Author Topic: Vertical stringing  (Read 10597 times)

Offline Dennis Glazener

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Vertical stringing
« on: August 07, 2010, 08:20:16 PM »
Took my .54 flint hunting rifle to the range yesterday to try to find a good load for it. It has a 38" Rice C weight barrel. Chambers Siler lock.

I was shooting 70 GR of 3F from a rest and it strung the 5 shots in a vertical group looked like each shot cut the first hole but about half a bullet hole higher (or lower).

When I used to shoot benchrest, assuming my holds were correct, this usually meant the load was off. So I tried 80 Gr of 2F and had the same problem. Had to leave so I didn't try anything else. Oh, on both loads I was using .010 patches and Lehigh Valley lube and I was shooting at 30 yards. I had been using .018 patches and they are far to hard to load for hunting purposes.

What should I work with next time patch thickness, powder charge or ? As you can tell I don't have much experience working on load development with a flint.
Dennis


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California Kid

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Re: Vertical stringing
« Reply #1 on: August 07, 2010, 09:01:53 PM »
Did you look at a recovered patch? Is it burned through? .010 is awful thin. How about .015.

Offline bob in the woods

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Re: Vertical stringing
« Reply #2 on: August 07, 2010, 09:30:39 PM »
My Rice barrel has deeper grooves than my other .54   I like a .530 ball and denim patch for hunting.
I use a .535 and the same patch for target shooting. You need a decent patch to make these shoot IMO
Patch is at least .018    You didn't mention the size of ball you are using, so maybe you can drop down a size?

roundball

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Re: Vertical stringing
« Reply #3 on: August 07, 2010, 09:34:11 PM »
What should I work with next time patch thickness, powder charge or ? As you can tell I don't have much experience working on load development with a flint.
Dennis

From my experience, I've never found a practical use for a .010" patch other than when experimenting with patch thicknesses...ie: a 005" and/or a .010" can be added to other main patches to temporarily try different overall thicknesses...but by themselves are usually too thin to survive the fire, too thin to hold any lube to speak of, too thin to really wedge into the grooves and transfer strong rotation, etc.

Also, if that Rice is a round bottom groove barrel, the .016" deep radius grooves on my Rice .58 made me move up from an .018" patch in a straight groove GM .58cal to a .022" in the Rice .58cal, because the round bottom grooves make it so much "roomier" in there.
« Last Edit: August 07, 2010, 09:36:36 PM by roundball »

Offline trentOH

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Re: Vertical stringing
« Reply #4 on: August 07, 2010, 09:48:07 PM »
Was the sun directly behind or directly in front of you?  The fact that the changes from shot to shot were so uniform leads me to suspect the light was messing with your sights.

Daryl

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Re: Vertical stringing
« Reply #5 on: August 07, 2010, 11:00:26 PM »
I  bought some material I thought was .015" for trying with over bore sized balls in the .40.  After washing it, I found it was only .012" thick, so I turned the entire 3 meters of it into shop rags.
.010 to .012" is useless for a patch in my most honest and humble opinion. RB spells it out.

Think about it.

If you have a rounded bottomed rifling by Rice, as RB says, it is about .016" deep.
If the ball you are using is .005" smaller than the bore, it already has .0025" windage on both sides to the tops of the lands and .0185" to the bottom of the grooves - each side.

If you are using a .010" smaller ball, it has .005" windage  on both sides of the lands and .021" on both sides to the bottom of the grooves.

Perhaps the crown needs some elbow grease, Dennis.  That may help you load a tighter combination.  That .010" patch and ball combo must  almost drop to the powder by it's own weight.

Leatherbelly

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Re: Vertical stringing
« Reply #6 on: August 07, 2010, 11:28:24 PM »
Den,
  As much as I hate to, I must agree with Daryls. ;D You might also need to break tradition and use a short starter.I'm thinking that a thicker patch will cure the stringing too.Maybe radius the crown with some fine emery.

