16" barrel M4 Bayo lug extension concept

[MSobal79]

Am looking at manufacturing a bayonet lug extension for my M4 w/ 16" barrel to better fit my Ontario M( Bayonet. wanted to get some Critique on the design concept. looking at making it out of 7000 series aluminum.

[MSobal79]

[Donk310]

Do it!1

[Revolver Ocelot]

Dont they make an extension that fits onto the hilt to extend it? Ive seen M7s with it.

[ar15barrels]

They sell extended bayonets that work on 16" carbine gas system barrels.
They also sell clamp-on bayonet lugs almost exactly like you have modeled above.

[wash]

I would put the screws in from the bottom, going from the top is making your clamp a lot wider than it needs to be.

I would look carefully at the other options mentioned because as it is, this one seems clunky. Also, threads in aluminum are risky, most quality stuff has helicoil thread inserts or some other way to make steel on steel threads.

One last thought, a one piece single fastener ring with the screw between the barrel and lug might be the least clunky way to do it and you'll spend 50% less on helicoils.

[MSobal79]

I recently purchased a M9 Bayonet and am looking to configure this for it. I have seen the clamp on adapters for sale but did not like that they didnt have any back stop or axial alignment.

[MSobal79]

I would put the screws in from the bottom, going from the top is making your clamp a lot wider than it needs to be.

I would look carefully at the other options mentioned because as it is, this one seems clunky. Also, threads in aluminum are risky, most quality stuff has helicoil thread inserts or some other way to make steel on steel threads.

One last thought, a one piece single fastener ring with the screw between the barrel and lug might be the least clunky way to do it and you'll spend 50% less on helicoils.

Thanks for the advise. I reduced the overall width aswell to 3/4" from 1"

[starsnuffer]

I'm guessing it would be for aesthetic purposes?

I'm not a fan of bolting dissimilar metals to each other in an environment with the thermal variance present on a firearm barrel. Using aluminum to attach a steel knife to a steel barrel seems like a failure point to me.

Use steel.

-W

[ar15barrels]

I recently purchased a M9 Bayonet and am looking to configure this for it. I have seen the clamp on adapters for sale but did not like that they didnt have any back stop or axial alignment.

Put a simple sleeve on the barrel to create the stop.
Never forget K.I.S.S.

[wash]

You can go farther than that and for aesthetics countersink the cap screw heads in the bottom.

Better idea: make it like a low profile gas block with a set screw in the bottom. Very clean, very slim, dimple the barrel and it's not going anywhere.

[MSobal79]

I'm guessing it would be for aesthetic purposes?

I'm not a fan of bolting dissimilar metals to each other in an environment with the thermal variance present on a firearm barrel. Using aluminum to attach a steel knife to a steel barrel seems like a failure point to me.

Use steel.

-W

Good point, I forgot about the thermal properties of aluminum. i was going for light weight initially but Steel is the Obvious way to go on this now.