What Twist For 6.5 Barrel?

[Savage 12BVSS]

I have a 260 deer rifle that has a LW match barrel on it, light profile and 20". When they made the bbl. they asked me what weight bullets would be used and were told 130gr and 140gr only no heavier or lighter. They produced the bbl' with a 1-7.75" twist and I began to work up loads for it. With the light profile for weight reasons its only good for 3 shots and then a cooldown, load work is slow I have doubts about the fast twist with the 130's and have not gotten the accuracy I was hoping for. What say you? Would think it would be very much like the 6.5CM in ballistics and what works for twist rate.

 

[338 dude]

I would have to say an eight twist is definitely the most popular and all I've ever had in this caliber but I don't know a 1in 775 is that different could it possibly be the light barrel and temperatures of multiple shots that is causing your in accuracies and you might want to try going up to a 140 weight bullet

 

[L.Sherm]

I dont think twist is your problem.

 

[lancetkenyon]

I have three different 6.5s currently, and have had 3 others in the past. Two are 1:7.5" and four are/were 1:8". Also, I have loaded for probably 20 other 6.5s with 1:7.5" to 1:8". Not a single problem shooting bullet weights from 85gr to 144gr in any of them, and 150/156 in quite a few too.
1:7.75" twist is not the problem. Try a different bullet, or powder, or primer.
Or even brass if you are using crap like Hornady brass. Try Lapua.
Since you didn't give any load data, I am speculating here.

 

[sierracharlie338]

I have to agree with the above, it's not the twist. I'd look at components and then possibly barrel profile as the suspect. I had a light barrel on a rifle and eventually gave up on it due to the heat sensitivity and went with something stouter.

 

[Jud96]

As others have already said, it's not your twist. A 1-8 is standard so a 1-7.75 isn't that drastic of a difference. I would just check over the rifle and make sure everything is torqued properly, make sure the barrel isn't bound up, make sure the action screws aren't on a bind, just check everything out. Then I would try a premium 130gr bullet. Something that is proven to shoot well like a 130gr Berger AR Hyrbid. Load some rounds up either at the charge weight you're using now or something you know is safe. Load 3 at your current OAL, then load 3 each in increments of .005 further back from either your current load, or start .030 off the lands and work back from there. If you're limited by your magazine box, then start .020 shorter than it and again work back in .005 increments. Seating depth has proven to make HUGE changes in accuracy and consistency for me. There are a million ways to skin a cat, but I find seating depth to be the simplest and cheapest variable to adjust and experiment with that can really tune in your load.

 

[Savage 12BVSS]

Sorry was focused on the twist as a possible problem, gun is fully tuned like all my savages. Rifle basic's 2 trigger, squared varmint action, match recoil lug, floated bbl with glass and pillar bedding, carbon composite stock with alum. bedding block. Have tried multiple powders, use lapua brass, and have moved OAL from .008 all the way out to .040 in very small increments. Varget and 4350 gave best accuracy but its not shooting like it should. I think its the very light profile of the short barrel, lot of two shot ragged holes and then a flier. I didn't want to think it was the tiny profile but if the twist isn't the culprit I believe it is. Barrel only has about 300 rounds thru it so I have to be content that its plenty accurate enough for deer hunting (1/2-3/4")and stop trying to get it to shoot ragged hole's. Thank You for confirming my worst suspicion.......The perfectionist part of me wants to take it off and replace with a heavier contour barrel. I tried to go too light with the barrel

 

[Jud96]

Sorry was focused on the twist as a possible problem, gun is fully tuned like all my savages. Rifle basic's 2 trigger, squared varmint action, match recoil lug, floated bbl with glass and pillar bedding, carbon composite stock with alum. bedding block. Have tried multiple powders, use lapua brass, and have moved OAL from .008 all the way out to .040 in very small increments. Varget and 4350 gave best accuracy but its not shooting like it should. I think its the very light profile of the short barrel, lot of two shot ragged holes and then a flier. I didn't want to think it was the tiny profile but if the twist isn't the culprit I believe it is. Barrel only has about 300 rounds thru it so I have to be content that its plenty accurate enough for deer hunting (1/2-3/4")and stop trying to get it to shoot ragged hole's. Thank You for confirming my worst suspicion.......The perfectionist part of me wants to take it off and replace with a heavier contour barrel. I tried to go too light with the barrel

If you still have some tinkeritis left in you, try seating those bullets .050+ off the lands. Sounds crazy to some, but I have found best accuracy in multiple rifles .050-.070 off the lands.

 

[J E Custom]

Lightweight barrels can be accurate but they are normally limited to two or three accurate shots before they heat up. They are also more finicky about the favored load and can be more difficult to work up loads for. They normally respond better with lighter bullets, so you
should try some 120's and see how it does.

Ammo quality is important in all rifles but more so in the lightweight rifles.

J E CUSTOM

 

[Savage 12BVSS]

Well Jud with the long bullets and short case length I can't go any deeper and have powder capacity. The powder charge is compressed at .040 to the point I can't go any deeper. Thats why I stopped at .040 off, I read your posts with interest about coming way back off lands and finding accuracy but with this cartridge I can't accomplish it. The gun is a good 3/4" gun as it is and that's ample for what I need.........problem is I can't accept that. All my guns shoot very well and I just like that, season is upon me so will keep it for back-up this season but I thought about it today and I will pull the barrel afterward and lean it in the corner of the gun room. I've got a line on a stiffer contour barrel in another cartridge so will screw it on this winter and start down another road. Charlie, Bill, JE, I will take your advice its probably spot-on, Jud would try your long jump idea if it was feasible. Will post up when I get things set back up..........anybody want a light profile 20" LW bbl in 260 with low miles give me a holler Dave

 

[lancetkenyon]

What is your charge weight w. H4350? Somewhere 41.5-44.0?
Shoot two, let cool completely, shoot two more at the same target. See how that does.
You really only need one shot anyway....

 

[JMW67]

I love a 260 and have owned a few they all seemed finicky once the right load was found they were great just took a little time to find it

 

[Savage 12BVSS]

To answer Lances question it's 44 with IMR4350 and 43.1 with H4350. Thats why bullet depth in case is such a tight deal. I was looking at my last targets this fall with 37.7gr of Varget and it shows promise but I need to try a weight spread from 37.5-39 and see what happens. I didn't get to do that before season came, by going with a powder that fills the case less I can probably try moving back some off lands as well and try Jud's suggestion. Won't take the barrel off yet and after season will give it a final go. Varget is the most accurate powder I use in both 7mm-08's so it could easy show some improvement over the 4350's. I do shoot three shots and then give it a 20-30 min. cooldown now so load work is painfully slow but don't want to give up without trying every possibility. Thanks Dave

 

[Cesky fousek]

I have a 260 deer rifle that has a LW match barrel on it, light profile and 20". When they made the bbl. they asked me what weight bullets would be used and were told 130gr and 140gr only no heavier or lighter. They produced the bbl' with a 1-7.75" twist and I began to work up loads for it. With the light profile for weight reasons its only good for 3 shots and then a cooldown, load work is slow I have doubts about the fast twist with the 130's and have not gotten the accuracy I was hoping for. What say you? Would think it would be very much like the 6.5CM in ballistics and what works for twist rate.

You should get 1:7 and you won't have to worry about any weight anywhere from 95 gr to 156