I recently took the plunge and bought my first AR. I have a Rem 700 bull barrel in .223 that I have reloaded for a lot and have got that caliber tweaked to my needs but was told that for the AR reloads that a SB sizing die was preferred to ensure functioning better. I bought a Sig with a 5.56 chamber if that makes a difference in reloading.

What say ye???

I have reloaded for a lot of different 223/5.56's,bolts, AR's H&K's and AUG's and I have never used a small base die.

Not at all.....as a matter of fact I just bump the shoulder .005 on mine and they run 100%

55 grn FMJ over 24 grns WC844 with CCI SRP and regular Hornady dies

What did you buy?

I also just bump the shoulder and use a bushing die for the neck (Redding Comp set) and have had no problems.
C.G.B.

I have SB dies in 223 and 308. The reason why: I buy surplus 223 and 308 once-fired brass, and an awful lot of it has been fired in select-fire or machine guns.

It only needs to be used the first time.

Rich

quote:

Originally posted by Idaho Sharpshooter:
I have SB dies in 223 and 308. The reason why: I buy surplus 223 and 308 once-fired brass, and an awful lot of it has been fired in select-fire or machine guns.

It only needs to be used the first time.

Rich

+1 I'm a big fan of LakeCity brass.

Chambers are not the same size.

You will find out if you need a small base die if your bolt gun brass starts sticking, jamming, or having the rim ripped off in your new SIG.

Regardless, set up your die with a cartridge headspace gage.

I shoot 223 AMU, Wylde, 556 Nato chambered reifles extensively (never had an AR in 223REM SAAMI). None require a SB die, even LC cases identified as MG fired (very conspicuous M249 ejector mark on the case head). Best to FL size to min for a test batch, load and fire, then measure the fired length to the datum line, set you die for about 3/1000 shoulder bump, crunch away.

Best;