Does anyone have any experience with this rate of gain twist for 6.5 PRC? I see a lot of people using smaller gaps in twist. I didn't know if this would be too aggressive. Finish length will be 28-30 Inches and I plan on using heavies.
- Thread starter ar152203
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I can't give you a direct answer, but here are a couple of data points that might help.
I did a straight 1:7 for my 6.5 PRC. I had a problem with 153g ATips blowing up when the barrel got a little worn. Hornady said it was spinning the bullets too fast, but Berger 153.5s (and everything else I have shot in it) worked just fine.
On my 6 Creed, I did gain twist. Bartlein's advice was a .75 difference, and I used 8 to 7.25 which has been working great.
I did a straight 1:7 for my 6.5 PRC. I had a problem with 153g ATips blowing up when the barrel got a little worn. Hornady said it was spinning the bullets too fast, but Berger 153.5s (and everything else I have shot in it) worked just fine.
On my 6 Creed, I did gain twist. Bartlein's advice was a .75 difference, and I used 8 to 7.25 which has been working great.
No reason that shouldnt work.
There’s a fairly significant price change between gains under one inch, and gains of an inch or greater. Seem to recall it was $40 vs $100, but cant find it on their site at the moment.
Also, they recommend subtle gains the last I spoke to them. If you google “gain twist + snipers hide” you’ll get a bunch of hits to threads here.
There’s a fairly significant price change between gains under one inch, and gains of an inch or greater. Seem to recall it was $40 vs $100, but cant find it on their site at the moment.
Also, they recommend subtle gains the last I spoke to them. If you google “gain twist + snipers hide” you’ll get a bunch of hits to threads here.
Every time I call bartlein to order a gain twist they end up recommending 0.75 gain regardless of the caliber I've ordered, I have quite a few now in .224, 6mm, 6.5mm, 7mm, and .30. All are 0.75 gain as per their recommendation.
I have heard of people experimenting with gains in the 2-3 range (like a 10 to 7 gain twist) to try and have one barrel shoot a wide range of bullet weights and velocities, but I've never seen any conclusive data from those tests.
I have heard of people experimenting with gains in the 2-3 range (like a 10 to 7 gain twist) to try and have one barrel shoot a wide range of bullet weights and velocities, but I've never seen any conclusive data from those tests.
If the final twist rate is appropriate for your bullet and velocity combo, go for it... I'm sure it will shoot great.
I've never asked bartlein on the phone if the recommendation for 0.75 gain is because it produces the best results on target or because it's the easiest/fastest for them to setup and machine, but I'll ask the next time I order some blanks.
I've never asked bartlein on the phone if the recommendation for 0.75 gain is because it produces the best results on target or because it's the easiest/fastest for them to setup and machine, but I'll ask the next time I order some blanks.
Hornady makes the shittiest bullets. This is what happens when you get them near and above 300krpm. Non uniform jacket and centrifical force blows the bullets up about 100 yard out of bore. Was joking about it at a class and people thought I was full of shit. 2 hours later home boy is blowing up every 3rd shot out of a 6 creed shooting factory Hornady match; 108s out of a 7tw tube.
Berger, Sierra, dtac, norma , lapua do not have these problems. Stick with them, especially with a fast prc.
I’ve had the 108’s blow up on a hot day before.
Yup. Hot = higher pressure = more velocity = more rpm.
Sooo...... I have a 6.5 Saum Chambered in a bartlein moddbb with a LH gain twist. I would go with Franks (from Bartlein) recommendation of a .75 gain. That being said I went 1/9 to a 1/8 exit at the muzzle of a 26inch barrel, thinking that the slower start would stress the bullet less. I would not go over a 1 inch gain. I've blown up hornady 147's but not 140's. Never blown up a berger or smk with this barrel. Shooting at an ipsc piece of ar500 at 200 and 500 yards and the bullet doesn't impact makes you scratch your head. I'm pushing berger 130's to 3200fps with an sd of 5. 62 grains of h1000 and a 130 berger is my favorite load. I've been tinkering with the 156 bergers and n570 and the 1/8 twist looks like it stabilizes them just fine, and I'm barely above see level.
My recommendation would be if you are absolutely set on a gain twist, go 1/8.5 to 1/7.75
My recommendation would be if you are absolutely set on a gain twist, go 1/8.5 to 1/7.75
Received the same rec... 8.25 to 7.5 on my 6.5prc build to shoot 153.5lrht & 156eol
@ar152203 other people have run 7 twist for long 6.5 bullets... I get 1.94sg gyroscopic stability for 153.5lrht .356g7 @ 3200fps, which should perform great (although I'd imagine you'll run them under 3,200fps). Why not just call Bartlein to ask though?
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Wow, this is about 2 years ago but Mark at Bartlein indicated that they favor a .5" gain...in my 6.5 manbun case that ended being 8-7.5. I originally was going to go with 8.25 - 7.5 until i spoke with them.
Perhaps their recommendations have changed....or maybe it really doesn't practically matter (more likely, IMO).
Perhaps their recommendations have changed....or maybe it really doesn't practically matter (more likely, IMO).
