Pinning aluminum muzzle device to 4150 CMV

[Rorge Retson]

How do I do this? My LGS says they can't do it. What is required? Tig? Mig?

In San Diego, would prefer someone local.

[Dave Hoback]

It can be done with low temp solder. Problem is, if you are are needing to pin/weld a muzzle attachment to bring a barrel to the legal 16” length, BATF requires I believe 1,100-1,200 degree Silver solder be used. This is right at or above the melting temp of the 6000 or 7000 series Aluminums needed for their strength.


Huh...maybe I do a thing or two about metallurgy. LOL!

[Rorge Retson]

Yes, it is to satisfy the 16" requirement. Putting a KAK on a 13.7" barrel.

[Bete Noire]

I had an aluminum faux suppressor put on and they basically burned through the aluminum and puddled up a weld such that the muzzle device is trapped by the weld and cannot turn at all.


Sent from my iPhone using Tapatalk

[ar15barrels]

How do I do this?
My LGS says they can't do it.
What is required? Tig? Mig?
In San Diego, would prefer someone local.

I drill a hole, drop in a steel pin and then an aluminum pin on top of the steel pin and then tig weld the pin to the muzzle device.
Most shops that are doing gunsmithing either do not HAVE an AC tig welder or simply will not weld aluminum.
Many shops either refer customers to me or the shops take the jobs in and bring them to me to do the work.

The BATF requirement for perm attach is that forceful removal of the muzzle device must damage the barrel beyond use.
That's why the steel pin goes in the hole first.
If you tried to forcefully remove the muzzle device, the steel pin will destroy the barrel like this:


An aluminum pin would shear off and NOT render the barrel useless so a perm attach job with only an aluminum pin would NOT pass the BATF test.

[ar15barrels]

Silver solder will not adhere aluminum to steel.
The BATF requirement is 1100f but the commonly available hi-temp silver solders flow at 1200f.

Melting is sort of a requirement of welding.
Here is a picture of one of my aluminum perm attach jobs:

[dozer wright]

Interesting how important to the Atf .That the barrel be destroyed if you try to remove the muzzle device by unthreading it. I see the one pic of the twisted barrel. Did someone not have a drill , Cut off wheel Dremmel or half dozen other tools and methods. Or was that for demonstration purposes?

[Triple765]

Un-popular Calguns opinion:

Do not comply. Thread whatever on & don't post pictures

[ar15barrels]

I see the one pic of the twisted barrel.
Did someone not have a drill , Cut off wheel Dremmel or half dozen other tools and methods.
Or was that for demonstration purposes?

The barrel was sent to me by a customer who didn't realize the muzzle device was perm attached and he forced the muzzle device off.
The fix was to cut off the damaged end, re-thread the barrel at the shortened length and then use a longer muzzle device to achieve 16" legal length.

[dozer wright]

The barrel was sent to me by a customer who didn't realize the muzzle device was perm attached and he forced the muzzle device off.
The fix was to cut off the damaged end, re-thread the barrel at the shortened length and then use a longer muzzle device to achieve 16" legal length.

That's crazy. To deform a barrel like that .

[ScottsBad]

Aluminum and muzzle are kind of bad ideas/materials to put together IMHO. I don't know what type of aluminum the muzzle device is made of, but aluminum tends to bend easily unless its like forged. 6000 or 7000 aluminum maybe?

Bent aluminum muzzle device = muzzle strike + aluminum shrapnel

Is the weight savings worth it? Just a modest question?

[Rorge Retson]

Aluminum and muzzle are kind of bad ideas/materials to put together IMHO. I don't know what type of aluminum the muzzle device is made of, but aluminum tends to bend easily unless its like forged. 6000 or 7000 aluminum maybe?

Bent aluminum muzzle device = muzzle strike + aluminum shrapnel

Is the weight savings worth it? Just a modest question?

I bought the KAK before knowing it was going to be such a PITA to attach.

[AregularGuy]

Like many here, I can vouch for Randall's work. I've had several devices pinned. Very clean. Send it off or bring it to him.

[m16]

Agreed, Randall does excellent work.

I’ve had him pin sight bases to barrels, and pin and weld muzzle devices.

Not once have I ever been disappointed by the results, his weld jobs always look professional.

I’ll continue using his services, especially since it seems to trigger the butthurt trolls on this forum.