Case Weight Ranges

[hounddawg]

well Nick in my experience the lowest SD's always without exception have gave me the lowest vertical spreads. I tune the horizontal spread using seating depth. Erik Cortina and Tony Bowyer use similar methods. No offense towards anyone but I trust Boyer and Cortina over internet wisdom. How many here shoot at 500 and out on a regular basis? Besides me maybe two or three other posters?

I think have posted enough pics of my load tests and match targets that most of the regulars know that my problem in matches is not getting good 5 - 20 shot groups. Getting those groups in the middle of the X is what kicks my butt. I have 3 solid good loads for my match rifles so my load development is done until I change barrels.

For hunting ammo small consistent 3 shot groups is all I need. If I ever get that Grendel upper back I am developing my hog load for 150 yards. That grendel has just too low of a velocity to be used for hunting past 300, which is the farthest I would trust myself to make a humane shot. So my goal there is 3 round groups with a CEP of a inch or less combined with the highest velocity. I will use that same goal for a whitetail load using the same Barnes 120gn TSX bullets for my tactical .260 Rem using the same goal. SD will have no bearing there just as it doesn't for my .223 load for 300 yards. The beauty of hand loading is that you can tune a load for the particular need.

[Bart B.]

Originally Posted by Unclenick

The day will come when software will exist that lets you plug in your gun's weight and barrel dimensions, as well as your load data and shooting position and rest information, and have it work out all elements of the firing event. We just aren't there yet. The main drawback? It will demand to know the shooter's weight.

Here is a way to see the concept.

http://www.geoffrey-kolbe.com/articl...vibrations.htm

It uses the 308 Win cartridge so use barrel times in the 1.0 to 1.4 millisecond range to estimate the bullet departure angle.

It is interesting to see how barrel profile changes cause a given load's bullet to leave at different angles. And that demonstrates how barrel tuners at the muzzle work.

Read the section "Why this program was developed".

I have observed 4 people shooting the same 30 caliber magnum rifle and ammo in long range team matches. Each used different zeros on the sights; metallic and scope. A 1.5 to 2 MOA spread often happened. They all "looked through" the sights the same; easily proved with a collimator. Each held the rifle different and they were not all the same size and shape in position.

[F. Guffey]

There is no SAAMI spec for case wall thickness or inside dimensions behind the neck, just outside.

And that just locks them up but, I do hope no one puts a lot of thought into it.

I thought about it and decided it made a lot of sense but did not want to get someone to consider the possibilities of something going on in there.

F. Guffey

[Bart B.]

Originally Posted by hounddawg

I tune the horizontal spread using seating depth.

Please explain the mechanics of barrel muzzle horizontal axis movement amount by changing bullet jump distance to the lands and why vertical amount does not change.

[hounddawg]

Please explain the mechanics of barrel muzzle horizontal axis movement amount by changing bullet jump disrance to the lands and why vertical amount does not change.

actually the groups shape can be changed from horizontal to vertical or the other way around


The Book of Rifle Accuracy
by Tony Boyer

chapter 22 explains how

[Bart B.]

Originally Posted by hounddawg

actually the groups shape can be changed from horizontal to vertical or the other way around


The Book of Rifle Accuracy
by Tony Boyer

chapter 22 explains how

Can you explain?

[hounddawg]

Can you explain?

I will let you and Guffy and Nick speculate on the about the why, all I care about is the results. If you guys want to reinvent the wheel I say go for it. Who knows maybe you do know more than Cortina and Boyer, do you ?

[zeke]

One time actually did an experiment to increase bullet hold for 257 wby and try out my new corbin tool. Put a cannulure in the bullet, and crimped it in. The velocity variation between 5 shots was only about 5 fps, but the accuracy sucked big time. Not being inclined to the statisticool crowd, did not plaster it all over the internet with subjective pronouncements. Was more concerned with the actual accuracy. And yes other factors at play in that little experiment.

Statistics is a useful tool, but can be really over done in reloading. For some it seems to be the end goal in and of itself. ES/sd almost meaning less in validity with smaller number of rounds shot. Course now there are those shooting 50 round groups.

Not that i am opinionated, but low ES/SD does not rule over accuracy and seems to be leading the new age internet statisticool crowd to higher pressures.

[Bart B.]

Originally Posted by hounddawg

I will let you and Guffy and Nick speculate on the about the why, all I care about is the results. If you guys want to reinvent the wheel I say go for it. Who knows maybe you do know more than Cortina and Boyer, do you ?

