Brass Failure

[bozo699]

To expand on what BoydAllen stated I have done experiments just dry firing once fired cases and the firing pin had enough force on some rifle to drive the shoulder of the case forward .001 each time the case was fired.

A good read on case life and full length resizing.

I would be interested in seeing if there was a difference if one of the same type of cases was "semi dry fired" with a live primer, to see if there was a difference in how far the shoulder was moved back. I live in a densely populated neighborhood, fifty minutes from the nearest range, so doing a quick test is not in the cards.

Very interesting indeed, I think I will do some playing around and measure the differences.

Ed,
Where did you get the endurance test picture? I was surprised Lapua saw case stretch first and Norma, known to be soft brass lasted the longest??
Wayne.

 

[spclark]

I'm not sure how much blast gets to you behind the rifle but a long time ago I had a 45ACP go KABOOM! with a 2x load of 231, took years before all the metal came out of my face and it ruined my shooting glasses.

Did the same thing with a new HK Expert one day using AA2. Cost me $240 for HK to put it back in working order; I bought an extra mag besides one to replace the one that got shattered. I don't use AA2 anymore, much prefer Clays.

 

[bigedp51]

Wayne

The photos are from Reloader Magazine and the article covered two major points.

1. Full length resizing shortens case life if the shell holder always contacts the die.
(hard cam over)

2. Partial full length resizing promotes longer case life.

NOTE: 99.9% of you already know this.

And even over resized Lapua brass will fall apart if it is abused.

The same rifle was used for all the testing but no mention of how far the shoulder was pushed back with each reloading and it could have been more technical in their testing. Meaning HOW far did the cases stretch each time they were fired.

 

[BoydAllen]

I think that that article was written before reloaders using precise gauges to measure shoulder bump became common. I hardly think that that advice applies if you know exactly where your shoulders are before and after sizing. No one that I know that shoots competition talks about partial FL sizing. The big issues are knowing the relevant dimensions, and having a good match between you die and the chamber. With factory dies and chambers, this is never the case.

 

[bigedp51]

I think that that article was written before reloaders using precise gauges to measure shoulder bump became common. I hardly think that that advice applies if you know exactly where your shoulders are before and after sizing. No one that I know that shoots competition talks about partial FL sizing. The big issues are knowing the relevant dimensions, and having a good match between you die and the chamber. With factory dies and chambers, this is never the case.

Mr BoydAllen

Some people come here to pick up the finer points of reloading, I do not have a custom made rifle and all I have are factory dies and chambers. This doesn't mean that us poor folk can't make our plain Jane rifles shoot better by picking you rich folks brains.

 

[bozo699]

I think that that article was written before reloaders using precise gauges to measure shoulder bump became common. I hardly think that that advice applies if you know exactly where your shoulders are before and after sizing. No one that I know that shoots competition talks about partial FL sizing. The big issues are knowing the relevant dimensions, and having a good match between you die and the chamber. With factory dies and chambers, this is never the case.

Mr BoydAllen

Some people come here to pick up the finer points of reloading, I do not have a custom made rifle and all I have are factory dies and chambers. This doesn't mean that us poor folk can't make our plain Jane rifles shoot better by picking you rich folks brains.

I am sure boyd is LHAO right now,....I can't wait for the reply,.....or p.m,......or phone call ;D
Wayne.

 

[BoydAllen]

Seriously,
I am no where near rich, and I reload with all sorts of dies. My varmint rifles all have factory barrels and are loaded with ordinary factory dies. They have been tuned and tweaked (the rifles). The point that I was making was that with inexpensive measuring tools that are currently available, there is no reason to guess about die settings. Back in the day, most of us hadn't a clue about measuring shoulder bump, when setting a FL die. Today, anyone with a Harbor Freight dial caliper, and an inexpensive Hornady attachment can know exactly what is going on. it makes a difference, and it is not expensive. One of the reasons that I write on this board is to help guys that shoot regular factory rifles and load with ordinary equipment in their quest for greater accuracy. If I seemed to be talking down to anyone, I apologize. It was not my intent. However I will admit that one of the things that irritates me is the lack of up to date reloading information that appears in "news stand" magazines. IMO they could do a lot better if they wanted to.
Boyd

