Competition Carbine

[Failure2Stop]

Putting together (read as looking at pictures) a carbine for primarily competition (3-gun, multi-gun, carbine). Pretty much figured out what I am going to do. Except for one little nagging problem.

Barrel Length.

I was thinking of an 18 inch barrel. But, is the ballistic advantage of an 18 overriden by handling issues or function issues? Should I just bump up to a 20 inch, since I am almost there anyway and I will get better trajectory? Or should I just drop down to a 16 inch carbine or mid-length system for the improved handling and only slightly inferior ballistic ability?

*help*

These issues are so much easier when they just give you a rifle without any choices...

[Zak Smith]

18" is fine. I've run a MSTN 17" 3Gun upper for almost 3 years now. You can dig up some old posts over on arfcom if you want to read about it.

Rifle-length gas is the way to go for 3Gun 17" or longer.

[Robb Jensen]

It all really depends on how far you'll be shooting.

Our 3gun/multigun/rifle side matches around this area are very rarely over 300yds, 95% of them around here are under 200yds. For that a 16" midlength is excellent.

If you'll be shooting 200yds+ a lot of the time, I too would recommend a 18" w/rifle gas system. I do wish JP would make a FF tube that would completely cover the gas block on a rifle length gas system.

[Failure2Stop]

Zak, gotM4-

Thanks, appreciate it.

[Zak Smith]

The 17-18" bbls are used in order to get the rifle-length gas system, not for the minute ballistic advantage. A RLGS has a more favorable recoil impulse than a MGLS or CLGS for fast shooting. A longer float tube is also useful for bracing against various barricades, obstacles, and natural terrain objects, though this is not strictly linked to gas system type.

On the FF tube, JP used to have a tube which would cover a RLGS gas block. I had one on my AR-10. Not sure if they have one anymore. This was before the VTAC.

-z

[Tuukka]

Having shot with carbines for years in Practical rifle matches and have transitioned to a rifle length gas system for much less felt recoil and faster splits at longer ranges from the prone.

All the carbines I shot simply have a much sharper recoil, even with a good comp.

So therefore my 2 cents worth also is = rifle length gas system.

[Failure2Stop]

I see your points on using the HG for support. Excellent. I forgot what full-size rifles feel like .

I had decided to go with an 18" SPR barrel from ar15barrels.com, and a JP/VTAC modular HG. MeOpta K-Dot and Larue SPR mount.

Probably just drop it onto a LMT lower. Not sure about buttstock, figure I will swap out my SOPMOD, CTR, and VLTOR until I find one that feels right or I will wait for the UBR to drop and screw me all up.