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Old June 16, 2013, 06:59 AM   #1
Pond, James Pond
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Over-pressure: how does the average reloader really know?

Once again, I read something that kickstarted my brain: particularly the "Am I doing something wrong" cortex in my "What if...?" lobe.

I have a .44Mag. It is on the short side at 4".

First of all, I have worked on the assumption that faster is probably better for a given bullet size, although I am beginning to realise that this may not always be the case.
All the same, if I want to get decent velocities out of it, I have to start pushing toward max-ish loads.

I have ordered some heavier .430 cal, 275gr bullets (which I hope to launch at anything from 1100-1200fps). I want to put them into a beefy round; dangerous to my target, but not to my gun.
This goal's difficulty is exacerbated by the fact that none of my reloading data feature the powders I use with the bullets I can get.

Initially I referred to materials telling me about this sign and that which would warn of over-pressure (rifle cartridges), and then I found that for revolvers (straight-walled cases) it is really only smooth extraction, loose primer-pockets and possibly non-incremental velocity jumps.

I then read this article (which made me want to rush out and buy a .454 SRH and load it with 45 Colt!!) linked in another thread and there I find examples that show even the primer and extraction signs are in fact fairly useless because sometimes they do not warn you of danger until well into very high pressures. That's like a seat-belt that only works if it is run over by a tank, but not if you drive into a wall!
In other words, you could have a load showing no sign of over pressure, yet with PSI at well over the SAAMI max for that round/gun!!

So what's left? Sudden jumps in velocity?

What can I reliably use to tell me, "Yes, this round is still OK. However, this one is on the excessive side and I need to back it off by .2gr..."
Sudden jumps in velocity?

At the moment it seems like a lot of it is conjuncture, gut-feeling and experience.
Well, mistakes are the mother of experience and I prefer to avoid mistakes.

Really.
What is left if you don't have pressure-reading manifold/apparatus in your basement??
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Old June 16, 2013, 07:46 AM   #2
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Buy a chronograph.

A loading manual may say that 47 gr of powder "A" is a max load, and will give you 2940 fps @ 60,000 PSI. If so, then 2940 fps is a max load and you will be getting pretty close to 60,000 psi at that speed regardless of how much powder you used. You use the bullet speed to determine what a max load is, not the charge weight listed in the loading manual.

Some guns will reach 2940 fps with only 45 gr of powder. That is a max load in that rifle. Other guns will only give you 2875 fps with 47 gr of powder. Some loaders would consider it safe to continue adding powder until you reach 2940 fps in that gun even if you load over the suggested max of 47 gr. I don't advise this. It might be safe in that particular gun, but what if that ammo gets loaded in a different gun?

It is not perfect, but using a chronograph is the easiest and cheapest way a handloader can get an idea of pressure.
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Old June 16, 2013, 07:56 AM   #3
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Yes, a chrony is as important as a powder scale.
But even that won't guarantee safe pressures.
There's conditions in reloading that can drive pressures up, without increasing velocity.
Increased friction, for example.
Like over sized bullets, bullets seated incorrectly, either too deep in the case, or against the rifling.
Or component combinations that do strange things, - anomalies.
That's why getting creative with the loading data can be dangerous.
It's best to stay with established data and verify with the chrony, just to be sure.
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Old June 16, 2013, 08:03 AM   #4
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Buy a chronograph.
Nice to read that in my first response because I have one already.

However, it opens up another can of worms.
My reference to velocity readings was about comparative jumps in speed. For example if I load at 0.2gr increments and my readings are 1200fps, 1220fps, 1240fps, then suddenly 1310fps, then that sudden burst of speed could mean a pressure spike and I need to back off a bit, returning to 1240fps as my max.

If I understand your description of using velocity, it implies that I need to text book standard velocity for a particular bullet and particular poweder combintation. I don't have that. Nowhere have I seen exact data for N350 or N110 with H&N 200gr plated bullets, N110 with FMJFN 240gr PRVI Partizan bullets, or now N110 and 275gr Cast Performance LFN bullets.
All from a 4" barrel.

Without that data to begin with, I don't have that max fps reading with which to compare my own load velocities: would I not still be "flying blind"?
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Old June 16, 2013, 08:06 AM   #5
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Quote:
It's best to stay with established data and verify with the chrony, just to be sure.
And therein lies my biggest problem:
I'd love to but I have none as I illustrated in the post above.
I am a novice reloader, trying to put together potent loads, with no solid data to work from: only approximations!!

Now you can see why I am so obsessed with these issues!

