Failure to Chamber / Eject

[capreppy]

I went to the range today. Shot thru 350 reloaded rounds. Occasionally had issue with failure to eject or failure to chamber.

Weapon: SA XDm .45ACP
Ammo: reloads
- R-P brass
- MBC 200 gr LSWC OAL: 1.225 Taper Crimp: .491
- CCI #300 LPP
- 5.0 gr Winchester 231

These were some early development rounds and have since identified an issue with my taper crimp. I need to find out if this is an issue with later developed rounds.

I've not heard if anyone with feeding issues using These bullets. I did not have any issues with the first 100 that I developed.

What are typical causes of a failure to eject or failure to chamber?

 

[rfwobbly]

• The Hodgdon web page shows that load to be 4.4 to 5.6gr, so it sounds OK.

• I think you meant .471" on the crimp

Failure to chamber can be too large crimp, or OAL too long. You can easily spot issues by dropping finished rounds into your naked barrel's chamber. They should go all the way in under their own weight.

 

[bloominonion]

Failure to eject: too low of powder or pressure recoil reliably. Also case expansion could cause it to catch from overpressure.

Failure to chamber: not enough crimp or too long of case.

Those are the only reasons I can think of, hopefully someone else has some better ideas.

 

[capreppy]

Yes meant .471 on Taper Crimp. I did check each round against the barrel and they "plunk" ok.

I don't think it is overpressure as this is a mid-range load recommended by more than a few folks for this bullet profile.

I didn't have any issues on the first 100 I did so am a bit of a loss. I'm going to recheck the taper crimp on the rounds I have left remaining to see if there is some discrepancy I didn't see before.

 

[bloominonion]

I don't think it is overpressure as this is a mid-range load recommended by more than a few folks for this bullet profile.

Yeah, I was just generalizing causes. I think it is better to give more causes to give someone ideas to think through (the engineer in me).

I would definitely check the remaining rounds. You may have bumped a die up a hair and the one set may have had a looser crimp. Otherwise I am at a loss. Good luck figuring it out!

 

[LiveLife]

capreppy, if the taper crimp checks out (around .470"-.472"), can you manually cycle the slide?

If the rounds feed/chamber when you cycle the slide by hand, they should cycle the slide at the range (5.0 gr of W231

Also, you do have the XDm and not the XD? XD had known extraction problem of SWC bullets while XDm fixed the extraction problem with a modified slide rib.

 

[capreppy]

I have an XDm. My taper crimp was .471, lowered it to .470 for it to reliably feed and extract (manually). I'm going to the range again tomorrow and will give the new settings a try.

 

[capreppy]

Well it looks as if the Taper Crimp may have been the culprit. Reduced taper to .469 and the round drops in and out of the barrel fine and cycled on the range just fine.

 

[rfwobbly]

Although you can buy a "cartridge gauge", the best gauge is to use your naked barrel. Rounds should be able to drop in all the way using only their own weight.

Congrats on a solution!