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4/11/2026 5:19:13 PM EDT
[Last Edit: SkiandShoot][Edited]
Upper was a 16" RRA dedicated 9mm upper I've had for probably 10+ years. Fun as heck rifle to shoot. standard stuff with carbine hand guards and a typical front site base.
Mounted on a standard lower and with G trigger. Ran like a champ.

Put a CAT-MOB on it about 2 months again and things have been going very well. Was a hub model and got a 1/2x36 pitch thread converter and direct threaded it on there. easy stuff.



Yesterday I had 2 new shooters with me and we were running 8-10 rounds per mag, PSA black steel colt pattern mags.

We were shooting factory Green and White boxed remington 124 grain, two different box types from various old cases I had. WWB (newer style packaged as a small cube) and then 10 rounds occasionally of 158 grain Norma subsonic.

When it happened, the  mag was of 5 norma at the bottom and then 5 WWB or Remington at the top.  First round "sounded funny" then 4 more rounds fired with lots of debris flying. We immediately stopped and the middle of the barrel in front of the sight base is straight up "bugs bunny banana-ed". Pretty amazing actually. Nobody was hurt but more amazement.




The CAT-MOB easily screwed off the hub mount and looks perfect. The hub mount looks like it might have gotten stretched on the end and I cant' get it off. It's probably a loss. You can see 2-3 rounds stacked on top of the squib or whatever between the barrel exposed metal. Pretty cool.



Moving on, I'm looking to rebarrel it to maybe a 10" - 12" barrel? Buy a raw barrel and a new handguard and the handguard caps, have a gunsmith mount and go? Is it that "easy"? What else do I need.


Related note, this is a fun training rifle and I had already SBR'ed the rifle but do not need a super high end barrel but more of a work horse that will mate with the RRA upper etc.

Any suggestions?

4/11/2026 5:48:49 PM EDT
[#1]
take the barrel off and send it to ADCO to cut down since you've already SBR'd the lower.

7/7/2026 12:43:26 AM EDT
[#2]
I have a 9mm blowback barrel I would sell pm me if u want it
7/7/2026 10:42:19 AM EDT
[#3]
You can get a replacement barrel from Rock River Arms in 10.5” or 7” length.   RRA has a chrome lined 9 mm barrels also.   Since you are already set up with mags and lower the barrel shouldn’t be hard to swap out if the upper receiver is undamaged.


https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=292
7/7/2026 11:24:31 AM EDT
[#4]
Post pics, OP:  https://www.ar15.com/forums/General/Picture-posting-tutorial-and-PICTURE-test-thread/168-638569/

Shouldn't need a gunsmith, just buy another barrel, or have the squibbed barrel cut down.
7/11/2026 11:58:54 PM EDT
[#5]
I hate to say it, but if you hear a pop and not a bang you stop firing till you put a rod through the bore. Too many years as a ro I guess.  It could have been a lot worse.
" Don't cry, nobody shoots Glocks anymore."

"But the new Admin. is a Master in IDPA"
"MASTER in IDPA..."

"is like C Class in IPSC!"

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