Semi Wadcutters and Jamming


February 14, 2013, 11:24 PM
I've noticed on a P90 that Cast 200gr Semi Wadcutters are having a little trouble cycling.

I've noticed the following symptoms with the jams:

1. One feeds about 1/3 and slide sticks back-drop the mag and it closes. (hooked on round below it).
2. One feeds too high and the entire round wedges the chamber wide open.
3. Once in a great while I get one that doesn't eject at all and the slide closes right back up. I have to manually eject the case before continuing.

Any ideas where to start?

The case neck measures .470" on average. The will drop into the chamber and also come out but won't just fall out, I have to tap the gun a bit (not too hard but some taps). I've tried a few different ovarall lengths without too much change. Round Nose 230gr seem to cycle a lot better with the same amount of powder charge. I've also upped the charge with the Semi Wadcutters and no avail.

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February 15, 2013, 10:15 AM
200gr Semi WadcuttersThere are 200 grain SWC's, and there are 200 grain SWC's.

The great ones, like the old H&G #68 and the Lyman #452630 mimic the nose contact point of a 230 grain FMJ-RN and feed real well.

Other like the Lee 200 grain SWC do not because the nose shape is too small and hits the top of the chamber too late in the feed cycle to pop the round up out of the mag at the proper time.

So, what kind of bullet are you using?


February 15, 2013, 12:11 PM
I found that 200-gr SWCs feed just fine in my Baby Eagle if I push the top round in the magazine as far forward as possible before I insert it. I use Rainier plated set to an OAL of 1.234".

February 15, 2013, 01:23 PM
On my P-97 (when I still had it) I shot many , many Lee 200 grain SWC without any issues so I'm perplexed.

ETA I do use the Lee Factory Crimp die

February 15, 2013, 02:51 PM
These are made by Mitchell in Texas -- bulletworks:
They are good people.

I've noticed that if I push on the slide a little bit when a round is mostly chambered I can get the slide to close. Many times just waiting a few seconds and the slide slowly shuts by recoil spring pressure. I'm thinking these reloads are a little tight fitting. I backed the crimping die back a little bit measured .471" diameter on some of the case necks. They do not plunk down into the chamber like factory Winchesters. They do go down but it takes a tiny bit of finger pressure to set them in there.

Also I noticed if I'm a little too long on OAL it constantly jams. I went .02 longer than where I found optimal and it jams almost every shot. I found 1.240" to be about where the gun cycles best which has maybe .020" of the main bullet rim above the case neck.

The last thing I've noticed is that the feed ramp gets a little grimy after 30 shots or so, as does the chamber and first 1/2" of the rifling.

I'm using CCI #300 primers and Hodgdon TiteWad powder. The cases eject about 6 feet at the 5 o'clock position (factory 11lb spring). No pressure signs that I've noticed on the cases. Fired the same 7 cases about 8 times each and other than marks from the dies and a little scraping here and there, they look very good still.

EDIT: Just talked to Jimmy Mitchell and he says that the round should just plop right in the chamber (barrel off the gun) like factory ammo would. He recommended a taper crimping die as the last step. My 3 die set has a crimp in the bullet seating die (combo) but it's mashing the brass pretty good right at the end of the case. He said a dedicated crimp die is what he recommends to help these load. He's gone far out of his way to answer my questions to get these to do what they're supposed to do. I've been very impressed with his service.

That said, I may running everything through a Lee Factory Crimp Die after everything is assembled on the Pro 1000 press. Adds a step but I guess that's life!

Shadow 7D
February 15, 2013, 04:21 PM
there is a reason you don't find factory SWC ammo for autoloaders....
why not use the Semi-Auto version the Truncated Cone?

February 15, 2013, 04:29 PM
You mean like this?


February 16, 2013, 11:14 AM
Ok... Getting better! I've got them crimped to where they'll plop in and out easily. I'm noticing that the ejecting shell's head snags and stops on the rim flat of the next live SWC. Anything I can do to make this run a little smoother?

February 16, 2013, 04:50 PM
Maybe if I had a little more of the rim showing on the SWC bullet it'd hang up less? But then I'm too long and hitting the barrel/rifling. The manufacturer recommend adding a little free-bore to the barrel. Maybe this is the best solution to get these to run.

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