223 ftr 7 twist surprise

[Hammer47]

Had the 223 at the range today tuning with 80 gn Bergers with good success. Had about 35 brass that needed to be fireformed to this chamber so I loaded them with 8208 and sierra 52 gn target bullets. I was expecting NOTHING in the way of accuracy out of a 7 twist bbl but was surprised to get sub 1 inch groups with 5 different powder charges. The groups were mostly 3 or 4 in a quarter inch then the "fliers" made the groups 1 inch or smaller. The range was 200 yds...............Imagine, a load used far from it's intended use performing like this? Blew me away.

 

[Rsadams]

My AR 1/7 twist will shoot the 50gr varment load in the AE black box like a Lazer beam... People don't think they will shoot light weight bullets well but I have seen them do it alot... Never gone below 50gr though....

 

[Twitchy]

I had outstanding results by chance with Sierra's 55g Blitkings in a 1:7.

 

[Boatschool02]

Same experience with a 7T 16" Krieger. Shot 55 blitzkings under 1.2" at 200 and 60 grain flat backs under 0.8." That's 5-shot groups from a bipod out of a short gas gun repeated across multiple charge weights and powders. Every now and then I'd have a super small group with the SMK 69s, but at 100 and 200, they were not as consistent as the two above... even though I really wanted my testing to reveal a different outcome.
FWIW, I also had some excellent groups with the lighter (52/53) SMKs as well.
I came to the quasi-conclusion that in that gun, my testing wasn't really demonstrating raw accuracy potential as much as jump tolerance while loading to mag length. I have no doubt the 77/80s, single loaded could be nuanced into better performance.

 

[Ned Ludd]

Going with a [much] faster-than-necessary twist typically isn't much of a problem, especially with a .223 Rem. I've shot 40 gr bullets out of a 7-twist .223 with no issues whatsoever. It's going the other direction and underspinning bullets where the trouble starts.

 

[1lnbrdg]

We were doing load testing on a calm day at 600 yds with 77 and 80gr bullets.

1 of the guys shot a string with 69gr bullets, about 4" group, then he shot 55gr HPBT's.

I was in the pits. The 55's shot an 8" group but they all came in subsonic. It's just a bit different hearing the "Tic" when the bullet goes thru the paper and then the sound of the report just behind it.

 

[Beau]

I only develop loads for 77 or 80 gr bullets. Every lighter bullet gets the same powder charge as the heavies. They all shoot great.

 

[Rstrick0352]

I know this is the wrong caliber but I shoot 125gr Nosler BTs our of my 10twist 16” bbl .308win into little bugholes at over 3k fps. Fantastic south GA deer load.

 

[XTR]

.... I've shot 40 gr bullets out of a 7-twist .223 with no issues whatsoever. It's going the other direction and underspinning bullets where the trouble starts.

The dysfunctional relationship with light bullets usually starts when you try to drive a 40gr bullet from a 1:7 at 3800 or 4000 or what ever the max you can drive those little buggers. They have a tendency to turn into smoke at about 75 yards.