From what information I could find the MKA 1919 uses the standard Browning Invector chokes. This Carlson's Winchester 12GA Tactical Muzzle Brake is for Browning Invector Plus models and will not work for that shotgun.
The Carlson's Winchester 12GA Tactical Muzzle Brake should work with that shotgun.
No, you can not shoot slugs through an Extra Full Choke Tube.
These Carlson's Winchester 12GA Tactical Muzzle Brake should work with your Winchester 1300 Defender 12GA. However, I recommend confirming your Winchester uses the Standard Invector pattern choke tubes first.
We have seen these guns with tolerance issues regarding the choke tubes. Most will accept the Winchester/Browning Invector style chokes, but some look like a Win choke but have a smaller OD which prevents the Win choke form installing properly. You can measure the OD of your factory chokes. If it is .808-.810 then this choke will work. If your OD is smaller it will not.
I am sorry but we do not have the information on the threading of this particular model of shotgun. The choke pictured is a Winchester/Browning Invector choke so if your gun is threaded for Winchester threads then this choke will work.
You can safely shoot slugs through the cylinder constriction, NOT the extra full.
No, this item will not fit. The RIA VR60 uses the Beretta/Benelli Mobil chokes. The Winchester thread pattern will not fit this gun.
Yes the Winchester style chokes will fit the Mossberg 930.
Most of the BA shotguns do use the Winchester/Browning Invector style chokes however some look like a Win choke but the OD is smaller and this prevents the Win choke from installing properly. If you can measure the OD of your factory choke it needs to be .808-.810 to ensure a Win choke will fit. If the OD is smaller than .808 then a Win choke will not fit. If this is the case we do not have chokes to fit your gun.