260 Ack Imp

[foxyloxy]

Hi guys.

Up till now all my guns / reloading have been fairly straight forward off the shelf callibres - 223, 6.5x55, 308 & 9mm. I recently bought a 260 Ackley Improved & I'm hoping for some load data as it seems fairly limited on-line.

Gun is a 1 in 8 twist 22" LW barrel on a blueprinted Remmy 700 action. The re-loads that came with the gun (RL19 & 140 AMAX), seem on the hot side - tight bolt on ejecting. I'm currently shooting to 6 - 700 yards but wish to get to 1000.

Ideally if someone would have any data for Viht N160 & 140 gr Amax, it would be much appreciated.

Thanks in advance.

FL.

 

[Ledd Slinger]

Start with SAAMI 260 Remington manual load data near MAX listed charges and work up loads in small .2gr-.3gr increments while carefully observing the brass for pressure signs. The SAAMI max load listed for a 260 Remington may give you the speed you need. Just depends on how fast you want to go.

 

[foxyloxy]

Cheers for that LS.

One of the manuals gives a max load for the 260 rem as 41.5 gr of 160 behind the 140 amax. Its giving a mv of 2520 but Im not sure out of what barrel. Ill start there.

In relation to increase in powder charge / speed / pressures, what could one safely expect with the Ackley cartridge over the parent cartridge? 2%? 5%? 10%?

FL

 

[22BRGUY]

Here's an article on Ron Tilley. I wouldn't be afraid to try N560 either but maybe with that shorter barrel N160 or even H4350 might work better.

http://bulletin.accurateshooter.com/2008/04/tilleys-260-ackley-improved/

Best Wishes

 

[savagedasher]

In our long barrels Norma MRP RL 22 was the best with 140 gr. Being your barrel is that short and with 130 both wont work . H 4350 looks good N150 would be a barrel burner N560 N160 is too slow burning. Win 760 looks very good. H4350 look best. Larry

 

[Ledd Slinger]

RL17 will most likely give you the best speeds with the lowest pressure. All of the mid sized and large 6.5mm chamberings react to it very well with heavy bullets in all barrel lengths.

 

[savagedasher]

RL 17 Will eat the chamber up as fast as a 284 does. Larry

 

[22BRGUY]

RL 17 Will eat the chamber up as fast as a 284 does. Larry

I've read the same thing from other shooters. In giving it a bit more thought, I have to agree that H4350 would most likely be the one to own.

 

[deepwater]

I did not realize that .284 was hard on chambers.

deepwater

 

[Ledd Slinger]

RL 17 Will eat the chamber up as fast as a 284 does. Larry

Yeah it burns hot. But if speed is what he wants, RL17 will get him there. I like it for hunting rifles because I don't shoot a lot of consecutive rounds. 3 to 5 shots in a row is all before allowing the barrel to cool.

Maybe not the best choice if long barrel life is a concern. But long barrel life is compromised whenever a fast 6.5mm is pushed to the max.

 

[savagedasher]

RL 17 Will eat the chamber up as fast as a 284 does. Larry

Yeah it burns hot. But if speed is what he wants, RL17 will get him there. I like it for hunting rifles because I don't shoot a lot of consecutive rounds. 3 to 5 shots in a row is all before allowing the barrel to cool.

Maybe not the best choice if long barrel life is a concern. But long barrel life is compromised whenever a fast 6.5mm is pushed to the max.

MRP with same pressure is 70FPS faster . ;D Larry

 

[Ledd Slinger]

Never tried MRP. I only buy powders I can get off the shelf of a local sporting goods store and I don't recall seeing them stock any Norma powders in the past. Often wondered about how some Norma powders would work, but if they are not readily available to me locally, I won't bother with using them.

 

[parker_chp]

I am running a 30" 1-8 twist HV Krieger on a stiller long action. I used 123 gr smk's and imr 4064 to fire form brass and was shooting .5 moa. My choice in bullets are the 140gr bergers, hybrid or vld. I'm using 48gr H4831sc and my magneto speed was putting me at an avg. of 2881 while grouping in the .2's. It's not a hot load but it does the job. I have also tried the 130gr vld and started to show pressure signs at 50gr of 4831sc, but also fell back into the accuracy node. I have not tried any other powders.

