Touch hole Erosion

[MikeChapin]

I just finished up my new 32 and put it together Thursday night. When I installed the touch hole liner it looked as if there was not much of a channel left going into the coned portion. I thought that amount of stainless steel should be alright.

I fired a few shots offhand to get a feel for the rifle. After a few shots I settled on 20 grains of KIK 3F and a .022 cotton duck patch. I managed to get four shots in about an inch an inch and a half below the spot I was using for a target.

I then put it on the bench on a clean target. The first two shots went in touching an inch and a half low. The next four sprayed all over the place. The last shot had the load go out the touchhole and not move the ball. I looked at the touchhole then and saw it was huge. In the space of 15-20 shots the touchhole had gas cut from 1/16" to over 3/32".

I ordered up a new liner when I got home. Had the wife give me a hand pulling the ball. I even found my easy outs that I haven't used for 15-20 years.

Installing the next touch hole liner I will definitly have to make sure there is enough meat between the face and the cone.

On the good side my goal of making a lightweight flinter equivalent of a .22 came out well. The rifle comes up well and looks like it will be a fine shooter.

 

[LRB]

I buy stainless liners from Dixie Gun Works. 1/4 x 28, with a screw driver slot. I bore them out larger and leave about .030 or a tad less than 1/32" of vent hole channel. Been using one in my FL for about six years, no erosion that I can tell. I think you just got a defective liner, or if you did the installation, maybe you didn't set it deep enough if you are using a non screw driver slot type, and had to file off excess leaving too little metal for the fire channel.

 

[MikeChapin]

I was using a different liner than I usually use. I generally use the one you describe and have four other flinters with them.

For some reason this one did not want to go in as far as the one I normally use. There seemed to be enough left when I got it in as far as it would go. Definitly wasn't though. The one I ordered up was the same as I have used before so should be alright.

I'll post some photos when I get the rifle back together.

 

[Birddog6]

Regardless of the type of vent liner used, you should have about .025 to .030 in straight wall thickness at the vent hole for it to hold up. With this you will get Thousands of shot from same liner.

:thumbsup:

 

[LRB]

Exactly! I like your thinking Birddog.