260 AI speed question

[huckjare]

My 260 AI is not up to par in my opinion. I am not reaching that 2900 fps mark that everyone else is with the 140's. I shoot 4831sc, 48.5 grains, and it just isn't there. I just thought I would see if anyone could give me some insight on an impovments I could make. It is built off a savage action with a Christensen Arms 26'' barrel. I'm not sure if I could change powders and get it up or not. I have heard that reloader 17 might be an option that guys are using in the regular 260. Thanks in advance

 

[RockZ]

I have found best accuracy with my 260AI at 2850fps with the 140gr amax.i think you are in a sweet spot with a 26" barrel. I'm using Norma mrp with great success.

 

[huckjare]

Ya mine seems to shoot well but with it being the AI I want more. There really is no reason to shoot the AI if you are only getting the same speed as a regular 260, that is my biggest issue.

 

[RockZ]

Here's a good link
Terry's Tactical Two-Sixty AI

 

[Sully2]

My 260 AI is not up to par in my opinion. I am not reaching that 2900 fps mark that everyone else is with the 140's. I shoot 4831sc, 48.5 grains, and it just isn't there. I just thought I would see if anyone could give me some insight on an impovments I could make. It is built off a savage action with a Christensen Arms 26'' barrel. I'm not sure if I could change powders and get it up or not. I have heard that reloader 17 might be an option that guys are using in the regular 260. Thanks in advance

Hodgdons data show ONLY 2686 FPS with 45.7 gr of that powder..???

In fact they dont show 2900 fps with ANY powder type or load with a 140 gr slug. Someone might be yanking your doodle partner

 

[huckjare]

The load data books are way conservative all the time. My buddy gets 2840 fps out of his 260 remington. I should be able to get at least 100 fps faster with the AI

 

[J E Custom]

Ya mine seems to shoot well but with it being the AI I want more. There really is no reason to shoot the AI if you are only getting the same speed as a regular 260, that is my biggest issue.

The "Regular" 260 velocity is close to Max pressure (55,000 Psi) when pushing a 140 grain bullet
at 2750 ft/sec so 2900 is a 150 ft/sec jump.

Any where in the 2800 to 2900 ft/sec is a good neighborhood, and without loading Hard or having
a 28''+ barrel it is tough.

I don't know what your velocities are but if they are not loaded to the max and are accurate I
would be happy.

More speed normally requires more case capacity when max pressures are reached.

Some barrels are a little faster than others but this difference is between 25 and 50 ft/sec
at the most .

Velocity is like gas mileage. the number is normally high. Believe only half of what you hear.

J E CUSTOM

 

[huckjare]

So my question remains, would changing to a different powder like RL17 or something similar increase my speed a little? If i could reach 2900 fps I would be happy with that.

 

[RockZ]

You can get more velocity with rl17 , my buddy got 100fps more with good accuracy in his 6.5-284.

 

[J E Custom]

So my question remains, would changing to a different powder like RL17 or something similar increase my speed a little? If i could reach 2900 fps I would be happy with that.

There are several powders that should increase velocity in the 260 AI.

I would look at IMR 7828, RL17, H1000.

47 Grains of IMR 7828 is a compressed load that reaches 2755 ft/sec in the standard 280. with the extra capacity of the AI you should be able to up the velocity and still be within pressure limits.

Also to increase velocity you may need to back off the lands .020 or .030 Thousandths.

J E CUSTOM

 

[huckjare]

Thanks guys. That is the info I was looking for. I didn't really think to seat the bullet back. Never knew that would help increase verlocity. I'll let you know once I get a chance to get some powder and try a couple different loads.

 

[SVG308]

I use 47.5g of H4831SC in my 260ai and get 2925 with 140 Amax.

 

[huckjare]

I've been shooting 48.5 grains of H4831sc and not even topping 2900fps. Every gun is different I guess. I'm gonna try a new powder and see what happens.

 

[Plade]

Hi Huckjare, just picked up on this dated thread re loading for a 260ai - chances are you already have your question answered by now but here's my little bit. I have a 260ai and have done considerable load devt work with mine. I (now) shoot 140gn berger VLD's exclusively as I am looking for high BC wind bucking bullets with good hunting and accuracy potential. To cut a long story short the best powder option I found ( velocity and accuracy + good case life) has been VV N560. I have tried most options and in my testing and with this bullet weight it wins hands down. I use 50.1gns in a formed case, loaded for a non compressed load and in my rifle with a 26inch tube consistently achieve 2950fps with low ES. I have heaps of data and experience with this calibre so if you have any questions ask away. It is a superb cartridge and really takes advantage of those great 6.5mm bullets without being too hard on the barrel. Cheers