Sig Tapered Barrel With Gemtech Halo

[Mot45acp]

I have a soon to be delivered Spear-LT 5.56 that I would like to pair with my Gemtech Halo.

My question is with the way the Halo clamps down on the A2 or similar dimension muzzle device, will I need the adapter that gives the tapered barrel a 90° shoulder?

 

[MachIVshooter]

If you want to use it with A2 muzzle devices, that or have the barrel turned with a square shoulder (better).

Otherwise, need to mount convert the Halo to use Bravo pattern mounts & adapters, with which a few Sig tapered barrel mounting options exist. On the right in FDE is what a Bravo converted Halo looks like with no mount installed

 

[Mot45acp]

Thanks for the quick reply. Follow up question.

Would getting the barrel turned to a square shoulder leave excess amount of threads or would you have to shorten the entire barrel? I believe if I have to shorten, then I would have to pin and weld the muzzle device.

Barrel is listed at 16" on the nose (406.4mm)

 

[MachIVshooter]

Typically best to cut it right at the front of the taper and rethread. Otherwise, yeah, you end up with a very long tenon that has a huge undercut. That may be fine with some muzzle devices, though. Some of them can be modified for it. If it's 1/2-28, our Gyrex brakes in that size are counterbored in front of the threads, would actually take a threaded part all the way to the internal shoulder at the front of the brake, 1.7" deep.