Lengthening barrel pin holes on Kibler SMR

Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RocketMan58

32 Cal
Joined
Dec 16, 2024
Messages
46
Reaction score
93
Location
SE NE USA
Working on my SMR kit and see that I'm supposed to oblong the barrel retaining pin holes a bit to relive stress as the barrel expands as it gets hot /cold. So my question to those with long gun building experience is, how and how much do you oblong those hole to allow for this longitudinal expansion. Jim's YouTube video shows him using a jewelers saw to complete this task but I'm not having much luck with this method. I'm thinking that maybe I should drill an additional hole offset to the rear of the existing one then connect them with the saw. .... I'm also thinking it shouldn't take more than a 1/16"" or so to accomplish the task but am not sure. Any advice/help from those in the know is greatly appreciated!
 
No, you don't need to drill any more holes. That's overkill. Elongating the pin hole just a tad wider than the width of the jeweler's saw blade itself is sufficient. I found it was easier to use the jeweler's saw blade to elongate the holes if I just grasped the blade itself with my fingers and sawed without the saw frame. Mounting the blade in the frame and through the pin hole is a bit of a nuisance. If you have a pointed round diamond needle file you can use that to dress out the ends of the slot.
 
Thank you Sir! BTW,, I did do a search on this topic before posting but came up MT. Then just now , I found this older thread in the list of Similar threads section below. I think I have what i need now.
Tight Groups,
Dave
 
I find using a jewelers saw like Jim does very tricky. My teacher taught me to drill a hole left and right of the pin hole so you have three then using a small jewelers file to remove the metal between and clean it up. This apparently is a pretty common way to go about it. Whatever you do don't be tempted to use a Dremel tool. That's a quick way to ruin your underlug.
 
PXL_20221126_163459066.jpg
PXL_20221126_163853780.jpg
PXL_20221126_164218228.jpg
PXL_20221126_164547892.jpg
PXL_20221126_180948481.jpg
 
Back
Top