The oddest thing...

[jakfrost1]

I made up about 65 dummy 9mm using nickel brass and Campro 121 round nose, running them thru my Dillon 650 with the primer and powder feed eliminated...seating them to my standard depth of 1.160". They worked fine for awhile, like a week or two of every other day dry firing, ( I like to use full mags to simulate the realistic weight for mag changes...) but then the bullets began to fall out of the cases in the mags. They drop onto a gym style foam pad on the carpeted floor so can't say the shock was all that much...but after a few days of noticing this I checked the remaining bullets and found I could PULL 50% the bullets out of the cases by hand. Soooo, I tightened down the crimping die, ( a dedicated die on my 650...) but to no avail, they still fell apart. 

I was suddenly alarmed by the prospect of arriving at the Florida Open, ( 3 day drive each way...) only to find the match bullets I had so carefully culled into 500 of the best...falling apart in my mags on the first stage!! I went thru each of the 100 round boxes checking about 25 in each at random, all as tight as can be. Now the only difference is these have primers and powder which should make no difference, but are all brass cases, not nickel, and use the Zero 125gr HP bullets, seated to the same length. What the heck??

 

Anyone have a theory as to why the nickel 121 Campro's pull apart and the brass 125 Zero's don't ??? Something about nickel cases I don't know? 

 

Cheers,

Jim 

[HoMiE]

Nickle cases are harder so they may not have as much neck tension as brass cases. 

[rishii]

I’ve had the same thing happen to my dummy ammo

I have a couple of dedicated dry fire mags and the heads work themselves loose after awhile 

[RangeHooligan]

Jim,

Are the Zeros's .356 while the Campro's are .355?

 

RH

[Guy Neill]

Repeated chambering will loosen bullets.

 

This is the primary reason law enforcement is taught to rotate ammunition and avoid loading the same round into the chamber over and over.

 

Guy

[Furrly]

6 hours ago, Guy Neill said:

Repeated chambering will loosen bullets.

 

This is the primary reason law enforcement is taught to rotate ammunition and avoid loading the same round into the chamber over and over.

 

Guy

This ..