.223 optimal neck sizer bushing and powder?

[dreamlander]

I got myself a Rock River varmint A4 and am going to start loading for it. Wondering what the best neck sizer bushing size is for lapua brass. Loading sierra blitzking bullets.
Also wondering what everyone uses for powder. I was accidentely sent 8lbs of benchmark (no returns on powder) so I was thinking of trying that out. I was also going to use it in my 6.8 spc so I might get something different for the .223 if it is overwhelmingly better.

 

[7mmRM]

Re: .223 optimal neck sizer bushing and powder?

I use a .249 with Lapua brass. Thats givin me .001 neck tension. Benchmark is a great powder for the 223. Id suggest full length sizing brass for the AR15.

 

[dreamlander]

Re: .223 optimal neck sizer bushing and powder?

Why full length size the brass? I haven't got the brass yet, but the other lapua brass i have used is right on with the specifications when new. Or are you talking after shooting once?
I was thinking .248 or .249 thanks for the input.

 

[7mmRM]

Re: .223 optimal neck sizer bushing and powder?

Yes, after you shoot it.

 

[Suasponte]

Re: .223 optimal neck sizer bushing and powder?

I would not suggest .001" neck tension for a semi-auto. The chance of the bullet being pushed back into the case is very high and that could cause potential problems for you. I wolud play with the bushing sizes until I got just enough to keep it from moving in the case when you push the bullet tip againist your bench. The bushing diameter will vary from brass mfg to mfg with the variance in neck wall thickness.

Terry