What makes pistol ammo jam?

Ryan500

Ryan500

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Well, I've finally got into rolling my own for the 10mm, it went well, all went bang, none to loud or quite. Gun is a Colt Delta 10mm.

But what i did run into is some jamming and i'd like to compile a little bit of a list to make sure I check all the things I need to before I make more..

I suspect on mine because of the large hollow point on the 200gr XTP's it was hanging up.... also my new starline brass had the primers hanging out a little (0.010") and that caused a few fore sure, I will not be shooting the other 30 of those I have.

Does crimp affect feeding? maybe that is part of the issue?

What I'm trying to accomplish is a gun that runs like a top, like all the rest I have. I know it's the ammo because my factory rounds went like nothing.

Thanks.
 
Just a couple common things for general auto pistol

Bullet that doesn't like the feed ramp, some GI 1911s like round nose but not wadcutter/hollow point etc. Polishing parts like the feed ramp or changing magazine brand or type for feed angle can help this.

Case not sized fully or correctly

Too much flare in case mouth/flare not removed or crimped back.

Bullet/overall length too long. Sometimes if say 1.555 inch is ok with one 200gr another brands same shape with need to be seated shorter 1.500 etc. so it doesnt hit the rifling.

I would work on one thing at a time and make 2-3 dummy rounds with no primer or powder to try manually cycling at home. When they work good I would load 5-10 and take them to the club to try out with those die/press/tool settings.
 
Jamming can be caused by many factors in your loads, assuming that you have no jams with factory ammunition.
The type of jam will help to identify what the problems might be. The problem(s) could range from overall length, crimp, to suitable powder type and charge. The feeding cycle of an auto pistol is actually tuned for a specific series of events, and if you are out of specification then it might not work properly. As an example, if you are loading below optimum velocity then it is possible that the slide is not coming all the way back and allowing for a proper strip of the cartridge from the magazine.
Perhaps if you identify what kind of jamming you are getting, more help could be provided.
Also, it is very bad quality control to allow high primers on any of your reloads. It could also be dangerous.
 
Pretty much the jams where failure to feed, not often but enough to piss me off. Ejections were good, cycling seemed fine. Just 1 out of every 20 or so would not feed all the way in.
 
When the round fails to feed take it out and look at it carefully,the area where it is hanging up will show some deformation or denting on the bullet. If you really want to shoot the hollow point or semi wad cutters you will have to take some metal off where it is hanging up. I tried some flat nose bullets but couldn't get them to feed properly so I went with round nose bullets and haven't had any problems since.
 
i've heard about the primer pocket issues as well with starline, you can buy a pocket reamer to fix said issues.
 
Your bullet seating die also crimps the case mouth . The crimp function is mostly to take off the flare you put on the case mouth so a bullet could be seated easily. Run your finger over the case mouth and make sure the case mouth has no "lip" at all.

To set up the crimp seat a bullet the way the die is currently set and then back out the seater stem. Now turn the die down an eighth turn and run a loaded round into it (with the seater still backed out). You should feel some resistance as the case mouth crimps. You should feel a little resistance, not a lot. If you over crimp the case mouth can bulge - also a source of jams.

Once this crimper is set up, it will not have to be adjust again. On my Dillon I Locktite the seater die in position so this setting never gets loose after it has been set.

The other factor is cartridge over all length. (OAL) Make 20 rounds at the length used before, and then 20 more with the bullet seated 20 thou deeper. One might work better than the other. What OAL did you use ? I run mine at 1.240"
 
Failure to feed can mean several things please be specific

Is the slide not stripping the round and locking up on a empty chamber?

Is the round hanging up on the feed ramp and the slide stays half open?

Is the slide closed on a loaded round in the chamber but not locked up?

What load are you using? AE 10mm (for example) is pretty hot in my Glock with a factory recoil spring but after adding a heavy spring any limp wristing causes issues... My handloads are more then hot enough to ensure reliable operation under any circumstances :D
 
Ganderite said:
Your bullet seating die also crimps the case mouth . The crimp function is mostly to take off the flare you put on the case mouth so a bullet could be seated easily. Run your finger over the case mouth and make sure the case mouth has no "lip" at all.

To set up the crimp seat a bullet the way the die is currently set and then back out the seater stem. Now turn the die down an eighth turn and run a loaded round into it (with the seater still backed out). You should feel some resistance as the case mouth crimps. You should feel a little resistance, not a lot. If you over crimp the case mouth can bulge - also a source of jams.

Once this crimper is set up, it will not have to be adjust again. On my Dillon I Locktite the seater die in position so this setting never gets loose after it has been set.

The other factor is cartridge over all length. (OAL) Make 20 rounds at the length used before, and then 20 more with the bullet seated 20 thou deeper. One might work better than the other. What OAL did you use ? I run mine at 1.240"
Click to expand...

I will make sure I have the crimp done properly. I feel like there is just a little flare left right at the end of the case. Switched to Dillon 10mm dies with a seperate crimp die now.

Thanks.
 
Hotwheels81 said:
Failure to feed can mean several things please be specific

Is the slide not stripping the round and locking up on a empty chamber?

Is the round hanging up on the feed ramp and the slide stays half open?

Is the slide closed on a loaded round in the chamber but not locked up?

What load are you using? AE 10mm (for example) is pretty hot in my Glock with a factory recoil spring but after adding a heavy spring any limp wristing causes issues... My handloads are more then hot enough to ensure reliable operation under any circumstances :D
Click to expand...

These ones.....

Is the round hanging up on the feed ramp and the slide stays half open.

Is the slide closed on a loaded round in the chamber but not locked up.
 
I will make sure I have the crimp done properly. I feel like there is just a little flare left right at the end of the case. Switched to Dillon 10mm dies with a seperate crimp die now.
Click to expand...

Then that should/maybe solve your problem.... I run all my pistol ammo thru a Lee FCD because i had similar issues to yours with 9mm when I first started loading pistol a while ago the FCD post sizes loaded rounds so even without crimping you can still remove 100% of the mouth flare... Next culprit I would look at would be your OAL if the crimp die doesn't solve the issue....
 
Thanks for the info guys, I'll setup the dies on a dummy and re-crimp the rounds I have made up, should be able to tell if that was it next time out.... going to ditch/pull the starline primer hanger outers.
 
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