9 Major reloading issues NEED HELP!

[Reloader98]

Hello everyone, I got my first open gun a couple days ago, a JL Hardy shorty 4.25” KKM barrel with comp and two popple holes. It came with 1 MBX 170mm  magazine (used in load testing) and two 140 STI mags and 1 170 STI mag. 
I’m having two issues. 
1. primers popping out of cases and jamming the gun

2. Rounds diving up into the barrel and jamming (could be the MBX mag, unsure) 
 

loads tested: 

- unfired, new, starling cases for both powder weights. 

-montana gold 124gr JHP

-Autocomp powder

-CCI small pistol primer

-COAL: 1.160

first load: 

6.8 gr autocomp

FPS: ranges between 1375-1400 (averaged about 1386) 

second load: 

6.9 gr autocomp

FPS: ranged between 1390-1419  (averaged around 1397)

The gun worked somewhat well, groups were great, but the issue was the primers popping out, like listed in the pic below. 
 

question: 

what can I do to remedy this, am I using to much powder? 
the rounds jamming into the upper left of the barrel could be the MBX mag, but I’m more worried about the primers blowing out. 
 

what’s y’all’s take on what I should do?

link to photos of spent brass. 
 

https://photos.app.goo.gl/239MZAJfC1vFcKyA7

 

 

 

[Dirty_J]

1.160 and you’re getting this? Maybe a slower powder would be helpful. AC is pretty fast. Fastest I’d use for open. 

Edited August 4, 2021 by Dirty_J

[Reloader98]

18 minutes ago, Dirty_J said:

1.160 and you’re getting this? Maybe a slower powder would be helpful. AC is pretty fast. Fastest I’d use for open. 

I wanted to try some other ones but autocomp and titegroup were the only ones I could find in stock for a decent price and I can’t use titegroup cuz it’s WAY to fast. Do you think a change in COAL could help? Or is mostly the powder? 

[36873687]

In shorty 6.8 ac sounds weak. An it’s used mags replace the guts in the mags

[zzt]

At 6.9 and 1.160" you should not be having pressure problems.  The primers are not flattened.  First thing to do is check the brass.  Yes, it is new Starline, but that doesn't mean they cannot have produced a batch with too large primer pockets.  Second, do the plunk test.  Drop a loaded round into the chamber.  Does the bottom of the case go in past the end of the hood?  Can you manually spin the round in the chamber?  If yes to both, it's a brass problem.  On third thought, measure the CCI primers.  You may have an undersized batch.

[Reloader98]

1 hour ago, 36873687 said:

In shorty 6.8 ac sounds weak. An it’s used mags replace the guts in the mags

 Correct  me if I’m wrong but if the primers are blowing out at 6.8 ore 6.9 wouldn’t they blow out at a height drop weight? 

[Reloader98]

1 hour ago, zzt said:

At 6.9 and 1.160" you should not be having pressure problems.  The primers are not flattened.  First thing to do is check the brass.  Yes, it is new Starline, but that doesn't mean they cannot have produced a batch with too large primer pockets.  Second, do the plunk test.  Drop a loaded round into the chamber.  Does the bottom of the case go in past the end of the hood?  Can you manually spin the round in the chamber?  If yes to both, it's a brass problem.  On third thought, measure the CCI primers.  You may have an undersized batch.

I thought the primers were flattened, because they looked very different when they came out, mild cratering on a couple of them as well. And can you eleborate more on the brass issue? If it fits the chamber and moves freely, what does that mean? Isn’t it supposed to be right at the barrel hood ? Or am I thinking of the plunk test incorrectly? 
thank you for your replies gentlemen. 

[Steve RA]

If you have any other brass. load up 20 or so and try them.  Possible, as mentioned above, that the primer holes in the brass are a little large.  If they all work, then that was your problem.  

[Reloader98]

1 minute ago, Steve RA said:

If you have any other brass. load up 20 or so and try them.  Possible, as mentioned above, that the primer holes in the brass are a little large.  If they all work, then that was your problem.  

Thanks Steve RA, I’ll have to try that out, when I loaded them, the seating of the primer felt pretty tight, as new brass should, but I’ll try out different brass. 

[vtecpaoche]

52 minutes ago, Reloader98 said:

I thought the primers were flattened, because they looked very different when they came out, mild cratering on a couple of them as well. And can you eleborate more on the brass issue? If it fits the chamber and moves freely, what does that mean? Isn’t it supposed to be right at the barrel hood ? Or am I thinking of the plunk test incorrectly? 
thank you for your replies gentlemen. 

If it spins freely and the brass doesn't stick out pass the barrel hood during the plunk test, the loaded rounds should work with the barrel.  If the brass sticks pass the hood or the round doesn't spin freely, you may need to load shorter or ream the barrel.  I would load a few dummies (bullets, no primer or powder) and check if any of the mags will load.  You can use some calipers to check the width of the feed lips.

[Reloader98]

So I made a video of the gun while disassembled, I attempted to do the plunk test with one hand while making the video, forgive my poor video work. 
 

as I’m pretty new to 9major and not doing the plunk test a whole lot before this, it would be much appreciated for y’all to watch it and tell me what you think. 
 

video:

 

https://photos.app.goo.gl/3QrfijaGKBizvEat8

 

[Reloader98]

27 minutes ago, vtecpaoche said:

If it spins freely and the brass doesn't stick out pass the barrel hood during the plunk test, the loaded rounds should work with the barrel.  If the brass sticks pass the hood or the round doesn't spin freely, you may need to load shorter or ream the barrel.  I would load a few dummies (bullets, no primer or powder) and check if any of the mags will load.  You can use some calipers to check the width of the feed lips.

