I'm considering building a long range rifle in 6m/m Rem. A.I. My goal is to push a 75 grain Balistic Tip to 3600 F.P.S. Does anyone have any experience with this cartridge? What would be the best rate of twist for this weight bullet?

I considered the 6m/m-284, 6m/m-06 and other barrel burners, but keep coming back to the 6 A.I. I'm only interested in 6m/m calibers. I have a beater Savage 110 that I was thinking of having blueprinted and installing a Sharp Shooter barrel (27"), trigger and stock. Thanks in advance for your ideas and experiences.

[QUOTE]Originally posted by Mike in Reedley:
Mike I have a 6/284 and it is a barrel burner. Mine is set up with a 1/14 twist for 70 gr bullets at 3800fps had it over 4000fps. I think you would like the 6mmRemAI alot better and the velocity you are looking for can be reached. I would go with either a 1/14 or 1/13 twist barrel. I have a 1/10 twist in my 6mmRem AI and I get 3391fps with a nosler 95 gr bullet. You can also get a 1/15 twist barrel to handle the lighter bullets say in the 65/68 gr range. I have a 1/15 twist for one of my 6ppc and it really likes the 65 gr match bullets. Well good luck! Tom

Mike, much the same as you, I built a 6mm Ackley for long range work on coyotes. I have a 26" barrel with a 1-12" twist and acheive 3600 fps easily with 70 gr Btips. This twist handles 70 to 80 gr bullets beautifly. However, in hindsight I wish I had gone with a faster twist in order to take advantage of some of the 6mm VLD bullets out there. Longrange means different things to different folks and I find that slow twist barrel and light bullets lacking for work on coyotes much past 600 yards. If I had it to do over again I would build a 6 Ackley with a 1-8" twist to shoot the heavy, high B.C. bullets available for 6mm cal. With these bullets and target turrets, shooter skill is the only limit on how far you can shoot vermin sized critters.

HILLBILLY

About 4 years ago I was mulling over the same things you are now, I considered the 25/284 and 6/284 and finally decided on the 6mmAI-actually the RCBS name is still the Remington 244 Ackley Improved,40 degree shoulder. The ultimate fact that got me to choose this cartridge is you only have to fireform the case. Certainly you will trim and turn outside ccase neck but you would do that anyway.

I have a 28 1/2" Hart SS barrel and shoot 50.0 grains of R-19 with a Federal Bench Rest primer and 87 grain Hornady V-Max chronographed @ just over 3700 fps. It shoots just under an inch at 100 yards about 3/4" at 200 and you can head shoot a rockchuck at 398 yards, in the eye if you want.

Obviously I am getting some yaw but that does not bother me as the bulet is amazingly accurate even past 600 yards. In my opinion a rangefinder is a must and you need to get software or have someone compute your trajectory and try and predict humidity and elevation where you will be shooting, as close as possible.

Another item I am noncompromising on is an inline bullet seater, an absolute must, in my opinion. If you would like more information send me an e-mail. Good Luck.

Good Hunting, "Z"

Was considering the same caliber (6mm Rem AI) but I intended to use 100gr. SBT Gamekings. I just need to rechamber a 6mm Rem I already have, which is using a Douglas Premium barrel.

I intend to use it for Pronghorn, what you do you guys think?

Still havent decided on poweder yet, but thinking H4831, H4350 or maybe H1000.

[ 02-22-2003, 11:27: Message edited by: Difranco ]

Hi Guys,
I will be dropping off my Rem 700 at the gunsmiths Monday to rebarrel to the 6mm AI. I'm looking at the #5 barrel at 26" and .700 at the muzzle.

What do you think? Should I go longer or shorter? The smith says he can maybe get 27" from the blank and he would cut and crown at 25" with a #4 barrel if it were his gun.

I'm not worried about the extra inch or speed gain or loss, but how the gun handles and points. We end up shooting the coyotes at very close ranges.

My frind uses a 220 Swift with a 26 inch barrel and really enjoys it. I would have to say that the 52 grain bullets at 3900+ seem to have quite an effect on those he gets before me.

Any information such as loads and or bullets to try would be most helpful. I will need to fireform brass as well.

Thanks,

Snapper

Don't get a slow twist barrel. When they wear a little they won't stabilize what they did before.

I reached 3600 fps with the 75 gr in my 26" .243 Win.

