suddenly shooting high?

[Black Jaque Janaviac]

Took my TVM .54 out yesterday to make sure she's ready for deer season.  For whatever reason shes shooting about 5" high at 50 yards.  The group is acceptable.  But I don't like it printing that high.  I'v had this gun for 17 years.  The only thing I can figure is I don't recall ever sighting in when temperatures were this cold.

I had some difficulty with groups changing location on the paper from day to day, and I thought I corrected this by elongating the pinholes in the staples. 

Do I need to ream them out more?

[hanshi]

That wouldn't be a bad idea as it is IMHO the most likely culprit. 

[smylee grouch]

I would question it shooting high for that reason but would check it out with about 3 more groups all the same combo,range and target aiming spot. Then I would check the same combo's with a different hold on the bench to see if that makes it shoot high, low or off to the side for that matter.

[Flint62Smoothie]

Have you pulled it from the stock recently??

[Mike Lyons]

I’m waiting patiently for the answer to this question.  I have been grouping decent groups in different places every time I shoot with two different rifles. What are pinholes in the staples?

[Marcruger]

The tabs that hold the barrel to the wood are "staples", "loops" or "draws".

The pins or wedges pass through these, holding the forend to the barrel. 

Some guns are built where the opening in the staple for the pin to pass through is a simple small hole.  Often the size of the pin or slightly larger.  If the wood or metal shrinks or swells that places the barrel and stock in opposition to each other longitudinally.   This tension can change the POI.  This can happen for example when the barrel heats up on a cold day's shooting. 

An accepted way to help with this issue is to make those holes into slots towards front and rear.  That way the wood is still held to the metal, but either can expand fore and aft without binding if the opening is a slot. 

I am sure there are masters out there that can explain this way better than I can.  I look forward to hearing the correct terms and methods. 

I hope this helps a little.  God Bless, and best wishes,   Marc

[Pukka Bundook]

Black Jaque,

Different lube?

[rich pierce]

The tabs that hold the barrel to the wood are "staples", "loops" or "draws".

The pins or wedges pass through these, holding the forend to the barrel. 

Also called underlugs.


I will say, despite all the knowledge about the need for slotting holes in underlugs so the stock can change move with humidity without changing pressure on the barrel, I don’t see slotted underlugs holes on originals.  Doesn’t mean it’s not important.

[Martin S.]

Wood does not change much, if any, in length.

Wood moves in width.

If you have a table or cutting board with breadboard edges, you can see this for yourself.  The breadboard edge will stay the same length, but during the year the table top or cutting board will shrink and swell across the width.

[Black Jaque Janaviac]

Flint62,
No, I have not pulled it from the stock recently.  Should I be looking for something?

Pukka,

Same lube as I've used all summer - deer tallow.

MarcRuger,
You've explained it as well or better than I could. 

Martin,
wood swelling may be a factor of changes in humidity.  However, the differential expansion/contraction of wood and metal is more of a factor with changes in temperature. 

[Black Jaque Janaviac]

Oh.  And I took it out again today.  Still shooting 5 inches high.  Today I tried reducing the powder charge and still got groups too high.  I don't mind a little high at 50, but 5-6 inches is too much. 

[Daryl]

Sorry, can't help. I have never had this happen to me.
For example, my .69 has not changed POI in 32 years.
Also, the barrel wedge fits the wedge - no slotting- never have
in any of my guns.

[Black Jaque Janaviac]

(sigh)
Last night I removed the barrel and lengthened the pin holes in both directions so that all three are about 1/8 long.

Shot it today. . . and no improvement. 

This just drives me insane.  Years of good service.  No change in load, powder, patch, or ball.  No damage to the sights.  And . . . wow . . . I don't get it. . . half a foot high at 50 yards!

I'm tempted to wrap the dang thing around a tree. 

The front sight is already a pretty tall front sight.  I don't have time to order and replace a rear sight.  Guess I'll just have to hope that I can remember to aim low in the heat of the moment.

Grrrr!

[Mike Lyons]

You could file down the rear sight.

[Black Jaque Janaviac]

I suppose I could.  But I don't trust that it will remain sighted in anymore.  I went through this early on when I first got the gun.  I'd file the sight until I had it dialed in.  Then some months later I'd shoot it and find that I must have over-filed.  So I'd get a new front sight.  Then I learned about slotting the pin-holes in the tennons.  And these problems went away for many years.  Now they've reared their ugly head with only days until opening of the season. 

I get the feeling I'm barking up the wrong tree now and the problem isn't the pinholes but something else.

[Mike Lyons]

Have you lost or gained weight?  Maybe your holding the rifle to your face differently.   I’m in your same boat sort of.  I think my problem rests more on the shooter.

[Black Jaque Janaviac]

Lost weight.  Nothing dramatic.  From 218 to 208.  I'm not convinced that this would be the cause since my eye still lines the sights up the same way. 

This is from both benched and off-hand positions.  I tried letting the forearm rest directly on the rest, and putting my hand between the forearm and the benchrest (to more simulate off-hand shooting).  I suppose I could let someone else shoot it.  T

[bgf]

Very different batches of powder?  I finished one batch of goex 2f and the next batch was 2" or so low On the same day; other way around, it would have been high.  Also, touch hole or nipple wear/replacement can change elevation.  Did you put new nipple or liner on?

[PPatch]

I would go back to the bench rest position and see if the rifle settles down. If so I would suspect that your hold on the rifle, or sight picture, changes when you shoot offhand; but if it shoots alright off the bench then you know it is something else. In that case, impact point going high when standing, compensate with a little Kentucky windage when shooting offhand. Are you sure you aren't flinching? That will sneak up on you sometimes and you may not know it. Try some dry firing while standing. Are you dressing differently now that it is colder? The bulkier clothing might be the cause.

Hope that sparks an idea for you.

dave

 

[Black Jaque Janaviac]

Ppatch,

Sorry, there's another similar thread about a guy shooting high when he switches to off-hand.  My problem is indeed the gun shoots high because it shoots 6" high BOTH from the bench and offhand.

I did change the torch hole a while back, but had since shot it with the new liner and didn't have any problems with it in the spring.

[bob in the woods]

Last year a friend helped load my vehicle to go to an event. My rifle was along side a shooting box, and he shut the door on it.  My shots at the event were 1 foot + off to the left. So much for scoring that day. The barrel was bent, and it took a bit to get it straight again.  You may have accidentally done the same...A thread run through the de breached barrel will tell.

[Mike Lyons]

Re-sight it in and go with it.  That’s about all you can do. 

[smylee grouch]

Black Jaque: try putting a series of tape marks on your forarm and shooting five (10 would be better) five shot groups and see where the groups end up using each of those forarm holds and use the same load otherwise. This will give you a better look at your self and save those targets. Same loads different hold I bet will tell you what you want to know.

[Daryl]

Re-sight it in and go with it.  That’s about all you can do.

spot-on

[Black Jaque Janaviac]

Well I decided to just keep my shots close and aim low.  I shot the gun twice during the deer season.  Both times it hit right where I was aiming.  Unfortunately the deer I shot was hit too low in the chest.  I recovered her, but it was not an acceptable kill.  I put the gun away and used a backup caplock.  At the end of the season I unloaded the flintlock and hit the mark about right at point of aim.

This is madness!