What can you tell me about this upper?

[alanint]

Originally Posted by cneider

This is some good information. So, to err on the side of caution, I should install a 9mm mainspring like this one http://www.gunpartscorp.com/Products/465390.htm Worst case scenario, it may not cycle .30 Luger ammo, but won't do any harm either. I always try to load to "Factory duplication" specs in my Lyman, FWIW.

I'm not sure why you are disagreeing, Richard, since you plainly state that you installed a 9mm spring, albeit "standard", in your convertible pistol. My concern is over firing 9mm loads, some perhaps hot, in a .30 cal. lower with the standard .30 cal. spring in it, which is what is being proposed.

Am I missing something?