Getting plated SWC to feed in .45ACP

[beatledog7]

I don't know if anyone else has has this experience, but I did today and thought I'd share it.

I built some PMC brass .45ACPs with Rainier 200gr plated SWCs (OAL = 1.234" and they passed the plunk test) and was having trouble getting them to feed. Specifically, the first round would not climb the feed ramp; thus, my Baby Eagle refused to go into battery, a behavior it has never exhibited before.

Having heard of this possible issue with SWCs in a semi-auto (but finding it a non-issue in my CZ-75 SA, 9mm), I thought, ok, what is the problem? The bullet's big, square shoulder grounds out before the relatively short nose reaches the feed ramp, jamming the slide out of battery.

So I had a thought. Can I get the flat nose to engage the ramp earlier? I discovered that I can. At least I think that's what is happening. All I had to do was push the first round forward in the mag as far as it would go before inserting the mag. Insert the mag, release the slide, and voila, she's in battery.

I sent the first one downrange, and the slide went right back into battery. All the subsequent rounds fed and fired without issue. Nice, eh? But I'm wondering, given that the first round didn't want to feed until shoved forward in the mag, what's now making it and the subsequent rounds feed cleanly? Am I right about the bullet nose now engaging the feed ramp earlier? Are the rest being pushed to the front of the mag by the recoil of the first?

I have a few more of these and will try to repeat this experience next range trip with a different mag. Anyone seen anything like this?

 

[MichaelK]

I had a similar problem with my 1911, shooting cast 200 gr SWC.

Actually, I discovered I had two problems. After diving into the 1911 literature, I discovered that guys before I was born fixed this problem. At least for my gun, the published OAL was too long for proper feeding. I finally settled on an OAL of 1.175" for proper feeding.

Once the cartridges were feeding into the chamber a second problem came up, that was not going into battery, as you described. While measuring my finished rounds, I found the mouth diameter was 0.474", while factory ball was 0.470-.471". My Lee crimp die didn't seem up to the task of crimping rounds properly. I bought a dedicated Lyman taper crimping die and the problem completely went away. By crimping the mouth down to a diameter of 0.471", I got flawless feeding and excellent accuracy, about 2.5" at 25 yards.

Getting back to your problem specifically, I'm thinking if you play with your OAL you can cure your feeding problem without fiddling with how cartridges stick out of the magazine.

 

[beatledog7]

I might play with the crimp a bit and see if it makes any difference. The OAL is already a little on the short side, which maybe contributing to the issue, but seating them longer would seem likely to exacerbate the problem, and I want to avoid overcrimping. If nothing else works, I can always just keep doing what I did today. Thanks.

 

[David E]

To get them to "hit the feed ramp sooner," load them longer.

My Colt prefers 1.265, but that's too long for the Para magazine, so I settled on 1.250. This works in everything.

 

[CZ57]

I agree with David E. My XDm has kind of a short throat but the shortest I go with the Missouri Bullet Co. 200 gr. SWC is 1.240".

 

[Kruzr]

For 200 gr. plated SWC's I find an OAL of 1.250 with a .469 crimp feeds well in 1911's.

 

[Skylerbone]

It's not a matter of hitting anything sooner. Take two identical 1911 magazines, fully load one and load a single round in the other. Now compare what you see. Each round fed will strike the ramp progressively higher.

Now to the problem. Could be your feed ramp, could be OAL is long, could be the magazine sitting too low in the frame. I would start with measuring the frame ramp's angle, depth and width to eliminate/include it as the problem. Next would be to shorten OAL to 1.200" on some dummy rounds. Shortening OAL will allow the cartridge to clear more of the feed lips (and begin nosing up) before hitting the ramp. Finally, if it isn't fully corrected you might consider an EGW "Higher" Magazine Catch. It will hold the mag. higher in the pistol thereby aligning that first (and subsequent) rounds to strike higher. Note that changing the mag. catch may require some other modifications, most frequently with magazine base pads. Most can be lightly filed and will work fine thereafter.

Not every SWC of equal weight will employ precisely the same profile so you must load for the one you use. You may consider calling the manufacturer for a recommended OAL.

Best of luck.

 

[KF5RMX]

My para has the ramp attached to the barrel. I have factory 230gr jams. Now I'm casting the lee TL452-200-SWC. I have oal of like 1.18 since the tumble lube SWC has a short ogive. Well the short oal causes the last round to float up and lock the slide open. The shorter oal has also caused the jam the be more pronounced and better detected with marks on the case. It showed that the sides of the ramp at the throat are creating a pinch point that isn't opened as much as the sides of the throat or the center of the ramp at the throat.

Just sharing my experiences......