9mm reloads issue with Missouri bullets

Status
Not open for further replies.

presspuller

Member
Joined
Jan 17, 2007
Messages
584
Location
NC
A semi-newbie needs some help.
Before I switched to Missouri I was using Midway 124 gr round nose cast with no issues. Then I switched over to coated from MBC, same weight, but the grooveless version.
https://missouribullet.com/details.php?prodId=391&category=5&secondary=8
Before, I seated to 1.135 and all was well. The new ones I seated to the same depth. Fast forward to actually getting to shoot them and I'm having troubles. Several times the slide would not fully seat forward, but would go with a push, the round would fire and maybe the next round, maybe after two or three it would be the same thing, slide not fully forward.
I finally stopped using that batch and went back to the plain cast bullets and everything was back on course, no more issues. I'm positive this is not a firearm issue, too many rounds was fired to rule that out.
I roll everything around in my head trying to think what could be different, not enough crimp/some flare left on those? Case too long? I check everything compared to the old bullets and everything is exactly the same. I remove the barrel and plunk test them and the old bullets will drop about .040 deeper. Now I'm perplexed.
I go to MBC website and notice on the page that it says these should be seated to approx 1.08. That was probably there when I ordered them, but didn't remember it if it was. Anywho, I can see that the shape of the new bullets is different. If I simply seat these to approx 1.08 will that fix my issue? These same bullets cycled fine though another pistol, but not the other.
Did I find my issue or is there something else I'm not seeing? Decreasing the case volume is not going to cause another issue will it? The load is 5.8gr of Accurate #5.
Thanks guys.
 
You've got it. The shape of the bullet's nose make a big difference in how deep they need to be seated to fit the chamber.

You'll have to determine what overall length your barrel requires for those bullets to fit properly. No two barrels are the same. Start with a bullet seated to 1.135". Do the plunk test (see below). Seat the bullet 0.010" deeper. Do the plunk test again. Repeat until the loaded round passes the plunk test. Then seat the bullet 0.010 to 0.020" deeper to ensure the bullet won't hit the riflings if some bullets have a slightly different shape.

plunk test: https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389

You might need to lower your charge weight. Western Powders shows a max load of 5.4 grains of #5 with a 124 grain lead bullet seated at 1.050.
 
You might need to lower your charge weight.

This X1000. In a small, high-pressure cartridge... like the 9mm... small changes in bullet seating depth can result in big changes in pressure. It is best when moving to a different bullet to reduce and work the load back up, taking into account bullet seat depth, cartridge OAL (with a different profile bullet,) and even a different primer.
 
Smallball are known to need a deeper seating/shorter OAL. I have to seat mine to 1.089” or so for my SIG and Beretta.
 
► The ogive shape of every bullet is different.

► The chamber on every brand of gun is different.

Therefore, the OAL on every new-to-you bullet has to be measured. Auto pistols are allowed a RANGE of OALs, and it's the fit of your bullet into your barrel that defines the upper limit of that range for your gun (only). This is sometimes called the Max OAL. All these measurements should be recorded in your reloading notebook for that bullet before you begin reloading.

Hope this helps.
 
Any time you change a component you need to verify it'll work.
But you already know that now.

Reloading is part science & part art.
 
Yep, MBC knows their product and they put that not there for a reason. The MBC bullets are not the same shape as the midway bullets.
 
Lyman 50th shows a max charge of AA#5 at 6.1gr with a jacketed bullet at 1.060" OAL.

Powder charge should be fine.

Seat 'em deeper and let 'em fly.
 
Lyman 50th shows a max charge of AA#5 at 6.1gr with a jacketed bullet at 1.060" OAL.

Powder charge should be fine.

Seat 'em deeper and let 'em fly.
Poor advice unless you’re citing ROUND NOSE OAL numbers. Just because a 124 grain jacketed, abbreviated hollow point bullet from a particular maker is published at 6.1 at 1.060" doesn’t mean that ALL 124 grain pills are necessarily safe at 6.1 at 1.060." that's pretty damn short for a RN.

to be sure you should measure how deeply the two bullets in question are seated.
 
Last edited:
Bullets with a similar profile may not be the same shape. Hence, they may require a different seating depth to chamber and function properly.

If you were loading bullets with a crimping groove, and changed to a bullet without a crimping groove, you may need to adjust your crimp.

Per Western Powders load data Version 7.0, your load is in the upper regions of powder charges for 124 grain RN bullets. If you seat the bullet deeper than trhe depth you were using with another bullet, I'd reduce the powder charge and work up again.

If factory ammunition works in your pistol, that is a good place to start with cartridge overall length. Again, you'll need to work up the powde charge level that you would like to have.
 
Whenever you go to a new projectile, especially one that has a different profile than the one you worked up a load for, you should always back off and work back up. This is one reason everyone that loads should have a chrony, so that you can compare loads of like bullet weights.

If you want to try a nice shooting bullet from MBC, my goto is their 145 (or maybe 147) grain truncated cone. It shoots nice and is forgiving of tight or short throats.
 
Status
Not open for further replies.
Back
Top