Sabot, nice to visit with you again. This gun is 209 bare primer. Looking at primers, it appears cost is very similar to caps at around 8 cents. I will have the primer tool. Is there a downside to using the primers? More blow back? I swab between shots and will be using primarily Prodex RS and some Schuetzen. Is crud ring a problem under those conditions with 209's? I was aware of some risk using BH in the plunger style guns. I guess ease of cleaning will play a role in whether I experiment with that.

That's a good looking gun. I prefer the thumb hole stock and will have an eye out for one if this gun (and shooter) go together well. Do all MK-85's fit an MK-85 stock or will it depend on the year of this weapon? How do I tell?

Not much of away to get around it... plunger guns get the breech area dirty, whether you are shooing a cap or a 209. There is a bit of concern shoot bare 209's in that the blowback can/could eject the primer back into the face of the plunger - force the plunger back and allow the 209 or parts of the 209 to fly out of the breech area... This is not very common with moderate loads and lighter projectiles until you get to BH. Caps can do the same thing except the tend to stay in the hood of the hammer.

Probably not, Pyro could cause the beginning of one but since you are patching between shots I doubt that you would even notice it...

Because BH is a smokeless progressive burning powder it has a longer duration of back pressure on the nose of the primer and could cause more frequent blowback problems.

Well according to some you need a MK stock... but both of the thumbholes that I have came off new Big Horns. Both of these stocks accept the MK without a problem. My MK's are both Predators, one has a GM barrel and the other a Wiseman barrel.

As always a thorough relpy. I think I shall use 209's and get myself a pair of yellow shooting glasses since I'll be using a scope and I need them for skeet shooting anyway. Thanks!

I use 80 gr of pyrodex P with an over powder wad and I use #11 mag caps. That load has 1150 FPE at 200 yards.
Ron

That's a thumper. How's accuracy @200?

I have it sighted in for 200 yards and I have shot milk jugs with it but I haven't shot groups. The front sight is a little big and I have to use a 6 o clock hold to hit something as small as a milk jug. Ron

Ah, thought maybe you had shot them from a scoped rifle. I had some long range success with open sights by placing the front bead on the target bull and elevating it above the rear notch(Williams sights). I was amazed how your eye can repeat what it has seen if you can check the POI through a spotting scope between shots for feedback to hone in at long range (200).