slotting of under lugs

[hortonstn]

how long of a slot does an underlug for a swamped barrel need to be?

[hanshi]

I'm no expert; but it shouldn't have to be much.  I use a "wire saw" and just get them oval.  Most of mine already came nicely slotted.

[g2608671@verizon.net]

Why does the underlug on a swamped barrel need to be slotted?  Excuse my ignorance, but I am about to embark on building a rifle with a swamped barrel and I know just enough about the process to be a danger to myself.
I know that on the last Traditions I put together that had I slotted the underlugs (fore and aft) I would have gotten a better fit where the stock joins in front of the trigger guard.  They would have drawn up tighter.

[EC121]

It allows for the barrel to expand and contract without binding while shooting.  Also the wood can move without pulling on the barrel.

[hortonstn]

i read a post on another sight by a well known barrel maker that compared it to a snake swallowing eggs.
if thats what i need for accuracy im in its about barrel harmonics..
thanks
paul

[Mark Elliott]

You need to allow for the expansion and contraction of the forearm with the seasons.   I can get up to an 1/8" of movement at the muzzle over the course of a year in my house.   I normally cut a slot that is three times the diameter of the pin.   I normally use 5/64" pins.    How far either way I cut the slot around the hole drilled for the pin depends on the season.   If Spring or Fall, I cut the slot equidistant.   If Summer or Winter,  I cut the slot all one way or the other depended on the way it will move.     If  Winter, the forearm will expand.  If Summer, the forearm will contract.   I hope that makes sense.   I cut the slots with a jewelers saw.

[Dennis Glazener]

I use a "wire saw" and just get them oval.

What is a "wire saw" and what size is it?
Dennis

[Ky-Flinter]

how long of a slot does an underlug for a swamped barrel need to be?

Slotting the underlugs should be done with straight barrels too.  It's about the wood expanding and contracting.  The wood don't care what kinda barrel it is

-Ron

[RAT]

I remember a previous post that discussed slotting vs. simply drilling a hole. The general consensus was that nobody had seen an original where the underlug was slotted... unless of course where wedges or keys were used instead of pins. Some posters said they didn't slot their lugs and never had a problem. Is this a modern overthinking of a problem that doesn't really exist? Or the natural evolution of techniques over time where we know more and do things better as a result?

[Mark Elliott]

On the original rifles that I have seen,  the holes for pins were at least a little oversized.

[Dennis Glazener]

I have never seen slotted cross pin holes on an original. I try to remember to slot them before I finish a rifle but to be honest I have only remembered to do it on 2 or 3 and I have never see or heard of a problem.
Dennis

[Mike Brooks]

I haven't seen elongated holes on originals either, but I have seen alot of cracked forestocks on old guns. I don't slot my holes untill I'm just about finishing up the gun. Many times the pins are severely bent from the wood either shrinking or expanding whilst I was building the gun. Ever try driving a bent pin through that hole? I have had the bent pin break out of the forestock on the far side where it wasn't supposed to be.

[David Rase]

I haven't seen elongated holes on originals either, but I have seen alot of cracked forestocks on old guns. I don't slot my holes untill I'm just about finishing up the gun. Many times the pins are severely bent from the wood either shrinking or expanding whilst I was building the gun. Ever try driving a bent pin through that hole? I have had the bent pin break out of the forestock on the far side where it wasn't supposed to be.

Thanks for sharing one of your gun aging secrets.    How many other screw ups have you converted to patina?
David

[Mike Brooks]

I haven't seen elongated holes on originals either, but I have seen alot of cracked forestocks on old guns. I don't slot my holes untill I'm just about finishing up the gun. Many times the pins are severely bent from the wood either shrinking or expanding whilst I was building the gun. Ever try driving a bent pin through that hole? I have had the bent pin break out of the forestock on the far side where it wasn't supposed to be.

Thanks for sharing one of your gun aging secrets.    How many other screw ups have you converted to patina?
David

Ah.....pretty much the whole build sometimes.