How long is your barrel? I realize the Bushmaster "slip on" moderator is 5 inches, right? But how far down the barrel it slips I don't know. Since the fake moderator is pinned on, do you still have to thread the barrel and install a flash hider? Thanks!

Randall shortened and threaded my barrel at 12 5/8 inches. With the pinned mod its right at 16 1/8 inches. Yes, it needs to be threaded to accept the moderator, whether its pinned or a slipover. The moderator is the flash hider.

make sure you get the proper grenade ring to go behind the bushmaster moderator. fyi, the bushmaster part is 4.5" long. not sure about the slip over style flash hiders, but they will weigh down your barrel significantly.

more great work by randall: lightweight profile 9mm caliber bbl on  cut down and blind pinned 4.5" moderator on a smooth side A1 upperxm177 e2

Quoted: Randall shortened and threaded my barrel at 12 5/8 inches. With the pinned mod its right at 16 1/8 inches. Yes, it needs to be threaded to accept the moderator, whether its pinned or a slipover. The moderator is the flash hider. home.earthlink.net/~mwsjb/pictures/mod2.jpg

same here, & AR15Barrels does excellent work!

Quoted: How long is your barrel? I realize the Bushmaster "slip on" moderator is 5 inches, right? But how far down the barrel it slips I don't know. Since the fake moderator is pinned on, do you still have to thread the barrel and install a flash hider? Thanks!

I'm sure that everyone has their own opinion on this but I'll share my view. If I were going to build an XM177 clone I would not use a slipover flash hider from Bushmaster. They just don't look correct. If you already have a carbine set up the way you want and just want "the look" then it would probably be fine, but if you are building a clone then you might want to look into having a longer barrel shortened to the appropriate length and use a more realistic version of the moderator. Bushmaster also sells a halfway decent 4.5 inch moderator that is fairly close to the original. It would need some work to be more convincing though. Total Silence sells a very close copy of the original moderator and I have a friend that is supposed to be producing some pretty soon.

Generally a barrel of around 13 inches will get you the necessary 16 inch overall length you need to stay out of NFA territory when using a standard 4.5 inch moderator. For the best results the barrel would need to be threaded for the flash hider even though it would be pinned in place. It would need to be blind pinned and welded in order to comply with BATF regulations. Then it would need to be refinished.

I know this has been covered, but can't find it - my question is specifically for Randall - which contour/size barrels do you prefer (easiest for you) to work you magic on for the XM177? BM Superlight? 16"HB? I mean, I KNOW you can do about anything with a barrel - I've seen enough evidence here of your work to know I'll be sending you my BM 16" fluted barrel to thread for a different build, but what are your recommendations for an XM177 build if a guy wanted to go the same 12-5/8" route?

member 45Bravo was reported to
be developing a Non-NFA Moderator

Quoted: Bushmaster Superlight J&T 16" A1 Carbine Either of these work great. and don't need to be refinished unless you want the bayonet lug removed as well.

If you are purchasing these barrels new, just ask for "post-ban compliant" and they will arrive without the bayonet lug.  

One less thing to worry about.

I order the post ban superlite for that reason. After 2 or 3 months of back order I call Bushmaster. I was told they only do lots of 50 barrel per run. They were waiting for more orders. I changed my over to pre ban and had it in a couple of weeks. This was in the beginning of 2006.
GVS

Hey Randall,

I have a ban era 14.5 Bushmaster M4 barrel. I was originally going to have the FSB replaced,    phantom installed etc. etc. Is it possible to use that barrel to make an XM177 clone? I never even thought about it before, but I have an old upper I was saving for my XM177 build  and since they don't have bayonet lugs anyway.... See what I'm saying? I don't know how far down the barrel the cut is, but maybe with the "moderator" and grenade ring I could get away with using it?

Thanks Randall!

Ah, I gotcha. Thanks Randall.

Maybe I'll just squirrel it away and send it to you to reprofile when I build my clone.