Question: I have a .260 that is in a HS stock. It was a 700 Mountain rifle. I am going to send it out to be rebarreled as well as the action trued. I was thinking of a .260 AI. does anyone know what the difference would be as far as FPS? Is it worth it? Is there a better cartridge than the .260? I wanted a little more distance and flatter trajectory than the .260. Maybe I should just stick with the plain .260. Any thoughts?

Airborne, if you already have a .260, you wont get much by going to an AI. I ma having a M700SA rebarrelled to the .260AI, but it was another caliber before. Might as well get the slight increase. If you were rebarrelling w a longer bbl./diff. profile, go for the AI. Realistically, you are only looking @ 50-75fps add'l. You can get that going up to a 24"bbl over the std. 22".

260 is a great deer round, for shooting out to 350-400 yards in the right hands. Like said before, you may get 50-75 fps increase by Ackley Improving the 260, but also you'd get longer case life, might be worth it. As long as you keep it 6.5mm of some sort, you'll be alright!

may want to consider a 7mm-08 with a 24" barrel. i have both and like both. i feel the 7mm-08 is a bit better and more versatile.

To get much more than the .260 provides, and using a short action, the 6.5-284, or the wildcat 6.5 RSAUM or 6.5 WSM would be the picks.

Factory brass & target ammo are available for the 6.5-284. You'd have to neck down the 7 RSAUM brass and 7 WSM brass to 6.5, but I'd expect little difficulty.

The 6.5-284 offers the ability to use the .260 bolt face with no alteration. The RSAUM & WSM require opening the bolt face.

The magazine feed mechanism will have to be altered to reliably feed the fatter rounds, and not every gun plumber does that well, so choose your 'smith carefully.

Cheers,
BigIron

i will add that opening the bolt face on a remington is a hard job and one that needs to be done correctly. this according to my gunsmith. hes built 100's of rifles in his 40 years and he advises against the 700 bolt face job. he said the ruger and the winchester presented no problems. just something to consider.

I have a .260 Ackley, also built off the Mountain Rifle platform, which I am very happy with. I settled on the 125 Partitions, which group under MOA and go out at 3034 fps, so I'm getting just over 150 more fps than the now-discontinued factory load that went out at 2875. I've also tried the 129 InterLock, but only got to 2850 before pressures stopped me. I understand that Norma's 6.5 X 284 brass is outstanding quality, but you'll want to make sure your smith knows how to get the 284 case to feed reliably, as sometimes it can be tricky. The nice thing about the Ackleys as opposed to the 6.5 X 284 or a necked-up WSSM, is that you can still fire factory ammo (although at a reduced velocity) if you want/need. I think the Ackley route is worthwhile for the velocity gained (also have a .280 Ackley that I shoot 160 Barnes X @ 2950 fps), with the qualifier that with the variation in "fast" and "slow" barrels, you may have to experiment a little to find a bullet/powder combo that maximizes accuracy and ekes out the improved velocity.

The only problem going to a 6.5x.284 is in the Rem. SA, you are going to have to seat bullets deeper, negating some of the add'l. powder cap. That's why I went to a .260AI.

texan: i got a 260 that flat won't shoot the 125 partitions. it has a shilen 22" match grade barrel. i get 129's, 129 sst's, and 140's to shoot great. plain will not shoot the 125's. give loads or advise you may have experienced. thanks!!

A friend of mine has a 260 A.I. and it averages 75 fps more accurate velocity that my standard 260 does with both the 120 class bullets and the 140 gr. bullets. My standard 260 will push the 120 gr. Sierra ProHunter, the 120 Ballsitic Tip or the 123 Lapua Scenar match bullet to over 3000 fps with three different powders IMR 4064, H4350 EXT, or RL-19. With the 140 gr. Sierra GameKing I can get 2750+ fps accurately with three different powders H4350 EXT, H4831 SC, or Vithavouri N560.

To me it is not worth the effort. If I want to drive a 6.5 mm bullet faster than that I will get a 6.5 X 284.

When you have your rifle rebarreled, do your self a favor and use a 1 in 8 twist barrel. At 260 velocities it handles the 140 gr. bullets better.

May I be half the man my grandson thinks I am...RiverRat

RiverRat,

How long is the barrel on that 260 that gets over 3000 with those 3 120 gr. bullets?

knobmtn

While you are getting opinions on the 260 or 260 AI, most are admitting 75 to 150 fps more. Even the 6.5 x 284 might give you 200 fps more velocity.

One thing 6.5 users, who are new, to the cartridge overlook is the aerodynamic efficiency of the caliber. It is one flat shooter.

Take a look at a trajectory chart and see what minimal gains you have in trajectory ( particularly at hunting ranges) by getting a 100 fps more muzzle velocity.

I shoot 260s, 6.5 x 55s, and a 6.5 x 57. I can get more velocity out of the latter, but in the trajectory end, it is really not worth the extra powder. I went no bigger than the 6.5 x 57 ( a 257 Roberts, necked up, or a 7 x 57 necked down), because when I looked at the 6.5 /06 or the 6.5 x 284, they gave me minimal velocity increases, for a big increase in powder consumption, which translates into quicker throat erosion.

That is especially why I love 6.5 mm bores, but see no reason logically for the 264 mag. You get diminishing returns very quickly, more powder, shorter barrel life, and another 100 fps or a 1/4 of an inch flatter trajectory. big Deal!

snider: a friend worked up the Partition load for me, using IMR 4064, Remington brass and Winchester primers - he uses a slightly hotter load in his 6.5 X 08 Improved (built before the .260 was brought out by Remington) and gets over 3100 fps. My rifle has a 23" lilja barrel and my friend's is 24" (don't know the make). Good luck

thanks s. texan. i have not used imr 4064 yet. i'll see what i can work up. thanks again.

IMR 4064 works great with 100 grain sierra's and ballistic tips. I have a 24 inch shilen on mine and can get 2900-3000 with 120-129 grain bullets using R19. I had my chamber specificly cut to shoot 125 grain partitions, and it does very well.

thanks rogue6. this was good info and i learned something. i'll try this reloader 19 recipe with some adjustment. whats your load with the 125 nosler partitions? thanks again.

knobmtn:
Sorry so long getting back. Work has been extremely demanding of late. My 260 has a Krieger 1 in 8 twist that finished at 24".

May I be half the man my grandson thinks I am.......RiverRat

Indeed. We are only as sick as our secrets.

If you are not confused by now you never will be. While I may be burn a little more powder I think I will just stick with my .264. I figure by the time I burn out the barrel I will ready to retire to the fishing pole.

Snider,
Sorry for not getting back sooner. I have found a sweet spot in 3 different 260's with 44-48 grains of R19 and the 125 partitions. If your barrel will let you get to the high end you'll probibly be mid 2900 to a little over 3000. Really anywhere from 2700-3000fps will make the 260 a hammer.

thanks for the info. i'll try some this weekend with reloader 19.