Lehigh/Knight Breech Plug Conversion???

[Busta]

Just got my Lehigh Conversion, what a joke!

The machining is superb like everything else Dave does, but the OAL with a primer is about .025" too short as compared to the Knight, which is also too short to begin with. I know there are going to be some pi$$ed off people, and I am one of them. Took them 6 months to come up with this, and they can't even get the length w/primer right? I cannot believe that this wasn't discovered before releasing these to the buying public. Unless you want to shim the primer pocket of every one of these, you are going to have a serious head space issue. I guess someone should throw up the red flag, might as well be me. GEEZE!

That powder well in the front is something else to. I hope they give refunds? What a waste of great machine work, and $39.50! Whoever came up with these measurements should be ashamed.

Guess that is why Sabotloader is grinding down washers to fit in his primer pocket?

 

[dalberg]

Does it still function as advertised? Reduced blow back and proper ignition with BH?
doug

 

[GM54-120]

Mine just arrived!!!

 

[sabotloader]

Busta

Busta, i shot my new Lehigh the other day also. I used the plug straight up no modifications at all. Sent Tom an email...

"Made it out this morning to shoot the new conversion....

Tom, I agree it is certainly cleaner than a FPJ and a NFPJ. And I also agree with you it is not blow back free, but much cleaner than the two Knight systems."

Basically those were my feelings at that point. I also indicated that I thought it could be better. The real problem exists with some of the design features of the Knight and the tolerances that are held in their manufacturing process. They never built the gun to be tight enough to offer a zero head space with any of their breech plugs. If you were to build a BP to be zero headspace for your Knight it may not provide that same headspace in the next Knight. In my experiance here I am finding the 45 Knights to be some what looser than the 50 Knights.

Toby did post a review on his site that seems very favorable to the Lehigh plug.

http://www.hpmuzzleloading.com/NewProducts10.html

I will tell you this - i do not really know Lehigh Dave that well, but what i do know is if you are not happy - he is not happy.

 

[GM54-120]

I noticed he said it worked good in the GMB54 too.

I guess i will find out before too long.

 

[k]

being very happy with the first NFPJ conversion i bought from knight's website and not knowing when the lehigh would be ready i ordered another from knight.i'm glad i did,this one is allso very clean,fits well and knight allso has dropped the price to $26.99.........karl

 

[txhunter58]

Well, I installed mine and fired off two primers. Went off fine, but I could not hardly pull the bolt back. I probably had to use 50 lbs of pressure on the bolt to to relase the primer??? I have had a couple with the original equipment that seem to stick and needed extra pressure to release, but nothing like this. Not good for follow up shots or even at the range........

We will see........

 

[GM54-120]

Just got home and tried to install it in the GMB54.

The primer holder fits the bolt assembly fine but the bolt will not close with the NFPJ breach plug installed. Its really close.

It closes fine without the breach plug installed. :cry:

 

[04jeep]

got the same problem with mine had to beat on the primer adp and the bolt will not close all the way might ask for my money back

 

[rt_con]

I just tried my new Lehigh plug in my .45 and .50 Elite's and they fit fine on both. But, I previously had the Knight NFPJ installed in both and had already deepened my Knight B/P tool with a 5/16" drill...to get a full purchase on the Knight plug. I believe you will definitely need to do this to fully install the Lehigh plug.

Also, the Lehigh adapter fit on the 2 bolts was perfect.

I'll try some 209 primers tomorrow.

 

[wayles]

New lehigh plug

Just wonderin how consistant the measurments are from Knight rifle to knight rifle. What are the plus or minus? Could there be that much difference from gun to gun of the same model? Are we getting some stacking. How much is this contributing to the overall fit. I don't own one for my .45 extream but I was planning on getting one. I went down to the mancave to measure mine but could not find a spot with the verniers. Took out the nfpj holder and tried to measure it that way. Dont work! The only way I could see to do it would be too take out the jacket holder and keep filing a brass or steel slug about 5/16 diam. and keep trying to close the bolt . When it just closes measure the slug. Question ? Should the slug go to the bottom or face of the breech plug.? The blow back on the Encore was easy to fix I just made a custom firing pin retainer plug. I made it so there is a press fit when I close the gun, Less than a .001 according to my feeler gauge
Wayles

 

[Busta]

Did anybody bother to measure the powder pocket? I did, and it measures .500" across, and .300" deep. So in a .45 caliber that leaves you with a powder chamber that is wider than your .452" bore. I don't think that will be very friendly to your rifling in the breech end of the bore. There is also a huge I.D. chamfer on the flame channel in my example, why?

