.223 twist rate

[Matt]

I was asked the other day what would happen if 55gr. bullets were used in a .223 with an 8' twist. Do they just spin faster than they need to or are there negative effects such as safety and accuracy?

 

[cliffy]

Swift Scirocco IIs in 75 grain packages where developed for your 1-in-8' application: Use them! 55 grainers work well in 1-in-12' twisters that they where designed for. Nothing is perfect in all applications! Yet with .223 applications, leeway is provided. cliffy

 

[zedsdead]

The 1-9 twist will allow you to shoot heavier bullets, but I have never had any ill effects from shooting lighter bullets in my fast twist .223 barrels. Definitely no safety issues.

Jason

 

[FTRshooter]

They spin at the same rate as any other bullet coming out of that barrel at the same velocity.

They will be spinning faster than slower bullets like 69, 75, 77 and 80.

They will be spinning faster than 55gr bullets coming out of slower twisted barrels like 1:9 or 1:12.

But who cares? I have shot plenty of 52GR SMKs and 55GR FMJs in my 1:8 and 1:7.7 twist barrels. They work just fine. The 52SMKs are like laser beams, fast an accurate; they just don't go far enough for my needs.

 

[2506]

I talked my buddy into getting a RR 1 N 8 twist AR. He had a bunch of 55 gr IMI FMJ bullets loaded up for his T/C Contender. I don't know what the load was. When we went out to shoot his new rifle I shot some little bitty bug hole groups with those 55 IMI FMJ's. So yes a 1 N 8 twist will shoot 55 gr bullets OK.

 

[cliffy]

1-in-12' Twisters were designed for 40 to 60 grain bullets! Faster Twist barrels were designed for heavier bullets. Want to hunt with a 1-in-8' twist? Check out the 75 grain Swift Scirocco II bullet. It will knock over a deer without an ounce of sweat. My 1-in-12' BARREL WAS NEVER DESIGNED FOR SUCH A POTENT, HEAVY .223 BULLET. CLIFFY

 

[MarkS]

Matt,

You will not get the speed from the 8tw as you would a 12tw. They should still shoot good.

Mark

 

[mwood]

Sometimes lighter bullets shoot MORE accurate.
I have a 1:9 twist CZ 223 that likes 40g the best, even though it will shoot heavier bullets. This is substanciated by the articles in magizines for this rifle that also noted 40g VMax to be the most accurate.,In light air) This is the Kevlar Varmitt CZ in 223.
Don't know why this is...but it is not just my experience on this rifle. Had chamber measured also and it is S.A.M.I. spec, so that is not the reason. Have to try them to find out is my answer.

 

[cliffy]

A 1-in-8' twist is tight! It will slow-down any light bullet velocitywise, or explode it in flight. If you want to shoot 40 grain fare, opt for a 1-in-12' twist for high velocity. Otherwise, load-up with 75 Grain Swift Scirocco II bullets and knock-over Whitetails. With my 1-in-12', I can't even use these fabulous bonded bullets. cliffy

 

[cooperman223]

My cooper .223 has a 1-9 twist barrel on it,
it loves 75gn Amax, but will equaly shoot 36gn barnes grenades,
they dont dont carry range like the 75s do though,
i think a 1-9 will do everything you need it to do.