard nothing but good things about Pressuretrace II for the past ten years. I just never had the confidence that I could use it. The main reason I never got one was that I could not find/read enough information about it to gain the confidence to use it. I did purchase my MGM barrel some five-six years ago, built the platform but just finished it last year. After that was a success, I decided to take the plunge and I am glad I did. I sent my first few charts to Jim and he talked me through them. I am happy with what I have for what I need it for.

After talking with Jim and now seeing Unclenicks replies here, I now have 100% confidence in the program but I still have a lot to learn and a lot of work to do. I wish I could resolve my "noise" issue but I may have to purchase some more strain gauges. What I have is good enough for what I need. I am going to go ahead and share this one chart on this forum. Jim is aware of the charts I shared on my web site.

This chart shows the result from Lee's and Alliant's old Reloder 7 data, Alliant no longer publishes. Lee has or had this load on their 44-40 three die pamphlet. A quick phone conversation with an Alliant Rep gave me the answer I needed. What the information did not call for was what type of bullet, they only listed a 240gr lead bullet. I used Acme's 240gr SWC. I have experimented with different primers and the amount of crimp pressure, neck resize and even no resizing. I have used Remingon 2 1/2's. I have had issues with Winchester WLP's so I used CCI-300's this time with a hard crimp.

I have tested 28 loads so far of various bullets and powders and other components.

240gr SWC, Reloder 7... 1,284fps from a 24" barrel (Marlin 1894CB)
This is a photobucket image link, I hope it works.

Edited: Posted with permission from Jim Ristow

Last edited by Savvy_Jack; November 25, 2018 at 07:18 PM.
Savvy_Jack is offline  
Old November 23, 2018, 10:23 PM   #61
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Stagpanther,

There is a reflected gas pressure wave phenomenon that can occur and that has been known to damage artillery pieces, but rifles are too short for it to occur in. There is a pressure (longitudinal) wave created in the barrel steel when a bullet hits the throat and the chamber starts to expand a little more, but that travels in the steel at around 17 times the speed of sound, so you see its ripples in the pressure trace. There is probably a much slower transverse surface wave associated with that, but I don't think it has much effect on readings. I'm not sure what Jim was referring to.

Yes, the actual pressure is locally much higher at the point of pressure. As I've mentioned in other threads, Texas gunsmith Charlie Sisk has actually blown muzzles off 338's with them. Took him nine or ten shots of a particularly severe one of these loads to do it, but he could do it on demand; totally repeatable. But the photos I saw showed the breech end remaining intact.


Savvy Jack,

Congratulations on getting the unit to work for you. I'll point out you can improve on the graphics resolution. From the 80K at the top of the left side of the graph, I can see you had it in rifle sensitivity mode. Set it for handgun sensitivity and you will see a shorter scale and see the trace more clearly.

Just to give credit where it's due, I'll point out it is actually the hardware in the yellow box that does the measuring. The companion program just downloads the data from the instrument's memory and puts it into files you can store and review or manipulate. Pretty cool system.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 24, 2018, 08:37 AM   #62
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
I couldn't find rifle/handgun but I did find a high res view, is this it?
Savvy_Jack is offline  
Old November 24, 2018, 03:32 PM   #63
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
I put the scope back on today, maybe now I can actually hit that 25 yard target!!!

I had to send off my chronograph to get repaired so it may be a week or so before I can test 6 or 7 more loads plus those I failed to get velocities.



Savvy_Jack is offline  
Old November 24, 2018, 04:33 PM   #64
stagpanther
Senior Member
 
Join Date: March 2, 2014
Posts: 5,645
That's a really cool machine! Be a REALLY cool pinball machine for an arcade.

just teasing of course.
__________________
I screw things up--so you don't have to.
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!
stagpanther is online now  
Old November 24, 2018, 04:52 PM   #65
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
That plot is what I expected to see. I think the software has changed a little since my older RS232 port version of the instrument was made.

The scope looks snazzy, but for such a short range, I think I'd probably use a laser bore sighter. Green ones visible in daytime are as low as $20 now on Amazon. That one claims to be adjustable for windage and elevation (centering). You could set it up to be right on, though you'd probably need a "top" registration mark painted onto it.

Nice setup, though. Not too many folks have their own version of a universal receiver.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 24, 2018, 05:30 PM   #66
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
It was fun to play with but the scope is just a novelty and to make folks laugh. With the fireing pin thigamjig doohicky pinball thingy removed I can see right down the bore!

I have the red bore sighter that is inserted into the end of the barrel that works much better than the scope. Would rather have the cartridge type laser bore for my rifles but nobody makes one for the 44-40...can't figure that out since it is such a popular cartridge!!!!

More importantly it was a cheep build specifically for the Pressuretrace II equipment. Figured you guys would get a good laugh out of it!!

