Birthing problems II

[mstarling]

Ok Guys,

After having taken as much off the RCBS #10 shell holder as I dared, I got to the point that I could get ammo that would chamber if:

1) I run it through a .223 FL sizer first with the short shell holder. Means the cases are being sized more in the base than usual. Unless this is done, no case can be made that fits the cartridge gauge!

2) The case is then run through the Redding 300/221 Remington FL sizer with the internal neck sizing plug in place.

3) I then took the internal plug out and ran it again to make sure the plug had not pulled the neck out any.

4) primed the brass with WSRs, and

5) load a boat tailed 147 .308 military ball bullet over a weighed charge of 15.5 gr of WW296. Is the starting charge listed several places.

The loaded cases were no worse at fitting into the cartridge gauge than before they were loaded.

I fired several rounds of this with the gas port closed. The cases stuck in the chamber and had to be removed with a cleaning rod. Primers are flat but not brutally so. I expect this ammo is a little hot ... will reduce the charge.

Looking at the fired cases the conclusions I have so far:

A) The shoulder is moving forward and sharpening up when a round is fired.

B) The base diameter of the case is probably what is causing the problems I am seeing. Need to go to a small base die.

C) The starting load is a little hot in the short case.

Am going to order a small base sizing die for .223 and see if that helps. Will have to toss a few pieces of brass I suspect, but only 10 or so.

Other thoughts?