The 1:8 barrel twist

**Slater** · 03-17-23, 15:12

There's not a ton of AR's on the market with this particular twist, but I see a few every now and then. What advantage (if any) is there in the 1:8?

**markm** · 03-17-23, 15:26

Originally Posted by Slater

There's not a ton of AR's on the market with this particular twist, but I see a few every now and then. What advantage (if any) is there in the 1:8?

1/8 is really what almost everyone should be running. 1/7 is military spec to stabilize the long ass M856 tracer, but it's overkill for almost every mag length round the average guy would ever use.

**1168** · 03-17-23, 15:51

1/8 offers nothing better than 1/7, though.

1/8 isn’t necessarily bad, but does not need to exist, and does exist in part due to how gun people love spreading ignorance.

**markm** · 03-17-23, 16:36

It's probably more about the individual barrel and load work up than the nominal twist rate. Perhaps a pool of Camp Perry .223 shooters might have a collective preference on twist.

But based on what I've shot, I generally like a faster twist the shorter the barrel. We run a 1/9 twist 20" gun that will stabilize 80gr Noslers, and even 88 gr ELMs. And those suckers are long. Shorter barrels don't get the velocity and thus RPMs to stabilize longer bullets as well.

**498cm3** · 03-17-23, 16:45

I don't really know, but I did notice most of the match barrels at Fulton are 1 in 8".

**markm** · 03-17-23, 17:05

Originally Posted by 498cm3

I don't really know, but I did notice most of the match barrels at Fulton are 1 in 8".

I think my White Oak might be 1/8 too, but I can't remember off the top of my head.

**danieljmaunder** · 03-17-23, 17:13

I've run both 1/8 and 1/7 twist on a variety of guns, I haven't noticed any comparable difference between the two twist rates. As markm stated, military guns were specced at 1/7 for stabilization of tracer rounds. My philosophy is this, if its a quality barrel, if its either 1/7 or 1/8 twist it doesn't really make a difference to me. I can shoot up to 77's out of either. I've had douglas 1/7 and 1/8 mk12 barrels and shot them side by side, with 77 smk's they shot virtually the same.