Heads up!! Generation II Lehighs are coming...

[sabotloader]

Test #1 of the new Lehigh Generation II Knight Breech Plug.

Been gone this past week to Missoula for some training, when I got back today I had a package with a NEW Lehigh Generation II breech plug in it.

The new plug is suppose to help in a couple of areas. It should provide a better primer pocket depth to reduce blow back from the primer area. It should also provide a better 'headspace' fit to the bolt face.

I could not resist the urge to try the new plug this morning in a 'primer cycling' test. I installed the plug in what i call my tightest fitting gun and in the loosest (not a word I know - but you know what i mean...)

From there I cycled 9 different 209 primers through both rifles. I cycled the longest primers I have the Winchesters, 2 types, and the shortest primer the Remington 209-4. I also cycled the CCI 209's both the 'M' and the regular primer. These primers are a bit fatter than than the others... The M's fit and pulled out just fine, the regular CCI 209 were snug going in and did require a small tug to get then out but they came out easily enough. I am confident a little use of the BP will polish and smooth the primer pocket to the point that the CCI-209 regular primers will work just fine.

Remember everyone, these plugs are machined to fit a true Knight DISC Elite or Extreme. If you try to use them in others in the model line, they may not fit as well. I have found Knight has some very wide tolerances in their manufacturing process. Now on the other hand it is my belief that they will work in may of these other Knights but you will not know for sure until you try.

Here is a pic of this mornings efforts....

Hope to shoot both this afternoon and tomarrow....

 

[sabotloader]

Generation II - Test 2 - Shooting...

Decided to run to the farm this morning and do some shot testing of the new Lehigh Generation II breech plug.

I decided to shoot the new DISC Elite - 45 cal as the first test rifle. Further I decided to shoot the dirtiest load combination I have. So I loaded up some T7-2f, touched off by a Winchester T7 primer. I ended up shooting some really old dark brown Knight 4045 cal sabots - just cuz I wanted to use them and save some of my good MMP - light tan sabots.

First off let me give you my perspectives of this testing. Both of the stock Knight ignition systems will allow blow back to reach up and eventually burn your scope. Both of the Knight systems leak a lot of blow back into the breech area. The goal, again my perspective, of the Lehigh plug was to significantly reduce the amount of blow back seen in the breech area and back onto the scope.

The Gen I plug and primer adapter solved the scope problem right out of the box, even the Gen I plug reduced the amount of blow back into the breech area, but for myself and others it was not good enough. Come-eth the Gen II plug.

I think Lehigh Dave would flat out tell you that he can reduce the blow back to ZERO if he had your rifle. I can tell you I can do the same thing for each of my Knights using a Lehigh plug. The PROBLEM - Knight manufacturing tolerances, they allow a large range of tolerances, which in the normal world is OK because the gun functions well and safely.

The Generation II plug is made to fit and work well in 90% + of the true Knight DISC Elites and Extremes made. Is it perfectly clean in all Knight rifles with all the different primers - NO! But it is significantly cleaner than the Knight offereings.

Test #2... was to shoot the new plug and see if it were worth the expenditure... After my trip to the farm i can easily reply - for myself - it is definetly worth it.

Here are some pictures to show my trip.... The first tens shots with the new conversion were with T7 and Winchester T7 primers.. and anybody that has shot them can tell you how dirty they can be. The last eight shots were taken with 110 grains of BH-209 and for the first 6 shots I used the suggested Federal 209A's - the last two shots were ignited with the meeger Remington 209-4 primer.

Here is a group of pictures showing todays activity....

In this gun... is it 100% Blow-Back free - NO... but it is far better than previous BP's. I beleive it will even be cleaner in my DISC Extreme which is a tighter gun than is this Elite.

 

[rt_con]

sabotloader: Looks like a winner ! Thanks for the report.

Did any particular brand of primer stand out as the best fit for use in the Lehigh ? (Looking to use it exclusively with BH209.)

