Yorkshire shooter
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UK
Philuk44.
Meet up would be good from Wakefield what about you.
Cheers Gary
Philuk44.
Meet up would be good from Wakefield what about you.
Cheers Gary
223, bullet weight and twists
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ArchAngelCD
Member.
Since you said there was no evidence of tumbling the weight and length of the bullet isn't the problem. Before you give up on a 75gr bullet try loading your own with some of the good recipes available here and in the load manuals. Just because the commercial ammo wasn't accurate in your rifle doesn't mean the bullet weight was to blame.
Yorkshire shooter
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PPU
Ok lads just picked up 2x boxes of 69grn 223 the quest for accuracy continues
For my Howa 1 in 9 twist
Ok lads just picked up 2x boxes of 69grn 223 the quest for accuracy continues
For my Howa 1 in 9 twist
Yorkshire shooter
Member
Sorry PPU
Yorkshire shooter
Member
Hi all,
Ok I have put a box of hornady 55grn steel cased ammo through the best I got was 1/and 1/2 ins at 100 m then I had a go with PPU 69 grn ammo 1and 1/4 ins 3 round group . Still not in the right ball park and now to make things worse my shooting buddy had 4rds of 223 kicking around in his shooting box Yehaaa sub 1ins group ,,, I then ask my shooting buddy what they where ,,,, his reply oh just some old reloads not too sure what they where.
If ever I wanted to shoot someone that was the time.
Cheers Gary
Ok I have put a box of hornady 55grn steel cased ammo through the best I got was 1/and 1/2 ins at 100 m then I had a go with PPU 69 grn ammo 1and 1/4 ins 3 round group . Still not in the right ball park and now to make things worse my shooting buddy had 4rds of 223 kicking around in his shooting box Yehaaa sub 1ins group ,,, I then ask my shooting buddy what they where ,,,, his reply oh just some old reloads not too sure what they where.
If ever I wanted to shoot someone that was the time.
Cheers Gary
Yorkshire shooter
Member
Hi all, getting there Bisley ranges 500yds 69grn SMK heads 5rds under 6ins getting there
More tweaking .,.but things are looking better .
Regards to all Cheers Gary
More tweaking .,.but things are looking better .
Regards to all Cheers Gary
Although I shoot a Rem. 700 in .223, it does have a 1:9 twist barrel. The most accurate load I've tried so far has been Hornady 75gr. Match ammo. I have gotten 3/8" groups at 100 yds. and a 15/16" three shot group at 200 yds. At least in my barrel, a 1:9 twist certainly works with 75gr. bullets.
Also, for what ever reason the steel case Hornady doesn't seem to shoot as accurately as the brass cased Match ammo with the same bullet in my gun. I have also tried Black Hills 68gr. BTHP using the 68gr. Hornady bullet and it shoots seemingly as well as the 75 gr. rounds. YMMV
Also, for what ever reason the steel case Hornady doesn't seem to shoot as accurately as the brass cased Match ammo with the same bullet in my gun. I have also tried Black Hills 68gr. BTHP using the 68gr. Hornady bullet and it shoots seemingly as well as the 75 gr. rounds. YMMV
Arizona_Mike
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Most of my match grade 5.56 barrels (all 1:8 twist) have been significantly more accurate with 69gr ammo than 75gr but that may be due to multiple factors. You are going to have to try it. As others have pointed out, length is the main issue (with weight just being an approximate predictor of length).
Not optimal form a design point of view but with a little luck you will get acceptable accuracy. You'll just have to try.
Good luck with your 1:22.86 twist
Mike
Not optimal form a design point of view but with a little luck you will get acceptable accuracy. You'll just have to try.
Good luck with your 1:22.86 twist
Mike
So, you got almost MOA @ 500 with these? I'd call the ammo quest over and just stick with this load. I doubt any other factory load would do better than this, handloading would be another story.
Unless these were handloads, either way I'd say you found the right bullet.
the heavier the bullet the faster the twist you want. I would say a min twist rate of 1-7 for that weight of bullet depending on o-give and other factors. here is a good chart for you to look at:
http://www.shootandreload.com/2011/06/15/bullet-weight-vs-barrel-twist/
http://www.shootandreload.com/2011/06/15/bullet-weight-vs-barrel-twist/
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Arizona_Mike
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Using the Berger Bullets Twist Rate Calculator: http://www.bergerbullets.com/twist-rate-calculator/
I used the Berger 75gr Match VLD and the published velocity of a Hornady 75gr match load and got this result:
As I mentioned in my last reply I see a significant difference in group size between PPU 75gr Match and 69gr Match in my 1:8 guns.
Using that calculator and a 70 grain and 75 grain bullet form the library, I get SG=1.42 (marginal stability) vs. 1.68 (Comfortable Stability) without adjusting the velocity upward.
Mike
PS. VLD bullets have an air space up front, conventional bullets will be shorter. Also if you have issues try switching to a flat-base from a boat tail of similar weight. Flat base bullets need significantly less twist (like 1=/3 less) than similar boat tail bullets.
I used the Berger 75gr Match VLD and the published velocity of a Hornady 75gr match load and got this result:
As I mentioned in my last reply I see a significant difference in group size between PPU 75gr Match and 69gr Match in my 1:8 guns.
Using that calculator and a 70 grain and 75 grain bullet form the library, I get SG=1.42 (marginal stability) vs. 1.68 (Comfortable Stability) without adjusting the velocity upward.
Mike
PS. VLD bullets have an air space up front, conventional bullets will be shorter. Also if you have issues try switching to a flat-base from a boat tail of similar weight. Flat base bullets need significantly less twist (like 1=/3 less) than similar boat tail bullets.
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