Hello,
I just received you link from a friend of mine who thought I might have some info. for you.
I have recently finished a 6mm ack. imp. built on a savage action. I had Fred Morrow from Sharp Shooter Supply do all the metal work for me and I purchased a heavy laminate blank from Richards MicroFit stocks in CA. Finished the stock myself and did the inletting job with steel bed and pillars. Can send ya pics if you reply by email. Also have the SSS trigger.
Mine is a 27" barrel with Sharp Shooters muzzle brake installed. Barrel and action is SS. Twist rate is 1-12". Barrel is a dougla ss. Had intended on shooting bullets in the 70 - 90 gr. wt. but got a suprize when load development began.
Initially tried the 70 -80 - and 95 gr. bullets during fireforming(laupa brass) but got very poor results.(groups from .75 up and over 1.5 in at 100yds. (my goal for this rifle was .5" avg. groups of 5 shots) Then tried some 55 nbt 60gr sierra and 65gr berger shorts. Thats when it got interesting. Below are some of the better loads.
55gr nbt
48gr.h380 3954 sd 16 .310
berger 65gr short
48gr h380 3882 sd 10 .191
49gr h380 3919 sd 12 .472
50gr h380 3989 sd 3 .074

Also used h414 with great results but decided on h380 as standard load.
It also shot 70gr. nbt well but not as consistent as with the bergers. Have some 65gr berger mef on the way along with some 66gr LD bergers and hope to see what they will do this week(if they come in)
Went to the range today and shot at various yardages(375 max)
5 shot group at 375 went into 1.875"
3 shot group at 375 into .945"
Also shot eggs at 200, 300 and 375!!!!! Yes I did say eggs at all yardages!!!
Im very impressed with the project as it has exceded my goals. I am impressed, to say the least with what it will do.
Email for more specific load data and pics.
Dont think you can go wrong with the .243 ack.
David Hamlin

Thanks for the comments David.

Sounds like you have a great shooter with the smaller bullets. Thats what I'm looking for. I really want to see what I can do with the 55 grain bullets and the 58 grain V-max was recommended to me also.

Is there any powder/bullet combination that really stands out in tnis cartridge?

The smith will start prepping my action next week. The barrel will take some time to get delivered.

Snapper

Nobody knows what this will do with a heavier bullet (100gr gameking)? Would I need a faster or slower twist rate?

What twist? I see Rem is putting a 1 in 9 on their barrels now and I see 1-10 common for the 6mm. The sierra bullet poster lists a 7"-8" twist to shoot their 107 grain match bullets.

I had a great talk with the folks at Sierra about this and they said get the faster 1-10 twist barrel and shoot everything from the 55 grain to the 100 grain bullets. The slower twist will only shoot the 55 to 80 grain bullets (maybe?).

Where I was hung up was in thinking that slow twist needed was for light bullets and a fast twist was needed for heavy bullets. The fast twist 9"-10" will shoot everthing you want to put through it.

Hope this helps.

The barrel is a Douglas Premium with a 1-10" Twist rate.

This should then be effective with Sierra Gameking 100gr.

Snapper: Go with the 27" barrel please! My Darrell Holland built 6mm Remington Ackley Improved shoots like a house on fire! It is superb in the Varmint fields for long range Rock Chucks and Coyotes!
It will be free velocity with the longer barrel and the extra barrel mass assists in obtaining steady sight pictures under field conditions! Yes a tad more velocity for free with the longer barrel and therefore a tad longer barrel life.
Good luck you guys with the 6mm A.I.'s!
Hold into the wind
VarmintGuy

Shot the 6AI for about 6 or 7 years on coyotes in an effort to flatten trajectory in a calling scenario. I was using the 55 Nosler at about 4200 f.p.s. I was saving fur, and the load worked OK, but then i got into long-range, and I drove the highest B.C. bullet that shot well as fast as i could-- 87 gr Hornady BTHP (v-max wouldn't shoot. nor would anything heavier). This bullet at about 3700 f.p.s. does quite a bit less than M.O.A. out to 800 yds. (the limit of my testing) in good conditions, but i believe that a guy could use that case and go out to +/- a thousand with a 100 grainer (the Speer or Sierra both have .430 B.C.'s) maybe the A-Max with a good degree of consistency on coyotes (see www.jacksonrifles.com for some closer range testimonials). The only thing i don't like is the fireforming step. I now have a 6-284, but i just bought it and nothings ready yet, and although many say you need to fireform any case for final load development, i've never found this to be the case, which is why i'm starting to believe the bigger 284 case would be the right way, certainly the faster way. In the pursuit of long-range you might as well drive the highest B.C. bullet as fast as possible to maintain good bullet performance, if that is what you want.