Thanks... Rob

 

[k]

my experience with the two nfpj conversions i have are quite differant than yours,neither have left any residue on the scope and the breech's are cleaner than your pics after twenty rounds.the only plus i see is the ventliner.i did just buy another .45 stainless laminate disc-xt and another NFPJ plug from knight so i'll find out shortly how good this one will do.......karl

 

[rt_con]

my experience with the two nfpj conversions i have are quite differant than yours,neither have left any residue on the scope and the breech's are cleaner than your pics after twenty rounds.the only plus i see is the ventliner.i did just buy another .45 stainless laminate disc-xt and another NFPJ plug from knight so i'll find out shortly how good this one will do.......karl

I see the Lehigh vent liner as much better than the Knight NFPJ with BH209. The flash hole at .034 vs .030 in the Knight. Plus the Lehigh has a shorter flame travel to the powder too.

 

[sabotloader]

rt_con

I only used 3 primers yesterday... Winchester T7, Federal 209a's, and Remington 209-4's. I will use others as I get to do more shooting, which I was suppose to do today - but the weather has gone bad.

You might be interested in this observation of mine... Even though Western and even Lehigh says to use the Fed 209a or the CCI209m with black horn... I have continually ignited, instantly ignited, 120 grain loads of BH, with any primer I have used. It is my belief that the Lehigh vent liner makes that possible.

One thing to remember the primer pocket is 0.195" deep.... and in some Knight Extremes/Elites that is going to be a tight fit with Winchester primers a good fit with the Federals and a looser fit with the shorter primers. And then again with other Knight's it could be just the opposite.


K

You are really fortunate if you Knight BP's are that clean. I have 4 different rifles and several Knight FPJ and NFPJ breech plugs and they all offer a lot of blow back material. Which in the day they were designed was still better than most of the competitors but in todays world everyone is looking for a cleaner breech area.

Which powder and volume are you shootig?

 

[Busta]

my experience with the two nfpj conversions i have are quite differant than yours,neither have left any residue on the scope and the breech's are cleaner than your pics after twenty rounds.the only plus i see is the ventliner.i did just buy another .45 stainless laminate disc-xt and another NFPJ plug from knight so i'll find out shortly how good this one will do.......karl

K,

I'm with you, I have never had any smoke or soot ever come close to reaching my scopes with the Knight NFPJ Conversion. This has been the case with all 3 (.45 cal DISC, .45 cal Elite, .50 cal Extreme MHC) of the Knight Disc Rifles I am currently shooting.

The breech area does have a little soot with the standard NFPJ Conversion, but none with my modded up plug. :wink:

For the record, I shoot Blackhorn 209, and everything from 155 gr saboted bullets to 495 gr full bore conicals.

 

[k]

rt-con

i will admit it would boost my cold weather confidence to have a larger flash hole but i've shot blackhorn out of my knight's down to 13* with no issue's

sabot loader

i've only shot blackhorn out of these knight's with the NFPJ
the .45 super disc has shot up to 120g vol. settleing on 110g vol.
under a lehigh .40 200g in a harvester smooth blue sabot
ignited with the regular blue box win. 209's.this has been the most accurate so far.
the .50 disc-xt is shooting 100g vol. under a 260g .451 nosler partition
resting in a mmp hph12 also with winchester primers.i believe the longer length of the win. helps with the blowback as it tightens the headspace

 

[sabotloader]

Busta

The breech area does have a little soot with the standard NFPJ Conversion, but none with my modded up plug.

Agree with you here, my modified Knight NFPJ's are blowback free and it is really easy to do... modify the plug I mean.

But, on the other hand I have 4 different stock NFPJ's and after about 10 rounds it is pretty black in the breech and the primers no longer roll out. Even in my tightest MHC I can not get it to go past 12/15 shots before it starts becoming a problem.

The headspace in each gun is different.

 

[GM54-120]

sabotloader

Head space/tolerances are different for sure in all 3 of mine and my testing confirmed this. The GMB54 is the tightest and worked fine with the Gen I. The Elite 45 is the "loosest" and within 15 shots i had to remove the bolt to remove the primer. The Extreme 50 is in between them and is "ok" for short sessions or some cleaning during a session.

Polishing the primer pocket walls seems to have helped a bit with extraction and carbon build up. Ive got some small fiber washers ive attached to some primers too but those are mostly for my CVA plugs. If one comes off getting it out of a Knight type BP would be more difficult vs a break open action.

