As far as I know there aren't any. They've been tried sporadically thru the years but not recently in long range BR AFAIK. When I called about an tight twist Krieger I was told no-go for a long time.
Frank Green might make one but I haven't heard of any being used yet.
I've got an old 8-7.5 gainer that's never impressed me.
The 6 mm gain twist (8.75" tw. to 8.3" tw.) barrels that Krieger is making will stabilize a Berger 105 VLD just fine . Larry Isenhour has pending IBS 600 yd. score record with a .904" 5 shot group while shooting just such a setup.
Bartlien is making gain twist barrels in everything right now and getting rave reviews.
I think Ron was working on a 300 WSM or bigger cartridge but I don't know for sure.I will e-mail him and see if he will post.
He is now in Wyoming and last I heard he really likes it back there.
I know he is missed at the Sacramento Club but maybe he will come on out for the Nationals?
I think Lou Murdica was talking about a relatively small amount of gain just to keep the bullet under a little bit of tension from the lands.I don't recall the details but it was something like 8.2 twist at the chamber and 8 twist at the muzzle.
Some of the guys are really going with a lot of gain on the order of a full twist or more.
I am sitting on two brand new Bartrliens right now because I haven't decided on 6 BR or 6 Dasher yet.Jim Borden sent me a 6 Dasher a couple weeks back and we had Alex Sitman put it in a stock but so far only 50 bullets have gone down the Bartlien barrel.It shot 6 extremely good groups so we are very close to making up our minds.
I plan on having my father shoot it at our next match in two weeks.
Right now I'd say Bartlien is the best of the best.
Waterboy
Krieger has made up to and probably more than 20 6mm barrels for Mike Davis to distribute. These start out with a 8.75 and end up 8.3 at 28 inches. Larry Isenhour has a pending IBS 600 yd. record using one of these barrels but that does not surprise me coming from Larry.
I shoot F-Class not BR but have been shooting a Bartlein 6.5-284 with a gain twist for the last 9 months. The twist is a 9.188” to 8.25” at 30”. It shoots at least as good and maybe better than all my other Bartlein’s which are very darn good. Water-line sub-half minute elevations at 1k are very common with this barrel.
If you have questions on gain twist talk to Frank Green at Bartlein Barrels.
Hi Al, I did move, near to Cody Wy, where I grew up. Bartlien is making gain twist, I think they call it "T" style rifling. I have a brandy new one set up for the .300 WSM, its 32" long and starts out at a 10.5 and goes to 9.5 at 32" I am working with H1000 and the 240SMK. Bartlien can and will make whatever twist rate you would ask for. Ron Tilley
I got my hands on one of the Krieger 8.75-8.3 gainers. I am having the smith chamber it for a dasher. This will be used for f-class shooting. I sure hope it works out as i passed up a good deal on a standard 8 twist krieger. I will post a review when its done and i shoot it a bit. Thanks for the info fellas. I appreciate it!! Lee
I have my gainer chambered for the dasher and started to form some cases. I was surprised to see the amount of copper i had to remove from this barrel during the first 10 firings while doing the one shot and clean method. I finally got to shoot a few groups at 100 yards with it today and they were pretty darn good for blowing the brass out still. The copper problem is diminishing after a good friend turned me on to Kroil. To early to tell, but i am feeling pretty good about this set up. More to come at a later date. thanks Lee