I bought this mountaineer New in 9/9/16, tried sighting it in with numerous bullets, sabots and powder loads. It shot like a dog, to make a long story short I purchased another barrel for it from Knight. When setting it up on my gun, since I had not shot the old barrel very much, it didn’t occur to me to measure the Flash Hole. I transferred my bare primer breech plug from the old to the new barrel.

Since then I read a post where someone said that the bare primer breech plug would only last about 100 shots with BH-209.

Since I shoot 110 grains of BH-209 normally, I measured the breech plug flash hole and it was a loose #65 Drill (.035+) then I measured my new spare breech plug at a #68 Drill (.031). Since I am going to be sighting in the new barrel I didn’t want to take a chance. With the old plug being .004+ diameter oversize from a new breech plug flash hole, I installed the New breech plug in the new barrel.

My question is at what point is a flash hole in a knight mountaineer too large to accurately keep shooting?

I have different muzzleloaders, Thompson Center Encore Pro Hunter, Traditions Strikefire, CVA Accura V2 & LR, all have good to reasonable groups “and now the Mountaineer?” In the past I would measure the BP flash hole and record it by date and size of hole and then measure it occasionally, as it was a long time between changing of a breech plug, and a lot of shooting with the muzzleloaders I had, shot 110 grains of BH-209 quite a bit in all guns. Now here is the mountaineer breech plug that just can’t hold up, what are they made out of?

The Knight plugs are made from 416SS but the brazed in vent liner gets weakened by the brazing process. To avoid patent issues and maybe even for safety Knight did not make the vent removable like in a Savage breach plug.

Bestill can set you up with a bushing plug made from 17-4SS like the original Lehigh plugs but the replaceable bushing is made from tungsten carbide. The bushing should last for 1000s of your type of loads.

These plugs cost about $80 DIY or around $125 if he custom fits it to your rifle. If you can take a few simple measurements the DIY isnt hard. He will send it to you based on the measurements he needs from you.

I change vent liners by roughly .035-.037 at the absolute most.

Thanks for the information: how do I contact Bestill

Just remember the plug is made for your specific barrel. It might work in another but its made to order with the primer you select.

Jeff builds 1st class rifles and is a first class shooter as well at Friendship.
https://www.facebook.com/pg/Bestill-...=page_internal

Here is mine next to a original Lehigh plug. Its fouled because i was testing it for fit which was perfect. If you look closely you can see the locking collar that retains the bushing.

I really appreciate the information and a quick response, Thanks a lot I'll get in touch with Bestill

Now all you need is a stock, bolt and trigger and you'll have two guns

I think the general consensus...when your rifle shoots well and then the accuracy goes away, the flash hole is often the culprit. Time to change.

I bought a Knight Mountaineer 9/9/16, will try to keep this short. Upon receiving it I took the breech plug out, when I put it back in the bolt would not close. Sent it back to knight, they checked bolt and sent back. Again I removed breech plug and after reinstalling bolt would not close again. Got my socket and drive and forced breech plug to turn in again until it stopped, had to do this twice more and bolt would close to battery. I sent gun back to knight and explained above. They ran a tap in the breech threads of the barrel and said it was fixed and shipped gun back to me. When I got my gun back the Remington 3 screw trigger assembly had been removed and a knight trigger assy with 5 lb pull was on my gun. Breech plugs threads were still bad. I sent gun back and told them I wanted my Remington trigger assy back and the breech plugs fixed or barrel replaced. A Representative of Knight called me and told me they could see nothing wrong with the breech threads in the gun, also that the trigger assembly was the correct one for my gun, they sent the gun back. I figured that was the end of my "WARRANTY", they were not interested in the fact that some one had stolen a nice trigger assembly and put on a defective one. Ultimately I had to buy a trigger assembly from Numrich as the one knight gave me would not hold an adjustment, never could get trigger pull below 4 lb. and every time you tested lbs. reading varied a lot. Then I started shooting the gun, POS. Groups all over the place could barely hold a 3 inch group at 100 yds., and that was with a new breech plug. I tried numerous bullets, sabots and powder loads, I have a CVA Accura V2 & LR, a T/C Encore Pro hunter and a Traditions strikefire. Any of them would make the knight look sick. Since I honestly couldn't sell the gun as it was, I bought a new barrel thinking I could at least salvage something of the gun. When I got the new barrel the little plunger on the side of the barrel that releases the bolt fell apart and the shaft fell into the gun. Luckily the bolt was out and I put some blue Loctite on the little threads and put it back together. Now I feel I am ready to shoot, not so fast. Someone on the forum said a knight bare primer breech plug would only get about 100 shots with 110 grains of BH. I checked my breech plug and with less than 100 shots Flash hole was toast. GM54-120 put me onto Bestill and as I couldn't afford as many breech plugs from knight as I would need (and not wanting to support knight) I sent my gun to Bestill. Also I asked him to take a look at my bolt operation as it sticks when trying to pull it back so you can load another primer. A great effort is required most of the time, and it really taxes that little plunger.
Anybody want to argue with me as to if knight builds a quality gun or not. Not only is their service bad, you may not get the same gun back after they "work on it". Sorry part is management absolutely didn't care.
Bestill could probably have built me a custom with the money I have in this gun.
In any event I am in a rage, I did have to buy a trigger assembly, a barrel & fix it, a decent breech plug and have my bolt looked at and hopefully repaired.
I gag whenever anyone says Knight makes a quality product. Nuf said.

Im confused, do you have 2?

Glad you sent it to Bestill.

I looked up the invoice from sportsman warehouse and it was 9/9/16 I can't even afford one much less two! Ha Ha, "GOT TO KEEP MY SENSE OF HUMOR" Maybe the gun will be a shooter.

Any news on how it worked out and what Bestill found?