.260 ai

PeterPan

PeterPan

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I am thinking about buying Savage Long Range Precision rifle in 2011. It comes with HS stock and my choice in caliber would be .260Rem.
How hard is to ream it to .260 AI and will this be a good choice for shooting 1000m?

Thanks
 
That 260AI got to be as fast as 6.5X55 or 6.5X284.(2800-2900fps)
I got 4 260rem build for myself, the best I could do is 2700fps.
 
The 260 AI will beat the standard cartridge by a solid 25 fps. There isn't enough increase in case capacity to do any more than that. This assumes everthing else to be equal. Same barrel, same throating, same chamber pressure.
The single problem with the 260 is it's short neck. There are those who claim the relatively shallow shoulder angle, in combination with the short neck, increases throat erosion. Their claim is that the sharper shoulder of the AI will increase barrel life. I can neither support nor refute that theory since I've not worn out barrels with each caliber to do so. I am sceptical but have that information from sources I respect so put it down as possible. Regards, Bill
 
Leeper said:
The 260 AI will beat the standard cartridge by a solid 25 fps. There isn't enough increase in case capacity to do any more than that. This assumes everthing else to be equal. Same barrel, same throating, same chamber pressure.
The single problem with the 260 is it's short neck. There are those who claim the relatively shallow shoulder angle, in combination with the short neck, increases throat erosion. Their claim is that the sharper shoulder of the AI will increase barrel life. I can neither support nor refute that theory since I've not worn out barrels with each caliber to do so. I am sceptical but have that information from sources I respect so put it down as possible. Regards, Bill
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My .260AI lasted 1800 rounds +- a couple and became unpredictable at long range the throat was heavily eroded. Basically if you want to push a 140 at 2900 fps or above it will do it but you wont get much more then 1800 out of it with constant results at long range 300m and beyond. It is a bit of a barrel burner but a very accurate when set up in the right rifle. I had mine shortened and rechamberd in 6.5x47 Lapua and hope to get a few more rounds out of the barrel before tossing it. I'm just about getting the same performance as with the .260AI and using less powder to do it and with a two inch shorter barrel.
 
308 case based AI cartridges don't gain much, there really isn't much of an improvement. Will it go a little faster? Sure. Measure the case capacity of a standard 260 case in cc's, then do it with a 260 AI case. Calculate the % of case capacity gain. Then divide by 4. That will be the percentage of velocity gain. As mentioned, 25-50 fps will be the amount, all other things being equal. - dan
 
I burned a barrel out at 1,500 rds with a 6.5x284 with velocities around the 3,000fps mark.
My 260 AI at around 2,000 rds with 2,900fps. Those were loaded at max pressures with N160.

My next rifle I'm building this winter is a standard 6.5x55. We shall see if lowering the pressure and longer necks @ 2,900 fps will give me better barrel life. All three barrels are MacLennan's. Not an exhaustive experiment by any means.
 
I had great luck with Ted Gaillard barrel, 6.5 1-8twist, in 6.5X55SM 26" , I got 2850-2860 fps, with no pressure sign from 140grian Amax, 47.5grain of H4831.
 
My 260Ai gets no appreciable velocity increase over standard 260rem - but brass lasts a dang long time and I don't trim it as often as standard 260Rem.

I hate case trimming. Every gun of mine will be an ackley version if I have my way JUST because I hate case trimming so badly.
 
Having shot the 260AI and 6.5 Mystic for the last several years in F class, I'll toss in my 2 cents.

Positives:

Very easy to tune out the vertical - under 1/4 min at LR is possible.
Consistent powder charges over 5 barrels using H4831SC, CCIBR2 and Win brass
Very long case life at elevated pressures (Quickload predicts 60,000psi)
Speeds of 2900+fps are no problem in 28" and longer barrels
Much better on throats then the 6.5-284 going the same speed.
V bull accuracy 1200 to 1500rds.
Readily available brass and dies - lower pricing for components.
Any standard action will work with this case in single feeding.

Negatives

Case forming [ Just found out Lapua will be making 260R brass so forming is no longer a big chore]
Will not easily feed from staggered mags
Run bests at OAL approaching 3" using 140gr VLD's so doesn't fit readily in 2.80 mags
Doesn't stack in most 308 style mags.
Will not reach 3000fps accurately/consistently

Depending on the rifle, the 260Rem doesn't reach the speeds that the improved version can AND still maintain good brass life, accuracy and consistency. The smaller case capacity and sloping shoulder isn't ideal for elevated pressures.

But there are a few 260R type chamberings being campaigned in F class and doing very very well.

If you are planning a rifle that will feed from the mag, go 260Rem. For single feeding as in F class or LR plinking, the improved version is a gem.

Jerry
 
I shoot 140 VLD's wth my 65-08 (260) at 2850 all day long, no pressure at all. At the "Running of the V-Bulls" F-Class Match in October, I let a friend use it. It was only the second time in his life he had ever shot a rifle, and he placed 4th (out of 19) in open class with it. He held center and his breath.

With the advent of lapua 260 brass, this cartridge has no real down-sides, and with only one step to the AI version, if it's what you want, go for it. I have been so pleased with the plain old 260, I don't feel like phucking with something that works. CyaN1de and Shockman have rilfes cut from the same reamer, and they are wickendly accurate rifles too.

Now that matrix has the high BC 277 bullet, my next foray into wildcatting will be based on this caliber....just cuz.
 
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