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Converting a Ruger American ranch to 6mm arc?

Eo12

Sergeant of the Hide
Full Member
Minuteman
Jul 23, 2022
130
34
HI
Would it be as simple as swapping a 7.62x39 barrel to 6mm arc? Or is the bolt face depth different and would need to start with the 6.5 grendel bolt for it to work properly? Any info is appreciated. Thanks.
 
Would it be as simple as swapping a 7.62x39 barrel to 6mm arc? Or is the bolt face depth different and would need to start with the 6.5 grendel bolt for it to work properly? Any info is appreciated. Thanks.
I know the parent case for all 3 of them is the .220 Russian, but I would start with a 6.5 Grendel version. You can use the mags and everything. You’ll only have to swap the barrel, and feeding will be proper, since 6 ARC was designed off the 6.5 Grendel, and is very similar in size, shape, and dimensions.

Also, I don’t know about the Rugers, but AR’s have a Grendel 1 (7.62x39) and Grendel 2 (6.5G specific) type chambers, with the Grendel 2 having become the standard. The bolt face depth is different in them. This is why I say start with a 6.5G rifle. Plus the other reasons I mentioned.
 
I know the parent case for all 3 of them is the .220 Russian, but I would start with a 6.5 Grendel version. You can use the mags and everything. You’ll only have to swap the barrel, and feeding will be proper, since 6 ARC was designed off the 6.5 Grendel, and is very similar in size, shape, and dimensions.

Also, I don’t know about the Rugers, but AR’s have a Grendel 1 (7.62x39) and Grendel 2 (6.5G specific) type chambers, with the Grendel 2 having become the standard. The bolt face depth is different in them. This is why I say start with a 6.5G rifle. Plus the other reasons I mentioned.
Was hoping that wasn’t the way to go. Already have the x39 version and was looking at the x caliber barrels on sale currently for the swap to 6arc. Guess I’ll need to measure the bolt face depth on the x39 bolt to see if it’ll work properly.
 
Was hoping that wasn’t the way to go. Already have the x39 version and was looking at the x caliber barrels on sale currently for the swap to 6arc. Guess I’ll need to measure the bolt face depth on the x39 bolt to see if it’ll work properly.
Well... The only way to find out if this will be a direct barrel swap, would be to contact Ruger, and find out if they use the same bolt face depth on both the x39 and 6.5G... If they do, they you will only need the barrel swap, and some nice 10rd stainless 6.5G Duramags for proper feeding. 👍🏼
 
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I've never noticed any difference between 6.5 Grendel & 7.62x39 boltface depth of the Howa Mini rifles I've bought & used to build custom rifles on, but then this is the 1st time I've ever seen it mentioned anywhere. And since I chamber a custom barrel to the depth that gives me correct headspace measurement with a go gauge for the round I'm chambering for, even if there were any difference between bolts, it wouldn't make any difference, as the chamber would be cut correctly for that particular action & bolt. If the OP is intending to have a gunsmith fit & chamber a custom 6 ARC bbl, then it won't make a bit of difference which cartridge his rifle was originally chambered for, as the 'smith will headspace it correctly for the bolt that's in the action.

As far as swapping out factory barrel for another factory bbl, I kinda doubt that Ruger or any other rifle company holds tight enough tolerances to allow a straight bbl swap without having headspace issues. IOW, it's not reasonable to expect to be able to do a straight swap without needing to do some gunsmithing to come up with the correct headspace.
 
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I've never noticed any difference between 6.5 Grendel & 7.62x39 boltface depth of the Howa Mini rifles I've bought & used to build custom rifles on, but then this is the 1st time I've ever seen it mentioned anywhere. And since I chamber a custom barrel to the depth that gives me correct headspace measurement with a go gauge for the round I'm chambering for, even if there were any difference between bolts, it wouldn't make any difference, as the chamber would be cut correctly for that particular action & bolt. If the OP is intending to have a gunsmith fit & chamber a custom 6 ARC bbl, then it won't make a bit of difference which cartridge his rifle was originally chambered for, as the 'smith will headspace it correctly for the bolt that's in the action.

As far as swapping out factory barrel for another factory bbl, I kinda doubt that Ruger or any other rifle company holds tight enough tolerances to allow a straight bbl swap without having headspace issues. IOW, it's not reasonable to expect to be able to do a straight swap without needing to do some gunsmithing to come up with the correct headspace.
For the simple barrel swap mentioned, it would be using go/no-go gauges and a barrel nut to set the headspace without needing a gunsmith for it. The rugers aren’t as precisely built like tikkas that can just use a shouldered prefit and be good to go.
 
There is no type 1/2 with bolt guns. Case protrusion depends on action brand. You should be able to swap out the bottom plastic in your ranch to run the ar plastic.
 
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For what it's worth, I have found that the American Ranch in 6.5 Grendel feeds far better from a mini 30 mag than it does from an AR mag. I changed out the mag well from AR to mini 30, which is used in the 7.62x39 version of the American Ranch and all of my feeding problems disappeared.
 
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