Bullets nose diving on RPB 380 magazines

[Gaujo]

Looks like it's time to troubleshoot my magazine. Any tips on where to start?

Bullets are consistently nosediving when I hand feed them out. Disassembled the mag and the follower goes all the way up and down with just gravity. When loaded, feeding feels weak too, and sometimes the round gets stuck one bullet position down and has to be jossled.

When I've experienced this in the past, disassembling the magazine would usually lead to a burr or something that the follower was getting stuck on, but that doesn't appear to be the case.

Mag in question
https://www.ftfindustries.com/product/RP-380MG.html

 

[jb573]

Send it back.

 

[Gaujo]

Already got a custom mag stop added for my big grip 380 experiment. I'm in for a pound at this point.

 

[chili17]

feed lips are holding on to the round to long is what it sounds like

 

[rybread]

When I shot .380 from my 11/9 I had the same issue. I dremeled a divot into the front of the mag so the brass wouldn’t catch, allowing it to move forward and hit the feed ramp. Your experience may vary.

 

[Gaujo]

When I shot .380 from my 11/9 I had the same issue. I dremeled a divot into the front of the mag so the brass wouldn’t catch, allowing it to move forward and hit the feed ramp. Your experience may vary.

Even hand feeding it out with your thumb? RPB mags?

 

[rybread]

No- that seems like a weak follower and or feed angle- I shot 380 from a ZMAG. When I tried firing .380 it jammed and I could observe the brass lip against the front of the magazine. If I may ask, have you test fired it yet? I’m admittedly not familiar with the “feed it out with your thumb” test. I am familiar with how rounds usually behave when fed out manually- but the bolt is going to strike it with more force than your thumb. Is this really a valid test of function?

 

[Gaujo]

No- that seems like a weak follower and or feed angle- I shot 380 from a ZMAG. When I tried firing .380 it jammed and I could observe the brass lip against the front of the magazine. If I may ask, have you test fired it yet? I’m admittedly not familiar with the “feed it out with your thumb” test. I am familiar with how rounds usually behave when fed out manually- but the bolt is going to strike it with more force than your thumb. Is this really a valid test of function?

Well, with most mags when I feed it out with my thumb, you get the next round popping into position right away. When I see that I assume i don't have a feed issue caused by the magazine, or at least caused by the spring/follower. When you feed a round out with your thumb, if the next one doesn't come up that tells you that you likely have a friction issue. That's what I'm seeing for one issue.

 

[jb573]

Follower ,spring ,and top feed lips and conversion area all play a part in proper feed .
If one of those are not correctly designed and mated to work with the other parts you have a problem.
I've made numerous 50 and 60 round stick Magazines for the original m-11 380 rpb and powder springs guns from scratch.
It doesn't take much to get the geometry off and have problems even once you get one first article to work perfectly.

 

[brenbuilds]

It sounds like a weak spring causing inconsistent feeding and indexing of the next round. Additionally, this could be caused by increased friction such as a burr, or point of bind on the follower. You might try installing a spring from a working magazine to rule out that variable.

 

[skoda]

Gaujo,

Are you shooting brass or steel case ammo? I find that the rougher surface of the steel cases absolutely inhibits smooth travel up the magazine. Steel case ammo used to be cheap. Now that Biden has banned more coming in it's a fading problem.

I also scrub the insides of new magazines to get out any processing junk and then spray the insides with a Teflon spray. When the mags are looking grungy I clean again and respray. Seems to keep thing going well.

 

[rodfarva]

I’ve had good success with those mags, but I’ve had to alter the lips on some to adjust the angle of feed. There is very little margin for error

 

[Gaujo]

Brass cases. Will look at cleaning the mag body

 

[CKxx]

Have you already tried shooting with it? I have one of those that does the same thing by hand, but runs perfectly fine in the gun.

 

[Gaujo]

Took it apart again and found a pretty good burr. Letter but still not great