Author Topic: Vertical hold weirdness  (Read 9640 times)

Offline Canute Rex

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Vertical hold weirdness
« on: January 19, 2015, 03:38:31 AM »
I have been shooting my Leonard Day 54 caliber smoothbore matchlock and trying to figure out the sight picture.

The numbers are .530 ball with .010" patch, Hoppes #9+ and a little spit for luck, 75 grains Goex 3F. Oh, and 10mm bucked and nitred braided hemp match.

At 25 yards it shoots dead on. I can keep my shots in a 3" group offhand. Variations by me, not the gun.

At 50 yards it shoots 6" high. If I aim dead on I get a rough group at 12 o'clock. I have to take a really low 6 o'clock hold to get the shots in the black. Horizontally I can generally keep my shots within 4".

You'd think it would be the other way around, 6 o'clock at 25 vs dead on at 50 yards. But you'd be wrong.

Is it that at 25 yards the ball is still on its way up in a long arc? Hard to imagine. Any other 54 smoothie shooters want to weigh in on this?

Offline WadePatton

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Re: Vertical hold weirdness
« Reply #1 on: January 19, 2015, 03:52:38 AM »
I'm not a smoothie shooter, but to answer your question, yes. 

  ;)
Hold to the Wind

Offline bob in the woods

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Re: Vertical hold weirdness
« Reply #2 on: January 19, 2015, 05:38:56 AM »
Remember that your eye is the rear sight. Stock design/ your hold is everything with a smoothbore…at least that has been my finding.  If someone watches you mount the gun, and then draws an imaginary line from the front sight to your eye, it is possible to approximate the height of a non existent  rear sight at it's usual location.  I like to test fire my smoothbores before I finish them so that I can make alterations to the stock to get the proper hold.  Others may have a completely different way of doing things , but this works for me. My smoothbore is very accurate and consistent

Offline Canute Rex

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Re: Vertical hold weirdness
« Reply #3 on: January 19, 2015, 07:25:12 AM »
I sight this one using the flush end of the tang screw as a horizontal reference. (Old style tang screw with the head under the trigger guard) For vertical I hold it so that a square of front sight shows above the highest point on the breech.

I had Leonard Day install a tall (1/4") front sight. Comparing the diameter at the muzzle and the width across the flats at the breech I figured that this would give me a line of sight across the breech pretty much parallel to the centerline of the bore. The tall front sight also reduces mirage.

Offline Canute Rex

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Re: Vertical hold weirdness
« Reply #4 on: January 19, 2015, 07:33:06 AM »
So Wade, that would mean that I need a taller front sight. Except that it would depress my POI at 25 yards as well, but roughly half as much as at 50. Hmmm. Taller sight and more powder = flatter trajectory and closer sight picture at 25 and 50?

Offline WadePatton

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Re: Vertical hold weirdness
« Reply #5 on: January 19, 2015, 07:53:44 AM »
Well really there shouldn't be 6 inches difference in 50 and 25 at "normal" velocities.  Couple-three is more like it.

Really should go over this with smoothie/one-sight shooters as there's likely more going on here.  Maybe strap on a temporary rear sight, see what happens.
« Last Edit: January 19, 2015, 07:58:26 AM by WadePatton »
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Offline trentOH

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Re: Vertical hold weirdness
« Reply #6 on: January 19, 2015, 03:37:48 PM »
Shoot it again, at 65 to 75 yards. I know the unrifled shots will group even more loosely, but if the effect is that it is shooting even higher, then I would suspect the barrel is bent slightly upwards, and will keep throwing the balls even higher as you get further from the target.

Offline Daryl

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Re: Vertical hold weirdness
« Reply #7 on: January 19, 2015, 09:27:30 PM »
6" difference sounds as if you are changing your head height when shooting at the longer range. I concur with Wade in that the ball is still going up.

My rifles with sights - pretty much all of them, seem to shoot 1/2" to 1" higher at 50 yards than their impact at 25 yards.  This means if sighted dead on at 25 yards, the balls will impact roughly (centre of the group) 1/2" to 1" higher at 50 yards with the same sight picture.

With my smoothbore, a .62, I cannot tell where the centre of the group is at 50 yards as the pattern of ball-impacts is all over the freeking place and changes each time- no consistency.

LB's 20 bore that we shot, however, some years back, at both 25 and 50 yards, followed what my rifles do, as the centre of it's 50yard, 3", 5 shot group was approximately 1" above the impact centre at 25 yards. It, unlike my own, was a good shooting smoothie. Mine is for sale, BTW - LOL.
Daryl

"a gun without hammers is like a spaniel without ears" King George V

Offline flinchrocket

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Re: Vertical hold weirdness
« Reply #8 on: January 19, 2015, 10:19:33 PM »
If using the barrel flat at the breech for a reference point, say 1 1/8 barrel, your line of sight would be
only be 9/16 from the center of the bore. If you are sighted at 25 yd, this would put a line through the center of the bore 9/16 above the line of sight at 50 yd. Close to Daryl's rifle! The ball should follow
the line of the barrel until gravity gets the best of it, around 50 yd. So, I'm like Daryl, I think your
doing something different with the 50 yd sighting.

Offline Canute Rex

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Re: Vertical hold weirdness
« Reply #9 on: January 20, 2015, 01:55:48 AM »
The breech is, in fact, 1 1/8" across. Up and down, too. The muzzle is 3/4" and the front sight is 1/4".

So the front sight is 3/8" + 1/4" = 5/8" above the centerline and the breech flat is 9/16" above the centerline. Only 1/16" difference.

With about a width (3/32") of front sight peeking above the flat of the breech I should be shooting almost dead on the centerline.

1/32" up over the 40" from sight to breech. Using my handy sight adjustment spreadsheet, that 1/32" would raise my POI 1.5" at 50 yards. Not six inches. I'd have to have my front sight a hair over 1/8" high to get 6" at 50 yards.

Maybe I'm exposing more front sight than I think, thus lifting the muzzle. It's way out there and looks mighty small. I'm thinking I might paint the back side of the front sight black except for the top 1/16".

Thanks to everybody for the input. Got me thinking, which is dangerous. 

Offline Daryl

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Re: Vertical hold weirdness
« Reply #10 on: January 20, 2015, 08:24:15 PM »
It would be nice if projectiles flew exactly as the math says they should - trouble is, they don't.   If they did, bore sighting with lasers would be capable of sighting in rifles - it does not happen except rarely.  I have used a commercial, high quality bore sighting system for aligning the sights to the bore since 1975.  I have observed 2 rifles that did exactly what the bore sighter indicated and heard of one or 2 others. That's it, in 40 years of bore sighting rifles.  There are many factors that dictate the flight of the ball or bullet after it leaves the bore.  Was the bore EXACTLY in the middle of the barrel, all the way from breech to muzzle?  Shilen and Douglas say this happens so infrequently, they mark such barrels as SUPER MATCH.

We know that most barrels are bored, rifled then the flats milled on concentric to the bore - hmmmm.   Barrel harmonics, flexing and expansion also come into the physics with barrel whip or movement as the ball travels down it.  Perhaps these are the reasons a bullet or ball does not travel exactly according to the math of sight elevation?

What we have, I believe, are trends. We are blessed with the imagination and/or skill to adjust the sights to allow us to sight in our rifles and smoothbores when they do not follow the math for, whatever reason.

Velocity plays a part in sighting.  The longer the projectile is in the bore, the greater the chance that it is in the bore while the gun itself is recoiling - up or even perhaps to a side, or even whipping in a 1/2 circle depending on design and fit and any irregularities or hard spots? in the steel.  Guns also print differently with different people shooting them- ow they hold the gun, how it recoils with their hold and how they see the sights.  Taylor's rifles, for instance, shoot 2" low at 50 yards when I shoot them. 

That brings us back to the C word.  "Consistency" - yes - it is most important - in all aspects, from loading to holding, to aiming, to breathing, to trigger squeeze - all are of equal importance.   When everything is perfect,
Murphy shows up.  
« Last Edit: January 21, 2015, 09:46:32 PM by Daryl »
Daryl

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Offline Dphariss

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Re: Vertical hold weirdness
« Reply #11 on: February 10, 2015, 07:14:01 PM »
Since I cannot see how this is possible so there are questions.

How high is the front sight from the bore c/l?
Do you have an actual velocity?
Is the hold a dead on hold i.e. the top of the front sight covers the impact point/center of aiming point?
Or is it a 6 o'clock where the top of the front sight is at the bottom of the impact or aiming point.   If the target is 3" in diameter then with a 6 o'clock the gun is not dead on at 25 its 1.5" high at 25.

This is for top of front sight at center of group.
This is 1400 fps which might be low. But it shows that with a dead on hold the ball being high at 50 is "difficult". This is with the front sight .75 over the bore c/l.



