Originally Posted by ColRJBrinkman
Comparison of 380 ball, HST HP and Underwood Extreme Penetrator and 45acp ball, Buffalo Bore JHP and Underwood Extreme Defender.
It may be the angle of your picture, but the Underwood looks a tad longer than the FMJ or JHP. That could present a problem in the Shield 45, because I find the magazines to be an extremely close fit to the FMJ rounds I've fired so far through mine. By that I mean tapping the back of the magazine on my palm seems necessary to make sure the rounds are fully seated.
They've functioned perfectly, but just seem to have an extremely tight cartridge length tolerance.