Ignition though is very good in all of them with just Win209s and IMO very good-excellent in the Elite 45. Im not sure if my imagination but in the Elite 45 ignition is really really good. It must be the over sized vent liner pocket (near 50cal) in a smaller 45cal bore.

Weather this weekend isnt cooperating with another run of the Gen I in the GMB54 and some bullet expansion tests. I need to spend more time with my dad and his wife anyway. Right now WE time is more important than ME time.

Scott

 

[sabotloader]

k

the .45 super disc has shot up to 120g vol. settleing on 110g vol.
under a lehigh .40 200g in a harvester smooth blue sabot
ignited with the regular blue box win. 209's.this has been the most accurate so far.

Is the Super DISC a 1/20 twist... if it is that should really be an excellent performing round for you. And loading 110/120 grains should enable you to shoot a huge variety of animals. That could be devastating....

In our collection of Knight gun information, we have generally found that with the Extreme bolt conversion the head space in any of the Original DISC's has been several thousandths (20/30) longer than in the next generation of Knight DISC Extreme/Elite series of guns.

 

[Busta]

k

the .45 super disc has shot up to 120g vol. settleing on 110g vol.
under a lehigh .40 200g in a harvester smooth blue sabot
ignited with the regular blue box win. 209's.this has been the most accurate so far.

Is the Super DISC a 1/20 twist... if it is that should really be an excellent performing round for you. And loading 110/120 grains should enable you to shoot a huge variety of animals. That could be devastating....

In our collection of Knight gun information, we have generally found that with the Extreme bolt conversion the head space in any of the Original DISC's has been several thousandths (20/30) longer than in the next generation of Knight DISC Extreme/Elite series of guns.

Sabotloader,

Your headspace information is different from my findings. I have an old D.I.S.C. Super .45 (1:20) twist, a .45 Disc Elite, and 2 .50 Disc Extreme MHC's.

The Super .45 has a longer loading gate and other manufacturing tolerance differences, but the overall headspace is IDENTICAL to my .45 Elite from the back of the bolt notch. This measurement is .026" longer than the .50 Extreme MHC that I am shooting however.

Another measurement that needs to be figured into the equasion is the distance from the bolt lug to the bolt face. There are differences from one bolt to another as well. Then you throw in the breech plug OAL tolerance as well.

This is one reason I really like the tip-up rifles. I can and have custom breech plugs that have been headspaced for the different primers. one for Winchester W209, one for Federal 209A and CCI 209/CCI 209M, and even one for shorter primers. These can be made completely blowback free with very little work involved. They are made a few thousandths too long to start, then the material is removed from the breech plug face for a custom fit.

Lehigh could also make some plugs on the high end of the tolerance that could be custom fitted as well. I know not everybody has the equipment or patience to perform this work, but it is really easy if you at least have a drill press. You start with a longer than needed breech plug...chuck up the hex head end in your drill press jaws...adjust your table up and clamp a flat plate to it...place/tape/clamp some sandpaper to the plate....turn on the drill and pull down the handle to remove material from the face of the plug....remove plug and measure/test for fit until it has the perfect headspace for your rifle/bolt/primer. Simple as that. Like I said this method is not for everybody, but would be another option to some to get a blowback free set-up. One worth having IMO.

If you don't have enough headspace with your current set-up to close your bolt with a primer installed, you have a perfect candidate for the above tweek, or use a shorter primer. If you have too much headspace, try a longer primer (Winchester W209 is the longest), or you will have to add material to your primer pocket or breech plug face. The right sized o-ring is an easy fix for those IME.

 

[sabotloader]

Busta

Thanks a bunch for the information... in my original statement probably mis-stated what I meant. I am a long ways from being a gunsmith and knowing the right terms.

The Super .45 has a longer loading gate and other manufacturing tolerance differences, but the overall headspace is IDENTICAL to my .45 Elite from the back of the bolt notch. This measurement is .026" longer than the .50 Extreme MHC that I am shooting however.

I think this is exactly the measurement that i was trying to suggest, and why i am not sure that the conversion will work well with the Original DISC. Only way i will ever know is if I could try one, but I can not find anybody around here that has an Original DISC.

