Knight Disc Elite
 

Just took delivery of a used Disc Elite 50 in "like new" condition and am happy to say, "it is". It is currently FPJ and I would like to set up NFPJ using the adapter and Lehigh breech plug with replaceable vent liner. I've done quite a bit of "surfing" and am unclear as to whether these components can be purchased new. Anyone been down this road lately?

Knight no longer offers the specific option you are talking about. They do offer the conversion but it is using the Mountaineer Style bolt with NFPJ breech plug but the vent liner is solid in place. Because of the Mountaineer bolt a primer adapter is not needed.

You may find one of the older Lehigh conversions on the net someplace or some one that hqs one and is willing to sell one. Lehigh is not building the conversion for re-sale at this time.

That is a great rifle! You are gonna love it :D

The Lehigh plug hasn't been available retail for a while. Knight had their own version with the adapter/plug, but for some reason they are no longer selling that setup, they have now changed over to the bolt/plug option. The bolt housing takes the primer directly now, no adapter piece needed. I know some places online did sell the Knight version adapter/plug, but not sure who might have one.

I see the Mountaineer bolt/plug is $99 or 600 FPJ's. I'm as interested in the replaceable vent liners as I am in eliminating the jackets. I don't suppose there is a plug with replaceable vent liner for FPJ Disc rifles?

No there is not but you can get a BP with a solid vent liner - use it till it goes bad then drill and tap it -then install a removeable vent liner.

That's a good idea. I have the tools to do that. Any thoughts on the vented FPJ plugs and their effectiveness in reducing blowback? Can that plug be drilled/tapped?

The FPJ wlll most always be dirty vented or non-vented because the jacket stretches and lets low back out... Go with the NFPJ for a cleaner breech area.

Also remember the vent liner is hardened you will need a #21 carbide bit to drill the vent liner out.

I guess whether it can be drilled and tapped may depend on its construction. Are the flash holes drilled, tapped, vent installed, then brazed? If so, I understand why you said "solid" in your reply and drilling out a vented plug could be problematic.

I replied to my own reply but before I hit send, you got between me. Lol
I get it now.
Thanks.

The brazed vent liner is a dome headed screw. What i do is use a 7/16" carbide end mill to remove the dome. Then i use a 1/4" end mill for about 1/8" deep, which is a start on removing the part of the vent liner below the dome. The next tool i use is a 9/64" drill all the way through the vent liner. Then i use a 82 degree 3/8" carbide spot drill to cut away what remains of the vent liner. Then i use a 5/32" drill through the remnant of the threads, and through the flame channel. This may or may not leave pieces of the vent liner in the threads. Then a 10-32 tap is used to clean up the threads.

The vent liner is extremely hard, and is hard on tools. It would be so very much better if Knight would sell these breech plugs without vent liners. Adding a vent liner to a plug without a vent liner is trivially easy, but removing the brazed vent liner can end up being quite costly.

Me, i am no machinist, so perhaps a real machinist could do the work more better.

That's a thorough step by step Ron, and may be enough to discourage my going after one of the vented BPs. My bit selection, while bountiful, is tired from assorted tasks in a wide variety of materials. I probably should have put the $ for this gun into upgrading that stuff. Nah. I think for now I'll get a 21 carbide as SL suggested, tap the bare 209 BP from my Wolverine and tap the Disc plug after shooting it FPJ for a while, and keep an eye out for a Lehigh bolt adapter. Thanks

Other thoughts. Have you tried an extractor to remove the liner after removing the dome? Or drilling through completely with a larger bit, inserting a solid plug, and drilling & tapping the plug? Wonder if either of those would easier.

Your second idea may work good. One could run the 7/16" end mill about a half inch deep. Then turn a stainless cylinder to be a tight fit in the breech plug. Drill through with the # 21 drill. Countersink, and tap the plug.

Or, tap the 7/16 hole, screw in a stainless bolt, cut off, grind, tap and thread vent liner. Bolt being ready made plug.

yes indeed

the bolt technique
 

A few years ago i used a bolt to convert the FPJ breech plug to an NFPJ breech plug.
















More information at the LINK. It took me a few days to get things working right.

Looks like nice work, and a lot of it!

All 3 of my Knight Disc Extremes/Elite have been converted to use the bare primer. My current bolts have to use the original adapter piece and I use the Lehigh Breech Plug with solid vent tube. I've just ordered the new bolt/plug conversion from Knight and I'll let you know how it performs. I don't fire as many rounds every year as many on the Forum do and so far I've not detected any issues with my present set up that would require a new vent liner/plug. You will enjoy the Elite; its very accurate and a nice handling gun.

Are you ordering the bolt because you only have one adapter and have to swap it when changing guns, or because you aren't completely happy with blowback etc.?

I have an adapter for each gun. I was getting more blowback than I liked with the CCI 209M primer as well as the Federal 209A so I switched to Winchester's regular 209 primer(its a slight bit longer than the other 2) and that solved the blowback issue. My reason for the change was because I liked the larger opening for placing the primer in the new bolt. Received the parts Friday and made a quick trip to the range yesterday. Installed the new BP and bolt and could not get the bolt to close completely. Long story short I finally realized the primer was not seating completely(deep enough) in the primer pocket to allow the bolt to fully close. I reinstalled my old Lehigh BP with brazed vent tube and everything worked. I tried the 3 209 primers mentioned above in the new BP and none of them would seat completely in the primer pocket unless I exerted a lot of force pushing down with a short piece of 2 x 4. Needless to say they were hell to get out. Some where in the manufacturing process nobody checked specs etc. Will be in touch with Knight tomorrow. I'll keep you posted on what they say.

Ugh. That's a hefty price to pay for that outcome. Keep us posted. If you get it worked out, you can sell me one of those leaky, blowback causing adapters! :)

Talked to Knight this morning and learned that Lehigh is still making the BP's for them and from time to time they have had one show up with that tight primer pocket problem. They polish it out with jeweler's rouge to fix it. I can do the same thing with JB's Bore Paste or similar product and CVS' brand of baby q tips. Already did that with all my other BPs. Send me your contact info at [email protected] and I'll just send you the adapter. I'll keep using the other one's I have until I decide if I want to order another bolt.

That's awfully generous of you. PM sent. When polishing the seat with a Qtip/JB's do you chuck it in a drill/press or is rotation by hand sufficient? I have a stubborn fit in a bare 209 plug in a Wolverine. Make sure it works out before sending the adapter.