Ok, here's the deal... I need a midlength carbine to round out the collection. Problem is, no one makes a 1/7" chromelined midlength carbine.

Soooooo... What's the longest length I can cut a bbl down to and use a midlength gas system?

-Thanks!
-Cap'n

Wouldnt it be nice if someone DID make a mid-length chrome lined?

Sure would be.

I just do not understand why companies like Armalite, that supposedly supply rifles to the .gov will not make us civilians 1/7" barrels in midlength. Same goes for Bushy, why 1/9" only on the majority of barrels? Why in the heck can't I get a NON-COLT 1/7" 16" or 20" bbl? What's up with that?

Is it simply because they've both bashed the 1/7" bbls for years to push their own 1/9" bbls, and they don't want to change their position? The facts are out there, heavy bullets ARE the next big thing for defensive and match usage, and some of us want the option to use them.

Also, what's the deal with this? I'd LIKE to see Bushy back this up. Maybe in 1 out of every 5 or 10 guns this is true, but I know NONE of my Bushy's can stabilize the 75 correctly.

"Q. What is the maximum bullet weight that I can fire in my Bushmaster? Can I fire the 65 grain bullet? I've heard people talk about having the barrel specially bored for the 65 grain bullet - is this a necessity?

A. No, you can safely and accurately fire up to a 75 grain bullet in the Bushmaster chrome lined 1 in 9" twist barrel - even an 80 grain can be fired safely but accuracy will suffer."

And then they go on to say that lighter bullets "explode" when being fired from a 1/7". I've shot 45 HP rounds quite a bit through my Colt, and have yet to see this. Accuracy isn't the best but it's still not horrid. O

And Armalite's Position on this?

.223/5.56mm

 

TWIST RATE:                         1:12                  1:9                   1:8

 

LIGHTEST BULLET               40                    55                    60

IDEAL BULLET                      2/55               68/69                75

HEAVIEST BULLET              60                     75                   80

Again, do they have proof of this? Can they back these claims up? So, going by this same info, my 1/7" wouldn't stabilize 55 grain ammo? And again, their 1/9" can stabilize the 75 grain? And the 1/9" wouldn't stabilize the 40 grain? Ugh...

Sorry for the rant, but this just irks me to no end.

-Cap'n

I cut 3 3/4" off a Colt crome lined and it uses the full length gas tube.  When I first did it I had a problem with functioning.  At the same time I went to a CAR stock/buffer sytem.  I also had a new bolt and carrier.  I ended up cutting a couple of coils off the buffer spring.  It works fine to this day.  I think the real problem was the new Mcfarland gas rings I put on the new bolt.  I was always going to try a full CAR buffer spring but what the hey...If the foo shits...

Halfcocked, that's exactly what i did with my first "Dissy" rifle about 3 years ago. Chopped an FNMI A2 bbl, recrowned, chopped the bayo lug, and... Voila, a perfectly fine Postban Dissy. If it works, it works, hehe.

-Cap'n

When you say exactly do you mean you had to trim your buffer spring too?

Like I said I was always going to replace that CAR buffer spring.

Sure did. It wasn't much though, just a little bit. Worked fine after that. This was using a shortened CavArms lower, w/ a CAR buffer and spring.

-Cap'n