Rainier Arms UltraMatch .223 Wylde Mid Barrel - 12.5"

[gatordev]

Another happy Centurion Arms 12.5" user here. The one issue, if you want to call it that, is that it tends to have larger POI shift than other barrels with a heavier barrel profile when shooting suppressed. Not a deal breaker by any means. Otherwise, mine has been going strong for just shy of 1,000 rounds over the last year and is my go-to carbine competition gun. I think I've even managed to clean it once or twice.

[Slippers]

That said just a couple of observations....if I SBR it and then suppress it I'm really not gaining much because the OAL is still out there. If I do it though I'm thinking a CMT billet lower and a billet slick side upper with a 12.5 CHF barrel.

I'm still not entirely sold on an SBR in general but the more I learn the more I can see its use.

They kind of go hand-in-hand. If you don't have an SBR for a suppressor, then the rifle is very front heavy, and very long. If you have a chance, shoot a 16" with a can on it, and you'll immediately see that you wouldn't want to use it for an extended period of time.

Louder bang and compromised ballistics (to some extent) in exchange for more fun and smaller/lighter weight. I use my 11.5 more than any rifle I own.

Also, once you realize how easy it is to get a stamp for a lower receiver, you'll probably SBR all of your lowers. And in the grand scheme of things, even if you do SBR some fancy-shmancy billet lower and get tired of it, you can always take all the guts out and put them in a new $100 forged lower, and SBR that one. $200 tax stamps are virtually nothing compared to the money most of us spend on ammo.

[alamo5000]

They kind of go hand-in-hand. If you don't have an SBR for a suppressor, then the rifle is very front heavy, and very long. If you have a chance, shoot a 16" with a can on it, and you'll immediately see that you wouldn't want to use it for an extended period of time.

Louder bang and compromised ballistics (to some extent) in exchange for more fun and smaller/lighter weight. I use my 11.5 more than any rifle I own.

Also, once you realize how easy it is to get a stamp for a lower receiver, you'll probably SBR all of your lowers. And in the grand scheme of things, even if you do SBR some fancy-shmancy billet lower and get tired of it, you can always take all the guts out and put them in a new $100 forged lower, and SBR that one. $200 tax stamps are virtually nothing compared to the money most of us spend on ammo.

That is a very thought provoking post there Slippers. Thanks!

I can already tell that this trust is going to get my wallet in trouble :)

I have a lot of thoughts in my head about an building an SBR.

[GOST]

I second what Slippers said, go ahead and do it. Now what lower are you going to form 1?

[alamo5000]

I second what Slippers said, go ahead and do it. Now what lower are you going to form 1?

I only have one! LOL

I am thinking about SBR'ing the one that I have, but then again I might just do a whole new build.

Check out CMT's facebook picture...

[docsherm]

Noveske used to make the best 12.5 CHF barrel on the market. They widely considered the 12.5 their best barrel. Not sure about the qualities of the new ones, but I've got a 12.5 from when Johnny was still around and it's been a great barrel. Still have an old 18T shooting a M4-1000 on it.

I have a 12.5" CHF Noveske I got from John when they first came out. I have tried several 12.5' barrels, BCM, PSA, and Daniel Defense. All of which were not in the same league. If you can find a Noveske grab it. Other then that I would go with the DD 12.5".

[alamo5000]

It's the Industry standard. Plus when have you ever read about a forged lower being "worn" out? I'm sure there are government Colt lowers in rotation that have seen untold millions of rounds and decades of abuse and still going strong.

What really sold me was this.. You will have this SBR lower for the rest of your life. What looks good now in billet might not in 2030. Forged lowers will remain a timeless look.

Edit: Here's the thread where I asked the same question billet vs forged for SBR. Guys smarter then i on the subject, giving better answers then i can give honestly.

I just read that thread that you linked into... good stuff. Right now even though I could probably afford it I have to prioritize what I am buying. First order of business is a suppressor. I've been waiting on the damn thing for a while. Long story short I just have to space out my purchases of major items some. Which one piece buy one piece none of it is a major purchase but by the time you build a complete upper or complete lower...you wind up spending $$$.

The thought in my head was to possibly get another (non ambi) CMT Tactical Billet and SBR it and at the same time get a couple of matched stripped upper receivers. I have a slick side with a dust cover but for the SBR just a straight up slick side might be better. Less stuff to hang on or fiddle with.

Honestly I really like the CMT stuff. It couldn't be more perfect for me. That said I have little experience with anything else.

What Slippers said about the balance of the gun seems perfect. I recently handled a rifle with an AAC can on the end of it and that was the first thing I noticed.

Don't get me wrong I am learning a whole lot. An SBR seems like it would be the go to thing for a street fight. Ducking behind a car or going around obstacles etc. That said you can only shoot what you can acquire (target wise) so I have to think about the optic and all that too.

Long story short there is virtue in building a rifle that has a completely different intent to it. My rifle now is set up to where I could tag a 700 yard target or shoot a small group or whatever. For the SBR the intention would be more for a street fight obstacle climbing gun so the ballistic loss really isn't a big deal considering the intention would be for a 100 ish yard gun. I would be aiming for a minute of man kind of gun rather than just something that will shoot tiny groups. Minute of man with fast target acquisition....