 

[Steve Blair]

However I will admit that one of the things that irritates me is the lack of up to date reloading information that appears in "news stand" magazines. IMO they could do a lot better if they wanted to.
Boyd

[br]
+1 My subscriptions to various gun magazines lapsed sometime in the mid eighties when I realized that they had nothing new to say except gushing about their advertisers' latest products. Compared to this site and several others, print magazines are not particularly appealing. Times change. Posts like the one George "Walker2713" did evaluating a new chronograph within days of hearing about it are what make this site so valuable. [br]
http://forum.accurateshooter.com/index.php?topic=3784927.msg36060801#msg36060801

 

[jo191145]

Another consideration is just how much that virgin brass needed to stretch on the first firing.
IMO if the gun is in sound working order its that first stretch that does most of the damage, dependent on amount of stretch of course.
If someone were to conduct a study and found virgin Winchester brass was headspaced at shorter specs than most I would'nt be surprised.
I've done no such study but whenever I've been shocked by the headspace measurements of virgin brass its always said Winchester on it.

I shoot lots of savage rifles. I set the headspace for a particular lot of virgin brass at .003-.004" crush fit much like an AI chamber.
Chambers tight but falls right out after firing.
As the case body expands to fill the chamber the shoulders are drawn rearward as opposed to the web stretching.
Same concept as creating a false shoulder just much less brass movement taking place.
Brass lasts forever even though I FL size everytime with over the counter dies bumping .001"-.002" after brass shows signs of getting tight.
Most of my shellholders have been modified already to allow this short chambering.
I decide to change brass I change headspace at the same time and readjust dies.
Needless to say changing brass is not something I do daily. ;D No real need too.

The few times I could'nt screw in a Sav tube far enough to crush fit virgin brass was Winchester.
Could be thats part of the OP's problem.

 

[BoydAllen]

Given your observations and results, don't you think that it might be a good idea for those shooting rifles that do not have barrel nuts, to have worked up an accurate load that has the bullet well into the rifling, with a lot of neck tension, at least for the first firing of new cases?

 

[bozo699]

Seriously,
I am no where near rich, and I reload with all sorts of dies. My varmint rifles all have factory barrels and are loaded with ordinary factory dies. They have been tuned and tweaked (the rifles). The point that I was making was that with inexpensive measuring tools that are currently available, there is no reason to guess about die settings. Back in the day, most of us hadn't a clue about measuring shoulder bump, when setting a FL die. Today, anyone with a Harbor Freight dial caliper, and an inexpensive Hornady attachment can know exactly what is going on. it makes a difference, and it is not expensive. One of the reasons that I write on this board is to help guys that shoot regular factory rifles and load with ordinary equipment in their quest for greater accuracy. If I seemed to be talking down to anyone, I apologize. It was not my intent. However I will admit that one of the things that irritates me is the lack of up to date reloading information that appears in "news stand" magazines. IMO they could do a lot better if they wanted to.
Boyd

I am proud of you,...you did real well

Given your observations and results, don't you think that it might be a good idea for those shooting rifles that do not have barrel nuts, to have worked up an accurate load that has the bullet well into the rifling, with a lot of neck tension, at least for the first firing of new cases?

Spot on!
Wayne.

 

[jo191145]

Given your observations and results, don't you think that it might be a good idea for those shooting rifles that do not have barrel nuts, to have worked up an accurate load that has the bullet well into the rifling, with a lot of neck tension, at least for the first firing of new cases?

Can't hurt to try Boyd. There is a contigent of shooters that believe the primer strike has enough force to jam the bullet deeper into the lands/case thereby nullifying the effect. I'm of no real solid opinion on that. Fairly certain that happens most often but can it be prevented entirely? Not sure myself. One would have to jam em real hard I imagine.
Many shooters much better than I swear by it. Thats a whole lotta shooters ;D