You load the same ammo for shooting in 11 different rifles. I'd say you are in the minority, here, lol.
For clarity, I have eleven semi-auto rifles (ARs, M1s, and M1As) chambered for eleven different cartridges. I do have a few duplicate rifles for cartridges like 300 BLK and 223 Remington. I like building ARs.
In general, one MIGHT want to size the case as little as possible for their rifle(s) while ensuring reliable chambering. This is for amount of work involved, case life, and accuracy.
Agreed depending on the purpose of the round. For general purpose work, I find cases fail for reasons other than an over worked body. Also, I have not seen any difference in accuracy from MY SHOOTING between carefully crafted ammunition and general purpose ammunition
If the size of the case doesn't matter, why do people make AR's with tighter "match" 223 chambers and Wylde chambers?
Cases fired in my Service Rifle AR can be resized with a standard resizing die and they will re-chamber just fine. But, cases fired in my Colt Match Target and resized in a standard resizing die may not chamber in my Service Rifle AR.
When you buy a rifle with a match chamber and then you automatically use a SB die, without first trying a regular die and brass dedicated to that gun, aren't you defeating the purpose? Just like one person might load the same ammo for 11 different rifles, I'm sure there are some benchrest shooters that load 11 different rifles with 11 separate sets of cases.
Precision rifle shooting is another kettle of fish. When I shot Service Rifle, I had dedicated cases and dies just for that purpose and rifle. Bench rest shooters and 1000 yard shooters have a completely different set of needs than I do.
Sierra Bullets in their essay on loading for gas guns recommends not spending alot of time preparing the cases as case life is so short any way
Another thing to consider is rifles operate at such high pressures that the case web expands a bit, depending on the size of the chamber. If your chamber is large enough where this back-and-forth is significant, could that make the web brittle over time, maybe?
The question I have is not "why were SB dies invented." I know the answer. Have you wondered why regular dies were made the way they are? I'm thinking for ammo where 60K+ psi is repeatedly fire-forming cases to individual chambers and accuracy matters (e.g. rifle ammo), the more size options the better. Heck, I'd like to have some more options in my pistols dies, even, for when I'm loading cast vs jacketed.
No disagreement here except that with a gas gun, chambering the round is the weak link and needs to be addressed even at the expense of some accuracy items.
In my opinion, part of the reason for the discussion on the need for small base dies is the accumulation of tolerances between dies and rifles. One gentleman will have a die at the upper edge of the specs while another will have one more to the center. The first gentleman has problems, the second does not.
I think someone that is having trouble with chambering due to the body not being sized enough could easily try another standard resizing die. It most probably will solve the problem but maybe not. Or he could just buy a small base die and be done with it.
All's I know for myself is when I fire factory PMC 223 in my rifle, the web expands. A lot. The PMC brass has soft caseheads and the fired cases show me my chamber ain't close to tight in the web. I would not go with a SB die unless I needed to. But I agree that if you want your ammo to have the best chance of working in any rifle, you have to use a SB die. And for .223, case life is not very important due to cost and availability.
The thing that really bugs me though is this: Manufacturers say that SB dies overwork brass and reduce case life. But HOW. My cases die of cracked nor loose necks or primer pockets. SB dies don't change neck dimensions. They are a couple thou smaller through the body and they size lower down the base. So what happens when these cases die? I can see how this works the neck more by causing more stretching in general. But where does all that extra brass you are trimming come from? I would be concerned this also increased web thining and casehead separation. In YOUR rifles, this might not happen. In my sloppy rifle, this might cause an issue. I'm not concerned regarding safety. I have had separations, and they're no big deal. But a jam is a jam. And I haven't had any jams that a SB die would have fixed. I have had jams that a SB die might possibly exacerbate.
When I first started using a small base die extensively (223 Remington) I was worried about short case life. I have found that I do not trim cases any more or have them fail sooner than before going to the small base dies. The lack of additional trimming tells me that the cases are not being worked much, if any over, the work put on the case in a standard resizing die.
My cases shot in my ARs, M1s and M1As are generally discarded before any troubles in the case head and body area shows itself. I have had one case head separation in my M1A most probably due to a case fired in a machine gun. I have scrapped those cases and will no buy any more once fired cases.