I don't know or care who knows the most. I think there are several whose knowledge base equals that of those two you mention.

I have never heard about adjusting bullet jump to tune for horizontal spread until this incident. Post a simple quote from that book explaining it.

[hounddawg]

amazing how some of the posters here think they know more about reloading than the most successful short range BR shooter of all time and the team Lapua Brux Borden Captain

@ Bart buy the book and read it, your shooting may improve from it

[old roper]

Bart, you never shoot BR right? Tony Boyer never shot long range and he does admits that.

https://bulletcentral.com/tuning-for-the-wind/

Bart was posting here before coming back

http://forum.accurateshooter.com/thr...#post-37433676

[Bart B.]

Originally Posted by hounddawg

amazing how some of the posters here think they know more about reloading than the most successful short range BR shooter of all time and the team Lapua Brux Borden Captain

@ Bart buy the book and read it, your shooting may improve from it

There are several who know more than I do. Be careful with your assumptions about what I know.

[Bart B.]

Originally Posted by old roper

Bart, you never shoot "BR right?"

I tried benchrest but my 30 caliber 3 position rifles shot smaller test groups slung up in prone or F class positions than match winning record setting benchrest ones.

Both disciplines' rifle's ballistic behavior are subject to the same laws of physics as far as I know, unless shooting "BR left" is different.

[scatterbrain]

So..... I have found that Nosler advertisied they ship in .5 grain batches, I have found tests on Lapua that fits 100 inside 1 grain, and Hornady advertisies that they are tightly grouped in weight.
I have a shell full of Norma ready to primer, I think I will seperate into 1/2 grain groups and see what happens.

[old roper]

Bart, you do know smallest group in BR is pretty small .

https://kriegerbarrels.com/smallestgroup.

Kind of odd that your test group at 800yds was pretty small but wasn't shot at match and you send target to Kreiger. Why didn't you send test target with 5 shot group to Kreiger if it's smaller.

[Bart B.]

Originally Posted by old roper

Why didn't you send test target with 5 shot group to Kreiger if it's smaller.

Because I don't get excited by a single, impressive looking 5-shot tiny group.

That target had four 5-shot groups made with an artificial supported rifle with a 20X scope. Each one was about half the size of the 20-shot composite.

I was measuring the quality of the ammo and rifle barrel. Not my ability to shoot the rifle's ammo with aperture sights without artificial support required in matches. Nobody shoots hand held rifles in three positions without artificial support as accurate as artifically supported testing ammo. That is easy for most to understand.

John Kreiger later sent me a free barrel. I put it up as a door prize at a reunion.

That .0077" record group is like all 5-shot record groups, they are the smallest ever shot in the match rules. All the others are larger. Has Stinnet set other records or won matches with the stuff used to luck out shooting that one?

The biggest ones are seldom discussed. Realistically and statistically, group records are mostly luck. Crap shooters don't get snake eyes every throw. Eight 10-shot agg's best define benchrest average accuracy and their records are the smallest, it is now about .19 inch at 100 yards.

If 20 or more shots are fired in a match, a single 5-shot test is a waste of barrel life and ammo.

Unclenick should post his graph showing the low probability of what few shot groups have for extreme spread representing what many shots will have.

[old roper]

Bart, Benchrest does post result so anyone interested can get them.

If small groups doesn't mean anything why you mention it.

Problem you have is you shoot score not group. So you could throw shot 2ft,4ft and still get score. You never won Wimbledon Cup and how many times you try?

Michael Stinnett may never set a record again but he's got something you never had.


Why don't you try and impress some who cares.

[Bart B.]

Originally Posted by old roper

Bart, Benchrest does post result so anyone interested can get them.

If small groups doesn't mean anything why you mention it.

Problem you have is you shoot score not group. So you could throw shot 2ft,4ft and still get score. You never won Wimbledon Cup and how many times you try?

Michael Stinnett may never set a record again but he's got something you never had.

Why don't you try and impress some who cares.

For crying out loud...... Winning matches does not require record setting performance in any discipline. None of the matches I won had record setting scores.

The VRPT is on its way to you.

[Metal god]

I was going to start my own thread on what I'm about to say ( still might ) but thought I'd toss it out here first .

