Wow!
Thanks Stomp, that's exactly the kind of answer I was looking for. Thank you.
Please forgive my ignorance...
C.B.T.O??? Please explain- Leo
The 260 Ackley with standard throats and even seated to standard short action lengths will do anything the 6.5-284 will do with less powder. My 260 Ackley is built on a long action with a Mcgowen barrel. I'm running 140 bergers at just off the lands at a c.b.t.o. of 2.217" even though its on a long action it would still fit and feed fine from a short action. I don't feel like I am giving up any performance by having the bullet seated slightly deeper than I would like but its nice to know I have plenty of room to chase the lands as the barrel wares. Using Lapua brass and 42grains of H4350 I am getting 2950fps out of my 26" barrel. For comparison I am running 57 grains of Retumbo in my 6.5-284 with the same 140 berger to get 2960fps. Barrel life, recoil and efficiency is all better with the 260AI.
I also have a 6.5-06 Ackley improved built on a winchester model 70 with 140 Bergers seated to mag length and I am getting incredible performance out of it. Using 59.5gr of H4831 I am getting 3180fps. This is my long range hunting rifle and it does not leave me wanting for more gun at all.
Wow!
Thanks Stomp, that's exactly the kind of answer I was looking for. Thank you.
Please forgive my ignorance...
C.B.T.O??? Please explain- Leo
Cartridge base to ogive
Got it!
Oops. Double tap.
What does your CBTO of 2.217 translate into COAL with a Berger 140?
Its right around 2.8 I believe but I would have to measure it. I will try to do that when I get home from work tonight.
2.812" C.O.A.L. is what I am running.
Great! Ya that would work on a short action too. Thanks for the info and the help.
I just got done building two 1903 Springfields in 260 Rem (not AI) with a .120 total freebore. These aren't AI so I don't know about feeding issues but my 22-250AI has NO such issues and my long 260 has NO issues. I just got done doing barrel break in with cheap Rem core lok 140gr and am starting ladders with 123 Amax loaded COAL 2.862". Hoping to get close to 3100fps.
Luke45 is approximately correct. But a 6.5-06 will significantly outperform a 260AI and be the equal of the 6.5-284. And then there's the 6.5WSM, which trumps them all.
As as the 6.5wsm I've found it to be less than ideal. Yeah it really screams but it takes a lot of powder to get there. When I had mine I think I was running 65 grains of powder to get just over 3100fps. By comparison my 6.5-06 Ackley with 59gr of powder is giving me 3180fps. Needless to say the 6.5wsm was soon sold off in favor of the more efficient 6.5-06 Ackley.
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