 

[foxyloxy]

Cheers for all the replies folks. Ill try and get a tub of H4350.

Failing that would the N160 suit any of the other high BC 6.5 bullets?

FL

 

[22BRGUY]

To add to the choices also, depending on what's available to you, VVN 550 could be in the running in my mind also. Just take a bit of time between shots with any of them and your barrel throat will love you for it.

 

[Sniper338]

H4350 would be my starting choice. I looked into doing a 260AI when I built my 260, but my gunsmith talked me out of it, he said it wasnt worth the hassle with this round. More work involved in reloading, harder to find good die sets, etc etc.. Mine turned out fine as velocity is fantastic anyways in the 2900s (Id have to look it up to see the exact numbers again) Plenty fast for me. Good luck, I'm sure it will be a hoot to shoot!

 

[22BRGUY]

H4350 would be my starting choice. I looked into doing a 260AI when I built my 260, but my gunsmith talked me out of it, he said it wasnt worth the hassle with this round. More work involved in reloading, harder to find good die sets, etc etc.. Mine turned out fine as velocity is fantastic anyways in the 2900s (Id have to look it up to see the exact numbers again) Plenty fast for me. Good luck, I'm sure it will be a hoot to shoot!

It's about the same as the discussion, or close to the same as to whether to go with a 6 Dasher vs. a straight 6 BR. All points well taken.

 

[hogan]

You got the .260 AI on a rifle you purchased?
Was the barrel new?

.260rem is a 1000yd ctg, just not as upwardly mobile in the velocity dept as the AI, 6.5x55, Swiss AI, or 6.5/284.

Might be worth redoing for a .260rem chamber, or going 6.5/284 if you really want flat shooting 1000yd plus capable rifle. Pretty easy to find 6.5/284 loading tools at good price. Redding Type S FL die and Forster Benchrest Seater and you are golden for maybe $120, not incl bushing(s).

.260AI is just enough enhanced capacity to reduce your barrel life, over std .260rem by half or more. You (should) expect that from a 6.5/284, barrel life around 800rds for match accuracy. Seems like you are limiting your range and velocity for minimally better barrel life with the .260AI Giving up a lot for minimal gains.

If you got a big-assed barrel shank, might think of rethread & rechamber, or just "improve" to 6.5/284 and eliminate any further guess work. If the barrel has more than 500rds; probably prudent to just write it off and stay with .260rem for best barrel life, or go .6.5/284 for best performance. Either way, die set about the same. None of the Big Bucks for special class C/D rarity dies.

Hope you didn't pay top money for rifle with a half burnt up barrel...
Good luck. Finding the AI dies or deciding on another route to go....

 

[savagedasher]

260 Remington with 105 gr Amax 22'' barrel at 58000 psi 2670 FPS
260 AI 58000 PSI 2852 FPS
6.5 284 58000 psi 2896 FPS
Tell me why you would want to shoot 10 more GR of powder for 30 FPS
Larry

 

[Ledd Slinger]

260 Remington with 105 gr Amax 22'' barrel at 58000 psi 2670 FPS
260 AI 58000 PSI 2852 FPS
6.5 284 58000 psi 2896 FPS
Tell me why you would want to shoot 10 more GR of powder for 30 FPS
Larry

I agree. The 6.5-284 is not very efficient. 260 AI is a far better choice in my opinion.

I considered the 6.5-284 when deciding on a faster 6.5mm hunting rifle cartridge. Didn't like the 6.5-284 back then and still don't like the design of it today. It's just not that fast for how much powder it burns and the amount it reduces barrel life. So I figured if I'm gonna go fast and have short barrel life, I might as well go really fast. The 6.5mm Remington Magnum is "arguably" the most efficient hot rod 6.5mm chambering in existence. Especially among SAAMI rounds. I've shot the 6.5 RM for years now and am on my second barrel. Accuracy is absolutely phenomenal and when getting 3210 fps with 140gr VLDs from a 26"barrel when only using 52gr of powder...That's just amazing

I had a 260 Remington I built years ago. Loved the low recoil and accuracy. Was really a pleasure to shoot. I sold the rifle because I had no use for it at the time. Figured if I did ever build another one someday, I would go with the Ackley version to get a little more horsepower.