An awful day at the range? How can that be?

[yerasimos]

cleared

[txinvestigator]

The only guns I have seen go down in shooting schools are ones with aftermarket parts.

Use your stock stuff and report back.

What type of gun, BTW?

[Houston1944]

I am also interested in knowing what pistol you are using. If I understand correctly you had 2 kb's. Are you talking about complete case separation or just mangled cases from inproper feeding.
As far as the "yellow" stuff I have been using FP-10 for all my lubrication and cleaning for a few years and I have never seen any yellow build up in my pistols. Before FP-10 came out I use Breakfree but never had any yellow residue with it.
I also agree with Tx, use the factory springs for carry. The only pistol I use non-standard springs with is my 38S and that is due to the loads I run through it.

[flintknapper]

Manufacturer of pistol?

Manufacturer of substituted recoil spring?

Cartridge weapon is designed to fire?

Cartridges factory made...or reloads?

Manufacturer of mags?



Sorry to hear of your unpleasant experience. You are smart to have taken time and made an effort to "test" the weapon. I am sure someone here can offer a useful suggestion as soon as we have more information.