5.56 1/7 twist rate

blackswamp · February 26, 2016, 10:52 PM

Can a 16" AR-15 with a 1/7 twist rate shoot 55 grain bullets accurately? These will be my reloads.

chris in va · February 26, 2016, 11:16 PM

Short answer...yes.

Water-Man · February 27, 2016, 12:30 AM

Another short answer. Maybe.

TMD · February 27, 2016, 02:58 AM

Define accurately.

cryogenic419 · February 27, 2016, 07:35 AM

They absolutely can and will.

With that said there are always exceptions to the rule, sometimes a barrel just won't shoot well but generally its not an issue.

I've taken my Colt 6920 out to 300 accurately.

Jim243 · February 27, 2016, 07:37 AM

1/7 Twist 55 grain, yes, but TMD is right what do you mean by accurate??

1.0 MOA or 0.50 MOA or less??

Your 1/7 twist will handle much heavier bullets, so you are not getting the full potential out of your rifle with just 55 grain bullets, I would recommend going to a 60 or 62 grain bullet.

Just my 2 cents.
Stay safe.
Jim

Jimro · February 27, 2016, 03:55 PM

Quote:

Can a 16" AR-15 with a 1/7 twist rate shoot 55 grain bullets accurately? These will be my reloads.

Can? Yes.

Will? Remains to be seen.

With a 1:7 twist you will probably get better accuracy with a 68 to 77 grain match bullet. Hornady 68s and 75s are pretty cheap if you buy them in bulk.

Jimro

**Unclenick** · February 27, 2016, 07:41 PM

It will depend on the quality of the bullets. Cheaply made bulk bulk bullets may suffer from imprecise jacket wall thickness, and that can result in bullets that wobble in flight (spin eccentrically) and drift off their intended trajectory. The faster you spin such bullets, the faster they drift away from the point of aim. But, as mentioned, Hornady makes bullets that are pretty good for less money than most of the makers do, and using their bullets and avoiding pull-downs and cheapies will go a long way toward avoiding the eccentric spin issue.

4runnerman · February 27, 2016, 09:18 PM

I just got a new AR15 with a 22" SS Bull, with a 1 in 7. Shoots 60gn V Max like a charm.

Metal god · February 27, 2016, 09:25 PM

Not to pile on here but yes a 1-7 can shoot a 55gr bullet accurately . As some of the more knowledgeable here have stated . The better the bullet the more accurate it can be but doesn't that go with out saying

I have a load that shoots right at 1moa or 1" @ 100yards . It's 25.5gr IMR 4895 and Hornady 55gr FMJ-BT . That's from a Del-ton 16" chrome lined heavy barrel . So it not only can be done . It does not have to be a Krieger barrel either .

blackswamp · February 27, 2016, 10:19 PM

I want to build another AR with open sights for two local military shoots. One shoot is open sights only at about 60 yards on paper. this one is a little tricky because if you go off target you loose points. The other shoot is steel targets from 50yds to 200yds timed. I got a lot of 55gr bullets on hand that's why I ask the question.

Road_Clam · February 28, 2016, 08:13 AM

I built a 20" WOA match service rifle that is 1-7" and I shoot Hornady 55 gr bulk fmj's for my training ammo. They shoot good. Keep in mind the 55's are not the best choice , (69's and even better is 77's are the best ) but shooting match bullets gets expensive so it's nice to be able to practice with the cheap 55's.

rodfac · February 28, 2016, 08:55 PM

Yes...up to the quality of the bullets...Rod

Sky Master · February 29, 2016, 09:56 AM

Have a 6920 myself, works fine.

February 26, 2016, 10:52 PM	#1
blackswamp Member Join Date: December 12, 2014 Posts: 24	5.56 1/7 twist rate Can a 16" AR-15 with a 1/7 twist rate shoot 55 grain bullets accurately? These will be my reloads.

