Quick 223 twist question...

[viking499]

In my "looking" I have been doing lately, I have a 223 bullet/twist related question.......

I see that 223 barrels come in 1:12, 1:9 and 1:8 twists.

What is the range of bullet weights for each twist of barrel?

 

[kwelz]

The longer (usually also heavier) the bullet, the tighter twist you want. So if you are going to be firing light projectiles for hunting varmints you want something like a 1/9 - 1/12.

I assume you are talking bolt guns here so I don't know what is best in that regards. But I know with an AR 1/7 is the most desired twist and will stabilize down to 55 Grain. Anything lighter than that and you want to start looking at 1/8 or 1/9 otherwise you can spin the rounds apart.

I personally only ever use 1/7 because I only shoot 55 Grain and up rounds with 75 grain being my primary defensive load.

This is in no way inclusive but it should fairly accurate.
1/7 twist 55 grain and up.
1/9 Twist 62 Grain down to about 50 grain. (maybe 45 but I am not sure)
1/12 Twist 40 Grain and under.

 

[LoonWulf]

1-12s might go as high as 70grns depending on bullet type. My old ADL had a 1-12 and did good with the 70grn speer semi spitzer.
1-9 does fine with everything i tried upto the lighter end of the heavy vlds 70+ish

 

[viking499]

So......
1:12 for the lighter stuff
and
1:9 for the heavier stuff......correct

 

[ugaarguy]

So......
1:12 for the lighter stuff
and
1:9 for the heavier stuff......correct

Almost. 1:12 for extremely light stuff. 1:9 for extremely light stuff up to mid weight stuff. 1:7 for pretty light all the way up to heavy stuff.

1:9 is a compromise twist that many civilian AR-15 makers thought was a good idea for some odd reason. You have to push a very thinly jacketed varmint bullet at very high speed to make it come apart in a 1:7 twist bbl. You should also keep in mind that the new lead free, environmentally friendly rounds (Barnes copper solids, Nosler E-Tip, Hornady NTX, etc.) are very long for their weight, and will require a faster twist bbl: These rounds are already mandated in California, and other states (or the feds) may follow suit, so it's a real concern. Some 1:9 may stabilize lead core bullets heaver than 70 grains, but these are the exception, and not the rule. After the success of the US Military's MK262 Mod 0 / Mod 1 rounds, loaded with a 77gr Sierra Match King @ 2750 fps from an 18" 1:7 bbl Mk12 SPR, the heavy rounds have become very popular. While most of these rounds are loaded match bullets not intended for hunting, Swift has released a .224" diameter 75gr bonded component bullet in their Scirocco II line.