45 ACP feed ramp problems

[lfpepsi]

I recently purchased a Caspian 1911 Frame & Slide at Camp Perry.

Apparantly I didn't notice that the frame was cut for a ramped barrel.

since I already had many hours already invested, I decided to order a ramped barrel. The gun is complete now, and I am fine tuning it to get the bugs out.

I am having a problem feeding 185 grain lead HPs. Some of the rounds want to nose dive out of the magazine, instead of going up the ramp. Any suggestions would be appreciated.

[G-ManBart]

Looks like your first post, so I'll say the important thing first....welcome!

A couple of things might be useful to know. What brand of barrel is it? What OAL are you running on the ammo and have you tried longer/shorter to see if it fixes the issue? What kind of magazines have you tried? Are the mags new or old, and if they're older, have you tried fresh springs and checked the feed lip dimensions? Are the rounds hitting low on the ramp, down where it meets the frame, or higher up?

Since the 1911 frame was essentially built around a cartridge OAL in the 1.260-1.270" range we run into problems with ammo that's shorter. Sometimes with the lighter weights in .45 it's hard to get the OAL long enough and when the round strips out of the mag, the nose hasn't hit the feed ramp like it would with a longer bullet and there's only one place for it to go....down. Some mags are better at helping avoid this based on their follower and feed lip shapes, but it won't always fix the underlying problem. R,

[irq23]

Sounds like the ramp is too steep. I had a similar problem with a ramped .45. If I remember correctly, the ramp angle should be 31 degrees +0.5 -0.0.

[tpcdvc]

Looks like your first post, so I'll say the important thing first....welcome!

A couple of things might be useful to know. What brand of barrel is it? What OAL are you running on the ammo and have you tried longer/shorter to see if it fixes the issue? What kind of magazines have you tried? Are the mags new or old, and if they're older, have you tried fresh springs and checked the feed lip dimensions? Are the rounds hitting low on the ramp, down where it meets the frame, or higher up?

Since the 1911 frame was essentially built around a cartridge OAL in the 1.260-1.270" range we run into problems with ammo that's shorter. Sometimes with the lighter weights in .45 it's hard to get the OAL long enough and when the round strips out of the mag, the nose hasn't hit the feed ramp like it would with a longer bullet and there's only one place for it to go....down. Some mags are better at helping avoid this based on their follower and feed lip shapes, but it won't always fix the underlying problem. R,

+1

Here are a few things I have learned lately.

The frame needs to blend in with the ramp as much as possible creating what amounts to an extension of the ramp.

Also, if you look at Schuemann's instructions for ramped barrels, Schuemann states that the first cut into the magwell will be .315" deep, measured from the top of the frame rails. This number might be a little shallow. Many respected builders seem to think you have to go as deep as .350". Since .315 is more shallow than "print" specifying .360" for .45ACP. Some go as far as .400 measured in the same way. This makes sense to me since it will lower the barrel and therefore the round has a better angle to overcome.

A lighter recoil spring will often help too because it won't pin the round on the ramp nearly as hard.

I talked to a guy at STI about this once and he has had luck with making the ramp a little flatter. This makes the contact area with a hollow point smaller and of course causes less friction.