6mmAI

[KNOTFERSAIL]

So, I have a bone stock red pad, tang safety M77 in 6mm Rem with 22" 9 twist that shoots 70-95's like a dream. For whatever reason I think I want to turn it into 6mmAI

I want to keep the rifle original except for obviously the chambering, and maybe keep and ream out the factory barrel….

I'm the original owner so the round count isn't a lot on the factory barrel.

Question for the pros: does it make sense to punch out the factory 22" or go with a aftermarket 24"+ barrel? I will stay with loading 70-95's, so I'll stay with a 9 twist.

Any recommendations for AI die manufacturers?

 

[Varmint Hunter]

I'd put on a new match grade barrel with an 8 twist. Sometimes it's just not cost effective to put the same gunsmith work into an older bbl.

 

[KNOTFERSAIL]

Makes perfect sense…

"Sometimes it's just not cost effective to put the same gunsmith work into an older bbl."

 

[Wilderness Blacktail]

Id rechamber it first. If it dont work or you get to yearnin for higher bc bullets u can rebarrel then.
I just read an article in handloader? On the 6mm. He was runnin the 103eldx just fine too. A 9 twist is much better than 10 so ur not in a horrible place, and since already like the bullet range ur in, no reason to rebarrel unless you feel like it.

 

[Idaho Lefty]

You can have it,. HAND Reamed,.. IF, done slowly and Carefully ! ( Reamers can Be, Rented )
The Hornady 103 gr. ELD-X's and 95 gr. Berger, Classic Hunters should shoot very Well, in a 9 Twist !
My grandson has dropped 2 Large Desert Mulies DRT with, the 87 gr H-VLD's, in his 10 twist, Tikka .243 Win at, 3,165 FPS.
The 6 MM Ai, is even Faster than the .243 win. and should Be, pretty "Wicked" with,. the right Bullet !

 

[Varmint Hunter]

I had a heavy rifle w/ a 30" Lilja barrel in 6.5x284. I used the rifle to shoot groundhogs out past 1,000yds. It eventually lost its accuracy, and I couldn't decide whether lop 3 inches off and rechamber or to just buy a new barrel. Despite my smith recommending a new barrel, I just had the Lilja shortened and rechambered. While accuracy did improve, it still was not up to my expectations. $450 wasted on that mistake. Eventually I ordered a new Krieger and paid for the gunsmith work (again), but it was the right move.

I will say, however, that sometimes shortening a barrel and rechambering does work out. I had a 22-243AI that I hunted with extensively. When the throat was washed out, I had 2.5" removed and rechambered in 22-243 (plain). The barrel was every bit as accurate as it was originally.

Overall, shortening & rechambering is a crap shoot. If you've got the money, rebarrel.

 

[std7mag]

To go AI on the Ruger, you're going to have to take the barrel off and have the chamber end machined off at least 0.04".

@Idaho Lefty,
Hand reaming to AI in this case won't work.
Namely because the Ruger uses a shouldered barrel, and the AI uses a shorter headspace.
You can get away with it on a Savage because they typically have the space between the bolt head face and barrel face.
Take the barrel off, ream to AI, set the headspace and tighten the barrel nut.

People usually go to AI for 2 reasons.
Less trimming and higher velocities.
If you're looking for higher velocities, i'd just go ahead and get a 24" barrel.

 

[Hugnot]

Go for another new barrel. The original barrel would need to be set back & rechambered to enable a crush fit for fireforming 6mm brass . A 9 twist would be OK for most 6mm bullets under 100 grains and would probably do OK with Barnes & Hornady 105 hpbt bullets. I have a 10 twist 6mm AI, 26", and only shoot the 87 VMax.




My rifle is a long action M77 MKII. It feeds the round shown above perfectly, a 87 VMax having a COAL just under 3 inches. At one time a had a 6mm Rem in a SA tang safety M77 and used 70 - 75 Sierra bullets with great results with a 12 twist.

 

[Tiny Tim]

If another 2-4" doesn't hinder the rifle's "usefulness" to you, I'd replace the barrel and likely go to an 8tw in case you ever change your mind and want to run heavier. This is from a 243AI user.

In either case, if I were spending the money on a rechamber job, I typically wouldn't "waste" my efforts on a factory barrel.

 

[KNOTFERSAIL]

std7mag might be onto something…for the fps gain of going to an AI, maybe just spin a 26" and gain +100 over factory 22" and keep my original 6mm dies and brass???

Decisions decisions

 

[Lapuatom]

I'd put on a new match grade barrel with an 8 twist. Sometimes it's just not cost effective to put the same gunsmith work into an older bbl.

this

 

[Panhandlin Pat]

I got on a hot 6mm kick a couple years ago, built a 6-284 and a 6mm ai. Like others said, since you're gunna have to machine the barrel beyond rechambering get. New barrel. If it were a 243, different story. Both my 6mm ai rifles started as 243 barrels, simply running the reamer in was all that was needed. One barrel is a factory savage I use for fire forming, but it's stupid accurate for what it is.