Just something I have always thought about but never experimented with in the past. Has anyone here tried turning and truing up the necks on a breech seated case and if so what might you have found. This probably pertains more towards the bottle necked cases of which are not typically used or possibly a straight necked 32-40 case more typically used. If not and there is an interest it might be something I would be willing to do after getting back some positive, negative or simply just untried feedback.

JLouis

Read an article in the old Precision Shooting magazine. For what it's worth the gist of the article was on turning case necks such as you posted. The article listed a few cases that could be sized down from and then neck turned. One case mentioned was using the 375 Winchester case to 30-30 and would give you a thick necked 30-30 case that then could be neck turned down to give you a better fit in the chamber. Never heard about sizing the 375 case to 32-40 though and wether or not in sizing down would give you the length needed for an original 32-40 case. Since the 375 cartridge is loaded to much higher pressures 50k versus the 30-30 40k naturally the case is of course thicker and heavier. If a slightly shorter case would be ok then the 375 case then it might work and the added benefit of having a stronger 32-40 case somewhat similar to the old everlasting cases. Sizing down the 375 case )maybe annealing first and making sure no dented case necks) Using Imperial case lube and running through a 32-40 die with the expander ball removed in increments rotating the case 180 degrees each short stroke the press handle rather than all in one shot. Realizing that 375 Win cases may be in short supply may make this all a moot point. Just my thoughts though. Now I have to did in my reloading supplies to find those freezer baggies of 30-40 Krag brass. 1898 Krag and 1895 Win saddle ring carbine. Please post results am interested in how it all turns out. Frank

I don't believe neck turning on a cartridge case with a breech seated bullet would provide any benefit. The reason behind neck turning brass, with the bullet seated in the case, is to insure that the grip on the bullet is equal and that it in perfect allignment with the bore. By breech seating, the bullet has already been placed in perfect allignment ( we hope), and the case is merely a container for powder. With the advent of cartridge cases manufactured with attention to wall thickness, which translates to neck wall thickness, such as Lapua, the need to turn necks is still neccesary, but not nearly as much. As an example, most PPC chambers were cut for a .262 neck, but many benchrest shooters are finding that .268 necks are adequate because the necks are more consistent. It wouldn't hurt to turn a case for breech seating, but don't think the return would be worth the effort and time involved. Just one mans opinion.   Krag

rkba2nd wrote on May 24^th, 2018 at 12:33am:


+1.  That is my view also.

calledflyer wrote on May 24^th, 2018 at 12:50pm:

Excellent idea, Pat! A test like that could tell you if the neck area had any influence on accuracy, good or bad.

Frank

All I really know here is that in physics I was taught that with expanding gasses  "pressure is pressure", whatever there is is the same everywhere in a closed container.  The gas coming out of the fired case doesn't just go forward, but pressurizes the entire space. In a rifle it'll 'grow' that space by moving the bullet forward(that's why muzzle pressure is different than chamber peaks). But, at any given time the number is the same everywhere. Don't matter if it's off center a thousandth or two.
The 'real' benchresters center the thing with turned necks for bullet alignment, not pressure reasons. But, you may be right about the neckless case not sealing that gas. 
And, that's enough of my gas for now.

Frankly, in a breech seated situation, I don't think it changes a thing. If you get a twinge that way, you need to keep upping the sample base. Then, you'll probably find out that it was just an abberation. Just call me Joe Brennan......

P.S. One reason I just thought of was that you don't even have a vague assurance the powder is in the same place from shot to shot. If something as important as the powder charge varies, the teeny change in case rotation is null.

Another variable, is the primer pocket and flash hole. 

You'll need to actually measure the amount of run out, that they have before you can say that it will or will not change POI on the target, when indexing a case. Not that it "looks" centered but, that it is actually centered.

Frank