Offline Roger B

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Re: Vertical stringing
« Reply #7 on: August 08, 2010, 02:04:31 AM »
I agree that you need a much thicker patch.  That being said; vertical stringing is usually either pressure, eyes, or light.  New barrels often need cleaning as they break in.  An increasingly dirty barrel results in increased pressure with the load which results in increasing velocities & vertical stringing.  Rapidly changing light will create optical distortion resulting in vertical strings.  Thats why bench & cross stick shooters have micrometer sights & adjust them frequently for wind & light.  Last; If your eyes are getting old like mine, lining up the sights with the target forces you to focus & refocus on the front sight, rear sight, & target which eventually leaves something fuzzy & can result in vertical strings.  I'd clean after every shot for a while & go to a thicker patch.
Roger B. 
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Offline Dennis Glazener

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Re: Vertical stringing
« Reply #8 on: August 08, 2010, 02:19:22 AM »
My mistake, I mic'ed the patches that I used, pre-cut, and they are .015 not .010.
It loads so much easier than the .018 patches that I thought they were .010.

I cast the balls and they mic .530. Sun was behind me but mostly in the shade.

I thought to look for patches but did not find any, strange because I found several sabot's from my friends bolt action!!!!!!!!!!!!!! muzzleloader. Grass/leaves are not that tall, not sure where the fired patches went!

I think I will go back to the .018 patch and may think about coning the muzzle if it shoots good. Yep Roger, old bad eyes! Supposed to have cataracts removed in a couple of months. Looking forward to seeing if I can shoot better!
Dennis

« Last Edit: August 08, 2010, 02:21:44 AM by Dennis Glazener »
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roundball

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Re: Vertical stringing
« Reply #9 on: August 08, 2010, 02:58:57 AM »

I thought to look for patches but did not find any, strange because I found several sabot's from my friends bolt action!!!!!!!!!!!!!! muzzleloader. Grass/leaves are not that tall, not sure where the fired patches went!


They can be hard devils to find sometimes for sure...slightest cross breeze and they'll land several feet off to the side...never find them 'cause we're not looking there, etc.
Or, if they were burning some, getting blackened , shredded, etc, they can blend in with ground & grass so well they're almost impossible to see.

Daryl

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Re: Vertical stringing
« Reply #10 on: August 08, 2010, 03:40:25 PM »
Burnt shredded pieces of patch are very difficult to find.

I tried .015" patches and got just that from my .010" deep .40. Yes - it takes more effort to load a tight patch - oh well.  I found I could use the .015" patch with a ball that was .002" larger than than the bore, but a .019" patch was more accurate. 

If innacuracy is OK, then by all means use whatever you want, Dennis. Afterall, it's probably a hunting rifle for you, not a trail rifle - if you can hit a 6" circle at 50 yards, it's a 50 yard deer rifle. If you want it to be able to shoot under an inch, you'll need to feed it differently.

Changing light conditions can cause elevation or windage error quite easily. Going from 'mostly shade' to sunny or varrying lighter sky easily causes one to hold more or less front sight - or to one side or the other depending on it's location.

Too, gas blowby reduces velocity, and residual fouling takes up some of that windage from the too-thin patch, producing more, then more velocity as the load gets tighter and tighter shot to shot. The result is usually elevation.  some guns shoot lower with more velcity, some shoot higher.

A good smoothbore will shot a 1" group at 25 yards.  I suspect a smoothbore with 2 sights would shoot 3/4" down to 1/2" or better.  25 yards is pretty much a waste of time trying to find an accuracy load, but is good for roughing in your sights while checking patches. 