That said the handling of an SBR if it's 12.5 or whatever inches would be a whole lot easier to handle, but when you put a suppressor on the end of it the OAL is still going to be right out there around 16". However having a balanced rifle is a very good thing.

I am not really one to half ass what I do. I would rather get what I want. I have learned through a lot of bad experience that buying good once hurts, but you wind up spending more if you buy bad.

Budget wise I try to keep myself to within $500 a month for shooting stuff...between ammo and this and that... sometimes I blow right through that....

[alamo5000]

For 5.56 what is the optimal barrel length for an SBR? I lean towards 12.5 but I see barrels that are down to 10.5. Do you lose anything by going 10.5 over 12.5?

[Dstrbdmedic167]

For 5.56 what is the optimal barrel length for an SBR? I lean towards 12.5 but I see barrels that are down to 10.5. Do you lose anything by going 10.5 over 12.5?

That's like asking which is better? 9mm or 40 S&W... Lol I'll let others chime in with more use with various lengths but I really like my 12.5".

[alamo5000]

That's like asking which is better? 9mm or 40 S&W... Lol I'll let others chime in with more use with various lengths but I really like my 12.5".

Initially I am leaning towards 12.5. That seems to be the predisposition, but an 11.5 might work too.

What I need to do though is figure out what the overlay is of the suppressor over the mount so that I can find the right barrel length/hand guard combo that can accommodate the suppressor.

I would definitely like to hear opinions though on 10.5 vs 11.5 vs 12.5.

FWIW I know it's all about velocity. You lose so much per inch but going from say 20" to 18" the drop off is minimal for the round. But dropping that short...I don't have any hard data to back up any theories I might have.

[gatordev]

I would definitely like to hear opinions though on 10.5 vs 11.5 vs 12.5.

Google will yield literally pages upon pages of responses. Assuming the barrel is ported correctly (which isn't a guarantee, depending on manufacturer), I'd argue velocity has very little to do with anything for a range toy/plinker. Pick something that gives you your preferred handguard length coupled with your overall preferred suppressed length/weight. The rest is mostly mental masturbation (again, for a range gun).

[alamo5000]

Here is something I found posted up by BCM:

"Q: Why BCM chose the 11.5" SBR over the 10.5"

I get this question a lot. It is a good one. When we spec our program we can build anything we would like, so we sat down and looked at the pros and cons.

First Statement: I know a good 10.5" SBR can run very well. I personally own a semi MK18 type and it runs great. No problems.

A: Dwell time.
Dwell time is the time that your gas operated weapon maintains pressure to continue the cycling of the weapon. It primarily exsists from the time the bullet passes the gas port in the barrel to the time the bullet exits the muzzle. When you pull the trigger and fire the weapon the movement of the bolt carrier group unlocks the bolt, extracts, and ejects the spent casing. Then it cocks the weapon, feeds, chambers the next round, and then locks again. One of the thing that can make SBRs finicky is the dwell time (or lack of).

The 11.5" carbine is approximately 4% longer weapon than its' 10.5" counterpart, but this extra inch gives the barrel a 40% increase in length for dwell time. IMHO, this is an excellent trade off. This additional dwell time (all other things being equal) will allow the carbine to be more forgiving to different ammo types, extremes in air temperature, weak or worn extractor springs, worn extractors, buffer weights, etc.

Last Statement: For those folks who have a 10.5" that works very well, I would reply; me too. (see first statement)

If I had to "go to war" with a AR15 Carbine, I would grab the BCM 11.5"."

Found here: http://www.ar15.com/forums/t_2_138/1...the_10_5_.html

That to me isn't just a cosmetic reason...

Then the question arises 11.5 vs 12.5. It's only an inch but I wonder if that would add to reliability with various ammo?

[docsherm]

John Noveske did a lot of testing on barrel lengths. He wanted to be able to shoot MK262 in an SBR and not waist it. After a great deal of testing he determined that 12.5" is the optimum length to properly stabilize the heave rounds out to distance. I have used many length AR Barrels and 12.5" is the best overall size that I have found.





And by the way .40 S&W is so much better than 9mm.....

[GOST]

10.3" run fine but both KAC and BCM make 11.5" barrels instead.

[alamo5000]

John Noveske did a lot of testing on barrel lengths. He wanted to be able to shoot MK262 in an SBR and not waist it. After a great deal of testing he determined that 12.5" is the optimum length to properly stabilize the heave rounds out to distance. I have used many length AR Barrels and 12.5" is the best overall size that I have found.





And by the way .40 S&W is so much better than 9mm.....

On one of these threads I kind of waffled around but said I was leaning 12.5 but I was just basing it off my my own feel and research. I think the 12.5 would possibly give me more ammo options. I am finding out that even with a short barrel I would still be able to shoot out to 400 yards with no problem...

But as Slippers was saying the balance matters, which was something I didn't think about.

My concept of the SBR though will be a ducking, dodging, running, hiding behind a car, quick target acquisition, reliably shooting type of gun. Not that I ever plan on it, but it would be more like a street fighting gun more or less.

The concept of my other upper got me exactly what I wanted. I can shoot sub MOA and I am confident I can hit targets 600 yards or more no problem. With an SBR I wouldn't be worried about any of that. I want a completely different concept of gun.