6.5 284 vs 260 ai

[codyadams]

Thanks for all the input guys! I have decided on the 260AI.

Now the fun begins piecing all the stuff together. Should have it built in 18 to 24 months, when it's done I'll post up some pics.

I would go with a 1:7 or 1:7.5 twist, especially if your lower elevation!! Berger will have their 156 EOL Hybrid out by then, and Sierra has a 150 that requires a 1:7.5 twist, and even the 142 Nosler LRAB bullets have a better bc with the tighter twist. And shooting a 140 or even a 130 through a 7 or 7.5 twist will not cause any problems. And with the right powders, if you go 26"+ or more, you will be able to push the heavy bullets fast enough. When the 156 is out, depending on where the node falls, I plan on 2950-3000+ fps.

Trust me, unless you want to shoot mostly 120 or lighter bullets, get a 7.5 or 7 twist. That is where the LR game is headed.

 

[longrangehunterII]

Build a 6.5x284.

- Great brass already, and a great designed case, all in one package.
- More long range matches have been won it so that speaks for itself.
- Barrel life will be the same or more, doing a AI you'll be fireforming which is barrel life
- If barrel life is a issue for you, use a smaller case to begin with.
- Sure you could form 260AI from 308 brass, and you'll be neck trimming due to the necks getting thicker, i. e. more work.
- The 260AI will still have the bullets deeply seated down into the case in a short action, so having a long action, and the bullets seated out w/the 6.5x284 makes better sense.
- Resale will be better too IMO.
- K.I.S.S. Keep It Super Simple, and you'll shoot more, and more often!

 

[Greyfox]

Cody, I think you are right on. These new offerings are very exiting for many 6.5 shooters. While they will be great for expanding effective distance for long range plinking/Competition, they potentially expand the scope of the 6.5 for long range hunting. If the Berger 156(Sierra) is driven to 2900FPS and delivers the ballistic performance and accuracy, it takes the magic 1000ft/lbs@1000 yards up 20% to roughly 1200 yards(4500ft). I will be very interested to see how these new offerings perform on game.

 

[B23]

Even loaded to OAL lengths to be used as a repeater in a SA the 6.5-284 still has a decent amount more case capacity than does the 260AI so, for me, I'd struggle to see how or why I'd ever go 260AI and go through the extra effort of fireforming when I could just do a 6.5-284, have more performance, and be able to load full house loads right out of the box. Even if the performance was exactly the same, I'd still go 6.5-284 so I wouldn't have to mess with any fireforming.

 

[stick man]

I live at 9000 feet in Grand county CO.
I was thinking I could get away with an 8 twist even for the 150 plus grain bullets? But now I think I might order a 7.
What's your suggestions on that?
Seems like I can get away with slower twist rates up here than lower elevations, with bullets that aren't supposed to work for the twist. IE my 22-250 loves 60 grain Sierra blitz kings at 3750 fps, and it is a 14 twist.

 

[MudRunner2005]

Even loaded to OAL lengths to be used as a repeater in a SA the 6.5-284 still has a decent amount more case capacity than does the 260AI so, for me, I'd struggle to see how or why I'd ever go 260AI and go through the extra effort of fireforming when I could just do a 6.5-284, have more performance, and be able to load full house loads right out of the box. Even if the performance was exactly the same, I'd still go 6.5-284 so I wouldn't have to mess with any fireforming.

Fireforming is not a very hard or complicated task... Everyone seems to talk about it like it's the boogyman. It's not difficult at all once you've learned the ropes.

 

[Deleted member 25294]

As others have said keep it simple
Fire forming a 260ai makes absolutely no sense when you can get 6.5x284 lapua brass and simply load and shoot.
Barrel life will be very similar,and the 6.5x284 will be a little faster, seriously unless you have a ton of tinkering time on your hands what's the argument here....

 

[B23]

Fireforming is not a very hard or complicated task... Everyone seems to talk about it like it's the boogyman. It's not difficult at all once you've learned the ropes.

Ohh, I'm pretty versed on fireforming considering I have a 223AI, 6-06AI, 6.5-06AI, 30-338 Lap Imp and 338 Lap Imp and with the exception of my 30-338 Lap Imp and 338 Lap Imp I wouldn't go "improved" on any of the others again. You're correct, fireforming isn't difficult at all but when there is so little gained or you can use a case that already has more capacity, why do I want to spend any amount of time fireforming.

