Here’s a new one for me

[benlineberry]

I usually shoot 180gr HP Montana Gold bullets and am coming to the end of my last thousand. As they are rare as hen’s teeth, I thought I’d try to find a suitable replacement. I picked up some 180 grain zeros, 180 grain blue bullets, and 180 grain Berry’s bullets.

 

The length of each are very close, so I loaded them all the same: 4.8gr Clay’s, COL=1.19”, twenty rounds of each. All three had an FTE on the last round. I loaded some of my last Gold’s, no FTE. 
 

All passed a gauge and cycled fine, except the last casing. The Gold was fine.
 

Any idea WTF is going on? They are shot through an SVI, BTW. 

Edited May 29, 2022 by benlineberry

[Farmer]

Is it a partial ejection, getting hung up half way out or hardly opening the slide. 

[benlineberry]

Looks like it’s getting partially out, but not completely ejecting. Maybe an extra 1/10th or two would improve ejection?

[Farmer]

Just what I was thinking add .2 grains.  The MG’s are probably making more PSI because of the jacket VS the coated lead and giving extra push. Maybe your mag follower gives more drag than a loaded round and that’s why it’s on the last one. 

Edited May 30, 2022 by Farmer

[zzt]

Either increase your powder drop or go to a 1 lb. lighter recoil spring.  Going 1 lb. lighter has always worked for me.