Your initial comments, Ted are pretty much on track. Your knowledge of such things is obviously greater than mine. But, how would using the wrong length ammo cause this problem if the gun fires and extracts the wrong length ammo with no issues when doing more normally paced shooting. I do plan to order some of the RST ammo that Skeettx pointed out to see how that works out. This gun has the BP over oval on shield proof mark indicating "Reinforced smokeless proof for shotgun barrels, pressure of 12,090 psi" (from appendix 3 in "Spanish Best", 2nd edition by Wieland). Barrel flats are marked F1 which should be 1960 manufacture. All comments are much appreciated.
