XM177: 5.5" moderator straight wall or conical?

[Todd.K]

Options:

1) By a wide margin. Find an over the barrel version you can get pinned to a 14.5” barrel.

2) Ask the manufacturer why they make two different designs and what they recommend for your needs.

[Todd.K]

1) By a wide margin. Find an over the barrel version you can get pinned to a 14.5” barrel.

This number 1

[Stopsign32v]

This number 1

Again cloning it. I don't care much about flash or noise it will be a range toy. I am nervous about horrible accuracy though with a 5.5" FH

[Ned Christiansen]

With that #1 option it will look the same but give you another 150-200 FPS which some day you may be glad you had, plus your accuracy concerns are gone. There is a guy that specializes in the clone thang, bet he has the preferred combo whichever you choose, but I can't think of his company name just now. Charlie's Clones maybe?

[Todd.K]

Again cloning it.

Are you trying to “clone” short barrel ballistics and not just the look, or did I not describe it well?

Because I’ve seen one done that way, and it looks just as close to original as any 16” OAL without a real moderator.

[Stopsign32v]

Are you trying to “clone” short barrel ballistics and not just the look, or did I not describe it well?

Because I’ve seen one done that way, and it looks just as close to original as any 16” OAL without a real moderator.

I just want a fun loosely built XM177 "clone". I like the clone game but not to the point of stressing over period correct parts vs repro. With that being said I also want to enjoy it at the range, so this one will have an A.R.M.S #2 on it with a Blood Diamond type optic because I much prefer optics over irons.

I really hate the idea of fake anything be it a fake suppressor to hide a 16" barrel or a fake 5.5" flash hider to hide a 16" barrel, just not my personal cup of tea. I do not care at all about ballistics (not that SBR ballistics bother me as my favorite go to is my MK18) all I want to make sure is that accuracy is acceptable.

[sinister]

I just want a fun loosely built XM177 "clone". I like the clone game but not to the point of stressing over period correct parts vs repro. With that being said I also want to enjoy it at the range, so this one will have an A.R.M.S #2 on it with a Blood Diamond type optic because I much prefer optics over irons.

... I want to make sure is that accuracy is acceptable.

I get it.

I wanted a "CAR-15" like I was issued in the old days. My desire to hit stuff where I'm aiming is always a consideration.

... so I bastardized the concept and built the CAR-15 I wanted. A detachable A1 carry handle (eh, why not?); a stainless Roscoe mid-gas barrel; free-float rail; and the Griffin XM Linear Comp (because I want it).

1967-70, evolved to GWOT:

[Stopsign32v]

Nice stick! So Sinister what flash hider is that and how does it group with it? I'm sure I'm overthinking this but I always do.

[Sam]

Is it a true moderator or flash hider that looks like the moderator? A true moderator would require papers like a suppressor right?

[sinister]

Straight, with as much clearance as possible.

You want the expanding bore gases to come out as symmetrically as possible, without kicking or tipping the bullet base and boat-tail in any particular direction, inducing bullet wobble about its axis -- why the National Match M14 flash suppressor was reamed out as opposed to tapered (kinda like in the diagram in your other thread).

Nez Rongero in Austin builds some of the most accurate custom M16 barrels in national match competition. He starts with a 30-caliber A2 compensator because they have a wider base for threading (5/8" rather than 1/2-inch) and he can bore out a wider internal diameter.

Example M14 flash suppressors -- standard on left, National Match on right: