.40 cal weather catastrophy

[Roger B]

So I went to our Feb. "chilly shoot" with my carefully prepared GM 1" .40 halfstock.  Just the week before I had worked out a load of 55grs FFFg. .020 Oxyoke, and Hoppes 9 and had it cutting Xs and grouping very well at 25yds.  At that time it was dry with the temp in the high 50s and the wind blowing like laways.  I shot it offhand thereafter and got similar good results.  Fast forward to yesterday.  Showers, temp in the 40s, and wind dead out of the north blowing as always.  I shot groups of 5 shots at 25yds that could be covered by a 50 cent piece.......3" low and to the left.  Consistently.  No hangs or misfires, but the breech was wet with moisture coming out of the nipple.  The rifle had an excellent crack and normal recoil.  Why?  Granted the light was different; overcast instead of partially sunny, but 3" low and left?
Roger B. 

[hanshi]

Excellent shooting under bad conditions.  Congratulations and can you post a target or two?

[Roger B]

Targets were all turned in, though I don't know why.....they were all reentry (specialty) and none of the groups scored a single point.  My single scoring shot was a called flyer that I pulled.  I got disgusted and went to the clubhouse to drink coffee, eat chili, and warm up.  There were other guys doing very well and my holds were good, so why did I shoot so far low and left consistently?
Roger B.

[heinz]

Roger, 3 inches is pretty significant ant 25 yards.  Is it possible you bumped one of your sights and changed the alignment? A 1" 40 cal barrel I would not expect to change much from the stock changing with moisture unless you have really uneven bedding in the barrel channel. The light conditions may have made the sight picture different  causing you to hold the front sight higher, but that is usually just an inch or so at that range.

Maybe if you give 1 inch to the wind, 1 inch to the lighting conditions, you can explain the the rest by a cold barrel, kept that way by the rain, and a slightly damper load.
All skill is for naught if and Angel p*** in the flash pan (old German saying)

[bob in the woods]

Damp perhaps acted on the stock/barrel .  The contact points , wedge tightness , stresses etc shift .  The point of aim shifts. Make sure the stock is sealed in the barrel channel, and at the breach.

[plastikosmd]

well if it makes you feel better, i need another cup of coffee. I read " 40 caliber weatherby" not "weather." I thought cool, a weatherby muzzleloader. I got to the end and couldnt find the weatherby reference, time to wake up.

Do u swab between shots? That moisture was rain or hoppes?  My guess was u were not getting full powder ignition, even with same report.

[blunderbuss]

 

 I always heard that the gun shoots low into a head wind and high with a tail wind. If the sun is out it will shoot to which ever side the sun is on.

[Daryl]

I cannot fathom the 3" low and left problem, Roger.  Like Heinz said, that is a LOT for 25 yards - but for 100yards or maybe even 50yards, I can see it with side wind not held for, or perhaps due to strong side lighting. Nasty.  I guess it's back to the range for more testing.

[Jerry V Lape]

I know that if I had been the shooter my first assumption would be I had developed some NEW bad habit in trigger or flinch or maybe just the extra clothing worn that day versus your normal at time of developing the load? 

[Roger B]

We were under cover and the gun was not wet, but there was a lot of moisture (black) around the nipple seat.  The sights are still good and solid.  I'll take it out asap on a good day and see what happens.  I thought perhaps the moisture/humidity had something to do with it and someone else might have had a similar experience.  I can't imagine that the shooter was to blame  .
Roger B.

[Roger Fisher]

We were under cover and the gun was not wet, but there was a lot of moisture (black) around the nipple seat.  The sights are still good and solid.  I'll take it out asap on a good day and see what happens.  I thought perhaps the moisture/humidity had something to do with it and someone else might have had a similar experience.  I can't imagine that the shooter was to blame  .
Roger B.

Roger, Roger, Rodger!!  Been there and done that on a v bright sunny day shootin over snow at 25 yds shot consitantly 2- 2 1/2 inches low with good holds and I blamed the lights up sights up syndrome..  (Remember now I was using up some Schuetzen 3 f since I was near out of good ol Goex.  Took her to the range and shot with goex and she was on the money.  Go figure.  So, I ask you young fella had you changed powder

My problem that particular day I do believe was a combination of v bright light on that frt sight and going to Schuetzen (less velocity)

[heinz]

Roger, you did not mention it was a percussion gun.  Percussion guns are reqularly penalized by the Deity especially in damp or snowy weather.  If give us godly flint shooters a chance.

[Dave K]

Where were you holding your front blade? In the bottom of the rear sight notch or flat across the top of the rear sight?

[Daryl]

 No hangs or misfires, but the breech was wet with moisture coming out of the nipple.   Roger B.  

Heinz - he was subtle - easy to miss.

[skullcap]

sighted in on level ground. then shooting down hill or uphill will change your sighting. and in turn the point of impact.

[Pete G.]

Humidity causing stock swelling and barrel pressure points?