PDA

View Full Version : So my .300 upper arrived with a 1:8 twist instead of 1:7



.40isthenew.45
04-19-2017, 14:52
I had ordered the 1:7 to stabilize the 220 gr subsonics better and hopefully reduce the risk of baffle strikes on the 10.5 barrel.

Am I overthinking it and the 1:8 will be fine, or do I need to figure out how to return this one and get the right one shipped?

--Chris

J
04-19-2017, 15:00
I'd stick with the 1:8. I have a 1:7 that I can only shoot subsonics out of (its suppressed with the can buried under the handguard). It keyholes like crazy with supersonics, and I stopped after one mag when I very luckily didn't get a baffle strike.

I have a 1:8 that shoots 147s, 208s and 220s great.

YMMV

DangerLee_Industries
04-19-2017, 15:10
J is on par as usual...... Just go buy some ammo and have some fun! [Beer]

.40isthenew.45
04-19-2017, 15:15
I have as many $$$ in ammo stacked under my desk as I spent for the upper already.[AR15] I just need to find some time.

I do appreciate the knowledge and quick feedback you guys provide.
Thanks.

Hoser
04-19-2017, 16:44
Your fine.

brutal
04-19-2017, 17:50
I'd stick with the 1:8. I have a 1:7 that I can only shoot subsonics out of (its suppressed with the can buried under the handguard). It keyholes like crazy with supersonics, and I stopped after one mag when I very luckily didn't get a baffle strike.

I have a 1:8 that shoots 147s, 208s and 220s great.

YMMV

Good to know.

However, what length barrel?

My AAC branded 9" is 1:7, no issues, no keyholing subs or supers (that I recall.) However, I really only shoot subs out of it now, and mostly my own loads unless I let someone else run it, then factory REM subs.

ray1970
04-19-2017, 19:08
Am I overthinking it

Yes. You are. [Wave]

KS63
04-19-2017, 20:06
My 1:8 16" shoots everything fine.

J
04-19-2017, 21:54
Good to know.

However, what length barrel?

My AAC branded 9" is 1:7, no issues, no keyholing subs or supers (that I recall.) However, I really only shoot subs out of it now, and mostly my own loads unless I let someone else run it, then factory REM subs.

8" polygonal rifled.

I'll check my supers. They might be lighter, but think they are 147s. I don't really shoot them any more.

I think I soiled my pants a little when I walked up and saw the target after shooting 10 through the gun and can. Jhood was there... You couldn't have asked for a more perfect sideways profile hole of the projectile through the paper. At 25 yards. Can't believe I didn't trash the can on that. Lesson learned the easy way this time.

It's very possible it's just this type/lot of supers I got, and would be fine with other supers.

Since it's buried under the handguard, I can't really test other supers in it, or the brake will blast off the finish of the inside of the handguard with no can. If I had a stronger desire, I'd swap the handguard for some unsuppressed testing and then swap back.

brutal
04-19-2017, 22:21
Thanks for posting the extra info.

The supers I've shot from the 9" have been Hornady 110gr factory loads, and from the 16", also the Hornady 110gr or 110gr (V-Max) hand loads.

The 16" is a factory DD upper with a 1:8 twist.

All the subs run through the 9" were either 220gr Rem factory, or 208gr A-Max hand loads.

I've not shot any 147gr through either.

Rucker61
04-20-2017, 11:15
8" polygonal rifled.

I'll check my supers. They might be lighter, but think they are 147s. I don't really shoot them any more.

I think I soiled my pants a little when I walked up and saw the target after shooting 10 through the gun and can. Jhood was there... You couldn't have asked for a more perfect sideways profile hole of the projectile through the paper. At 25 yards. Can't believe I didn't trash the can on that. Lesson learned the easy way this time.

It's very possible it's just this type/lot of supers I got, and would be fine with other supers.

Since it's buried under the handguard, I can't really test other supers in it, or the brake will blast off the finish of the inside of the handguard with no can. If I had a stronger desire, I'd swap the handguard for some unsuppressed testing and then swap back.

May do more than blast the finish:

70235
70236