Jam in feed mechanism on SIG 1911

[DaFadda]

Hi all, thought I'd give y'all something to chew on for Christmas. My SIG GSR just came back from the factory where it was ultra sonic cleaned, springs changed, trigger job, night sights installed as well as new grips. I've had it out to the range several times, with no problems using factory ammo.

Took it to the range yesterday, and had failure to cycle properly. I was shooting my own handloads, which have fired over 1000 reliable rounds from this gun. Running 230 grain Montana Gold JHP over 5.7 grains of Universal Clays.

I would duplicate the malfunction with a snap cap, but the gun won't cooperate. So, the description is: Cartridge is at about a 60 degree angle, bullet up, and the slide slams shut, causing an indentation on the middle of the cartridge. indent is caused by the bottom of the slide, just below the firing pin. Happening on the last round. Clears easily, just never ever had a problem prior to sending the gun in for cleaning and upgrade.

Any thoughts?
thanks in advance,
Da