The effects of case volume

[Brad]

Does it matter? Sure, if the gun and shooter are up to snuff and can truly see the difference. I would say that 99.9% of shooters and firearms are not in that group, I know I am not. Just because a BR shooter does it doesn’t mean it has relevance for Joe 6 packs and his 94 Winny.

In handguns it matters a whole bunch. Small cases like 9mm are very sensitive to case volume- it is a pressure thing as much as an accuracy thing.

I will say this- it is not something I even think about outside of good neck tension for handgun loads.

 

[popper]

Good post Brad. If BR shooters use just one case, as I posted earlier, is it due to case volume (fill) or that the case is fireformed to fit the chamber perfectly and breach seated? My calc were to show weighing doesn't insure the same internal volume between cases. I'm in the 99% group that load at the bench and go shoot.

 

[JustJim]

Good post Brad. If BR shooters use just one case, as I posted earlier, is it due to case volume (fill) or that the case is fireformed to fit the chamber perfectly and breach seated? My calc were to show weighing doesn't insure the same internal volume between cases. I'm in the 99% group that load at the bench and go shoot.

Serious question: would it matter why it works, if it works?

I had a high-wall with a .33-47 Pope barrel for a while. I might have shot it 1,000x total, only ever used one case. With it, I shot what I thought of as "way over my head", and I always attributed it to "Pope magic". But I later used similar methods to load another rifle (an Italian repro in 38-55) and again shot over my head.

I thought I had it figured out! Then a friend let me try his heavy-barrel Remington 722 in triple-deuce and I put ten rounds selected from a box of 50 into .75" at 100 off the bench . . . .

I think that as loaded, either of the two single-shots was more inherently accurate than I could shoot, but doing things that way let me shoot up to my potential--the rifle/load was no longer the limiting factor. When I tried the 722 and saw the 9th round was still in that group, I didn't have the jitters when I fired the tenth shot.

It was a very confidence-building summer.

 

[JWFilips]

Something I never had to worry about, until I started loading the Ranch Dog 75 grain FN -32 caliber bullets These you can not go by OAL!
They are short and stubby....Instead you have to worry about seating depth based on the base of the bullet to the inside head of the cartridge!
This is the critical distance...OAL & COL are totally meaningless! It is how much volume that is left in the case that determines the pressure!

 

[popper]

would it matter why it works, if it works? True until you change something and then wonder what happened.