Tenon pins

[Bill of the 45th]

Bill, I've followed you on this, and another site for years, and absolutely consider you to be our TC expert.  You are in my opinion the most clinical in your quest for hunting accuracy, in the scientific way you go about  building a load for a gun.  Your methods are impeccable.  My point is that there is not necessarily no right or wrong, as long as Matt warrantees his work it's fine, but history pushes towards slots to relieve stress of weather over the years.  PM sent

Bill
 

[Dennis Glazener]

but history pushes towards slots to relieve stress of weather over the years.

Bill, I am not questioning you but I would love to hear of someone that has seen slotted tennons used on period original rifles. I am NOT saying I have not seen them but I have seen a fair number of original rifle tennons and I have never seen one that is slotted. I admit most of the rifles were southern mountain rifles but also have seen several that were not mountain rifles and have not seen a slotted one.

Please some of you familiar with early originals were the tennons normally slotted? Like I said earlier it makes all the sense in the world but I have several early 1800's rifles that are not slotted and no evidence of any problems.
Dennis

[Jay Close]

This a fascinating discussion. Just a couple of points.

First, a stock splitting from lack of  slotted tenons seems a catastrophic failure, indeed. I can well imagine it is a rare occurrence. I'd be more concerned with accuracy being effected. That might be a subtle enough issue that a manufacturer may never hear about. That is, just because no one has sent a rifle back under warranty complaining that the point of impact alters when shooting in the rain or after a series of rainy high humidity days, doesn't really mean that the phenomenon doesn't occur.

Historically, I'm not sure how common slotted tenons are. Certainly,  any barrel that employs the staked in staple is "slotted" just by the staple form. But I also know that 18th c. furniture makers often ignored wood movement in their furniture construction, or at least felt it not as significant as modern cabinetmakers do. I've also seen lots of cracked sides on period case goods because of differential wood movement. It may be that in homes lacking central heat and AC the wood movement wasn't severe or perhaps it was just slow enough to be accommodated in the object without failure.

By analogy perhaps the period gun builder could get by with unslotted tenons given how firearms were used and stored. I bet at least some chose to slot them, but not every tradesman chooses "best practice" even today. Yet, it's a small thing that might make a noticeable difference given our modern living environments.

NEWS FLASH: I just checked my photos of a Christian Oerter rifle dated 1774 -- slotted tenons and the wood is relieved on either side of the tenon too. Master Oerter was concerned about wood movement.

Anyone have thoughts on the difference between air dried and kiln dried wood and stability?

[LRB]

  Just my opinion, but I believe TVM is blowing smoke. I have seen pics somewhere of separated forearms due to expansion of the wood, but by my own experience, I have experienced a change back abd forth in zero that was corrected 100% by slotting the tennons.

[flintriflesmith]

Dennis,
Jay nailed several key points in his post. Modern forced air heat and have AC during the summer puts a recently made rifle under a lot more stress from expansion and Modern forced air heat and having AC during the summer puts a recently made rifle under a lot more stress from expansion and contraction due to moisture changes than living conditions ca. 1800.

In the late 1960s we shipped a rifle made in the CWF Gunshop to customer living up north. It had been made during the heat and 90% humidity of the summer in Williamsburg. When winter came, and the customer’s heat kicked in, the stock simply pulled itself apart at not one but two of the barrel pins. The relative humidity outdoors is low in the winter up there and in a house heated by forced air it can easily go down below 30%. The rifle was stocked in very curly maple and, although it was well seasoned, it failed due to the shock of the sudden shrinkage and the fact that the loops were not slotted.

If we had taken the rifle there by wagon or horseback and the owner had lived in a period house heated by fireplaces the stock would have adjusted over several months and may not have broken.

Shortly after that incident we began to look hard for a solution that would be period correct. We discovered that that most were pinned with such small diameter soft iron wire that the pins simply bent as the stocks changed slowly over the years. We also found that some of the better period rifles had slotted barrel loops for the round pins.

Knowing what damage occurs to stocks original rifles from removing bent barrel pins we decided to use slotted loops. We sort of independently hit on the idea of using longer slots progressively toward the muzzle THEN 10-15 years later we took apart a good quality European gun with the rear loop just drilled and each one toward the muzzle with a longer slot. That maker understood both wood technology and gunmaking. As Jay said not everyone used, or uses today, the best practices.
Gary

[LRB]

  An excellent, and irrefutable example from a true master of gun making. Can more be said ?? Flintriflesmith, I applaud you post, although it may have been just a tad overdue. This is one of those cases where common sense should prevail. Wood, no matter what wood, is not completely stable even in the best of conditions, and all too often, "Murphy" will rule, if he is allowed to.

[Dennis Glazener]

Jay,
Gary,
Thanks, that makes sense to me. All but one of the rifles I have built over the last few years were built/stored in my basement shop which is NOT air-conditioned and little heat in the winter. Maybe that's why I have not had problems. Maybe folks that bought them did but just didn't let me know. I have made furniture and had it to crack/twist etc when put in a modern home.
A friend and I built a nice cabinet out of oak for our church. It literally has split almost every board in it, none in a glue joint just down the middle! We did not allow for any movement, used glue and screws. Never saw such a mess after about 6 months inside the church!

Thanks, guess I will start slotting the tennons!
Dennis

[Dale Campbell]

With respect to unslotted tenons on modern barrels and stress on the barrel. 

