Knight KRB7 powder questions

[whitetailer]

Hey guys...newbie here.

I have a KRB7 that after some trial and error I found that T7 pellets along with Win T7 primers was the best for my gun...it does not create that crud ring as bad and I can now shoot 4-5 rounds if I wanted without spit patching.

I want to move to powder and like what I have read about BH209...but reading here It seems that its not a good choice for my gun...I was told that I could mill out my breech plug to .035 to get a good burn with normal shotgun 209's...but I dont want to kill myself either.

I want to use powder to better control my loads for consistancy...what say you all?

 

[GM54-120]

The easiest way is to switch to T7 loose and go from there. Since you are not having a crud ring issue then T7 loose might even be a bit better than pellets. I wouldnt mind needing to swab every 5 shots or so either.

You can go the route of modding the breach plug for better BH209 reliability but the reviews are still a bit mixed on that breach plug. It works fine for some and others still get an occasional hang fire.

Next year i plan on more T7 loose testing to save my "black gold". Ive been using MX Bore Conditioner and they are all well "broke in" now plus "JB"ed. Im hoping my past crud ring issues wont be as bad now. My old ThunderHawk did very well with it last time out and it is well "seasoned" so just maybe......

 

[Hatchet10]

In my experience with my KRB, I got noticibly less crud ring and improved accuracy when I switched from T7 pellets to lose T7 fff....

 

[Hornet22savage]

When I bought mine used the previous owner had started the process of modding a BP to shoot BH209. So far with that plug my best is about a half second delay with CCI 209M primers. From the looks of it he took the stock plug milled the dome of of it and recessed it deep enough that a Lehigh Ventliner after install is even with the top of the plug. He went through the process of installing the Ventliner and that plug is the one I'm testing. The lehigh Ventliner has a .035 hole in it and at the same it he drilled out the space behind the ventliner to 5/32. Others here can explain why this is done better than I can. Basically I have been told that if you can't get a good seal between the primer and the BP you won't get good ignition of BH 209, but I'm still tinkering and will post my results as they become available.

 

[Anonymous]

Powder pocket plus vent liner may work better igniting BH209 n your gun. Its the same as Ron has been doing with CVA plugs with great results. Triple 7 is still a good powder if BH209 is not reliable.

 

[sabotloader]

whitetailer

It is my understanding, and I do not own one (a KRB) there is a problem with the lock-up of the block against the primer that causes part of the problem. The lockup does not insure the primer holds pressure in the breech.

Can someone else with a KRB make a correction or comment?

 

[Hornet22savage]

Well thats what I beleive Busta told me. However with my testing the primers I have shot come out clean. But I have a delay with mag primers. I beleive I need a deeper powder pocket which I'm working on.

 

[wildhobbybobby]

I tried very hard to get BH209 to work in my KRB-7 when I first got it. I drilled the breech plug flash hole out to .035 and also put a dimple in the face of the BP to create a "domed" effect. Nothing worked, and although the hangfires I continued to get were not severe, they happened all the time.

The only way I could get BH209 to work in the rifle was to drop 5 grs. of Goex FFFG blackpowder down the barrel before dropping the Blackhorn. I then got instant ignition, good accuracy and the bore remained as clean as it would have with BH alone. The BH seemed to consume the BP fouling.

I now use the KRB strictly with blackpowder and lead bullets (No Excuses and MaxiBalls) with good success. I like the rifle very much, but unless you want to duplex-load it, it is not suitable for use with BH209 in my opinion.

 

[sabotloader]

Well thats what I beleive Busta told me. However with my testing the primers I have shot come out clean. But I have a delay with mag primers. I beleive I need a deeper powder pocket which I'm working on.

No it is not the depth of the powder pocket - that really has nothing to do with it. It is the size of the flash channel and flash hole.

When shooting a mag primer the amount of pressure and debris coming from the primer clogs the channel and the flash hole until the pressure reduces somewhat and then it can flow to the powder. It wiuld actually be better to have a longer flash channel such as that in the Triumph.

If you shoot a milder primer not as much pressure or debris so it tends not to over whelm the channel ot flash hole so it works better works better. One thing to kinda remember the KRB plug was designed to reduce blow back pressure felt against the nose of the primer so the flash is smaller than normal.

The problem is when you correct the plug you still have the problem with the primer leaking pressure do to the locking up device.

 

[ShawnT]

Whitetailer,

I am shooting 110 grainsV of 777 2F, W209 primer, and a 250 grain Deep Curl in my KRB. I have found that the KRB does burn the powder very well and does not leave any real crud ring to speak of. You could easily shoot 3 to 5 rounds without swabing if you chose to. I have not had mine long but I had read a lot of the posts about them. IF I were you for now I would go to 777 2F and have fun. IF you want to make your load even more consistant you can start weighing the charges and putting the pre-weighed charges in vials. By using the vials you will find that it is just as fast to load loose powder as it is the pellets. The Volume verses Weight conversion has been discussed several times so you can search the forum for it.

As to the design issues, While I have not tried BH 209 in the KRB, there are some issues with the action style that I beleive would casue some problems. As Sabotloader mentioned, the Rolling block does not lock up as tight as say a Bolt action or a break action. In the Bolt action, your bolt will have no rearward movement so it will pretty much maintains a contant position of the primer, even if it is not bottomed out in the primer pocket of the breach plug (OEM plug). If it does not bottom out then there have been some mods others have done to seal that off, ie. o-rings or washers. In a break action the standing breech will stop the rearward movement of the primer when there is pressure.

