Full Length or Neck Only; What's Best Resizing for Accuracy?

[birdiemc]

If the higher velocity loads had more neck grip on the bullets, that would make them shoot faster.

So would more powder....

 

[birdiemc]

So would more powder....

I bet a longer barrel would too

 

[Rich Coyle]

I concluded the energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases. All were loaded exactly the same except for the sizing.

 

[Rich Coyle]

I concluded the energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases. All were loaded exactly the same except for the sizing.

 

[Bart B]

I concluded the energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases. All were loaded exactly the same except for the sizing.

Did you ever compare each sizing technique's force needed to pull the same bullet type out of the case neck?

I think you would have to measure chamber pressure to confirm energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases.

 

[Rich Coyle]

I never gave it a thought about bullet pull. Both had 1/8" of bullet in the case neck.

 

[J E Custom]

I concluded the energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases. All were loaded exactly the same except for the sizing.

Interesting .

I had heard that fire forming used up some of the energy that could otherwise push the bullet. but had no way to prove it.

J E CUSTOM

 

[Mram10us]

I concluded the energy needed to form the case to the chamber on the full length sized cases was not needed by the neck sized cases. All were loaded exactly the same except for the sizing.

In another thread, bigngreen mentioned it took 25k psi to fireform medium sized brass, in his testing. Wouldn't an easy test be to load both a neck sized and virgin piece of brass with the same load and chrono them? That would tell us how much energy is used for the ff part .... I might be off here though

 

[Rich Coyle]

During the test I compared random factory cases against weight sorted cases, squared heads against random factory cases, necked and full length sized cases, neck turned and random factory cases, square and champhered mouth against random factory cases, various primers with out changing the rest of the load. I don't remember what other things I compared. I do remember measuring the amount of throat errosion to be .010" per 100 rounds.

About 2,000 rounds the groups opened up to about 1 1/2". I mentioned to a fellow the barrel was shot out. (I am used to magnums.). He told me it should last 10,000 rounds. I replaced the Burris Signature 8-32X with a Tasco World Class. The next five shots were .312".

 

[J E Custom]

During the test I compared random factory cases against weight sorted cases, squared heads against random factory cases, necked and full length sized cases, neck turned and random factory cases, square and champhered mouth against random factory cases, various primers with out changing the rest of the load. I don't remember what other things I compared. I do remember measuring the amount of throat errosion to be .010" per 100 rounds.

About 2,000 rounds the groups opened up to about 1 1/2". I mentioned to a fellow the barrel was shot out. (I am used to magnums.). He told me it should last 10,000 rounds. I replaced the Burris Signature 8-32X with a Tasco World Class. The next five shots were .312".

Sometimes I set the shoulder back one thread and freshen up the chamber buy re cutting it, and this also helps the lead, neck, and the throat on really good shooting barrels. it also adds many more good rounds to the barrel life.

J E CUSTOM

 

[Rich Coyle]

Sometimes I set the shoulder back one thread and freshen up the chamber buy re cutting it, and this also helps the lead, neck, and the throat on really good shooting barrels. it also adds many more good rounds to the barrel life.

J E CUSTOM

This was a very good shooter for a factory rifle. Ten shot group at 200 yards measured .870".

Being the genius I am I rechambered it to a wildcat .224MBOC. A shortened .264 Win Mag. It had the same capacity as a .30-06. Never got it to shoot again.

My son-in-law grew up in the inner city. He asked, "What does that stand for? Mexicans, Blacks, or Caucasians?"

It meant Magnum, belted of course.

 

[Bart B]

About 2,000 rounds the groups opened up to about 1 1/2". I mentioned to a fellow the barrel was shot out. (I am used to magnums.). He told me it should last 10,000 rounds.

A 223 barrel should last 10,000 rounds? Yes, if using military service rifle standards. About 3000 using Sierra Bullets' standards, 1/4 MOA average opening up to 3/8 MOA. So says my formula based on 22 caliber bore capacity charge weights.

Bore capacity equals 1 grain of powder for each square millimeter of bore cross section area. 24 grains for 223 Rem. Increase charge 41% in larger case, barrel life is cut in half. Increase 100% doubling the charge, one fourth the life.

 

[Rich Coyle]

Since my strong suit is ignorance, I was in no position to argue.

Thanks for the formula.

 

[birdiemc]

A 223 barrel should last 10,000 rounds? Yes, if using military service rifle standards. About 3000 using Sierra Bullets' standards, 1/4 MOA average opening up to 3/8 MOA. So says my formula based on 22 caliber bore capacity charge weights.

Bore capacity equals 1 grain of powder for each square millimeter of bore cross section area. 24 grains for 223 Rem. Increase charge 41% in larger case, barrel life is cut in half. Increase 100% doubling the charge, one fourth the life.

I'm not tracking what you are trying to say here Bart