Keep us all posted. It's great that someone is finally bringing the .257/.264/.277 into the long-range arena with what sounds like outstanding hunting bullets. Even the 6mm with 110/115gr pills is interesting.
I have a LA 700 Sendero (7mm RM) that needs a new tube on'er. Sounds like a good candidate for the .257STW or one of the AM's. Can the brass for the AM's be made from an existing case or not? Later, Johnny K.
I think you are being ultra conservative (admirable trait) once again, on your predicted velocities for the 22/6mm AI of 3600 - 3700 with the 80 grain bullet out of a 30 inch barrel.
My "unimproved Clark" with 30 degree shoulder achieved 3,735 fps (56.5 grains H1000) at maximum pressure with the 80 grain Sierra in a 25.25 inch barrel.
The case when stuffed with as much H870 as I could fit in (61.5 grains), produced 3,663 fps at mild to normal pressure.
Several other users of the 22/6mm AI with 40 degree shoulder who I have swapped notes with, achieved velocities of around 3,750 fps with 26 - 27 inch barrels. So I predict you will be pleasantly surprised at what your 30 inch barrel might produce.
I am in the planning stage of my next .224 Clark, and yesterday emailed Richard Graves to see whether the new .224 dies he was waiting on, could make bullets of 85 grains or heavier.
I will be interested to hear how your 22/6mm AI project progresses. Regards, Brian.
Brian is probably correct about a conservative estimate. My 22/243AI will shoot 80gr bullts at >3,600 ft/sec.
My favioite load consists of a max charge of RE 22 under a 75gr A-Max (moly) bullet for an average velocity of 3,670 ft/sec. Accuracy is incredible.
One question I have is what are you seeing for barrel life on the 22/6mmAI and the 22/243AI at these velocities. I witnessed a 22-284 barrel go south in less than 1000 rounds and it's powder capacity is not that much greater, it was a 6 groove barrel and I know my 3's hold up better in other caliber's.
p.s.Varmint Hunter nice pic.
I have a fair amount of 22-6mm AI rifles out right now but only one that ahs any real number for roudns through it.
This rifle was designed with a standard 1-14" twist for the 55 gr Sierra Blitzking bullets.
The load I developed with this bullet was with 55 gr Rl-22 over a CCI-200 primer. This load is punching the 55 gr tipped pill out at 4200 fps out of the 27" barrel and when it left the shop it was shooting an average of .298" ctc for five three shot groups.
I recently had the owner bring the rifle back and we range tested it and it averaged .549" for five, 5 shot groups with this same load and the average velocity had dropped to 4135 fps.
The throat is warn pretty bad and the origins of the lands are eroded back several thousandths but the rifle still shoots very well.
In fact, we loaded up some test loads seating the bullet farther out to get back to the lands and those two groups were in the .3's but velocity was still less at around 4140 fps.
Can't replace the worn throat but this is still a screamer of a round and still going strong.
The rifle jsut topped 1200 rounds but the owner does take very good care of the bore. I expect him to get around 1500 to 1700 rounds through it before he has it rebarreled again.
On average, I would say that this is a 1000 to 1200 round rifle for sub 1/2 moa grouping.
Not a high volume varmint round by any means but with the heavy pills, it will last a lifetime of shooting for most shooters.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Not to throw a wrench in the party here but i got some of the Wildcat 338's and here are my thoughts.
1) The meplat is too large for the caliber ging a poor BC number
2) The rebated boattail has too big of a step which will hurt accuracy
3) The lead core extends all the way to the top of the meplat.If J4 jackets were used this could be a potential problem as jacket stress at maximum acceleration will be compromised.
In my humble opinion you will get better accuracy and less recoil using a 300 gr Sierra and a better BC number.The whole reason to choose a 338 over a 30 caliber in the first place is to get that high BC number.I have only looked at the 338 bullets in 2 weights and haven't looked at his other bullets so won't comment.