I have just seen the ballistics for this calibre.

Wanting to build a custom varmint rig this calibre looks really interesting. Compared to the 22 250AI.

Have anybody have any experience with this calibre as a varmint rifle?

Looks like it could work: 75gr VMax at 3850fps.

The heavier bullet range over the 22 250 might just be why I go with the 6mm Rem AI.

Any input will be appreciated.

Gerhard

Varmit shooting in South Africa! Cool!

However 3850fps with a 75 grn sounds a little high. That's a bit above 240 Webbie territory.
If your looking for absolute velocity try the 6mm WSM or the 240 Gibbs ( the Gibbs is max case capacity for the '06 hull) Both should give your desires.

Gerhard

I don't regret building a 6mm AI. I'm shooting the 58 grain Vmax at 4100 fps and not seeing the results I'm looking for. I will be using a heavier bullet for coyotes this fall. I would like to try heavier Vmax bullets and the 70 & 85 grain Sierras also. My buddy shoots 52 grain Sierra's at about 3900 fps out of his Swift and has excellent results on coyotes.

My gun is a Rem 700 Classic with a 26" Krieger barrel and med taper around .650 at the tip.

Try this link for more reloading data:

http://www.angelfire.com/sd/6mmackley/

Gerhard,

Here is a link to a very detailed article on the 6mm A/I. The builder/owner of this rifle has a great reputation as a marksman & gunsmith. For hunting varmints and small game (75 kilos), I think this would be a great choice to meet your expectations. http://www.6mmbr.com/gunweek042.html

Good hunting,
Dave

Gerhard:

Why not build one? I don't think you could go wrong! As to the cartridge you choose, the only limiting factor would be action length.

I built a 6mm-06 on a 700LA, and am driving 87 Honadys @ 3700fps +, with groups in the 3's and 4's.

Good luck with whatever you choose.


Jerry

If your going to use standard bullets, I don't understand why an improved version? A 6mm Rem should push a 75gr V-Max about 3400fps. If that doesn't kill a varmit, 3850 won't either! But a few companies make some heavy weight's that might benefit from an improved chamber. The Hornady 105gr SST might benefit fron an improved chamber. Wildcat make a 110gr, 115gr and a 120gr 6mm bullet. Probally need a fast twist but they really ought to carry if your thinking long range.

Thank you for the input guys.

Just to confirm with the 6mm AI I will need a standard action?

What rifle twist would you recommend for bullets from 75gr to 100gr?

This rifle will be used for jackal and other varmints as well as small to medium size game like springbuck.

Thank you.

Gerhard

Mine is on a short action Remington 700, as my previous five have been. Having to seat the bullet deeper doesn't affect the accuracy or velocity at all. Remember, the 6mm comes from Big Green in a SA. Some guys build them on long actions to seat the bullets out "where they ought to be", but John Barsness from Rifle/Handloader magazines has proven that there is very little gain, if any.

Gerhard,

The 6mm Rem. A/I is based on the 7x57 Mauser case, so it would fit nicely into a standard action. As far as the best choice of twist rates that will depend on the OAL of the bullet itself. A 1-9†twist will handle the longest bullets up to 90 grains and a 1-8 ½†will cover the longest 100’s. In the U.S.; the 6mm is considered an exceptional calibre for long-range predator hunting such as calling coyote; and along with the .243 Win it is one of the most popular rounds for Pronghorn antelope & Whitetail deer. Thus said; it should prove to be a fantastic choice for jackal and springbuck With proper shot placement and a sturdy bullet it would also suffice for larger antelope such as nyala and bushbuck. On the open range I would not hesitate to use it for blesbuck or hartebeast either. Best of luck with your project and keep us informed of your progress.

Dave

quote:

Originally posted by Don Fischer:
If your going to use standard bullets, I don't understand why an improved version? A 6mm Rem should push a 75gr V-Max about 3400fps. If that doesn't kill a varmit, 3850 won't either! But a few companies make some heavy weight's that might benefit from an improved chamber. The Hornady 105gr SST might benefit fron an improved chamber. Wildcat make a 110gr, 115gr and a 120gr 6mm bullet. Probally need a fast twist but they really ought to carry if your thinking long range.

There's an implication here that the AI version will gain 450'/sec over the standard round.

This is more than doubtful!

