Well, it's all about the price of the barrel for me (cheap barrel and me).
I'll have to admit that I wanted to use the DA7 and a 0.750" barrel, but this barrel dictates a larger GB. Now I might change to a different block but I'm going for the SLR.
As for the tube, I just ordered a rifle length tube and will alter as my prior post. The only thing with this barrel is I've read that CMMG had some earlier barrels that had threads cut off axis of the bore. So if I use a suppressor I need to set up this barrel indicating on the bore and chase/recut the threads to straighten them up with the bore. If they're off that is (still need to be checked).
farm use wrote:My question is why would CMMG make a GB .936 in a pistol gas system knowing you cant get a straight gas tube for the block in pistol length?
I agree! I wish more barrels were made with pistol length and 0.750" diameter, but I guess the demand is carbine length. I just like to have more control as I like to tinker with hand loads. I knew when I started I was going to use a 16" pistol length and I couldn't find a barrel unless it cost too much, so when I saw this barrel I decided I would make it work.
I might add, that has yet to happen, but my fingers are crossed.
Jim Timber wrote:How are you going to seal the front end of the tube when you cut it down?
I'm not cutting off the GB end, I'm going to cut the key end off.
So I'm going to assume you have pipe swaging tools to reproduce the ball end that ensures a proper seal in your gas key?
The gas block end is by far the easier/cheaper solution to your problem. Shove in a piece of round stock (machined to the proper diameter) and TIG weld it on the end, grind it to fit the hole again, then drill your two holes where they need to go.
Personally, having all the tools to fix this situation and the skill to do it, I wouldn't buy that barrel. A regular heavy profile barrel is too heavy to walk around with and I get sub MOA out of my S2W Daniel Defense barrel all day long so there's no justification for the added weight.
Jim Timber wrote:How are you going to seal the front end of the tube when you cut it down?
I'm not cutting off the GB end, I'm going to cut the key end off.
So I'm going to assume you have pipe swaging tools to reproduce the ball end that ensures a proper seal in your gas key?
The gas block end is by far the easier/cheaper solution to your problem. Shove in a piece of round stock (machined to the proper diameter) and TIG weld it on the end, grind it to fit the hole again, then drill your two holes where they need to go.
Personally, having all the tools to fix this situation and the skill to do it, I wouldn't buy that barrel. A regular heavy profile barrel is too heavy to walk around with and I get sub MOA out of my S2W Daniel Defense barrel all day long so there's no justification for the added weight.
In reference to swaging the end..I miked both ends and the key end you make reference to is the same diameter as the GB end (0.799"). About 1/8" (I haven't measured yet) from the key end the diameter is around 0.172" or so for a couple inches or so. This makes it appear as it has been swaged larger but in reality it has not.
I agree about the weight of the barrel, but again I liked the price. If I like the 300BLK I'll probably build a lite weight later.
Every AR15 gas tube I've ever handled has had a ball swaged into the end of it. The area before the ball is drawn down so it doesn't have added friction on the gas key. The radius on the end is to prevent it from scraping as it follows the chamfer in the key's inlet hole (compensating for minor misalignment), and preventing fouling from building up and jamming it from excessive friction.
I'm not trying to tell you not to do it, I'm just looking at the obstacles you face in the process from my perspective.
Jim Timber wrote:Every AR15 gas tube I've ever handled has had a ball swaged into the end of it. The area before the ball is drawn down so it doesn't have added friction on the gas key. The radius on the end is to prevent it from scraping as it follows the chamfer in the key's inlet hole (compensating for minor misalignment), and preventing fouling from building up and jamming it from excessive friction.
I'm not trying to tell you not to do it, I'm just looking at the obstacles you face in the process from my perspective.
I'll look at this again. I ordered a pistol length tube and miked it, maybe I missed something or have a defective tube to begin with.
I have this barrel but have not used it yet. The barrel profile is .750 from the step for the gas block to the muzzle threads. It would be slightly lighter, and then you could go with the DA7 and standard pistol tube. It will put you slightly over budget $40. If you can send the other back?
dellet wrote:I have this barrel but have not used it yet. The barrel profile is .750 from the step for the gas block to the muzzle threads. It would be slightly lighter, and then you could go with the DA7 and standard pistol tube. It will put you slightly over budget $40. If you can send the other back?
I also have one of their earlier barrels that was carbine length with a 1/8 twist that I have been pleased with.
I might take you up on that. I actually have already sent one back earlier due to weight but decided the M4 profile would at least be some lighter than a 556 due to the bore.
