6mm AI

Anyone on here shooting varmint at long ranges with this caliber? If so how do you like it and what is your set up? Action, barrel length, twist rate, bullet and bullet weight, velocity ect. I have been strictly using a .204 ruger for woodchucks, but will be going to wyoming for prairie dogs this summer and would like a little larger caliber to reach out there. Any info is appreciated.
Thanks,
Adam
Plenty of 6mmAI info can be found here:

 
Adam 330, you didn't qualify what you consider "long range". If you are looking at a 6 mm round, then I would suppose over 400? I have been going to S.D. whacking PDs for about 12 years and now can shoot out to almost 500 with just a 20PPC. I use it and the 17 WSM for shots out to about 3-350. For those in another zip code, I break out the 6 Creedmoor. Having said that, it's way more fun whacking close and with small bores. As someone has said, it don't take much to kill a PD, but there are other targets that sometimes appear. Wind is a big factor but I found in S.D. my bullets also fly flatter than they do here in Va. A hi BC bullet is a go to bullet for out there. Have fun !
 
I have a 10 twist 6mm AI, should have got an 8 twist, but have killed various rodents using the 87 VMax at just under 3,500. During the current component emergency I have used all sorts of powders like Tubal 8000, 4000MR, SW4350, RSMagnum, VN165, IMR4831, RL16, & RL23. I am currently using 50.0 - 51.0 VN165 with PPU or Rem 6mm brass & CCI 34 primers. I plan to try R-S Hunter. No plans for other bullets than 87 Vmax's.

Despite its modest BC of .4 the 87 VMax gives real good performance beyond 400 yards with hits up to 800. COW fireform. Have made brass with PPU 7X57 - extra dies & neck turning. The 6mmAI is not a good high volume rodent rifle (burn out). I use an 11 twist, .20P for high volume shooting with with 40 gr. VMax bullets & powders left over from .223 use. The tiny little .204 40 VMax's @ 3650 are good for an easy 400 yards.

6mm AI rifle is a long action R77 MKII. I am using my 6mm CM, 8 twist more because I have more small rifle primers - close enough to 6mm AI velocities.
 
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I just haven't fire formed all my brass yet so have not looked for anything faster. It's a great cartridge.
I several AI's. I've been fire forming for over 30 years and I do it with full on AI amounts of powder. I've even brought a chrono along to prove it to friends. Their is NO difference is velocity from the being fire formed and the previously fire formed shells.

You are just wasting time and money fire forming shells just to reload later.

To the poster I have a Rem 700 SPS Varminter 26 inch barrel and added a 2 inch brake. Harris tall bipods 8X32 60mm objective in 243.

IMO from years of testing on critters the hornady 87 gr Hornady V-max with big doses of Superformance traveling over 3350 fps just works! I also use a 80 gr SPBT at 3500 fps. There is a point where to heavy becomes to slow and you just punch holes. sub 80 gr. in 6mm con go really fast, but poor BC becomes a limiting factor. bullet construction gets you the red mist. :)

The 6mm has additional case capacity over my 243, but I have made a 1000s of 243's from 308 cases pre covid when you could get buckets full at the range. I have a goofy friend who built a 6mm-06 to burn 8 gr more powder than me. So we are out pounding away and couldn't see the difference in critter destruction
 
Somehow we got into A.I. talking. Sooo, I had Insight Shooting Systems build me a 223 A.I. Now, Mr. Ackley never did that cartridge; he actually didn't like the 223 at all! But, someone down the road did it. You probably know that just about all A.I. 's give about 100fps faster velocities. But, I have crono'd my AR15 in 223 A.I. several times and got an amazing 3600 fps! I'm rounding it off, but it was not below 3600 and with a 55 gr. Sierra Blitz King. Shoots dots ,too. Sorry to butt in.......
 
6 Rem AI-0 freebore chamber
26" shilen 14 Twist
70g Nosler ballistic tips
51g of Win 760
Rem 9 1/2 primer
4100 fps on fire-formed cases, bug holes abound!
Work up to this load in your rifle, and if you are shooting a 8,9,10T barrel, you may not be able to reach this powder charge without excessive pressure. I had a 10T Douglas that was 100 fps slower, right at 4000 fps, still shot bug holes with the 70gNoslers

80g Sierra Blitz BT
R#19
CCI 250 or Fed 215
3800 fps

AA2700 is a great substitute for Win 760 and is one of the coolest burning powders made. N160 and N165 would be great choices also as they are cooler burning powders also.

A friend has an 8T with .070 freebore, and he is shooting the Berger 108's at 3350 fps and the Berger 95's at 3500 fps.

Back in the late '80s, I shot the barrels out of two 6/284's using 85g Sierra BTHP, IMR 4831, CCI 250 at 3650. Barrels lasted around 1200 rounds, as IMR 4831 with about 56g is not easy on barrels. I would do another but that reamer was set up for Winchester brass, not Lapua, and there are case dimensions to be taken into account.

In today's world, with shortages of all components, brass, and bullets, there are two easy buttons:

243 AI-you need to know if the reamer is SAAMI spec or CIP spec for norma and Lapua brass

6 Creed which is shorter than the 243 AI, brass, and dies are available

The 6/284 and the 6 Rem AI work best on long actions unless you are single feeding. I was hunting coyotes with the 6/284 and a repeater was a must. I had one on a short action, but never ever again, same on a 284 Winchester.

The 6 Rem AI is right at home with the AA2700, H414, Win 760, and H380 which give longer barrel life with 60-87g. The 6/284 likes a slower burning powder, which could be related to case fill. Pard I sold the reamer and dies to is using R#19 with the 85-88g bullets of various types, and simply loves it.
 
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Mine a. Benchmark barrel 10tw on a mauser action. Wish it was an 8tw but it shoots 87vlds so good I gotta keep it the way it is.
1.5" groups at 600yds.
Must have shot 200rds getting there but it was worth it.
87vld or 95sst both at 3500ish
Tried almost every powder with ok results until I tried some imr4955 and it was like the magic potion.
WMGLR primer.
 
I've shot a lot of ground squirrels with a .243 with 55 grain bullets up to 100 grain. Comparing that to my 6 Dasher shooting 105's, I'd op for the BR sized case to get much less recoil with similar performance. Anything good at punching paper will be good on small vermin. I think 6mm is an "all you'll need" jump up from 20 or 22 cals for small varmints. They give much higher BCs than lower cals and are still light enough to shoot 3000 fps+ in most cartridges. I like the 204 for anything inside 500 yards.
 
VinceMule, you gave me some hope! I Re chambered a ruger #1 to 6 Creedmoor, thinking the twist may be at worst a 12 . I shoulda checked, but would have still done it. It was 14 ! I've been working with some old custom 68 gr. bullets and about 3400fps. At 50 yrs it was one hole. I was zeroing and my first loads. Still need to get out and do some more serious work. Nice to know the 70s can work! Thanks!
 
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