Im sorry if this seems harsh, I was just expecting something better than the Knight NFPJ conversion. The machine work is superb like everything Dave does, but someone needs a new set of calipers, or more sample rifles.

Wayles,

That is how you get the OAL for your headspace. You leave out the bolt adapter and INSERT IGNORE a 209 primer with a priming tool, then either shim in back of the primer or in the pocket. Remember that the bolt cams forward when dropping the bolt handle. IMO, you want about .003" of compression on a solid primer pocket. This will only compress the rim of the primer and keep things tight.

If you have some lead wire or even soft solder will work as well to get you an OAL measurement with different primers. The lead will conform to the space, then add the thickness to your primer and breech plug OAL. Just be careful if you use unfired primers, and don't measure where it flows into the firing pin guide in the front of the bolt.

 

[wayles]

headspace

Busta what you said for determining head space will work just fine.That would be a better method. Thanks. Hard part would be fixin it! Getting a dish face plug or one with a dished vent liner that had the flame channel spout left long so it could be custom trimmed to each individual rifle. No washers, no "O" rings ect. Perfect! . I bet Dave rethinks and makes it right one way or another. Had some e-mail correspondence with him once about his bullets and he appears to be an alright guy.
Hindsight is always 20 20 but a few more proto's sent out to serious knight shooters might have found the affore mentioned prob's before they became prob's. I will measure mine as you said. Just because I want to know what it is . I hate to do it but I may have to make a plug if I want to get it perfect. Being able to buy one off the shelf though, would be nice. Maby Dave will get it figured out asap. I also hope he relents and start selling the 185 grain with a ballistic tip. Couldn't talk him into it last year.
Wayles

 

[rt_con]

As I said in my previous post.. I installed the new Lehigh adapter and B/P in my .45 and .50 Knight Elites.... both fit fine and the bolt cycled without issue without a primer. Note... I used a Knight B/P tool with the center drilled out with a 5/16" bit.

This A.M. I attempted to cycle 3 different brands of 209 primers (W209, Rem STS, and Fed 209a) and had the same issue with all 3. The primer would not drop into the adapter... and I had to apply serious thumb pressure to INSERT IGNORE it. When I closed the bolt, the primers seated in the B/P neck fine... no problem. However, after opening the bolt and attempting to dump the primers... all got stuck in the adapter. I had to remove the bolt from the rifle and pry them out with a screwdriver.

The opening in the adapter appears to be slightly too small to accept the primer without forcing the primer in or out of it. See pic below of a W209 primer hung on the adapter opening/rim. (This does not happen with the Knight NFPJ adapter)

Not bashing here ... and I bet I could probably buff with some 0000 steel wool and try to fix it myself (not sure, but there may be some tooling marks on the edge of the opening), but I think I should notify Dave so he can address it.

 

[Busta]

rt_con,

I have the same issue with my bolt adapter, primers sticking in it even before they are fired. The adapter is slick as a whistle on mine, no burrs or anything, and the opening is too tight for several primers. Then add some blowback carbon to the equasion? Mine would require more than slight polishing or buffing, it will need some material removed. After closer review, there is a raised portion where the cutter obviously had a nick in it when it cut that opening. The raised portion only measures .240" at that point, the area fore measures .245", and aft .244". This area measures .253" in 2 of my Knight examples. Didn't bother to measure the rest, but primers will swell and catch in the Knight with heavy charges of BH209.