February 27, 2016, 07:37 AM	#6
Jim243 Senior Member Join Date: January 5, 2009 Location: Just off Route 66 Posts: 5,067	1/7 Twist 55 grain, yes, but TMD is right what do you mean by accurate?? 1.0 MOA or 0.50 MOA or less?? Your 1/7 twist will handle much heavier bullets, so you are not getting the full potential out of your rifle with just 55 grain bullets, I would recommend going to a 60 or 62 grain bullet. Just my 2 cents. Stay safe. Jim __________________ Si vis pacem, para bellum

February 27, 2016, 07:41 PM	#8
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	It will depend on the quality of the bullets. Cheaply made bulk bulk bullets may suffer from imprecise jacket wall thickness, and that can result in bullets that wobble in flight (spin eccentrically) and drift off their intended trajectory. The faster you spin such bullets, the faster they drift away from the point of aim. But, as mentioned, Hornady makes bullets that are pretty good for less money than most of the makers do, and using their bullets and avoiding pull-downs and cheapies will go a long way toward avoiding the eccentric spin issue. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 27, 2016, 09:18 PM	#9
4runnerman Senior Member Join Date: January 16, 2010 Location: Minnesota Posts: 3,577	I just got a new AR15 with a 22" SS Bull, with a 1 in 7. Shoots 60gn V Max like a charm. __________________ NRA Certified RSO NwCP- Performance Isn't Optional

February 27, 2016, 09:25 PM	#10
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	Not to pile on here but yes a 1-7 can shoot a 55gr bullet accurately . As some of the more knowledgeable here have stated . The better the bullet the more accurate it can be but doesn't that go with out saying I have a load that shoots right at 1moa or 1" @ 100yards . It's 25.5gr IMR 4895 and Hornady 55gr FMJ-BT . That's from a Del-ton 16" chrome lined heavy barrel . So it not only can be done . It does not have to be a Krieger barrel either . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; February 27, 2016 at 09:30 PM.

February 26, 2016, 11:16 PM	#2
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	Short answer...yes.

February 27, 2016, 12:30 AM	#3
Water-Man Senior Member Join Date: March 23, 2008 Location: Jacksonville, FL Posts: 2,126	Another short answer. Maybe.

February 27, 2016, 02:58 AM	#4
TMD Senior Member Join Date: August 9, 2011 Posts: 1,293	Define accurately.

February 27, 2016, 07:35 AM	#5
cryogenic419 Senior Member Join Date: March 29, 2009 Location: NW Ohio Posts: 569	They absolutely can and will. With that said there are always exceptions to the rule, sometimes a barrel just won't shoot well but generally its not an issue. I've taken my Colt 6920 out to 300 accurately.

February 27, 2016, 10:19 PM	#11
blackswamp Member Join Date: December 12, 2014 Posts: 24	Thanks! I want to build another AR with open sights for two local military shoots. One shoot is open sights only at about 60 yards on paper. this one is a little tricky because if you go off target you loose points. The other shoot is steel targets from 50yds to 200yds timed. I got a lot of 55gr bullets on hand that's why I ask the question.

February 28, 2016, 08:13 AM	#12
Road_Clam Senior Member Join Date: November 21, 2013 Location: New Hampshire Posts: 1,695	I built a 20" WOA match service rifle that is 1-7" and I shoot Hornady 55 gr bulk fmj's for my training ammo. They shoot good. Keep in mind the 55's are not the best choice , (69's and even better is 77's are the best ) but shooting match bullets gets expensive so it's nice to be able to practice with the cheap 55's. __________________ "To be old an wise you must have been young and stupid" Last edited by Road_Clam; February 28, 2016 at 04:29 PM.

February 28, 2016, 08:55 PM	#13
rodfac Senior Member Join Date: January 22, 2005 Location: Kentucky Posts: 3,624	Yes...up to the quality of the bullets...Rod __________________ Cherish our flag, honor it, defend it in word and deed, or get the hell out. Our Bill of Rights has been paid for by heros in uniform and shall not be diluted by misguided governmental social experiments. We owe this to our children, anything less is cowardice. USAF FAC, 5th Spl Forces, Vietnam Vet '69-'73. Last edited by rodfac; March 3, 2016 at 12:18 PM.

February 29, 2016, 09:56 AM	#14
Sky Master Senior Member Join Date: May 30, 2009 Posts: 136	Have a 6920 myself, works fine.