|
|
Post by rjhans53 on Aug 20, 2012 19:16:00 GMT -5
Ok I know at times I wish for a lot but has anyone tried to modify the non plastic jacket breech plug by drill out the flash channel and installing a vent liner in them
|
|
|
|
Post by sabotloader on Aug 20, 2012 19:28:50 GMT -5
Ok I know at times I wish for a lot but has anyone tried to modify the non plastic jacket breech plug by drill out the flash channel and installing a vent liner in them Yep! several of them - not difficult at all. It will not be as clean as the Lehigh or the Knight - but it will work. You can make it clean by adding shims in the primer pocket.  |
|
|
|
Post by lakeplainshunter on Aug 20, 2012 19:49:30 GMT -5
I have done 5 to date and all work excellent with zero blowback.
|
|
|
|
Post by rjhans53 on Aug 21, 2012 4:28:19 GMT -5
Thanks, did you install a vent liner or just stop making the flash channel bigger 1/2-3/4 of the way down. I don't know if I have anything to make the bevel for the vent screw, do they sell or make a bit for that, if so I'm sure that I can be creative and get it done, I only have about 3 of them around somewhere, be nice to have them for backup if nothing else.
|
|
|
|
Post by ronlaughlin on Aug 21, 2012 7:38:25 GMT -5
You just about have to install a vent liner if you drill into the dome. What happens is you destroy the flash hole. Here is a drill with the correct 82* angle for the vent liner head.  You can also use a 3/8" diameter counter sink with a 82* bevel. |
|
|
|
Post by sabotloader on Aug 21, 2012 9:38:43 GMT -5
Thanks, did you install a vent liner or just stop making the flash channel bigger 1/2-3/4 of the way down. I did install Lehiegh vent liners in all of the BP that I modify. These two plugs have a vent liners 0 one is recessed into the body of the plug the other is on the nose of the plug. One of the reasons rhat Knight created the domed plug was to help reduce blow back gases by shedding them to the side, Onther effect of the domed plug was to increase the volume of gas the 'flash channel' could hold also helping reduce blowback pressure on the nose of the primer. I got the best of both worlds by modifing the plug to allow it to breath better and the installation of the domed Lehigh Vent Liner on the nose of the plug. MSC sells a 'spoy drill' just for this... www1.mscdirect.com/eCommerce/NavigationServlet/Holemaking/Center-Drills-Combination-Drill-Countersinks-Spotting-Drills/Spotting-Drills-Sets/Spotting-Drills/_/N-1yyabc7Z77h5e?refinement=4290086885&searchandizedOk=YYou will need a #21 wire bit to drill the flash channel and a 10-32 tap for the threads of the vent liner. Here are a couple of pictures.. This is a recessed vent liner in one of the Knight NFPJ's  Other Pics...   Converting a Power Stem Breech Plug  One last thought...  |
|
|
|
Post by rjhans53 on Aug 21, 2012 20:09:29 GMT -5
Thanks guys I appreciate it. Seemed to work, now just have to try it out
|
|
|
|
Post by Al on Aug 22, 2012 3:08:31 GMT -5
Sabotloader.........nice pics and details!!
|
|
|
|
Post by sabotloader on Aug 22, 2012 20:42:36 GMT -5
Sabotloader.........nice pics and details!! Thank you - i understand pictures better than words |
|
|
|
Post by AJ on Aug 22, 2012 22:05:02 GMT -5
Is there a real benefit of the domed vent liner over the flat version the Savage has?
|
|
|
|
Post by ronlaughlin on Aug 23, 2012 6:24:57 GMT -5
A while back i shot through the domed vent, then a flat vent, then the domed vent, then a flat vent,...................................., and clocked these shots with a chronograph. The speeds were virtually the same with either vent liner. My conclusion was, there is no advantage to the domed vent. www.huntingnet.com/forum/black-powder/359195-vent-liner-shape.htmlThe domed vent is much much harder than the flat vents, and one would think it will last longer, however i haven't tested longevity. |
|
|
|
Post by AJ on Aug 23, 2012 7:20:13 GMT -5
Thanks Ron, I read that thread and chamber pressure will be the same with either design. Bolt thrust is different and may be reduced by the domed design. It will not affect velocity but possibly can reduce wear on the bolt.
|
|
|
|
Post by ronlaughlin on Aug 23, 2012 7:37:56 GMT -5
If i understand correctly, bolt thrust is determined by the pressure, and the area of the bolt face. The area of the bolt face is constant. If the chamber pressure is the same using either vent liner, then it seems to me the bolt thrust has to be the same with either vent liner. Keep in mind, i am just an old retired carpenter; no engineer am i.
|
|
