Todays Project - Drilling a Knight Vent Liner Out

Joined
Nov 30, 2012
Messages
1,264
Location
Northern Idaho
The weather here was not good today rain and high winds... Not good for shooting

For something to do I decided I would tackle the replacement of a Knight Vent Liner in the breech plug. I had collected the bits needed - I just did not have lathe to do it on! A fellow ML shooter here in Moscow has one and I was planning on him and I doing the project together, but his lathe was on the fritz! So I decided I would use my drill press in the wood shop.

Heated the shop up and began the project. The first step in the project was to insure the drill press table was perpendicular to the chuck. Use a long drill in the chuck and a square to the table to 90*

Also - I felt it was important to slow the drill press to it lowest speed to reduce heat and provide more control. So I move it down to 640rpm.

Next I inserted a the 3/8" mill end bit in the chuck and the Breech plug in the table vice. Then I centered the drill on the hole in the vent liner. Pulled the bit down to the hole and turned the chuck by hand to confirm the etching on the vent line was equal.

3-8_Inch_Carbide_Jobber_bit.jpg


After the operation began.

Placed the 3/8" Carbide Jobbers bit in the chuck and started the drilling operation. I would only drill for a few seconds and lif the bit up and out. Using compressed air I would blow the BP out and observe my progress. The observations were to insure that I was only drill Vent Liner - I did not want to drill in to the BP metal. Repeated the drill and observe steps several time. Finally I thought I could feel the bit touch the BP metal as the bit turned easier and more smooth.

Remove the Carbide bit and insterted the 3/8 x 82* bevel Mill end and cut the seat for the new Vent Liner.

Remove the Mill bit and Install a #21 Carbide Wire bit to drill out the old Vent Liner Stem to the BP flash Channel

Remove the #21 bit and install the 10x32 Tap in the chuck. Lower the Tap to the hole insert the tap and turn the chuck by hand to clean out the old existing threads and to cut a few additional threads in the BP.

Remove move bit from BP and BP from vice. Install a new Lehigh Savage Vent Liner and test for fit... All is good

He is a composite pic of the operation

Drilling_Composite.jpg


Some additional pictures that might be hard to see in the Composite

Bits_Used.jpg


Completed_Project.jpg


Drilled_-_New_Plug.jpg


Project BP on the Left a new Lehigh Breech Plug on the right.

This whole operation turned out to be much easier than I expected.
 
Last edited:

ChrisA

WKR
Joined
Apr 7, 2014
Messages
411
Location
Belle Plaine, IA
I finally got a drill press this winter and hope to be able to up my game in the fabrication and repair department. I'd love a lathe and knee mill but it just isn't in the cards. I can barely pull the trigger on a good set of drills and vise.

Chris
 

ole hunter

Lil-Rokslider
Joined
Aug 25, 2014
Messages
197
Location
eastern Oregon
Mike got a question being a ML newbie ,What's the reason for a new vent liner . Is this a Mod I should do ? Nice work ,You could come to Oregon anytime and use my lathes or mill ,, They don't just make little winches ....
 
OP
sabotloader
Joined
Nov 30, 2012
Messages
1,264
Location
Northern Idaho
Mike got a question being a ML newbie ,What's the reason for a new vent liner . Is this a Mod I should do ? Nice work ,You could come to Oregon anytime and use my lathes or mill ,, They don't just make little winches ....

You know I was thinking the same thing... I actually have a Williams FP peep base I need milled. They do not make a base for the MK-BK flat top receivers any longer so I was thinking about milling down a round top base...

At some point your flash in your vent liner in your Ulite is going to erode out and the liner will need to be replaced. It is much cheaper to replace the vent liner than buying a new BP. If you have some pin gages you can grade your existing vent liner.

The factory Vent liner new should pin at about 0.031 when they get to 0.034" you are looking at an effect on your accuracy....

If you decide to pin - do it carefully I hate sticking anything in the flash hole it can help accelerate the erosion...
 
OP
sabotloader
Joined
Nov 30, 2012
Messages
1,264
Location
Northern Idaho
Might just end up doing that... I will also end needing to drill and tap 6x48 screw hole in the receiver to attach the base also... Hole pattern is a lot wider than the new round top receivers...

Might have a WRGS coming that might fit it said it was for a MK receiver but we will see when it gets here...
 

ole hunter

Lil-Rokslider
Joined
Aug 25, 2014
Messages
197
Location
eastern Oregon
Ok very busy right now but can get your base done same day I get it. Don't and wont drill tap gun's tho that's out of my comfort range.
 
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