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Post by rjhans53 on Mar 15, 2009 18:21:36 GMT -5
I reported yesterday that I had 0 problems shooting 209 out of my MK 85. Today was a different deal, no clue why but I shot BH out of it 3 times and had a lot of blow back. No the bolt didn't recock, the primer did not come apart or leave the chamber area. But the blow back today was enough that I finished sighting in with 777.
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Post by robnj on Mar 15, 2009 19:51:49 GMT -5
That's strange. I have an MK-85, but it's still in it's original configuration. The 209 conversion uses the FPJ breech plug right ?
I'm sure you used the same primers right ?
Only thing I can think of is the breech plug is not fully seated or it's flame channel and flash hole is partially clogged with primer fouling. But then again, you used 777 right after that and didn't experience the blowback ?
Just a WAG...Did you clean out the flame channel with a 1/8" drill bit... from the primer end all the way down to the reduction. And poke a nipple pick thru the flash hole at powder end ?
Breech plug channels get plugged up with a hard, crusty, fouling that is difficult to distinguish from the steel walls of the breech plug itself, and solvents alone don't get rid of it.
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Post by rjhans53 on Mar 15, 2009 20:23:55 GMT -5
no the original 209 conversion is a NON jacket, just a bare primer, what's strange to me is that I shot it 10-12 shots yesterday with out any problems at all, it did fine when I went back to 777
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Post by minst7877 on Mar 15, 2009 23:24:28 GMT -5
Trip 7 is much easier to ignite thus the special trip 7 primers. BH 209 is hard to ignite and needs a strong primer thus the increased fouling of the flame channel. It is very important to keep that channel clear to insure good ignition with BH 209. Even the Knight disc guns need to have the channel cleaned on a regular basis usually 15 to 20 shots. Drill out the channel and run a pick thru the orifice and it will probably start working again. The conversion I have for my MK uses the red jacket
DC
DC
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Post by robnj on Mar 16, 2009 8:59:37 GMT -5
+1 to what minst7877 said. I have the Disc Elite with the NPFJ and it's working great so far with BH209. I shot it 25 times on Sat with the Rem STS primers, which seem milder/cleaner than even the W209. I had some serious reduction in the flame channel due to build up of hard fouling... I had to use an 1/8" drill bit in a t-handle to ream it out.  Curious... did you switch primers when you went back to 777 ? I'd clean the B/P real good and try it again. |
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Post by rjhans53 on Mar 16, 2009 18:49:05 GMT -5
I've been shooting savage's smokeless for 3 or 4 years now so I'm well versed in the drilling out the breech plug. I've used this 209 conversion on this 85 (my brother's, nephews and my bosses 85) for a number of years now, seems like forever. This particular set up really get's messed up if you use anything other than winchester 209's. Stuck primers mostly I guess when I talked to knight about getting some more of the old style a few years ago they told me that they where having to many problems with them because everyone wanted to use other 209's so they quit making them. No I don't get a crud ring, yes I get a fair amount junk in the chamber area but when my hair was getting blown back it was a bit much so like I said finished with 777. I might try the red disk as I have that set up also. the amount of blow back I get in my disk is hardly any and it does clean up really easy, right up there with my ML II's
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Post by tpcollins on Mar 17, 2009 9:51:12 GMT -5
I put a 209 conversion kit on my MK85 years ago, and for whatever reason it just didn't seem as accurate as before. Then I read an article about the extreme force of the 209 primer could dislodge the bullet siting on top of the load before the powder charge has fully burned. Season before last I was cleaning my rifle and noticed how the 209 breech plug is necked down to a small opening inside at the bottom. The powder charge sits at the end of the plug and the 209 primer ignition has to travel just over an inch, gets squeezed through the small opening, and then ignites the powder charge on the other side of the plug. This build up of pressure makes me understand why the 209 primer was always blown out of the plug after firing and caused me to realize how the excess pressure could dislodge the bullet prematurely.
I dug out my old percussion cap plug and noticed it has a hole the same size all the way through it. The entire inside of the breech plug gets filled with powder, the nipple seats directly against the powder, and the percussion flame only has to travel half an inch or less and seems like it would get the powder to burn it quicker.
I looked on Knight's website and found they still offer the percusion breech plug but now the nipple doesn't have to be removed first as was the hassel of the older styles. $20 later I had a new plug and socket tool. Last fall I headed to the range - same powder, same bullets, same rest - just went back to percusion caps and it seemed like I had a better shot group. At least I didn't have the occasional flyer.
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Post by robnj on Mar 17, 2009 10:29:12 GMT -5
With all this talk regarding the MK-85... I may have to take it out and shoot it again. ;D I retired it 5 yrs ago.
Yeah, I noticed Knight has redesigned the nipple end of the #11 breech plug. Does it reduce any fouling.. or just make it easier to handle the caps ?
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Post by tpcollins on Mar 17, 2009 18:06:09 GMT -5
Just makes it easier to remove the breech plug without first having to remove the nipple. I like to swab between shots at the range.
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