This might be good for a STICKY.

What about the 1:12 for the SPS-V? Good info you have here for those just getting into shooting 223/5.56.

Basically I found 1:12 will shoot your 40-55 gr and nothing over that (or at least my gun won't).
 
What about the 1:12 for the SPS-V? Good info you have here for those just getting into shooting 223/5.56.

Basically I found 1:12 will shoot your 40-55 gr and nothing over that (or at least my gun won't).

I have shot 60gr bullets out of a 1:12 with good results. Normally I would shoot 52/53's but I shot a hunters match and the ammo had to be legal for deer.
 
If you can measure the bullet you think you want to shoot, you can run the Greenhill formula on it and get the optimum rate of twist.
Since it is algebraic you can run the formula backwards and figure out what length will work best for your twist. Length not weight is what matters, weight is just a by-product of length.

Tickled, thanks for posting every little bit helps
 
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