Magpul ACR PTS Hop-Up Issues

[Salty6924]

Thanks for the info. Additional question, when I remove the lower receiver to take a look, the hopup is pretty loose in the upper receiver. Is that normal?

 

Yes, its loose so that Removing and replacing the inner barrel as well as the lower receiver and gearbox is a smooth operation. If everything had tight tolerances, there would be no room for error between parts and this would cause unnessicary wear.

 

I was worried about this too, but came to realize that when the rifle is fully assembled, everything is locked in place pretty solid.

[mimesis]

The nub is a figure eight shape, half of it is enclosed by the hop arm.

 

Ares Tavor hop-up disassembled. Just how similar are they?

 

[Salty6924]

That nub Looks identical. Taking the acr hopup out is a bit of a task though. There are quite a few pins and screws to get the trunion out.

[AnakChan]

Ares Tavor hop-up disassembled. Just how similar are they?

 

http://i46.photobucket.com/albums/f128/irishpuding/DSC_51080001.jpg

Different hop chamber, but the nub's the same (note, no spring) :-

[Apocalypsemeow]

From the Masada review thread I remember someone saying you should be able to fit a regular hop up arm into it but from that picture I'm not sure

[mimesis]

Different hop chamber, but the nub's the same (note, no spring) :-

 

Many thanks! Picture much appreciated. So the positioning of the nub is entirely dependent on the cam on the adjustment wheel, and whether the adjustment wheel stays put is entirely dependent on the little plastic fixture with screw that fits into the other side of it?

[AnakChan]

Yep, U got it. I must say though that (at least for me) once set, it doesn't move - at least it doesn't appear to do so (i.e. I don't have to re-adjust hop). I've not done any marker checks yet.

[xPLAN303Ex]

Yep, U got it. I must say though that (at least for me) once set, it doesn't move - at least it doesn't appear to do so (i.e. I don't have to re-adjust hop). I've not done any marker checks yet.

 

Thanks for the pic, very helpful. How did you remove the chamber from the upper receiver? It seems to be held by two spring pins that as far as I know the only way to remove them is to hammer them out.

 

Thanks in advance.

[AnakChan]

Yep, you have to hammer those pins out. Plus a few other screws but (naturally) the screws are easy, but the lower pin seems harder than the upper pin to hammer.

[mrwcmpsol]

Anyone have an issue with the bucking getting jammed into the barrel? I've tried different mags, at least 3 different buckings...Madbull blue, KWA 2x, Systema...and all have the same issue. The portion of the bucking that extends past the barrel...the lip is what I call it...is literally pushed into the barrel by a jammed BB after one or two mags. When I get home I'll post a picture to better illustrate what's happening.

[Salty6924]

Anyone have an issue with the bucking getting jammed into the barrel? I've tried different mags, at least 3 different buckings...Madbull blue, KWA 2x, Systema...and all have the same issue. The portion of the bucking that extends past the barrel...the lip is what I call it...is literally pushed into the barrel by a jammed BB after one or two mags. When I get home I'll post a picture to better illustrate what's happening.

 

Could it be a lack of lubrication? I always over lubricate and never experience problems like it getting stuck.