GH: trouble opening after firing, your help is requested

[Richard Flanders]

Some Parkers have rim recesses that are a tad tight for the poorly made ammo of today which often has out of round extractor rims that jam into the recesses when you close the gun and make it very difficult to open. I have a 28ga Repro that does this also. Remington STS ammo works in my DH12 but Win AA's can lock it up tight so that it has to be broken open over my knee. The recesses can be reamed but it is a touchy thing to do. All vintage paper shells also work in my DH12. Take a few shells and put the rims into the recesses backwards and rotate them to see if they are fitting or not. Take a block of something and push on your firing pins also to see if they're retracting properly or hang up. Could be enough gunk/corrosion inside to bind them up.