PS
And just to make the point, I've just had an answer from Lapua (on a Sunday ) stating that they can give no data on my chosen bullet/powder combi as they've not tested them. Can't blame them, but still feel a bit abandoned.
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Old June 16, 2013, 08:22 AM   #6
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Pond, James Pond, we are not talking about electricity, volts amps, ohms and watts , there is nothing about powder that reminds me of a rheostat, as in dial it up or dial it down, pistol powder is fast, the window between not enough and too much is a very narrow window.

Then there is driving, there are a few drivers that can not stay out of the fast lane, sometimes they confuse the fast lane with the a no passing lane, still there is nothing that will keep them out of the fast lane, they just have to jump out there, those drivers do not need to become reloaders. Back to the narrow window, discipline, I know reloaders that have absolutely no curiosity what effect 1 more grain will have on the accuracy and or safety.

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Old June 16, 2013, 08:24 AM   #7
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Re: Over-pressure: how does the average reloader really know?

I have written 3 different powder manufacturers via email with specific component combinations and all all relevant specifications of the weapon I was developing a round for. All have replied with starting and max loads. 1 asked me to report on my results as I was developing a special purpose round. A varmint round for 9mm carbine to rid critters from the garden on a small plot. I am having good results but have yet to complete my development.
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Old June 16, 2013, 08:33 AM   #8
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IMHO, I am not a great fan of max loads. A constant diet of max loads has been well known to cause premature wear on some revolvers. I have seen more than one Model 29 worn out by a constant diet of max loads. If you want more power out of a 44Mag, make sure you revolver can handle it. I would rather buy a 460 S&W if I wanted real power from a .429 caliber handgun. I could still shoot 44Mag & Spl thru the barrel.

Same idea with the 45 Colt. I would rather own the SRH in 454 Casull.
As far as cooking up some super hot 45 Colt loads and shooting in a SRH 454, I would warn you to pay close attention to your cases. Some WW & RP cases were not designed for such pressures. I would use 454 brass for power and the Colts for practice. My 2Cents.
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Old June 16, 2013, 08:33 AM   #9
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Quote:
Pond, James Pond, we are not talking about electricity, volts amps, ohms and watts , there is nothing about powder that reminds me of a rheostat, as in dial it up or dial it down, pistol powder is fast, the window between not enough and too much is a very narrow window.

Then there is driving, there are a few drivers that can not stay out of the fast lane, sometimes they confuse the fast lane with the a no passing lane, still there is nothing that will keep them out of the fast lane, they just have to jump out there, those drivers do not need to become reloaders. Back to the narrow window, discipline, I know reloaders that have absolutely no curiosity what effect 1 more grain will have on the accuracy and or safety.

F, Guffey
I'm not sure I follow your driving analogy with respect to my initial question, but I do understand that that the windows of "opportunity" in pistol powders is not great: all the more reason, if I have no available data, to have reliable methods of assessing where that max might be. If you have methods, such as interpreting chrono data, please share them.

Quote:
I have written 3 different powder manufacturers via email with specific component combinations and all all relevant specifications of the weapon I was developing a round for. All have replied with starting and max loads.
I'm glad you've had success. I, myself, have not. Perhaps the Lapua rep was just exercising a bit of C.Y.A., but I got no useful data from the exchange, except that they have not tried these bullets; some thing I already knew...
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Old June 16, 2013, 08:43 AM   #10
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MHO, I am not a great fan of max loads. A constant diet of max loads has been well known to cause premature wear on some revolvers. I have seen more than one Model 29 worn out by a constant diet of max loads. If you want more power out of a 44Mag, make sure you revolver can handle it.
I have a Ruger Redhawk: it should handle the power. I am not looking to shooting max loads all the time. I want to develop a load, based around the 275gr LFN that will be near max, as a woods load. I will develop the load, load up a couple of dozen and that will be that. Aside from the occasional practice shot to remind myself what they feel like, I will mostly be back on the mild 200-grainers and a few fuller 240gr loads.

Folks:
Whilst I appreciate the time taken to post, this is not a thread to discuss the merits of my chosen bullet/load. The ins and outs of my gun and ammo are just to put the discussion in context.

The issue is what is a dependable means of gauging when one's loads are exceeding max pressure if one does not have actual pressure gauging equipment
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Old June 16, 2013, 09:53 AM   #11
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fer-real MAX; I usually just guess

If at any time any anomalous behavior is observed, STOP.
Check EVERYTHING.
Do NOT move forward until the process, components, and testing equipment are confirmed.



Chrono-mapping: Add powder in .2g increments, chrono plenty, and as you work upward in charge weight you hope to observe a similarly progressive increase in fps.
Usually you will.

But, as queried, what if you see a sudden spike in velocity (fact: it can spike in either direction)?

