Failure to feed when loading mag

[Wobbly]

Nothing - I just have two different people recommending different things so I haven't done anything... Yet [emoji4]

Crimp on the factory rounds is .376 - .377

Then it looks like the factory agrees with yours truly.

 

[MarilynMonbro]

Thank you Wobbly. I read over your thread again last night.  Very helpful !

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[Jmoser]

I tested 50 factory rounds and had no issues. I tested 30 reloads and 2 failed to go in. The crimp on those is 0.3785 and 0.3780

Dillon calculator says

Neck tension only_(.000)0.375
Very Light Crimp_(.001)0.374
Light Crimp_____(.002)0.373
Moderate Crimp__(.003)0.372
Heavy Crimp____(.004)0.371

And

Neck tension only_(.000)0.377
Very Light Crimp_(.001)0.376
Light Crimp_____(.002)0.375
Moderate Crimp__(.003)0.374
Heavy Crimp____(.004)0.373

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Not sure how you are setting and measuring crimp but I always use an empty sized case for my 'light' crimp setups.  Measure ID/OD with calipers, run thru crimp die, adjust die to get desired reduction.  Not exact since case will bulge with seated bullet but easy way to get calibrated case mouth reduction.

Also carefully examine your feed ramp and the lip where it melds with chamber; look for any telltale signs of cases catching or hanging up.

[copemech]

Like Trump says:

"Make 9mm straight again" and that is all you need to do!

"CRIMP" is just an expression!

[Wobbly]

Not sure how you are setting and measuring crimp but I always use an empty sized case for my 'light' crimp setups.  Measure ID/OD with calipers, run thru crimp die, adjust die to get desired reduction.

I don't think this method is advantageous. Due to the spring-back quality of brass, anytime you work the brass an "anvil" is needed to back up the the work of the "hammer". So when you swage the brass in a crimping action, it's best that a bullet be in place to "back up" the action of the die.

In other words, to get the most accurate results it's best to be building "test cartridges" with no powder and no primer. That's as close as you'll get to production settings.

 

[bigdave24]

I have seen this kind of failure in CZs with Remington UMC, where the OAL is very short.  Round nose bullets may help as well.  A stronger recoil spring could also help.

[IDescribe]

377 for 355 bullets
378 for 356
379 for 357

I dont bother measuring brass because I dont sort by headstamp or length.  If you aren't sorting by both of those, your precision crimp determination is wasted. 

[M1A4ME]

377 for 355 bullets
378 for 356
379 for 357

I dont bother measuring brass because I dont sort by headstamp or length.  Of you aren't sorting by both those, your precision crimp determination is wasted.

Don't you just hate it when you run across those harder to crimp cases and you notice the head stamp?  And then, a bit later you have another one you can tell is harder to crimp.  And it's the same head stamp?  An then you look through your primed brass in the loading tray and you see a couple more and you set them down next to some others of a different head stamp and you see some are longer than others?

I haven't really seen it with 9MM but I got into awhile back with .357 SIG.  Sort of ruins a reloading session when you have to stop and take care of "stuff."

[IDescribe]

377 for 355 bullets
378 for 356
379 for 357

I dont bother measuring brass because I dont sort by headstamp or length.  If you aren't sorting by both those, your precision crimp determination is wasted.

Don't you just hate it when you run across...

I don't notice it so much as I know it's there.  The taper crimp die is obviously tapered, so if our cases aren't the same length, they're not getting crimped to the same degree anyway, and if we're using different headstamps, our case walls aren't the same thickness.  With mixed headstamps, we can go more precise than what our gear can make use of.  And if we're not shooting out to 50 yards or more, who cares?  I find the measurements I use to work well, and at the end of the day, if I leave the crimp die at .378 or .379 through a variety of diameters, I can't tell you I see any difference.  Anything .380 or less should work in any 9mm pistol.  Over-crimping is a problem, but under-crimping, so long as it's within spec for the caliber, doesn't seem to have any impact at action pistol distances.


And obviously, yes, some cases take some extra oomph through the sizing die, and when that happens, I wonder what that is doing to the other dies on the shellplate with the shellplate under more force on one side.  Truth be told, I more often notice it go easier than expected -- "How did that .380 case get in there?  Whoops! I let a split case get through." 

[MarilynMonbro]

I believe I've fixed it.

I switched to a round nose bullet instead of truncated cone. I have to load them shorter than the TC but I haven't been able to replicate the issue in my OP

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[Wobbly]

Don't you just hate it when you run across those harder to crimp cases and you notice the head stamp?  And then, a bit later you have another one you can tell is harder to crimp.  And it's the same head stamp?  An then you look through your primed brass in the loading tray and you see a couple more and you set them down next to some others of a different head stamp and you see some are longer than others?

Some of those "harder to crimp" might be brass plated steel.

[Wobbly]

I believe I've fixed it. I switched to a round nose bullet instead of truncated cone. I have to load them shorter than the TC but I haven't been able to replicate the issue in my OP

Well, that's good news.

[toteone]

After reading through this thread, I did not notice anyone asking if using a single stage press vs a progressive stage press was being used.  Assumed a progressive, but you know what happens when you ass-u-me.  On my Dillon 550C progressive (manually turned) press I have found it very advantageous to make sure ALL die positions are being utilized when trying to set accurate measurements for any single die function...from sizing to seating depth to crimp (9mm wall straightening).
I does make a difference I assure you.

Any further thoughts?

[Wobbly]

I believe I've fixed it. I switched to a round nose bullet instead of truncated cone. I have to load them shorter than the TC but I haven't been able to replicate the issue in my OP.

You've simply swapped one type of chamber interference for another. See the cartoon below...



? The former conical ogive bullet fouled the chamber at the end of the freebore/ beginning of the lands, as in the example on the far left.

? Your new RN ogive bullet fouls the lands in the middle of the ogive, similar to the example on the far right.

It's never absolutely clear where a bullet will encounter the chamber. That's why you need to do the Max Oal test on every bullet that's new to your chamber. You simply cannot tell by simple observation.


Look at the 2 bullets below...



The Zero has a Max OAL of 0.993 (less than 1.000"), while the Berry has a Max OAL in excess of 1.200". That's a total OAL difference of over 0.200" simply based on ogive shape !!