Gerhard, the 1 in 12 is mainly for 90g on down and the 1 in 9(or 10) for the heavier bullets on down to the 75g. I have had some slow twist barrels that would shoot up to 85g partitions fine and fast twist ones that would shoot 58g bullets. Every barrel is unique unto itself.I would go with a 1 in 9 or 10. I really like the 95g BT's and partitions in this cartridge.

quote:

Originally posted by vapodog:

quote:

Originally posted by Don Fischer:
If your going to use standard bullets, I don't understand why an improved version? A 6mm Rem should push a 75gr V-Max about 3400fps. If that doesn't kill a varmit, 3850 won't either! But a few companies make some heavy weight's that might benefit from an improved chamber. The Hornady 105gr SST might benefit fron an improved chamber. Wildcat make a 110gr, 115gr and a 120gr 6mm bullet. Probally need a fast twist but they really ought to carry if your thinking long range.

There's an implication here that the AI version will gain 450'/sec over the standard round.

This is more than doubtful!

3850fps comes from the origional post. 3400fps comes from the Hornady manual for the 6mm Rem. I doubt it also!

450 fps faster than the factory round? I kinda don't think that will safely happen, not even in P.O.'s wildest dreams.

quote:

Originally posted by Don Fischer:

quote:

Originally posted by vapodog:

quote:

Originally posted by Don Fischer:
If your going to use standard bullets, I don't understand why an improved version? A 6mm Rem should push a 75gr V-Max about 3400fps. If that doesn't kill a varmit, 3850 won't either! But a few companies make some heavy weight's that might benefit from an improved chamber. The Hornady 105gr SST might benefit fron an improved chamber. Wildcat make a 110gr, 115gr and a 120gr 6mm bullet. Probally need a fast twist but they really ought to carry if your thinking long range.

There's an implication here that the AI version will gain 450'/sec over the standard round.

This is more than doubtful!

3850fps comes from the origional post. 3400fps comes from the Hornady manual for the 6mm Rem. I doubt it also!

Yea Don...lets just call it like it is!!!

My 23" Douglas barrel gets 3545 fps with the 70g NBT and 3688 fps with the 58g V-Max. These are maximum safe loads in my rifle and more in line with what to expect from the 6mm AI.

Jakkals: I have a heavy Varmint Rifle in caliber 6mm Remington Ackley Improved!
What a wonderful performing cartrdige it is.
I have used it very successfully for long range Rock Chuck Hunting and Coyote Hunting. I have also done some Medium size "Big Game" Hunting with it (Deer and Antelope).
Back when I was doing load development with this Rifle it shot groups as small as .380" (five shots at 100 yards) with bullets I later used to Hunt Varmints with.
My Rifle weighs 14 pounds 1 ounce and has a Leupold 6.5x20 variable scope on it.
The barrel I chose was a Hart 26" extra heavy weight. If I had it to do over again I would add an inch to that and make it 27".
Free velocity there.
My Rifle likes Nosler 70 gr. partitions and any 68 gr. BR type bullet.
I have owned this Rifle for for going on 12 years now and probably have 900 rounds through it.
It is still going strong.
I highly recommend the caliber and hope if you decide to try one that it turns out well and satisfying for you.
Hold into the wind
VarmintGuy

I have a 6mm Rem on a Model 700 long action, and it is long throated... with a 24 inch heavy magnum barrel contour... I also went with the one in 7 twist on this one...

After testing 15 different powders with the 75 grain Hornady HP... the most accurate above all others was H 414/ 47.5 grains... MV was maxed at 3750 fps...

I didn't see the need for the extra work of the AI version...

I'd recommend the one in 7 or 8 twist... It works on the smaller bullets, but also I use it for the 115 grain Berger match bullets, with an MV of 3250 fps with that one..

Once again, out of a rifle throated for the bullets to be seated magazine length....

Still waiting to be finally built, is a Mauser Action in 6mm with a 31 inch bull barrel on it..with a one in 8 twist... this thing will weigh about 20 lbs with the heavy stock on it also.. which I have to finish...

It is waiting for a bolt to be finished that is being modified for this rifle... it will be interesting to see what the velocity potential is going to be with the 31 inch barrel....

cheers
seafire

Hi,


If you are looking for information on the 6mm Ackley Improved, check out Mike J's 6mm Ackley Improved web site. He has a lot of great info about this caliber. I also have a section there under The Big Dog.

