Barrel length ratings workaround

[Longranger44]

So I've got a 10.5" 5.56 and the can I just bought (Yhm r9) is only rated for 16" 5.56s. I knew going in to buying this can that I wouldn't be able to use it on my 10.5" 556 ar, but I was thinking, would there be any reason I couldn't just add a 5.5" threaded barrel extension to my 10.5" barrel and be able to use the can with it that way? Of course making sure it's still concentric would be important, but if that'd be feasible, what would be the best way to attach the extension to my barrel? I'm guessing a crush washer wouldn't cut it.

Also I'm curious if I'd need all 5.5" inches or if the extension would lower pressures enough by the time it reached the suppressor, since the bore diameter of the extension would be larger than the bore of the barrel, that I could get away with a shorter extension like 4" or 4.5" for example. Those lengths seem to be a lot easier to find than 5.5" and would save me some overall length on the gun. Thanks in advance!

[Historian]

You present an interesting idea.

Extrapolating for the esteemed long ago designer
Don Walsh's patent EP0107273A1, PDF on Line,
you could mill out a through slot along its length
and encase it with a cylinder a la Don's design.

Alignment preserved, fast initial decompression
that reduces blow back, and could achieve your
goal. A 2 stage suppressor with a novel blast chamber.

Keep us updated.


Best.

[Longranger44]

Interesting. I looked up that patent and some more information on him, he seemed like a pretty innovative guy who was ahead of the times.

Yeah I'm hoping the aforementioned extension would allow me to use my 10.5" 5.56 for coyote hunting, it's not the idea gun but it's the only 556/223 I have and the vmax still performs out to about 300 yardes. I use it as is but the flash and noise is pretty incredible especially at night, it makes it almost impossible for follow-up shots or shots on multiple yotes. I'm thinking maybe the can would take the edge off enough to make it more practical. Anyway I'll definitely report back, the can is in nfa jail right now but hopefully the e file wait period isn't too bad I'm anxious to get it

[Capt. Link.]

I hate to point out the worm in your apple but no-matter what you do a 10.5 barrel will suck in the ballistics department. I would recommend switching to a long barrel for hunting it takes all of a few minutes to do. The 5.56/223 comes alive at 20" and longer barrels. Still love the M-16 A-1

[Longranger44]

I hate to point out the worm in your apple but no-matter what you do a 10.5 barrel will suck in the ballistics department. I would recommend switching to a long barrel for hunting it takes all of a few minutes to do. The 5.56/223 comes alive at 20" and longer barrels. Still love the M-16 A-1

I only hunt woods for coyotes so 300 yards is the absolute maximum distance with 90% of shots being under 100 yards, the vmax still frags out of the 10.5" out to around 350 I believe. It's not ideal but I'm not a serious coyote hunter so it works for what I use it for. Yotes ain't worth the cost of building another upper