I just tested my first semi auto 308 a week or so ago . Today was the first time I had a chance to look at the cases in detail and do some measuring . I was mostly just trying to find what my fire formed head to datum point measurement was ( better known as …… never mind ) Anyways it was long , much longer then my bolt guns so I tried comparing it to my NOGO gauge and they were a tad longer . I did test the chamber before I shot it and it passed the GO gauge and would not close on the NOGO . OK I'm rambling now so to my point . I decided to size a few cases to see if sizing them down .003 or so would allow them to still chamber and this would put them right around the NOGO gauge length .

So I proceed to size some cases using my bushing die with my usual .335 bushing . Only I can't feel the expander pull back through the neck hmm that's odd ??? So I think maybe I put the wrong bushing in , nope it's the .335 . So I check the expander button , yep correct size . So I try to put a bullet in the neck by hand and I'm able to easily push it right into the case .

Then it hits me WOW the neck wall thickness on this brass must be really thin ?? Yep sure enough it was a total of .005+ thinner then my LC and Fed brass . At that point I thought if this brass is so thin the bushing I almost always use does not work I wonder how much lighter these cases are as well . Ten cases averaged 156gr while my LC and Fed cases averaged 176gr+ . An internal volume test is next but any guesses as to what brand this brass is ?

Anyways my point to posting here is that case volume is not the only thing you need to worry about when it comes to case weight . If they get light enough everything gets thinner .

[zeke]

Winchester brass has noticeably thinner case necks in 308, and there may be others. The variations in 308 brass is reason a lot of people use the bushing dies with multiple bushings to be able to provide adequate case neck tension for various brass makes. It is considerably lighter brass.

It takes an increase in powder in Win brass to equal velocities gotten from same powder charge in mil-spec or Fed brass. However, have been able to get multiple reloads out of it in semi 308's, easily equaling the number of reloads from military brass.

The shoulder datum from brass fired in semi's is often longer than bolts due to the action type. If mixing them with bolt fired brass, the dimensions stay varied even after resizing.

Another reason for paying attention to components in reloading information.

[F. Guffey]

Anyways my point to posting here is that case volume is not the only thing you need to worry about when it comes to case weight . If they get light enough everything gets thinner .
__________________

There was a crowd that went through singing the praise of volume, to them there was nothing else and they went on to say nothing else matters. And then another crowd came through declaring if it is heavier it is thicker.

Me? I thought they were in the business of making this stuff up.

F. Guffey

[hounddawg]

reading these forums one would think every poster here is capable of shooting 20 round 1/4 MOA groups if they just had the right ammo and rifle...sure. Try spending the time wasted weighing cases on dry firing, it will be time better spent

[Bart B.]

Originally Posted by Metal god

So I proceed to size some cases using my bushing die with my usual .335 bushing . Only I can't feel the expander pull back through the neck hmm that's odd ??? So I think maybe I put the wrong bushing in , nope it's the .335 . So I check the expander button , yep correct size . So I try to put a bullet in the neck by hand and I'm able to easily push it right into the case.

Expander balls are typically not used with bushings. Remove the expander ball so it doesn't bend the resized neck.

Use a bushing diameter .002" smaller than loaded round neck diameter. Sometimes, .001" smaller is enough.

[Bart B.]

Originally Posted by hounddawg

reading these forums one would think every poster here is capable of shooting 20 round 1/4 MOA groups if they just had the right ammo and rifle...sure.

I do not think that way. I know better. I also think most others don't.

When Sierra was in California, their good match bullets tested sub 1/4 inch/MOA at a hundred one 10 shot group after another during production runs, They did no case prep or sort and metered charges into full length sized cases.

[Metal god]

Use a bushing diameter .002" smaller than loaded round neck diameter. Sometimes, .001" smaller is enough.

Yep and is what I do . How ever in this case I was not actually loading the case , only sizing it to see if it would chamber . In that case I still needed to size the neck down so I grabbed my most used bushing .

Expander balls are typically not used with bushings. Remove the expander ball so it doesn't bend the resized neck.

Agreed in general but I have a very good reason for using it but this is not the thread to explain . Maybe I'll PM you about it . Actually I found the thread I talked about this issue and why I use the expander with the bushing die . Feel free to PM me if you have any comments or questions .
https://thefiringline.com/forums/sho...ng+die+do+this

Winchester brass has noticeably thinner case necks in 308

DING DING DING ! We have a winner , they are Winchester cases .