messing with the feed ramp

M

Metric

New member
Someone I know has a Beretta 71 that the previous owner screwed with, before selling it off.

The 71 is the most reliable .22 pistol platform that I've seen. But this one was attacked by a bubba with a dremel tool. The aluminum frame was apparently "polished" (aggressively) where it fits against the barrel's feed ramp. Since metal was removed from the frame, this created a tiny gap with a slightly "overhanging" feed ramp.

Not surprisingly, the overhanging feed ramp now catches bullets as they are feeding out of the magazine, and shaves a bit off them and/or causes jams (failures to feed).

This, of course, is extremely annoying. It looks to me as though there is only one realistic fix -- taking an equal amount of metal off the feed ramp to eliminate the "overhang."

I have never done this before, and I'm well aware of the possibility of screwing things up even more. But I want to know if it's effectively "next to impossible" to do it right, or if some work with a needle file and then polishing could possibly help.

The overhang is very small, and with the best possible ammo (mini-mag) it creates a jam perhaps once every 10 shots, on average. With other ammo, jams are much more common. It's very easy to see how that overhanging ramp is shaving bullets.

What would you do?
 
F

FrankenMauser

New member
Have a skilled TiG welder replace the metal that was removed.
Then return the feed ramp to its original shape, as well as possible.
 
M

Metric

New member
We decided to risk it. I broke out a needle file and re-shaped the feed ramp to eliminate the slight overhang, then polished. Haven't shot it yet but it will now hand-cycle everything flawlessly (ammo that was giving guaranteed jams every mag when hand-cycled before).

Will try shooting over the weekend.
 
M

Metric

New member
Thanks for your thoughts and responses Franken, I'll update the thread after I've tested. I'm pretty sure it will be improved, but my main uncertainty is whether it's completely fixed or still throwing the occasional failure to feed.
 
T

tangolima

New member
Polishing deep into aluminum frame is a permanent damage done. The metal is soft. It requires the hard anodized layer to work as a pistol frame. I'm afraid the new frame ramp will wear rather quickly.

The barrel ramp may be cut back to eliminate the over hang, which is a no no. The barrel must be behind the edge of the frame ramp enough to feed well, and the frame needs to have sharp, not rounded, edge. But grinding back barrel ramp too much will reduce support to the brass head. Ruptured brass may result.

Building up the frame ramp may be a better choice, if you can tig weld aluminum. But it will still lack the anodization.

-TL

Sent from my SM-N960U using Tapatalk
 
M

Metric

New member
Tested with ~200 rounds of ~6 varieties this morning, from lead bulk ammo to premium hyper-velocity. Also had four shooters participate. Zero failures to feed with any of them (I did encounter one dud in the bulk ammo, but not much to be done about that).

The overhang was quite small, just enough to reliably snag bullets on every mag, so the barrel ramp did not need a massive change. That's the reason I went ahead with it -- it wasn't a radical operation.

I will watch for accelerated wear on the polished part of the frame, but I wouldn't expect the directing of 22LR bullets to require a high-hardness surface -- the force of the recoil spring is quite mild, and the bullets are soft. It's easy to imagine a different story with something like pointy FMJ centerfire rifle ammo.
 
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