I personally continue, as I have learned that the loads can return to a progressive increase.


To all following this thread, the OP has a specific goal for his load; he would like a defense-capable load for bear up to 600lb.
So, consider goal during the development process.

Based on goal, the .430" 275g bullet will need at least 980fps to provide sufficient penetration, and more velocity will aide further penetration.
Too much velocity may damage the bullet on impact, or during penetration, reducing its ability to penetrate further.


The specific bullet chosen is tough.

Since the final load will not be fired by machine, its recoil signature literally affects its effectiveness. The load must offer controllable accuracy, which is directly at odds with ever-increasing recoil as the velocity increases.

The platform used is tough.

That is not to suggest it is indestructible (I bent my 5.5" 44 Redhawk using a 300g lead bullet and poor loading process).


Starting will be easy.

With no published data for the specific combination, extrapolate a start load by using data for similar bullets --in this case hard-cast lead-- that weigh more and less.
Start.
Test.

Recoil will be a prominent factor during development; it will allow you to decide what more velocity may mean regarding controllability.
Maintaining controllability, work upward. Slowly.


The powder chosen has a progressive nature.

That does not automatically render every load safe. Testing in the specific platform will give data on its nature through the specific platform.

I promise: A 275g .430" bullet, regardless of velocity, means recoil. How much?
Personal in feel, and shooting results.

Vihta's data offers a 267g lead bullet, close to the chosen 275g lead.
They also show 300g data for two jacketed bullets.
Take all three start loads, and use (in this case) the lowest, since they are all close.
The bullet will not stick in the bore.
Work up in .2g increments, making five to test. Chrono, consider, add, test, observe.
Maintaining progressive behavior, and permitting controllability?
Since the goal will be readily met with velocity in the 1100--1200fps range, stop when you're satisfied.
Then make more, and test.
Still good?

Make many more and test; test in varied environmental contitions.
Still good?
Yer done
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Old June 16, 2013, 09:58 AM   #12
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pricey but effective

The only way I have to determine MAX is to exceed it, and back down.....so I stop before that.
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Old June 16, 2013, 03:00 PM   #13
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@WESHOOT2

Wow.... simply wow!

That is a post and a half...!!

Thanks for the pointers. I just need to determine that sweet-spot starting charge.

For N110 here are those I've found so far from different sources:
Jacketed 265gr: 16.6
Cast 267gr: 19.8
Cast 267gr: 20.3
Cast 267gr: 20.4
Jacketed 270gr: 16.2
Jacketed 300gr: 16.0
Linotype 300gr: 14.2
Jacketed 300gr: 18.1
Jacketed 300gr: 18.7
Jacketed 300gr: 17.8
Jacketed 300gr: 17.7
Jacketed 300gr: 17.3

Based on those, especially the cast 267gr bullets, I'd probably look to start around 18.5-19 gr of N110 over a standard primer.

I also think I'll go for velocity in the order of 1050-1150fps.
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Old June 16, 2013, 06:59 PM   #14
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Quote:
Originally Posted by chiefr
IMHO, I am not a great fan of max loads. A constant diet of max loads has been well known to cause premature wear on some revolvers. I have seen more than one Model 29 worn out by a constant diet of max loads. If you want more power out of a 44Mag, make sure you revolver can handle it. I would rather buy a 460 S&W if I wanted real power from a .429 caliber handgun. I could still shoot 44Mag & Spl thru the barrel.

Same idea with the 45 Colt. I would rather own the SRH in 454 Casull.
As far as cooking up some super hot 45 Colt loads and shooting in a SRH 454, I would warn you to pay close attention to your cases. Some WW & RP cases were not designed for such pressures. I would use 454 brass for power and the Colts for practice. My 2Cents.
That would in fact be one very unique 460 S&W! They aren't .429".
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Old June 17, 2013, 05:51 AM   #15
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I trust my Redhawks

I would be very comfortable with a start charge of 20.0g.
Chrono.


The chosen bullets are expensive, and you don't want to use them all up just learning......


I say that because I used 5.5" Redhawks in 41 and 44 Magnum, and 45 Colt, for ammo development. Extreme ammo. Not worth mentioning how incredibly tough the 7.5" 357 version is; its cylinder, sized to take 45 Colt, has those wee holes punched in it.
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Old June 17, 2013, 03:26 PM   #16
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I would be very comfortable with a start charge of 20.0g.
Chrono.
So if I start at 20gr, manage a speed of 1050fps, and can control it, that will be the quickest load development of all time!!

