Stuck cases - 243 LBC

[labattred]

Hey, so I've just installed a new BHW .243 LBC barrel, and I'm running into issues with the cases getting stuck in the chamber.

I'm using new Lapua brass loading 90gr Sierra TGK game changer bullets to 2.200 COAL. I'm resizing the brass using a .269 bushing in a Redding type S die. There's a slight bulge at the base of the case neck after resizing, but I've read elsewhere on here that that isn't uncommon on the first sizing (note: this isn't an issue on once-fired brass).

My first ladder test, I ran into this issue. However, I assumed it was a gas problem. I struggled through the first 10 rounds by manhandling the charging handle to get the case to clear, sometimes more effort than others. These 10 rounds gave great results on the chrono, and even though the powder charge was increasing, still printed a respectably tight group at 100 yards.

I've since resized these cases, and adjusted my gas block all the way out for another trial. Unfortunately, I got the same results. This time, I realized that these cases are sticking once chambered into the barrel, prior to actually being fired. I sprayed out the chamber with some CLP and ran a bore snake through just to make sure there was some lube and it was clean(ish), but the next cartridge I chambered was stuck again.

I can't see any visible defects in the chamber (burrs, roughness, porosity, etc.)

Thoughts?

[GLSHOOTER]

There is nothing wrong with your chamber. It is your ammo. Just bump the shoulders back further. You should have 0.003 to 0.004 shoulder set back from a fired case. On yours just screw the die in about 1/8th turn and try a sized, not loaded, round in the case with the upper off the lower. The BCG should close by hand and then you use the charge handle to extract. You should encounter NO RESISTANCE in pulling the case out. Once you reach that point lock it down and measure your shoulder for repeatability. Do five cases and check for verification.

Greg

[labattred]

Thanks for the quick response! I agree that the issue is very likely to be my ammo. The info about the barrel/chamber was just adding context in case those questions arose. I'll definitely try bumping the shoulder back a bit using your method, and see if that resolves the issue. I wouldn't have expected the rounds to have fully chambered, if I wasn't getting enough setback

[GLSHOOTER]

Aug 29, 2020 14:39:43 GMT -8 labattred said:

Thanks for the quick response! I agree that the issue is very likely to be my ammo. The info about the barrel/chamber was just adding context in case those questions arose. I'll definitely try bumping the shoulder back a bit using your method, and see if that resolves the issue. I wouldn't have expected the rounds to have fully chambered, if I wasn't getting enough setback

When that BCG slams home propelled by that buffer spring you can definitely move the shoulder just enough to chamber. That also means you have virtually zero room for the case to expand and contract so you have induced your "stuck case" condition by merely dropping that BCG. Guys that think they are going to neck size only learn this on their first trip to the range.

Greg