Leanin Chair

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Re: Vertical stringing
« Reply #11 on: August 13, 2010, 02:52:20 AM »
According to old Dutch Schultz down in OHIO a vertical string means too much powder, a horizontal string means not enough powder.

northmn

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Re: Vertical stringing
« Reply #12 on: August 13, 2010, 02:09:37 PM »
70 grains is hardly too much powder in a 54.  Mostly I agree with what is stated.  An 016 deep rifling would need patches of at least 018 thickness.  A clean bore almost always chronographs lower velocities than a fouled bore whcih will start the stringing.  It takes a couple of shots for a chronographed string to settle down.  There is also the issue of heat build up as they get shot.  The best option would likely be a smaller ball and thicker patches.  Also as Daryl stated the use may dictate the accuracy requirements.  A hunting rifle that consistantly vertically strings with the first shot being lowest needs to be sighted in cold.  Our obsession with 5 shot groups is great for bullseye targets and next to meaningless for hunting rifles. 

DP

Offline bob in the woods

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Re: Vertical stringing
« Reply #13 on: August 13, 2010, 02:45:14 PM »
I had another thought , since it occurred to me that I had the same thing happen to me when I didn't elongate the holes in the barrel lugs. As the barrel heated up, it shot higher, giving me a nice vertical string.
Opened up the slots and problem solved. Something you might want to check??

Offline Dennis Glazener

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Re: Vertical stringing
« Reply #14 on: August 13, 2010, 04:48:53 PM »
Quote
to me when I didn't elongate the holes in the barrel lugs. As the barrel heated up, it shot higher, giving me a nice vertical string.
I will have to check that. I doubt seriously that I elongated the holes. I rarely do.
Dennis
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California Kid

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Re: Vertical stringing
« Reply #15 on: August 15, 2010, 07:46:04 PM »
In my experience slotted or unslotted underlugs, didn't make any difference. Kind of like square patches or round patches. Just what has worked for me. I usually slot them but have shot the same gun both ways and no difference.

Offline Darkhorse

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Re: Vertical stringing
« Reply #16 on: August 23, 2010, 11:23:20 PM »
Dennis, your problem is simple. It's that Lehigh Valley your using. Just mail me all your supply and try something else.
Problem solved.
American horses of Arabian descent.

Offline Dennis Glazener

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Re: Vertical stringing
« Reply #17 on: August 24, 2010, 01:37:10 AM »
No deal! That's some good stuff. Not crazy about the spray bottle but I like what's inside.
Dennis
"I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend" - Thomas Jefferson

Offline Jerry V Lape

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Re: Vertical stringing
« Reply #18 on: August 24, 2010, 02:59:59 AM »
My experience with hunting loads in a .54 would indicate a heavier powder load.  I use 90gr of FFg Swiss, an .018 denim patch and SPG lube rubbed into the outside of the patch material until it is completely filled.  Gives me less than 3" group at 100yds which is more than adequate for elk at 50yds or less.  My rifle is a little on the light side so with that load  I need to hang on with the left hand. 

Does that Lehigh Valley lube work for a long term lube in a hunting load? 

Daryl

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Re: Vertical stringing
« Reply #19 on: August 24, 2010, 03:30:38 AM »
Taylor tested it and found it lacked longevity protection.  Hoppe's #9 Plus was much better and worked over a 5 day period.

Dphar swears by Neetsfoot oil and I like mink oil sold by track.  I will use either of these oils, no liquid solvents with water in them.  The mink oil lubed patches stay quite soft in cold weather.  I suspect Neetsfoot oil will as well.  Any warmth at all instantly makes mink oil wet.  In my .40 and .32's both of these oils allow unlimited shooting without wiping.

Offline smylee grouch

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Re: Vertical stringing
« Reply #20 on: August 24, 2010, 05:38:15 AM »
Hi Dennis: One thing I have done while shooting off the bench is to get gun in the shooting position and then close my eyes for about 15 sec. and then open them and try to get your shot off as sone as posible. This helps me with my old eyes as trying to focus for too long a time will usualy tire your eyes into fuzzyness.    Just a thought. Good luck.    Gary

Offline hanshi

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Re: Vertical stringing
« Reply #21 on: August 24, 2010, 08:22:55 PM »
That must be my problem.  I've been closing my eyes just before pulling the trigger and not opening them until the smoke clears.  ;D
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