About the only way I'd ever do a 260 improved is if I had Defensive Edge build me one of their 260 Terminators because they sell brass that's already fireformed for it.

 

[stick man]

I live at 9000 feet in Grand county CO.
I was thinking I could get away with an 8 twist even for the 150 plus grain bullets? But now I think I might order a 7.
What's your suggestions on that?
Seems like I can get away with slower twist rates up here than lower elevations, with bullets that aren't supposed to work for the twist. IE my 22-250 loves 60 grain Sierra blitz kings at 3750 fps, and it is a 14 twist.

 

[stick man]

?

 

[Gregg C]

Just out of curiosity, why would you ORDER a barrel in sub optimal twist rate that MIGHT get you by ? Sorry, dude, but that makes no sense. Suppose you wanted to drop down to the flatlands and shoot ? Would you then load up different ammo ? Pet load development takes time and money, doesn't it ? Why not get the absolute best for your money? Are faster twist barrels hotter, or slower ? Just trying to wrap my head around your question, is all, please take no offense, as none is being offered.

 

[RockyMtnMT]

I could flip a coin on the two cartridges and argue both for all the resons mentioned.

Short action=260ai
Long action=6.5-284

One more vote for the 7" twist barrel.

Steve

 

[Greyfox]

I wouldn't consider myself an expert and probably will be chastised for my position, but simply declaring that everyone should simply buy a fast twist(7)barrel may not be the no-brainer that many are implying. Yes, the heavies(155) do require a faster twist if that makes sense for your use. Push a faster 130/140 gr bullet into that faster twist barrel at higher velocity and depending on the bullet construction there be a negative effect on accuracy and throat wear. There is a reason that Benchrest shooters pick the slowest twist they can get away with while still stabilizing the bullet. It takes a longer time in the barrel with more energy for a bullet to take a bite into the rifling of a fast twist barrel. The fouling produced in this process can be an issue effecting accuracy and throat erosion, thus the principle behind Bartliens gain twist barrels. With LR hunting as my primary objective, until I understand the terminal performance on game of the heavies, I'll stick with. 1:8 twist. "Pinpoint" accuracy with the resultant precise bullet placement with well proven bullets is what makes the 6.5x284/260AK so effective as a LRH cartridge. I wouldn't want to trade that off until the terminal performance(and BC) of the heavies are understood. Unlike the long/heavy high BC 30 caliber bullets that have more mass and frontal area, the 6.5's rely heavily on the bullets ability to shed energy in the animal. I'll be quick to jump on the fast twist "bandwagon" IF the 6.5 heavies perform well on game.
The opinion of an old fart!

 

[Gregg C]

I wouldn't consider myself an expert and probably will be chastised for my position, but simply declaring that everyone should simply buy a fast twist(7)barrel may not be the no-brainer that many are implying. Yes, the heavies(155) do require a faster twist if that makes sense for your use. Push a faster 130/140 gr bullet into that faster twist barrel at higher velocity and depending on the bullet construction there be a negative effect on accuracy and throat wear. There is a reason that Benchrest shooters pick the slowest twist they can get away with while still stabilizing the bullet. It takes a longer time in the barrel with more energy for a bullet to take a bite into the rifling of a fast twist barrel. The fouling produced in this process can be an issue effecting accuracy and throat erosion, thus the principle behind Bartliens gain twist barrels. With LR hunting as my primary objective, until I understand the terminal performance on game of the heavies, I'll stick with. 1:8 twist. "Pinpoint" accuracy with the resultant precise bullet placement with well proven bullets is what makes the 6.5x284/260AK so effective as a LRH cartridge. I wouldn't want to trade that off until the terminal performance(and BC) of the heavies are understood. Unlike the long/heavy high BC 30 caliber bullets that have more mass and frontal area, the 6.5's rely heavily on the bullets ability to shed energy in the animal. I'll be quick to jump on the fast twist "bandwagon" IF the 6.5 heavies perform well on game.
The opinion of an old fart!

Ok, that makes sense. Thanks for helping THIS old fast understand something new.