I really do like the Railguns but no way I can afford to venture that avenue.

Oh, the black pinball knob handle (thanks Stagpanther) is off of a door from a Maule aircraft :-)
Savvy_Jack is offline  
Old November 24, 2018, 05:56 PM   #67
stagpanther
Senior Member
 
Join Date: March 2, 2014
Posts: 5,645
unclenick is right--you deserve accolades for going above and beyond in trying to further your (and our) understanding of the complex science of ballistics (if that's what this even could be called).
__________________
I screw things up--so you don't have to.
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!
stagpanther is online now  
Old November 24, 2018, 06:27 PM   #68
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Jack,

If you know anyone with a lathe, they could certainly turn a brass adapter for you to let you use a 9 mm or a 38/357 cartridge-type bore sighter.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 24, 2018, 07:54 PM   #69
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
Ya know, I think I will add that to my bucket list!!

That was a great article too. I failed to mention it earlier.

Last edited by Savvy_Jack; November 24, 2018 at 11:21 PM.
Savvy_Jack is offline  
Old November 26, 2018, 08:56 AM   #70
F. Guffey
Senior Member
 
Join Date: July 18, 2008
Posts: 6,682
Quote:
Powder too slow for the bullet weight. The collisions here can ring barrels and Texas gunsmith Charlie Sisk has been able to repeatedly blow muzzles off 338's with them
.

What does that mean?

F. Guffey
F. Guffey is offline  
Old November 26, 2018, 09:08 AM   #71
F. Guffey
Senior Member
 
Join Date: July 18, 2008
Posts: 6,682
I ask because: Sisk was in Iowa Park, Texas and another smith, master machinist etc. was in Ft. Worth, Texas. The Ft. Worth smith/family decide they would venture off into blowing up guns, about the time they succeeded they drew up a different rational for the failures.

F. Guffey
F. Guffey is offline  
Old November 26, 2018, 09:44 AM   #72
stagpanther
Senior Member
 
Join Date: March 2, 2014
Posts: 5,645
Quote:
about the time they succeeded they drew up a different rational for the failures.
What was their rationale?
__________________
I screw things up--so you don't have to.
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!
stagpanther is online now  
Old December 3, 2018, 07:04 PM   #73
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
I hope this explains why I am using PressuretraceII

Using PressuretraceII allows me to use powders not listed in handloading manuals. Loads for this caliber [44-40] are few and far between. Only three bullets listed of which one is discontinued. It also allows me to compare all powders, including black powder pressures. Even black powders of today can be "weaker" than the black powders of yesteryear. PT-II allows me to load low pressures for my vintage firearms and allows me to get "the most" for my modern strong weapons.

unclenick

Here is a link to some of John Korts writings about early smokeless powders that added to my interests in me wanting to know modern pressures for the 44-40 in psi rather than in CUP using SAAMI's 11,000psi max.

https://www.44winchestercenterfireca.../Early-Powders

Many think the "weak link" into the 44-40's low pressures are attributed to the Winchester 73's weak toggle link when in reality in may actually be the weak steel used in black powder frame pistols. John hits a little on the early Winchester [1895 era] "RED" label smokeless powder offered for the 44WCF.

Early RED label boxes show only the Winchester 73' on the top label with the Winchester 92' being on the side labels indicating early smokeless powder was indeed safe for the 73' contrary to what many think today. It is noted at least on the 1900-1903 boxes that the ammo is for both the 73' and the 92 but "NOT FOR USE IN PISTOLS".

The nomenclature indicated the early smokeless powders were...again...indeed safe for the 73' BUT NOT FOR PISTOLS!!!

Thus it seams that smokeless powder, even those that produce 11,000psi, should never be used in black powder frame revolvers but are safe for all rifles and later stronger steel frame pistols.

To continue...the 1903-1938 Winchester "High Velocity" loads that produced 22,000cup...those Yellow label boxes...on the side label that has the small print, there should be included; "They should never be used in Winchester 73' Rifles". Early 1909 dated boxes show lavender labels "Winchester 92' Special" on the box top but also show "Low Pressure"...indicating truth in the fact that some early smokeless powder actually produced less pressure than the back powder. This causes many modern day shooter's brains to explode with confusion, myths and misconceptions. Even then the side label says "They should never be used in Winchester 73' Rifles".

The High Velocity loads were at some point around 1910 increased in velocity and probably pressures by again changing the label color to Yellow. At some point the Yellow label" High Velocity" loads show for use "Especially for Winchester Rifles 92'" and "NOT FOR USE IN PISTOLS".

It gets really confusing but the Label colors differentiating Smokeless vs Black Powder etc also used later on date codes and file code that explained the date code changes. The date code did not dictate the date the ammo was manufactured but covered the dates to changes made on the labels as well as cartridge component changes such as POWDERS and grains of powder, bullets primers etc used.