Otherwise, I'll follow your 0.2gr increment progression. In order to preserve what you rightly saw as a limited supply (especially if I want at least 12 workable rounds by the end of it), I'll only make 6 rounds at each charge.
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Old June 17, 2013, 03:32 PM   #17
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BTW, what about OAL?

Just seat it to the crimp cannelure?
The manuals vary from 42.7mm (1.681") for the 267gr Intercast and 40.8mm (1.610") 265gr JSP, to 43.6mm (1.717") for some of the 300gr Jacketed bullets.
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Old June 17, 2013, 04:24 PM   #18
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I don't even try to get close to max on any of my handloads.

If I want max handloads for a given task, I purchase Buffalo Bore loaded rounds.
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Old June 17, 2013, 04:27 PM   #19
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the standard reloader has the following to go buy with over pressured loads on a straight walled revolver case as according to linebaugh:

bulged cylinder, blown up cylinder.
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Old June 18, 2013, 06:39 AM   #20
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I might even suggest just three rds made for start load chrono-testing; normally, given good chrono-data collection, three WILL give you a fair indication of velocity.

Seat to crimp groove; crimp firmly.


To reiterate, heavy long bullets need only 'sufficient' velocity for them to successfully do their work. History teaches us that from handguns, between 1000--1200fps is normally 'sufficient'.

Folks can study successes with handgun vs grizzly and polar bear.
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Old June 18, 2013, 01:38 PM   #21
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Quote:
BTW, what about OAL?

Just seat it to the crimp cannelure?
WESHOOT2 is already giving the finest advice, and he said this also, but I'll re-iterate as it is VERY important:

You must be using the crimp groove on these bullets. IMO, if you use the crimp groove and they end up being too long (quite unlikely) then you cannot use these bullets.

For a load like this, you must have that firm crimp. I mean FIRM! Two reasons. First is that if you want this load to develop it's pressure properly and consistently, you must allow the pressure to build with the (relatively speaking) slow burning powder. A firm, solid roll crimp is -THE- way to ensure that.

Secondly, especially when using heavy slugs in a large caliber and running harsh recoiling loads...the heavy roll crimp will keep the other five rounds loaded in the revolver from lurching forward under recoil. We call it "jumping crimp" and it you WILL experience it if you aren't using a solid, heavy roll crimp.

What happens is that you fire the round in chamber #1, and the loaded rounds in all five other chambers are sitting there at rest. Sizable recoil throws the entire revolver backward when you discharge #1, but those five heavy bullets in the other chambers are observing the laws of physics. They are at rest, and tend to want to stay at rest.

Without a firm roll crimp, those other five slugs will attempt to stay where they are while the entire revolver and the five cases holding those slugs will recoil backward.

The net effect is the bullet appears to have lurched forward. (it didn't go forward exactly...they stayed in place for a moment while everything else lurched backward)

How much will they move? Don't know. You'll see! Maybe after shot #1, the other 5 haven't moved much... but as you keep shooting, the remaining ones will. Eventually, you can absolutely tie up a revolver. It'll be locked up like a bank vault until you can pound them backward from the front of the cylinder with a dowel. At that point, you have only a club for bear defense.

If you can't build a heavy hitting, heavy bullet load in a large caliber without using the supplied crimp groove of the bullet...you'll either need to buy a different bullet, or find a way to shorten your brass so that you CAN use the crimp groove in the bullet.
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Old June 18, 2013, 03:38 PM   #22
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Given that I have a Redhawk, which I believe are known to have long cylinders, I can probably seat to the groove and still fit the cylinder with ease.

Now... on to crimping...

If I am frustrated by the lack of published methods for monitoring over-pressure, I am equally bothered by the lack of published data on effective/sufficient crimps.

There is nothing there in any of my manuals. In fact, my first ever attempt at crimping was a horrid disaster: mainly because I had no point of reference.

The only information I have ever had is through here, TFL. From then on, things looked up, but this is a different load altogether.

At the moment, even on my stout 240gr loads, I am only using a "third of a turn" crimp with my Lee FCD, based on advice here. I have not worried too much about bullet creep so far because they have never crept forward enough to cause problems.
In any case, if it goes in the cylinder it gets fired, so it would only suffer the accumulated recoil of 5 rounds, never more!

What sort of crimp are we talking for these, as an educated guess, given the likely velocity and existence of a cannelure?

Half a turn? A full turn? More?!

Should I even consider ditching the FCD in favour of crimping in the seating die. (I'd rather not: keeping seating a crimping separate suits me).
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Old June 18, 2013, 04:31 PM   #23
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When we are talking a STOUT, heavy bullet in a large caliber, you really won't "over crimp" until you distort the bullet or you distort the brass.

