Modern Sporter - Build Discussions

[Ryang5177]

+1 om confirming the CMMG kit works flawless after the ATRS conversion. mine gets used a crazy amount and run great. the thing i've found is that it needs to be run pretty wet or cleaned very often otherwise i get some FTE.

[mmcintyre1220]

I believe they shorten the CMMG BCG overall then add a small block to the rear portion which prevents it from going back into the buffer tube. The AR bcg works fine because in an AR it retracts probably 3/8 to a 1/2" behind the ejection port so there is a larger tolerance. In the MS it only clears the ejection port by about 3/16." Maybe someone else can explain more clearly but the ATRS mod on the CMMG kit runs perfect .

No this does make sense thank you ! I am assuming the root of the issue is caused by the buffer putting too much forward pressure on the .22lr BCG when its design is intended not to have this forward pressure. What does ATRS charge for the modification ?

[Ryang5177]

No this does make sense thank you ! I am assuming the root of the issue is caused by the buffer putting too much forward pressure on the .22lr BCG when its design is intended not to have this forward pressure. What does ATRS charge for the modification ?

150$ from ATRS

[mmcintyre1220]

150$ from ATRS

Not horrible at all ! Thank you

[ColinD]

I made a dedicated 22lr upper with the help from ATRS, it’s almost flawless. The only issues I get is when it’s unbelievably dirty. She has seen between 15-20K rounds

[ENIVUAG]

Hi, has anyone had a problem with the front pivot pin? When I put the lower and upper together I can push the pin with the strength of my finger but I need a little punch and a hammer to pull the pin out for disassembly. The upper and lower are very tight it is normal ? thanks

[Regulate]

Dw too much about it they wear in a bit, yes they are supposed to be tight. You could use the corner of a mag or piece of brass in the field and that works well to punch it out

[JFK1]

Hi, has anyone had a problem with the front pivot pin? When I put the lower and upper together I can push the pin with the strength of my finger but I need a little punch and a hammer to pull the pin out for disassembly. The upper and lower are very tight it is normal ? thanks

All my ATRS builds do the same thing, Like Regulate said I use a spent casing to pop mine apart for cleaning / servicing.

[ENIVUAG]

thanks for reply

[ENIVUAG]

Hi, I have a problem when I insert my pmag gen3. When the mag is empty, no problem fit perfectly but when is full or just few ammo in, it is very difficult to clip. I have try many different mag. I don't know its the mag catch part the problem or is the pmag ? Other people have problem with mag ? Thanks