This is one reason I really like the tip-up rifles. I can and have custom breech plugs that have been headspaced for the different primers. one for Winchester W209, one for Federal 209A and CCI 209/CCI 209M, and even one for shorter primers. These can be made completely blowback free with very little work involved. They are made a few thousandths too long to start, then the material is removed from the breech plug face for a custom fit.

Totally agree about the ease to fix a tip up... Just, I am to old - tip ups work well in shot guns, but I am not sold on them in a rifle - I Know!!! but it is one of those personal preference things...

Custom BP adjustments.... following along with your thoughts I did send Dave an email and ask him to save the Generation I breech plugs instead of tossing them, for exactly that reason. It is very easy to customize them to fit your gun and to fit various primers if you wanted to go to that step. I am thinking it would be easier to customize them than it would be the new Gen II plugs that are coming out this month sometime.

I said this method is not for everybody, but would be another option to some to get a blowback free set-up. One worth having IMO.

This reasoning is exactly what the Generation II plug is aimed at. I think Dave redsigned it to work across a wider range of varibles and yet have have it function cleaner and better than the Knight factory plugs.

IMO - just the addition of the vent liner is large step forward especially for BH shooters, but I even like it for shooting T7. I beleive it will be cleaner than most Knight NFPJ applications which really is a bonus.

When this whole project began - I really thought I could use it at the range and then for hunting I would switch back to a Knight FPJ, but now I am thinking that I will stay with the Lehigh conversion even durng hunting season... I have figured out a way to get those pesky little primers in the gun now with little effort even if it were cold. And as much as i hate to say it if moisture is my worry about a bare primer one of your simple 'O' rings would solve that problem in a jiffy.

 

[wayles]

Lehigh plug

I for one would like to get my hands on a plug I could custom fit to my .45 extreme
Wayles

 

[k]

sabotloader;

i have two origanal d.i.s.c. rifle's.a blued .45 super-disc 1/20 and a stainless .50 i would be happy to measure for you,just let me know what you'd like.........karl

 

[jsteurrys]

k,

We need the dimension from the face in the receiver where the breechplug bottoms on to the surface where the back of the bolt body by the handle contacts the receiver. My .50 DISC Original measure 4.322" which is .022" longer than my DISC Elites. I needed to use a breechplug to help get this measurement as I could not get a depth micrometer in there to measure to the receiver face directly. Let me know if you have any questions on the measurement. Please post your findings.

 

[k]

k,

We need the dimension from the face in the receiver where the breechplug bottoms on to the surface where the back of the bolt body by the handle contacts the receiver. My .50 DISC Original measure 4.322" which is .022" longer than my DISC Elites. I needed to use a breechplug to help get this measurement as I could not get a depth micrometer in there to measure to the receiver face directly. Let me know if you have any questions on the measurement. Please post your findings.

i take it your talking about the back of the "slot" that the bolt handle ride's in correct? if so i'll measure it at the bottom because of the taper.
i'll also measure by using the breech plug and adding the dimn.
i may also make a gauge rod and check it this way....karl

 

[sabotloader]

k

That would be great....

 

[jsteurrys]

i take it your talking about the back of the "slot" that the bolt handle ride's in correct? if so i'll measure it at the bottom because of the taper.
i'll also measure by using the breech plug and adding the dimn.
i may also make a gauge rod and check it this way....karl

You are correct in measuring to the bottom of the slot. That is exactly how I measured mine using the breechplug. Thanks for getting these measurements.

 

[Busta]

You guys can run a caliper depth blade down in to the breech and guage off the back of the receiver behind the bolt notch, then subtract the measurement from the back of the receiver to the bottom rear of the bolt notch. Each example will be slightly different on most of these numbers, but both my .45's are exactly the same when it is all said and done. Not all bolts or breech plugs are created equally either, so that throws in another couple variables, not to mention the primer length.

My measurements are:

.50 cal Extreme MHC = 4.272"

.45 cal Super DISC = 4.298"

.45 cal Disc Elite = 4.298"

Remember, the bolt actually cams forward as the bolt handle is pushed down. My measurements would be a minimum OAL, and you could probably go longer for primer rim compression. This is also dependant on the primer length you choose to use.