Remember modern barrels tend to be lighter and thinner relative to old barrels.  It is easier to stress and change the point of impact due either to barrel heating faster than the wood when shot or wood expanding and contracting with changes in humidity. Think about it.  You're on the line shooting an A weight .45 with four X's.  Do you want some guy pushing down on the end of the barrel while you're aiming for the fifth?

[Don Getz]

Good subject.   Some guns will work fine with just a hole drilled thru the tenon, others will not.   Every piece of wood is
different.   In my experience, we had a local shooter came to the shop complaing about our barrel not shooting well.  We
took the gun apart, saw the drilled holes thru the tenons, we elongated the holes and it solved his accuracy problems.  I
also owned a great Isaac Haines rifle built by Mike Gahagan, great piece of unusual wood.   Every time I took the gun along to the super humid place called Friendship, the stock would swell to the point of where the nose cap was about
1/16" beyond the muzzle of the barrel.   As I stated before, not every stock will do this, but when it does it can create
problems, both in accuracy and perhaps a split stock or bent pin.....it can happen...........Don

[Swampwalker]

Bottom line is, we know the wood will move with time and changes in humidity.  It's silly not to slot the tenons to allow for some movement!

[Dr. Tim-Boone]

Probably not....unless one of the stocks turns out to be one that grows and shrinks easily and to a significant degree.........or you stay in a highly humid environment for longer than a few hours.......   

Just me.......its so easy to drill another little hole right on either side of the one that is there and file it smooth so the pin can move if needed......jeweler's saw makes it even easier...

are you going to worry about it cracking your stock in the middle of the night sometime??  If so then its an easy modification to give you piece of mind..... if your aren't worried then put her together and get ready for hunting season!!

[Jerry V Lape]

I find it curious how there is actually resistance to accommodating the possibility of wood expansion and contraction.  I have several pieces of furniture in the house made of real wood (not veneer over mdf).  On all of them if you look at the edges of the panels (which are set in rabbets rather than glued/nailed/screwed) there is clearly evidence of 1/4" to 5/16" of movement of those panels over their 12" - 15" panel width.  Admittedly, Arizona and it's very low humidity is at play here.  Wood in this area usually drys down to 7% moisture content which changes cell structure quite a bit. This past month we went for more than a week with humidity at record levels of only 2%. So what would happen if I took my longrifle to a humid place for a couple weeks of hunting.  You cannot seal humidity out or into wood with any of the traditional finishes.  And if you did, any screw hole or unfinished surface such as under your nose cap or where barrel or pipe lugs penetrate the wood are sufficient to give it access.  Clearly a 1/4" change in forend length is going to make something ugly happen. 

[LRB]

  I wonder the same as Jerry. You asked a question, and  most of the answers did not fit your predetermined position on the matter, so you want to argue your position. You knew you weren't going to slot your tennons when you asked about doing it. No one here is going to change your mind, so just take TVM's advice, and forget it.

[Jerry V Lape]

Roundball, I apologize for coming across as being critical of your situation and choices. That wasn't my intention and earlier I stated I understood your reliance on the TVM warranty.  I can see in retrospect how that could offend.  Clearly none of us can look at your presented scenario and specifically answer what may cause your rifles to be distressed.  Obviously the ability to answer such a question is beyond our reach.  We have already answered what may cause damage and also the best ways to prevent the damage.  Aside from that not much more we can do to help.

[LRB]

  Nobody here being a smart aleck. I was dead serious. Jerry, you were no where near out of line, and wasted an apology. This guy has done this stuff before elsewhere. He likes to ask questions, then argue about the answers he gets. 

[chuck-ia]

I just feel better slotting the holes a little, don't know if it prevents cracking or whatever, but sure cant hurt anything either. Another thing, if slotting a 1/16" hole, or how ever big, I wouldn't think the slotted hole would have to be slotted to a perfect 1/16", couldn't you slot it bigger, keeping in mind it is the bottom of the tennon hole that pulls the stock snug to the barrel? Not a big deal, but seems a little easier putting a little pressure on the file towards the top of the tennon while sneaking up on the bottom. Am I making sense? chuck

[chuck-ia]

Thinking about this. I think most builders leave a little gap behind the plug tang for recoil, so the barrel could move back and settle in a bit, if the holes are not slotted it might recoil against the pins every shot. Just my thoughts. chuck

[flehto]

Although I do slot the bbl lug holes, provide wood clearances  fore and aft of the bbl lugs and do provide a small amoumt of clearance behind the tang and all these things do make sense to me, I  really can't say for certain if the stock will crack or the rifle will become inaccurate because these precautions weren't taken. I do know however that in the course of building a few LRs that I've had to plug and redrill  screw holes and go back and further elongate forestock lug slots because of wood contraction and/or expansion caused by the change in humidity. TVM supplied you w/ a written warranty which is something many COs wouldn't do and they're to be commended for this, but some of what's stated as to their reasons for not slotting the lugs and not elongating  the forestock slots fore and aft of the bbl lugs  doesn't make sense.  TVM produces an excellent product backed up by a warranty and you should feel confident w/ their assurances that no failures will occur due to not incorporating the above precautions. One point though...if you had built a few LRs and witnessed fairly large changes in the wood,  would this have any bearing on your decisions?.....Fred

[jeager58]

not only does the wood move with the humidity but the barrel moves when it heats up from firing, so since the barrel is anchored at the breech I have the pins slotted for forward movement .  1/16  pin   the total slot is 1/8 inch..phil;