To see if you've distorted the bullet, trying giving it a SERIOUS crimp, then pull the bullet via kinetic puller and examine the slug, and compare to a new, unused bullet. If you have it set to the proper length and you are crimping in the designated groove, you won't be damaging the slug.

And if you can chamber the round with no resistance, you won't be damaging the brass. (beyond the typical work-hardening that crimping any piece of brass will simply do over the life of that brass)

As for "how" to crimp, I'm not at all sold on the Lee FCD in handgun calibers. Also, being that I don't own one, I won't comment further as I'm not hands-on familiar with them. However, with your third seat/crimp die, you may find advantage in using that same die TWICE to best accomplish your goal.

First, unscrew the die to impart ZERO crimp of ANY manner, and use it simply to seat the bullet to exactly the right spot. This lets you seat the bullet perfectly instead of allowing the possibility that your die is trying to seat the bullet a bit more while at the same time also imparting a heavy roll crimp.

When the bullet has been seated to the perfect depth, now screw the body of the die DOWN while screwing the bullet seating stem OUT the same amount (or more) to be safe, to know that you are now ONLY crimping...and not unknowingly seating the bullet deeper.

This method works WELL, but at the cost of time and the hassle of constantly changing your die settings. Here, a second seat/crimp die is a fine luxury to have. Same exact die, each used for a different purpose, each keeping it's settings intact all the time.

NOTE: we typically don't do much trimming in handgun rounds, and casual reloading of handgun ammo might never EVER need any trimming. However, in many revolver rounds, especially in HEAVY rounds and in cases where a perfect and HEAVY roll crimp is necessary, having cases of exactly the same length is important.

If you really wish to do this the best of your ability, consider trimming your brass to a consistent length...or using factory new brass. (but check THAT stuff for consistent length, too!)
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Old June 19, 2013, 05:12 AM   #24
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eyeballin'

-There is sufficient length in the Redhawk cylinder.

-Most highly recommend crimping using the Redding Profile Crimp Die.
While it is still possible to over-crimp (which normally distorts the case --bad), the Redding die first provides a gentle taper, then finishes with an extremely symmetrical roll crimp.
It has been tested repeatedly to show lower velocity deviations and finer accuracy on target.
I use one for every revolver cartridge I make.

-"How much crimp?"
Ah, the age-old question, one that's been asked (and joked about) since we started making metallic cartridges.
-"Enough."
Why yes that's a crappy answer, but in fact IS the answer.
Enough to retain bullets from 'jump'; enough to promote sufficient combustion before the case releases the bullet.

Easy way? Open some boxes of premium factory ammo in any chambering (hopefully there is a gunshop where this is possible and permitted; ask politely) and carefully inspect what they think is a proper crimp.
Try to emulate that.

If continuing use with your LEE die, suggest adding more crimp in MAXIMUM 1/8th turn increments (mark your dies' turning pieces with a marker to help determine turns).
Often 1/8th turn is too much, and even finer turn increments are demanded to add more crimp.
Think "wee teeny bit", as it's possible for a small change to over-crimp and distort the case.


Big makers have methods to determine bullet pull; we only have our guns.
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Old September 27, 2013, 03:52 PM   #25
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Time for an update:

I recently posted pictures of my crimp on my 275gr hand-loads, together with some 200gr .44Spl, some .38Spls and today I shot them all over the chrono.

The first thing that struck me was how surprisingly manageable the recoil was. Despite being 275gr hard casts they felt lighter than my 240 FMJFN loads.

Using Starline brass and Fiocchi LP primers I had loaded 3 rounds at each increment starting at 19.4gr of N110 and going up to 20.4gr, in 0.2gr increments.

Unfortunately, there were a few Err readings on the chrono, meaning the first two charges only gave two readings not 3. Also a number of the rounds gave out of range readings.
For example the 19.6gr loads gave higher velocities than both 19.8 and 20gr!

It may be because I initially seated the bullets about 0.5mm from their cannelure rim and then crimped, and later decided to seat them to rim and case mouth were flush. Having said that I did this for all the cartridges, not just that charge.

Anyway, average velocities were as follows: 19.4gr: 1162fps, 19.6gr: 1205(!), 19.8gr: 1180, 20gr: 1198, 20.2gr: 1224, 20.4gr: 1238.

Based on those values and my hopes of a 1100-1200fps velocity, I am probably going to try and exploit the 19.8gr or 20gr load.

Once again I must say how surprised I was by the milder-than-expected recoil of those rounds. My 1350fps 240gr loads bite much more!!

I may also need to increase the crimp by a tiny bit.
After 6-8 shots, my control cartridges had increased their OAL by 0.5mm and the cannelure was much more visible as the bullet crept out.
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