I have had or have loaded for 5 different 6mm AI's. One with a 1-7" twist, one with a 1-8", one with a 1-9" and two with a 1-10". I will NEVER do a 1-7" twist again. It was blowing up every bullet in site. The 1-8" is good for long range benchrest but a little to much twist for me. The 1-10" twist is great for bullets up to about 95gr. The best twist in my opion is the 1-9" twist. It shoots everything from the 55gr Nosler BT to the 105gr Hornady Amax. I have one with a 1-9" and one in 1-10" now and they both shoot!!!!!!!!. I took 1st place for the year with my 6mm AI with the 1-10" twist. It likes the 70gr TNT's and the 70gr Blitzkings. It has a 25.5" barrel and pushes them at 3650 fps. It isn't the hottest load but it is the most accurate. 10 shots in 3" at 500 meters.

This is a great caliber and I will always have one in my safe.


Catch you later

quote:

Originally posted by Jakkals:
Have anybody have any experience with this calibre as a varmint rifle?
Gerhard

Precision Shooting had an article a few years back comparing a 6mm AI to a 6mm-284, and it was pretty interesting stuff. The 6mm AI can apparently be loaded to approach 6mm-284 velocities with the right barrel length.

Big Dog

Ant help on powder to push those 70 grain bullets?

How do the Blitzkings work on Coyotes?

Thanks

After all the info it looks like a 26 inch barrel with a 1-10 twist is the most versatile barrel.

For a bullet weight from 55gr to 100gr.

What do you suggest.

Gerhard

There's no reason not to go with the AI version, although the gain is not huge over the regular version. I have two standard .244/6mms, both on Sako L579 actions. If you intend to use it for game and utilize the 90-100 grain bullets, then a short action magazine is a little restrictive, but if it is purely for varmints and using 75 grain and under bullets then the short magazine is plenty long enough.

My 24" HB tops out at about 3600 fps with 70 grain Nosler Btips. You can add 50-75 fps for the AI case and 50-75 fps for another two inches on the barrel. I wouldn't look for more than 3750 fps with a 70 grain bullet.

Hi Snapper,


Of all the powders I've tried, Accurate Arms 4064 gave me my best results. If memory sreves me right, I think the load was between 44.5 / 45.5gr of AA 4064. I have that load data written down on Mike J's 6mm Ackley Improved web site. Look under The Big Dog for my loads. The Blitzkings shot a little better than the TNT's but not by much.


Catch you later,

The Big Dog

I currently have three of these, and my latest 26" Shilen has not been chrono'ed yet. I am anxious to see what it will do. I have had some 22" factory barrels that would exceed 3200 fps with the 95g partition. I think my 23" Douglas bull barrel (which I referenced in an earlier post) is a "slow" barrel that will not handle warm loads as well as the others w/o excess pressure signs. The attainable velocities seem to confirm this.

Saeed has posted a lot of load info on the AR home page.. there is a link somewhere there.. he has posted some phenominal velocities with the 6mm Rem...

I think they are the type that 2 shots is about the life span of the brass.. but if you can live with that....

http://www.accuratereloading.com/6mmrem.html

I have an UN-Acklied 6mm remington. I get great accuracy and great velocity with the 87 V-max. H-414 is the powder and I get 3450 FPS. Not a hot load in my gun.

In the case of the 6mm you will not see the big gains claimed by the 257AI or the 7x57AI. The 6mm is already loaded to 65,000. Big gains in the other two come from pressure vs low factory pressures. The AI at the same pressure on the 6mm will give you less than 100fps. I had my own wildcat 6mm-280Imp actually had 1.5-2 grains more capacity than the 240Gibbs. I couldn't get close to 3845. Even Gibbs claimed a max of 3605 for the 75gr.

I had a factory 700VLS 6mm that would get over 3600 with the 70 NBT and IMR-4064 and 3450 with the 87 V-Max and RL-19,

for the size of targets we got I traded for the 204 and use about halh as much powder and cheaper bullets,and get to watch them hit,

I`d go straight 6mm or have a 25-06 built to take the 85 gr NBT.

Thank you for the advice.

Its helping a lot.

Gerhard