If you have not yet checked the link I posted, go do that now for some more explanations. Here is the link again.

https://www.44winchestercenterfireca.../Early-Powders

Also some Colorful cartridge box colors and their meaning.
https://www.44winchestercenterfireca...artridge-Boxes


I hope this explains why I am using Pressuretrace II

Thanks to all that helped get me started.

Last edited by Savvy_Jack; December 5, 2018 at 06:41 PM.
Savvy_Jack is offline  
Old December 22, 2018, 02:18 PM   #74
Savvy_Jack
Member
 
Join Date: February 4, 2018
Posts: 64
A very interesting thing happened today. I was finishing up my pressure testing today and shot a lot of groups. I decided to shoot some more black powder loads as well. This time, however, I used some original BP brass cases. A variation of Western, REM-UMC and WRA cases. four of the WRA cases used small pistol primers.

First, I shot 15 modern RP cases and 5 Winchester cases. I used 39gr of Swiss FFG in the Winchester cases and 40gr in everything else. 39gr of Swiss FFG gave me an average of 1,221fps from my 20" test barrel producing 8,843 PSI. The 40gr in the RP cases resulted in 1,257fps and 8,648 psi. Here is the kicker.....

I used 40gr of Swiss FFG in 16 original semi-balloon head cases of which four were small pistol primers. Same powder, same bullets, except for the four pistol primer cases...basically the same primers.

1,373fps @ 14,100psi!!!!!! HMMMmmmmmmm!!!!!!


On another note, to include the BP tests, I shot 42 pressure testing groups of at least 10 shots per group over the past few months.
Included are all of Lyman's 49th, page 299 and 300, MAX loads for both Group I and Group II rifles using Unique, IMR4227 and 2400 with the published bullets, primers, case lengths and AOL's.

All of my Group I loads ranged between 6,594psi to 9,389psi
My "Control", Buffalo Bore's 44-40 "Heavy" was set to 11,300psi.
All of my Group II loads came in between 11,363psi to 17,837 psi

What I failed to do was shoot all loads at the same out side air temps. The "Control" was shot in about 55 deg, some loads shot around 35 deg and the rest also around 55deg. This does change things a little but not too awful much. Some could increase as much as 1,500psi and those shot in 55deg could increase in 90deg weather.

However, out of all of the loads I have ever come up with on my own, only TWO were higher than the Lyman's MAX pressure results of 17,830psi. Those two were 19,500psi and 19,628psi.

Only one Reloder 7 load came in over 13,500psi and it was a 240gr LRNFL bullet and it achieved 1,446fps.
Other 240gr LRNFP bullets with a lighter load stayed below 11,000psi

Most case capacity Reloder 7 loads stayed between 10,000psi and 13,000psi. Even a caseload of Trailboss surpassed SAAMI max out to 15,182psi

The Pressuretrace II system was well worth the $$$ for a little piece of mind as well as closing the mouths of a few Mr, been handloading for 55 years, Know-It-Alls.
Savvy_Jack is offline  
Old December 22, 2018, 03:07 PM   #75
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 15,565
Jack,

Interesting about the cases and BP velocities in particular. Have you measured the actual case volume? How much water weight each case will hold when they are the same length?


Quote:
I ask because: Sisk was in Iowa Park, Texas and another smith, master machinist etc. was in Ft. Worth, Texas. The Ft. Worth smith/family decide they would venture off into blowing up guns, about the time they succeeded they drew up a different rational for the failures.

F. Guffey
I thought I had answered this earlier, but I must have started to compose the post and never finished. Charlie Sisk is a member at The 24hr Campfire forum, which is where I saw his photos originally. I'm glad I looked again for this reply, because there is now (as of 2015) some additional data from Denton Bramwell suggesting the size of the pressure jump may be an instrumentation artifact, but doesn't explain why it appears only with the light-bullet, slow-powder combinations and goes away when you either go to faster powder or a heavier bullet. The barrels blew off OK, but Sisk, who mentioned it in a June 2004 Handloader article, says he was never satisfied that they found a clear answer to the problem. Only that using very slow powder in 308 Win, 338 Win Mag, or 374 H&H let him routinely blow the ends of barrels, shortening them to about 21.7" regardless of the barrel contour or its length beyond that 21.7" point.

Denton Bramwell suggests the energy in the powder is inadequate to explain the blow-offs, but I know that's incorrect. Muzzleloaders have experienced barrel bulging by what is called "short seating" for decades, but Bramwell is correct that the damage splits them lengthwise when it happens in the range of three to six inches in front of the normal location of the end of the powder column.

So, the mystery deepens. Here is the 24 Hr. Campfire thread with more recent theories from 2015. Sisk also comments in it.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:00 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.09998 seconds with 8 queries