Now with a 6 o'clock hold its possible to be on at 50 but not 6" high.
If we increase the velocity to 1600 and make the ball strike 1.5" over the top of the front sight at 25 we have only about 2.6" high at  50 and dead on at 100.
6" high at 50 gives this for 1600 fps.


Dan
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Offline Dphariss

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Re: Vertical hold weirdness
« Reply #12 on: February 10, 2015, 07:22:14 PM »
Changing the front sight height to .625 changes the trajectory very little.

Dan
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dagner

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Re: Vertical hold weirdness
« Reply #13 on: February 11, 2015, 10:31:08 AM »
 daryl

  I agree on your center boring . called run out. don getz told me he considered .030  over a 36 inch barrel great.most of muzzle loading barrel makers had a real problem with deep well drilling .my buddy paul Griffith got fed up with it and made his own super deep well drill .he was getting under .010 on 48 inch barrels.i watched my friends that realy shot smoothbore competivately bend the $#*! out of their barrels to make them shoot

Offline Long Ears

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Re: Vertical hold weirdness
« Reply #14 on: February 11, 2015, 07:30:03 PM »
Interesting thread. The way I understand it is the projectile never rises above the line of the bore. So you are lobbing the ball by actually sighting high. So at zero being 200 yds then anything closer will be some what high depending on the location of the target in the arc. This is why a faster flatter projectile if more forgiving at closer ranges. Is this correct? Bob

Offline Daryl

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Re: Vertical hold weirdness
« Reply #15 on: February 11, 2015, 08:00:50 PM »
It is right, Bob - A ball is always dropping from the line of the bore - if the hole is in the centre of the bore, once the ball leaves the muzzle it is always dropping from the line of the bore.   If the hole is angling up inside the muzzle end of barrel, the ball will actually rise above what appears to be the line of sight, even though the pure physics make it drop immediately, it simply appears to be angling upwards, but that is due to a manufacturing error, not a defiance of physics.

Think about Douglas octagonal 'blanks'. The instructions indicated you were to put the thin spot at the top or bottom.  That was due to the run-out that occurred during the deep hole drilling stage of making the barrel, the hole did not end  up in the middle of the octagonal blank.  

If the thin spot was placed at the muzzle's top, the ball was actually angling up above the plane of the barrel --- at the muzzle. Thus, that barrel would shoot high with perfectly even height sights,seemingly breaking the laws of physics, conversely with the thin spot at the bottom, it would shoot low - wow - gravity is heavy today - more powder! just joking.

If the thick/thin muzzle was mounted sideways, they'd shoot to one side or the other as the 'angles' declared.

If these thick and thin 'ends' were placed at the breech, by the time the hole got to the muzzle, it might have run in the centre of the barrel for long enough length that the ball flew true - Yahooooo.  Any barrels Douglass drilled that ended up with the hole in the middle at both ends, why, they were called XX or XXX or some such super match designation which allowed them to charge more for these 'perfect' barrels.  Yes- Douglas barrels shot well and were accurate, no matter if the holes were in the middle or not.  

However, it was impossible to tell if the hole was in the centre all the way though and if it angled at all inside that octagonal tube.  If the hole was angled, it would throw the ball in the direction of the 'angle' - left, right, up or down or any directional combination thereof- if it angled, that is. Adjust the sights and be done with it.

For example, I shortened a barrel by 4", which had the hole centred at both ends. When I cut the 4" off the muzzle, it was plainly obvious that the bore was not even close to being in the centre of the rifle's tube.  Now, this barrel appeared to be a perfectly straight, tapered barrel.  Thus, where the hole approached the side of the barrel on one side, the wall was only some .030" thick, whereas on the other side, it was almost .100" thick.

 Such a barrel will not throw the ball straight with the 'line' of the sights, indeed it was sloppy mfg'ring.  This off centre deep hole drilling, is not restricted to muskets or Douglas barrels by any means. It happens. When it does, the deep hole drilled blank is usually chucked on centres and planed or turned perfect straight between the breech and muzzle - but - is the hole actually straight inside?  Maybe it is only in the middle at the breech and muzzle?  Where it is and where it goes will determine if it shoots in line with the 'plane' of the top flat  or rounded surface. Sometimes they do.

Today, the big name makers of modern barrels have gauges, air gauges, X-ray machines and other magical instruments and methods that tell them if the hole is actually straight through the blank.  Not only how straight and even the hole is, as in never varrying in diameter or off centre more than .00015" (1 1/2 ten-thousandths"), it becomes not only a match tube, but a super match tube.

