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

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

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

J is on par as usual...... Just go buy some ammo and have some fun! [Beer]

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.

Your fine.

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Originally Posted by J

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

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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.

Quote:

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Originally Posted by .40isthenew.45

Am I overthinking it

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Yes. You are. [Wave]

My 1:8 16" shoots everything fine.

Quote:

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Originally Posted by brutal

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.

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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.

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.