Frustrated Loading .38 Super

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P-990

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Good morning all! I've been scratching my head trying to figure out what I'm missing making up my first .38 Super loads. In making a series of dummy rounds with a .356" Berry's 124gr RN bullet (for 9mm) I'm having a 33-40% failure to pass the plunk test in my Colt barrel.

The details:
Dies: LEE 3-die carbide set. My go-to for standard pistol reloading, I've used my 9mm Luger and .38/357 sets for years without issue.
Brass: once fired Fiocchi
Bullets: 124gr Berry's plated RN, .356"
OAL: seated to 1.25-1.245"
Press: LEE Pro 1000 3-hole progressive
The Gun: Brand new stainless Colt Competition .38 Super, runs like a top with the Fiocchi 129gr FMJ ammo

After making the series of dummy rounds, I sized a handful of cases and checked them. All fell in and out of the chamber with ease, ruling out a sizing die issue. I then seated a couple of bullets without flaring the cases, and with the seater die backed out to disengage the crimp, and those passed the check.

So "obviously" the issue likely lies with the flaring/crimping stage. :confused: Which has me puzzled because I need the flare step to drop the powder charge, and to allow the bullet to sit without manual guidance into the seating die. And the crimp step is to undo the case bell, thus returning the case mouth to a diameter that will fit in the chamber. But what is happening is after adding these two steps some rounds chamber perfectly, while others stop about halfway in.

At this point I'm looking for suggestions for other things to check. I know it's just an adjustment or a measurement I'm missing, but I'm so frustrated I almost wish I hadn't gotten the Super in the first place! :mad: (Which I know is just from frustration, I actually really like the way the pistol and round combination work on the shooting range.)
 
How hard are you crimping? Should be very slight, just enough to close the case flair/bell. Perhaps you are crimping to much and creating a bulge lower in the case?
 
You're either crimping too much or flaring too much. I've loaded countless thousands of 38Super rounds and it's almost always been one or the other that caused problems. I do the minimum on each of those operations. I don't have Lee dies, but I assume they are taper crimp dies? All the crimp you need is simply just enough to get rid of the flare. No more.
 
There's always the chance that the problem rounds are with different make brass than the ones that chamber.
Maybe a slight difference in case thickness.
Then there's the chance you've inadvertently been using the wrong caliber die.
Like .38SPL instead of .38Super.
Easy to do and easy to check.
Just a thought.
 
with a .356" Berry's 124gr RN bullet (for 9mm) I'm having a 33-40% failure to pass the plunk test in my Colt barrel
Click to expand...
Crimp being the issue, maybe and I say that because if crimp were the issue wouldn't it be on all the rounds. My bet is on concentricity is the cause and with a RN bullet that is more of a blunt point rather that a more pointed bullet profile definitely my thought is the cause
 
Almost forgot, if nothing obvious turns up, measure everything you can for both the rounds that work and the ones that don't.
Maybe something that's different will stand out.
 
Thanks for the advice and suggestions all! I *think* I got it sorted this morning. Basically I pulled the seating/crimp die, disassembled it, sprayed it with cleaner and then scraped it clean. From the looks of the inside I must have run a couple of cases through with it set too far down, there was a ring of material built up. So that got removed.

Next I backed the die off and made 3 dummy rounds to a variety of OAL (1.275", 1.260" and the last went under 1.23" due to losing track of the number of turns on the seater). Two of the 3 passed the plunk test without crimping, the 3rd would enter but not seat. (Ah-ha! The problem definitely wasn't the bullet ogive!) I then adjusted the crimp using the problem round until it plunked in as well. Ripped of 3 more dummies, all passed the plunk test and all passed a magazine feeding check.

Whew! Time for coffee now. :D Hopefully I get to run off some live ammo later this week and give them a try this weekend.
 
Not all crimps are the same.I don't know what crimp style is built into your seater die,but typically they are a roll crimp.
Great for revolvers,not so much for semi-autos.
Semi-autos like taper crimp dies. And someone somewhere will suggest a dimension to crimp the OD of the case mouth.

Another fearure,which I believe was pioneered by the Lyman "M" die,is a different sort of "bell" Instead of a funnel sort of flare,it simple necks up a short length of neck to freely accept the od of the bullet.The crimp irons it back out.I believe Dillon and Hornady dies might incorporate this feature,too.
 
I'd look at the crimp. Too heavy a crimp, even taper crimp, will bulge the case. But, whenever there is a fit issue, measure! Measure the diameter of an offending round in a few places; diameter at case neck, diameter at midway on case body, measure diameter near case head, measure case head. When you know where the case is too big, you can determine when and why it's too big...
 
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