Nowadays, some are also measured for consistency (that word again) of the rate of twist, and the attempt is made to cut the barrel's muzzle where the rate of twist is actually increasing - slightly - an almost imperceptible amount of gain twist, but it can be enough to turn that bench rest barrel into a screamer barrel, one that seems to defy logic and physics.  They are few and far between.
« Last Edit: November 05, 2015, 08:44:57 PM by Daryl »
Daryl

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Offline Kermit

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Re: Vertical hold weirdness
« Reply #16 on: February 11, 2015, 09:17:54 PM »
My old black-and-white analog television sets had a knob for adjusting vertical hold.
"Anything worth doing is worth doing slowly." Mae West

Offline Canute Rex

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Re: Vertical hold weirdness
« Reply #17 on: February 12, 2015, 04:37:45 AM »
Thanks for all the input. I have done a bit of shooting since my last entry and I have gotten the thing somewhat under control. (Shot 7 out of 9 with it at the Southern VT Primitive Biathlon, including one of the killer half-a-playing-card gongs at the end.)(Spent the next day randomly spraying lead around the countryside with my flint rifle. Couldn't hit a cathedral from the inside. Go figure.)

To answer Dan's questions, I was using a dead on center hold at 25 and 50 yards. No idea about velocity. Front sight 5/8" from the c/l.

What I have done more recently is to paint the back of the front sight flat black except for a thin line right at the top. Basically the corner. At 50 yards I expose just that shiny corner - make it disappear, then raise the muzzle so it just barely winks at me. That allows me to use a 6 o'clock hold at 50 yards and get the balls in the 4" square. Same sight picture but dead on center at 25 yards.

I am thinking that the off-center speculation is right. I may have a barrel that is drilled a bit low at the breech. The muzzle is thin, round, and symmetrical. I may have also been slightly changing my sight picture when focusing on a more distant target, exposing more front sight. The combination gave me that six inch vertical drift.

Kermit, I like the way you think. This being the 21st century, I'm going to make a socket in the side of my matchlock so I can plug my iPhone into it. There must be an accuracy app.

Offline Kermit

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Re: Vertical hold weirdness
« Reply #18 on: February 12, 2015, 09:29:43 AM »
But don't they only work with stainless inlines?
"Anything worth doing is worth doing slowly." Mae West

Offline Daryl

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Re: Vertical hold weirdness
« Reply #19 on: February 14, 2015, 08:49:09 PM »
But don't they only work with stainless inlines?

lol
Daryl

"a gun without hammers is like a spaniel without ears" King George V

Vomitus

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Re: Vertical hold weirdness
« Reply #20 on: February 15, 2015, 11:33:17 PM »
   My .540 smoothie shoots better with more powder. With a slight "cocked over" position, it hits nothing I'm aiming at. My gun shoots a full sight(no barrel showing) at all close ranges, I just adjust on the target with my same hundred yard hold.(added: a trick I learned from Roger Fisher) My powder charge is 80gr of 2F Goex, 025(compressed) patch  and a .513 RB. It pounds the 100 yard gongs!
« Last Edit: February 16, 2015, 10:37:01 PM by Leatherbelly »

Offline Daryl

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Re: Vertical hold weirdness
« Reply #21 on: February 19, 2015, 07:30:15 PM »
Yeah - we hates those 54 smoothies. They be nasty guns.
 ;)
« Last Edit: February 20, 2015, 10:03:25 PM by Daryl »
Daryl

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pd230soi

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Re: Vertical hold weirdness
« Reply #22 on: November 05, 2015, 12:07:03 AM »
Sort of a simple question, but.... is that patch too thin to give you repeatable results?

Offline Hungry Horse

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Re: Vertical hold weirdness
« Reply #23 on: November 05, 2015, 02:33:08 AM »
 It's a .54 smoothbore matchlock for Pete sake. This is like saying I am spitting watermelon seeds at twenty feet, with my bi- focals on, and can't get a group smaller than two feet, what am I doing wrong? You have to work within the reasonable expectations of the firearm. JMO.

  Hungry Horse

Offline Daryl

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Re: Vertical hold weirdness
« Reply #24 on: November 05, 2015, 08:49:35 PM »
When my hankies (snot rags) become only .010" thick, I sneeze right through them. They are garbage.
Daryl

"a gun without hammers is like a spaniel without ears" King George V