Have the M16A1/M16A2 side sling adapter like the one in the image below. On the M16A2 side, it fits perfect on my 0.750 barrel. When I flip it to the M16A1, it does not fit a 0.625 barrel. Tried it on two set ups. Big gap and it can rotate and slide. Was their a shim also part of the kit?
I think the slide sling was an evolution of the govt profile era. There wasn’t a way to put it on a light weight barrel to my knowledge.
These transition pieces are supposed to be usable on m16a1 and M16a2 barrels by reversing the piece the pins go through vs the original M16A1 and M16A2 only style that is only cut on one side of the clamp. You can just make out the markings when you view the above pic at full size. In theory good for both 0.625 and 0.750 barrels.
I’ve two barrels with 0.625 FSB’s and I can’t get this to fit either.
If it’s authentic it’s supposed to fit.
After-market – who knows?
If I’m not mistaken, the units with reversible bar are all aftermarket. Even when you put the GI swivel on the gov barrel, there is some play. If you put it on a LW barrel there’s more but it’s tolerable. I have some on 6520s and 6720s and they meet needs.
I wouldn’t expect a shim to to stay in place.
Is this a question of how much play is still an ok fit?
I’m not getting a lot of good information either which is frustrating.
It looks like the M16A2/M4 version for a 0.750 barrel journal is part # 12991254.
The part # for the adapter assembly with the swivel looks to be #12598617 and the reversible “dog bone” to use on the A1 or A2 barrel appears to be part # 12598618 which is what was stamped on mine.
I one I picked up I was told was NOS USAF inventory / take off parts. The seller is taking it back and getting me one that will work on my 0.625 A1 barrel only.
They were M203 sling adapters before the M4 came along. The “dog bone” will fit either barrel diameter, I believe you need p/n 8448379 for the side where the swivel mounts. Not 100% on the part number, there are definitely 2 different ones though. Numrich used to sell them but it’s been a while.
TOS EE has a guy selling 10 - .625 side sling adapters. No affiliation, not a member of the site so I cannot even tell you a user name.
Andy
That’s the seller I was working with. Didn’t want to call anyone out with out getting more info and trying to resolve things first.
We did an exchange and I got the M16A1 stand alone which worked fine. He’s traveling for work and will get back to me when he returns and trie s to figure out why the dual a1/a2 adapter didn’t work. It looks like the one on the left above. My assumption is that the dog bone is out of spec, but that’s just spit balling.
Wow. A lot of side sling info.
After playing with a few of the A1 adapters, they are not as tight as the A2 version. The A2 locks into place pretty solid. The A1 has a tiny bit of movement forward and back but doesn’t rotate. 3 different ones on four different barrels had the same results.
And yes, this is more than I thought I’d ever post about side sling adapters…