View Full Version : NEW ITEM: Quick Change retrofit for barrels

M&A Parts
08-31-07, 14:47
Take a look at this new product. It replaces the barrel nut and allows for quick change of any barrel on your AR15/M16


A brand new item.

09-01-07, 18:03
If you guys get a chance, additional pictures and a writeup would be appreciated. I've been thinking for the past few years that there had to be a way to retrofit existing receivers to quick change barrels. Glad that someone came along and made it happen!

M&A Parts
09-11-07, 15:18
About all the pix we could come up with! Shot a bunch, but these show it pretty well.

Okay, how about this, to get the word out, take $20 off of the regular price, get them for $50.

For a limited time. You guys do a little T&E, we liked them in use, and are sure that you will, as well.

05-12-08, 19:39
Wow... good things are worth waiting for. Here is a quick write-up the Mission Specific Barrel Quick Change System (MSB) from M&A Parts.

I had a familiar problem with too many matching lowers to every upper receiver I owned. I decided to look at using a single upper/lower combination and to change out the barrels depending on what my need was going to be for the day. I look at a number of systems, which included the MGI setup, but at $600, it proved to be too cost prohibitive.

I ended up ordering the Quick Change Barrel Kit (http://www.m-aparts.com/productsDetail.asp?id=1415) offered by M&A Parts, Inc.

The kit itself was simple. It consisted of a replacement barrel sleeve, two barrel nuts, a barrel nut wrench and complete instructions.

The kit comes ready for being able to swap out two barrels to the same upper with additional barrel nuts available for any additional barrels you may have. My target for this build was a 16” M4 carbine on a Mega upper that I wanted to swap out with a 20” 1:8 SS for target shooting I also obtained from M&A.

Now to setting up the upper receiver. The replacement sleeve screws onto the upper. Here is a shot minus the weld spring, delta ring and c-clip.

I removed the nut and proceeded to assemble with the delta ring, weld spring and c-clip.

Try to get the spring and c-clip lined up together somewhat close BEFORE screwing the assembly onto the upper. It makes things a lot easier that trying to chase them around once everything is mounting to the upper.

Now time to attack the barrels. You need to remove the FSB in order to remove the original barrel nut and to slip on the replacement nut that secures the barrel into the newly sleeved upper. Install the nut so that the cutouts for the castle nut are towards the end of the barrel. Now re-read this and check the nut before you get the FSB pinned back on, you’ll thank me. Here is the completed assembly:

This was the really fun part. Take the barrel assembly and slide it into the sleeve on the upper:

Snug up the nut (snug. not torqued) with the supplied wrench, snap on the hand guards and you’re ready to go. The barrel nut is designed to securely hold the barrel with a minimal amount of torque.


The system works fantastic. I can now go from a 7” SBR to a 20” target barrel and back to a 16” carbine in less than a minute per change.

After 600 rounds, I found the barrel nut to be as secure and was easily removable as when I first installed it.

Here is a quick movie I put together to show a barrel change - VIDEO (http://s18.photobucket.com/albums/b132/Zadvark/video/?action=view&current=b96ffa34.pbr)

09-13-08, 13:44
Any plans for various barrel nuts for FF rail set ups? Also is your barrel nut drop in rail compatable?


Robb Jensen
09-18-08, 06:20
Pretty cool looking system.

09-18-08, 09:08
Any plans for various barrel nuts for FF rail set ups? Also is your barrel nut drop in rail compatable?


Your answer is coming... please hold :D

05-09-13, 10:26
What happened with your new design, didn't answer almost 5 years :))
By the way if anybody interested , I got a new re-designed version, you can use with a Spikes Tactical BAR handguard! I can show the adapter ...