I have a 1 in 8 twist 6mm Remington with a 29" barrel which I have considered improving and lengthening the throat on. This is my long range coyote rifle, which I would like to make as flat shooting and wind defying as reasonably possible out to around 700 yards. I am currently shooting 105 Amax at 3200 fps. Is the "improvement" worth it? The rifle is built on a standard Model 70 action, so I have plenty of room.
6mm Remington vs 6mm Ackley
- Thread starter Mack Hunt
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backwoods83
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Its worth it for case life, due to having to work the brass less. You can also step it up by switching bullets like 107SMKs, 105 Bergers, or 115 DTACs they all have higher bc's than the 105 A-MAX's.
Like said: Case life will go up. how about these high BC vld 107 and 117
.243 Caliber Bullets Custom Built for Accuracy | Matrix Ballistics
Sendero_Man
Well-Known Member
I shoot a 6mm Crusader, GAP's version of the 6mm AI. It has a gain twist barrel, starts at 9 and ends in 8. Incredible shooter ! 105 amaxes at 3355 fps here at 4650 asl.
5 shot group with the 105 Amax. shoots like this all the time !
The 105 performs incredible, you can always find them to buy them... great on paper and critters !
5 shot group with the 105 Amax. shoots like this all the time !
The 105 performs incredible, you can always find them to buy them... great on paper and critters !
Outlaw6.0
Well-Known Member
Fireforming is the only down side to the 6mmAI, wonderful cartridge & probably one of the easiest to reload for in my arsenal. I made the mistake of putting on a slow twist barrel (1-12) so I cannot comment on the heavies, I can say that the 90's & less often shoot the bugholes Sendero_Man has shown. The one mod I had to do to was modify the feed lips of the mag, it was originally chambered in 243, then 243AI then 6mmAI (Savage 110), I had to adjust the feed lips to feed properly, there was a "pinch point" near the case shoulder that was starting to become a pain as it would allow a round to jump out of the mag every once in a while, I pulled the mag while I was bedding the new stock & made some minor adjustments with hand tools, basically just taking the taper out of the mag, works just fine now all for 10mins of work.
As stated in the Sierra 5th edition "....out of all of ackley's designs, this is one of the better ones..."
You won't be sorry. gun)
As stated in the Sierra 5th edition "....out of all of ackley's designs, this is one of the better ones..."
You won't be sorry. gun)
Sendero_Man
Well-Known Member
32 degree shoulder, longer neck, better throat life, Hydro die from Hornady to form brass instead of fireforming.....
The Reg 40* shoulder offers same advantages. Hornady makes those dies for whatever fired cases you send them. Bitchin dies.
IMO if you are going to make any of the 6mm Rem improved versions you should start with virgin brass. Unless things have changed recently that I missed you will have a hard time finding 6mm Rem brass.
Why not rechamber to 6mm-284 and bump up the performance to a much higher level? 6.5-284 Lapua brass is available and necking down is easy with no fireforming. You can get 3450 fps or more with a 28" barrel and the 105 berger hybrid using Retumbo or RL-33. I know I had one.
Why not rechamber to 6mm-284 and bump up the performance to a much higher level? 6.5-284 Lapua brass is available and necking down is easy with no fireforming. You can get 3450 fps or more with a 28" barrel and the 105 berger hybrid using Retumbo or RL-33. I know I had one.
I guess it just depends on what your doing with the gun. I'm personally building a 6mm Rem Ackley with a 1:12 twist to shoot 70-90 grain bullets. I already own a 6.5-284 that I shoot 143 ELD-X's out of. We do a lot of Belding ground squirrel (rats for slang), rabbit, and Rock chuck shooting out here from 100-600 yards during the winter, spring, and summer. That gun should fit the bill perfectly for that. If I need to make a shot when the wind is bucking pretty bad or of greater distance then I can pull the 6.5 out. 6mm Rem Brass was hard to find but Hornady starting producing it. It's $34 per 50. Also we have a guy local who has an annealer. He does it for $5 per 100. Can't beat that.
If you have a short action do NOT have the throat lengthend. My 6AI fits my Savage Short action well.
The neck on a 6AI is long enough that you will never impede case volume with 105 gr bullets.
Do a search for Norma 7×57 Mauser brass ( 6mm Rem parent case), its usually available. Midway has them on sale frequently.
I neck turned after just running them through a 6mm Rem die. But I really didn't have to.
IMPORTANT, get a Redding 6AI body die and Lee collet neck size die and you will have close to zero bullet run out!!!!!!
The lee bullet seater and collet neck sizer will work for the Ackley version of the parent case.
spdcrazy
Well-Known Member
great info. debating on making my #1 into an AI as well. i'll be keeping tabs on this thread.
