Breech Plug -- Vent liner

[ronlaughlin]

Breech plug is made from a 9/16" x 18 grade 8 bolt. Vent liner is made from a 10-32 holo-krome screw. Breech plug fits Woodman Arms Patriot rifle. Second such plug made here.

The screw/vent liner started out with a flash hole of 0.028", but now has grown to 0.033". The breech plug is long enough it has enough compression on primers to eliminate blow by.

 

[sdporter]

How did you drill the vent liners? I’ve drilled a couple of breech plugs with some HSS wire gauge bits but, it’s scary on the lathe. I have a special attachment I made for the tailstock so I can hold the bits in a tiny chuck by hand, so I can better feel the pressure on the bit so I don’t break them.

 

[Steelheader323]

Looks good! I’ve got 2 cva hex head plugs I have to eventually get to this winter. Have even thought about modifying my traditions accelerator plug. I haven’t needed it to be any better than it is so far but I would really like to not know what it’s like to have a misfire in 15 degree weather when a big late season buck walks out in fact one of my omegas will probably go with me just for that reason til I know for sure the traditions will go off every time with bh209

 

[ronlaughlin]

Wise

 

[ronlaughlin]

How did you drill the vent liners?

Drill, and tapped square steel rod for the screw; clamped it into vise on hobby drill/mill; use #70 cobalt drill made in USA. Sometimes drill is good for 20 vent liner. sometimes 4, or sometimes none before it breaks. Spin motor nearly as fast as it can run. Takes patience, and guts, sensitive feel, not too slow, not too fast. One need hold mouth just right. You know exactly what it takes, luck isn't good enough.

Making vent liner is least favorite.

 

[sdporter]

I buy my tiny drill bits at McMaster Carr and haven't broke one yet but, they get dull pretty fast in stainless.
This is real similar to the tool I built....

 

[HC]

Use bacon grease as a lubricant. It works really well on stainless.

 

[sdporter]

I will try that

 

[Steelheader323]

Ron have you had any issues with the modification being off entered at all? Not having a lathe and working with what I have the plugs are never perfect but seem to always work. Even the ones I didn’t install vent liners into and just made the face of the plug concave and made the hole larger they all have worked but never do really look centered exactly

 

[LarryBud]

Ron or anyone else. At what size do you switch out the ventliner?

Thanks,

 

[ronlaughlin]

Ron have you had any issues with the modification being off entered at all? Not having a lathe and working with what I have the plugs are never perfect but seem to always work. Even the ones I didn’t install vent liners into and just made the face of the plug concave and made the hole larger they all have worked but never do really look centered exactly

A dial test indicator may help center work.

 

[ronlaughlin]

........At what size do you switch out the ventliner?

0.037"