In the case of the KRB, the Rolling block is held in the forward (Firing) position by only a spring and ball detent pushing up on the back of the rolling block so any rearward pressure can cause that rolling block to move back a little on the spring, so you will not be able to maintain as tight of a seal on the primer. I think this is what Sabotloader was referring too.

The primer pocket in this plug is a bit loose too, in my opinon. What I mean is, the diameter of the pocket is a little large. I think this is to allow the primer to sort of "self align" when you move the rolling block forward. I suspect that the primer does not bottom out in the pocket either, though I did not have time to check. I think these are the 2 reasons that you get blow back soot even when shooting 777.

I am planning to study the trigger group a bit to see if there is anyway to overcome some of that. But at the moment I don't have the trigger group handy. After the deer season was over for me I sent mine to Sam at Knight for a new hammer. My trigger group had one of the problems that they had with this model. If there is a hammer spur on the hammer it will never strike the firing pin, no spur and it goes bang every time. The added weigh of the spur causes he hammer saftey to "Tip" up slightly when fired, so the safety catches on the rolling block. Sam told me that there were some that got out with that problem and he would replace the hammer on it for me and that would resolve it. I am not sure if it is a problem with the safety, the spring for the safety, or what just yet. I did not have the time to ask to many questions that day. I hope it comes back this week, but with the holidays who knows.

 

[whitetailer]

Thank you all for the replies. I should note that when using Winchester 209 primers with T7 pellets I had an aweful time with the crud ring...I mean it was terrible.

I switched to T7 209's and problem solved. Now, in order to improve my accuracy I want to go loose powder...so after reading review BH209 seemed like a good choice until I began reading posts...much like everyone here, all say this gun isnt really good for it.

So, I'll move to T7 ff and go that route...I dont think I need to weigh it...but I do feel I wont have the variance in my mearuring as pellets do...or at least from reading on Chuck Hawkins site about variance in pellets.

This is awesome...thank you all.

 

[ShawnT]

Whitetailer,

I think that the Win209 is a bit hotter primer than your T7 primer and is partly causing the crud ring, the pellets contribute to is as well. My guess is that if you use the T7 primers with the T7 loose powder you will see virtually no crud ring. I see only the slightest Hint of one when swabbing between shots (and that was while I was looking for it) using the Win209's with 90 - 130 grains of 777 2F.

ShawnT

 

[GM54-120]

Also try T7 FFFg. Some people get even less crud ring with it when combined with T7 primers. I use WinT7s even with BH209 under ideal conditions and correct breach plug designs without any issues.

Another affordable primer are the RemSTS primers IF they fit well in your breach plug. I usually avoid them with FPJs but with T7 FFFg they may still work..

 

[JStanley]

My experience with T7 and crud ring is the same as GM54-120. The hotter the primer the worse the size & hardness. Switching to T7 primers helped a lot. Then I heard about Variflame adapters to use small rifle primers. The SR primers are usually about $3 per box and produce a milder but still effective flame like the T7 primers. Another bonus for me was the Variflame is a bit on the long side for 209 primers and gives my Omega a real nice & snug headspace fit up. Crud ring = gone. Groups = tighter. Blowback mess = nil. The main cost for all these benefits is the slight effort to reload the SR primers in the adapters (and not to forget after each shot and throw the used primer away!) I think I paid $14 for the original Variflame kit that comes with 10 machined brass adapter cups. You can easily get 500 shots from a set of adapters (YMMV) If you don't feel like fooling with this, the T7 primers work great and the extra cost isn't that bad.


GM54-120

Do you notice any accuracy difference using the T7 primers with BH vs normal, hot 209 primers? You know, the whole pushing the bullet a little off the powder before ignition thing. I've never tried anything but normal 209 primers with BH.

 

[Anonymous]

If you can find some Fiotcchi primers give them a try with T7.

 

[GM54-120]

GM54-120

Do you notice any accuracy difference using the T7 primers with BH vs normal, hot 209 primers? You know, the whole pushing the bullet a little off the powder before ignition thing. I've never tried anything but normal 209 primers with BH.

So far my best groups are with standard Win209s but i use pretty snug sabots usually. IMO the tighter sabots and/or heavier bullets move less before good ignition begins.

I only use the T7s to test breach plugs with BH209. Im in no way suggesting they be used with BH209 except maybe at the range.

 

[JStanley]

Sounds like wisdom, thanks.

 

[ShawnT]

JStanley,

Could you measure the vari-flame adapter for me? I would like to know the diameter of the body, and the overall length of the Brass insert.

Thanks,

 

[sabotloader]

JStanley,

Could you measure the vari-flame adapter for me? I would like to know the diameter of the body, and the overall length of the Brass insert.

Thanks,

Shawn I just measured mine... they are significantly longer... w209's are right around .300 - these PR's on average are .316/7 long and run .241 in diameter..

 

[JStanley]

JStanley,

Could you measure the vari-flame adapter for me? I would like to know the diameter of the body, and the overall length of the Brass insert.

Thanks,

I measured several of mine and they are .308 empty length and can go as high as the .316 Sabotloader measured, depending on how well you seat the primer in the adaptor. Dia = .239 on mine.

Be blessed.