Barrel lug notch length

[Muggsy1776]

I am finally getting toward the end of my first rifle build and it’s time to put the barrel back.  Te barrel lugs have been drilled out with a 1/16” hole for the pin.  I know I need to elongate the opening for wood expansion/contraction.  My question is how long should the notch be? Do I need to go a full 1/16” on either side of my hole or is 1/32” enough?

[mikeyfirelock]

I have never been particular about that……I think that the depth is more important so that the barrel is held vertically stable.   Probably any reasonable tolerance is good. I think ( off the top of my shade tree hillbilly head that 3/32 would be fine.   I have never measured it, and have never had any problems ( but then I’m not good enough shooter to know !)

That’s 3/32. For wedges…….you are probably good with 1/16 “.  For pins. Just make sure you seal your finish inside barrel channel with a good sealer as well as the outside of stock.

[bama]

The pin holes should be elongated as mentioned.

I usually go about a 1/16" on either side which should be more than enough. To get an exact measurement you could find out what the coefficient of expansion is for the steel your barrel is made from and calculate the amount at the max temperature your barrel gets during the firing process. The hotter your barrel gets the more it expands. The expansion will be less at the lug closest to the breech and the greatest at the muzzle end lug. If calculated I think you would find that the expansion is not that great but it is enough to cause wood damage over time and can have an effect on accuracy. I think this is why some rifles have a tendency to start wandering on the target over the course of several shots.

Here in the south where the air temperature is already between 90 and 100 degrees on any summer day at a shooting match, the barrel will get hot to the touch. You want to make sure those slots allow for the barrel to grow. Something else to consider is radial expansion on the barrel, your barrel grows larger in diameter as it heats up. Everybody loves a tight fitting barrel channel but I am not convinced that a real tight fit might have an effect on accuracy also. I think that why a lot of target shooters have gone to free floating their barrels.

Sorry for the long post, 1/16" either side should do the trick.

[Daryl]

Barrel floating with modern guns is for consistancy thorought a shooting session, not for improved accuracy over a tightly fitted or bedded barrel.
In many instances, over 10 shots are fired in rapid succession, and consistent impact accuracy to the same group, is vitally important.
Some guns, primarily lighter weight sporting rifles actually shoot better when tightly bed in glass/epoxy.
With heat and humidity, I see your point, bama.

[Jim Kibler]

Wood movement with changes in ambient humidity is more significant than thermal expansion of the barrel.

[kutter]

I've elongated the hole for the bbl pins on a very few of my builds. The majority, I never did.
They run from Muskets to L/W rifles
None have ever had any damage one way or the other in wood cracks or splits around the pins in the stock.

It runs from mid to high 90's in the summer to single digits in the winter here in WNY. Humidity is what you would expect.

Maybe the stock walls are so thin and the pins small enough in dia that they move a bit and it's not noticed.
Is it a fixation like the need to 'vent' a percussion system was some years back?
It did no harm, but was it really necessary to avoid some waiting Catastrophe.

...Or maybe it just doesn't figure into the picture at all unless you are in to ultra accuracy at long range.
Many are, but I can't see that far.
If I get a nice 5shot cluster group at 50 or 60yrds and I'm happy.
On to the next one.

[Muggsy1776]

Thanks everyone.  I’ve got an idea now.  As for the inside of the channel I did put sealer in there already.   This first one is a slow build..lol….  But it’s coming out better than I expected. 

[Daryl]

Pretty sure Taylor doesn't lengthen or enlarge pin holes, but could be wrong.(again?)

[bama]

Jim, you are probably right about the wood, especially here in the south where the humidity is very high. For those that do not lengthen of elongate the pin holes I hope the best for you and that you never have a problem. As for me, I have done enough restoration work to know over time the forearms of many a nice rifle have been pulled apart at the pin holes. Now this is probably from wood shrinkage more that barrel movement as Jim has mentioned. If a slotted hole helps prevent this or helps my accuracy then I am better off, if it doesn't then I have not lost anything but a little time. Most the antique rifles I have worked on did not have slotted lugs, but most of them had forearm damage. To slot or not slot, that is the question.

[Steeltrap]

Humidity and wood.

On my last build I had the lock inletted perfectly . It functioned great. Took it out on a hot humid day....shot it....and came home to clean it.

Cleaned it up and went to put the lock back in....and it refused to go back in. After some looking and tinkering I discovered the wood had swelled just a tad and now hit the mainspring when attempting to put it back in.

I relieved the wood and it went in great. The third time out, again on a hot humid day, it did the same thing!!  I just had to scrape a few more thousands of wood for that (again) mainspring to clear.

[Blacksmoke]

Have seen many original longrifles with stocks torn apart because there was no movement allowed for the wood to move longitudinally!  Slot your log holes!  Fluctuation in humidity is the culprit. H.T.

[Spalding]

Seeing as it literally takes only a few minutes with a jewelers saw, I see no reason not too.

Bob

[smart dog]

Hi,
A slot 1/16" on either side should be enough.  I find the stock moves the most near the muzzle and less as you move toward the lock. The key hole to elongate is in the lug near the muzzle.

dave

[flatsguide]

Don’t slot the lug closest to the breech and like smart dog said slot the rest of them about a 3/16. This will give you best accuracy..
Cheers Richard