Thank you sir, just tried it, it does not go   past the barrel hood, and it does move freely for the most part, it may be a little difficult to move sometimes, but it does move freely. As stated earlier, it may be the brass, I read a website called ballistictools.com with some graphs on primer pocket dimensions, for small pistol/rifle primers it said the minimum diameter for a primer pocket is .1730 and the max is .1745, I measured the primer pockets with my caliper and they read .1745 but if I press harder than usual, it goes to .175 could this be the issue? 

[AHI]

Sounds like you're ammo is to long. The over length ammo is driving the psi way up.

For some reason I can not see your pics or video.

[BritinUSA]

Exactly what bullet diameter is being used?

What is the case mouth dimension of a loaded round?

 

I’m wondering if you have too little crimp and the bullet is being pushed into the case when it hits the feed ramp.

[dansedgli]

Push a loaded round against a bench with a little bit of pressure and see it if shrinks in OAL. 

 

 

[Reloader98]

31 minutes ago, BritinUSA said:

Exactly what bullet diameter is being used?

What is the case mouth dimension of a loaded round?

 

I’m wondering if you have too little crimp and the bullet is being pushed into the case when it hits the feed ramp.

Thank you Britin, think I may have figured it out, after reading a lengthy article from an engineer and reloader, he pointed out that crimp should be, for 9mm Luger cartridges, only between .378 and .379, my reloads were crimped at about .375 which may have been causing a pressure spike, this makes sense
 

I don’t mean to sound like a newb here but I feel I’m getting inconsistent measurements with my caliper, as far as hand pressure goes, if I press a little harder on the caliper I get a smaller measurement than with light pressure on the caliper while measuring, does this make sense or am I just being to analytical about it? 
 

should I always press hard on the caliper to get an absolute measurement or just lightly? 

[konkapot]

Your video played fine for me; your plunk test sounded perfect. 

 

Where in Virginia are you?  I'm local-ish and would be willing to meet to take a look at this stuff if you can't figure it out. 

[Sarge]

Just now, konkapot said:

 

Where in Virginia are you?  I'm local-ish and would be willing to meet to take a look at this stuff if you can't figure it out. 

Nice!

[Reloader98]

1 minute ago, konkapot said:

Your video played fine for me; your plunk test sounded perfect. 

 

Where in Virginia are you?  I'm local-ish and would be willing to meet to take a look at this stuff if you can't figure it out. 

That would be awesome! I’m in Fauquier county area, northern Virginia, how about you?

[BritinUSA]

26 minutes ago, Reloader98 said:

...should I always press hard on the caliper to get an absolute measurement or just lightly? 

I always used a light touch, if you apply pressure then the tool could flex a little giving an inaccurate reading.

 

9mm crimp should be =  (2 x case thickness at rim) + bullet diameter

[Reloader98]

2 hours ago, BritinUSA said:

I always used a light touch, if you apply pressure then the tool could flex a little giving an inaccurate reading.

 

9mm crimp should be =  (2 x case thickness at rim) + bullet diameter

So I tried that, maybe my math is off but I got .380, the only issue is that my cases while belled are .379, maybe cases are not belled enough during seating? Anyway I can’t get to .380 if my belled diameter is only .379, I should note, I’m using the Dillon xl650, with all Dillon carbide pistol dies. 
 

I was told by one of their salesman that their dies are “undersized” leaving a weird, semi-hour glass shape to them. Could this be another issue ? 

[Nolan]

3 hours ago, Reloader98 said:

Thank you sir, just tried it, it does not go   past the barrel hood, and it does move freely for the most part, it may be a little difficult to move sometimes, but it does move freely. As stated earlier, it may be the brass, I read a website called ballistictools.com with some graphs on primer pocket dimensions, for small pistol/rifle primers it said the minimum diameter for a primer pocket is .1730 and the max is .1745, I measured the primer pockets with my caliper and they read .1745 but if I press harder than usual, it goes to .175 could this be the issue? 

 

I use these primer pocket gauges.

https://ballistictools.com/store/swage-gage-small-primer-pocket

 

Very handy for checking primer pockets.

 

Nolan

 

 

[ltdmstr]

3 hours ago, BritinUSA said:

Exactly what bullet diameter is being used?

What is the case mouth dimension of a loaded round?

 

I’m wondering if you have too little crimp and the bullet is being pushed into the case when it hits the feed ramp.

 

Crimp doesn't prevent the bullet from moving back in the case.  There needs to be an interference fit to prevent that.  And that's accomplished by sizing the case down at least .002 smaller ID than the bullet OD.

[Glock17open]

15 hours ago, Reloader98 said:

That would be awesome! I’m in Fauquier county area, northern Virginia, how about you?

I also live in Virginia, Ruther Glen in Caroline county.  I have been shooting open for five years.  I load 124 delta precision over 6.9 of each 1.165.  wspm primers.  I would be glad to help out also

[Reloader98]

1 hour ago, Glock17open said:

I also live in Virginia, Ruther Glen in Caroline county.  I have been shooting open for five years.  I load 124 delta precision over 6.9 of each 1.165.  wspm primers.  I would be glad to help out also

Thank you very much Glock17open, I don’t know if you’ve seen the pictures I linked earlier in the chat, but essentially, primers are popping out of the brand new star line cases, at 6.8 and 6.9 grain of autocomp, and I can’t seem to figure out why. 
 

I have changed the level of crimp, which from my reading, was tighter than it’s supposed to be, so I’ve basically taken away all crimp, besides what’s required to remove belling, about .378 and it was at about .375-.376, I’m at the range now, and I’m gonna test that ammo and see how it does. I made 20 rounds, so let’s see what happens! 
mill be leaving an update soon.