I have tried the conversion in 3 seperate Disc rifles; a Super .45, a Elite .45, and one of my Extreme .50 MHC's. This is with 2 different Extreme/Elite bolts. It will only function in the Super .45 with both bolts, in the Elite .45 with one bolt, and neither bolt in the .50 MHC. In this case, the bolt will not fully lock in the down position.

The headspace is really close on all my rifles, and different bolts will give slightly different readings. You can also change your bolts fit by backing the big collar on the back of the bolt out one revolution. I had to do this on one of my bolts to make it work. What was happening, when the bolt handle was being cammed down, this collar was actually stopping forward movement. This does not happen with any of my Knight NFPJ conversions, and all the Knight conversions work with all the bolts, in all the rifles.

The good news is a 6.5 mm O.D. x 4.5 mm I.D. x 1 mm thick o-ring will fit in the bottom of the primer pocket. This o-ring is about .040" thick. The bad news is after closer review, including the I.D. chamfer on the powder chamber it comes out to .515" to .520" where the mating surface contacts the barrel. Now with a .45 caliber in .452", that levaves a .063" to .068" larger diameter chamber. This would also be slightly larger in diameter than the .50 caliber (.502") bore as well, at minimum the lands.

I guess there is a reason why the Knight bolt adapter has a much looser fit in the bolt, this allows it to conform to more bolts and rifles. The Lehigh tolerances are much tighter, but are not going to work in every bolt or rifle. The bolts are cast, and obviously not all bolts are going to be identical.

Just too many variables to control, for a one-size-fits-all approach. That is why I final fit my custom plugs to the individual rifle and primer. My Winchester W209 plugs headspace is too long for the Federal 209A and CCI 209M, but they will all work in that plug. I have other plugs that are fitted for the Federal 209A and CCI 209M that the longer Winchester W209 primers will not lock up in, and we are only talking a mere .002" to .005" difference.

It is a lot easier to remove material for a precision fit, than it is to add it however.

 

[rt_con]

Busta....I notified Dave.

Certainly willing to give Dave a chance to get these right. As you said there's so many variables here...Now we're seeing why Knight didn't implement this fix !

I especially like the vent liner concept. I'm finding I get under 400 shots out of a T/C Omega breech plug with Fed 209a primers before it starts getting serious erosion... along with blow back. My 25 ACP conversion has 3x that many shots with T7... and still no erosion.

Please fix this Dave.....else it's back to messing with o-rings and drilling out Knight B/P's :x

 

[Busta]

rt_con,

Here is the problem with my bolt adapter and why primers are sticking going IN. Notice the ridge in the primer opening about 1/3 of the way down in these pics. Obviously a dull/chipped cutter, or a programming error/oversight. Heat treating usually changes dimensions as well, usually shrinking the object somewhat. This primer gate/opening is also about .008" to .010" narrower than the Knight adapter.

I'm sure Dave will get this all figured out, but they have been toying with this since at least last September that I know of. Tom posted a report on it back then. Others have had these for a month or two as well? Surely should have had the bugs worked out of it by now? I am also willing to give him a chance to get it right, I'm sure he was only going by the feedback he was getting, and MIGHT not even own a Knight Disc himself?

 

[rt_con]

Busta
Yes... my Lehigh adapter looks exactly like yours... definitely has the same "ridge" and tool markings in the area we're talking about.

No disrespect meant but I got the feeling Dave's relying more on feedback from others on this undertaking. Again not a bad thing... but we've been waiting a long time for a solution here... first from Knight with the promise of the Ultimate Slam, now Dave (Lehigh). So our frustration level is high.

 

[wayles]

lehigh

Busta
you got a scorce for a custom knight plug?
Wayles

 

[dalberg]

My new Lehigh plug will not screw in my extreme, I can only think that I have a build up of crud in the threads inside the barrel. It goes in about half way then gets extremely tight to the point where I think I am going to screw up the threads on something. The original Knight plug still goes in and out very easily. Not sure what to think? But it will go in my Elite but it is a tighter fit than the original, Federal primers seem to go in and out okay but that is the only ones that it will work with Winchesters and CCI muzzleloader primers are a no go have to take the bolt out to get them out. This is all without firing them.
Doug