tinker
.416 member
Reged: 12/03/05
Posts: 4835
Loc: Nevada
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Nice!!
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--Self-Appointed Colonel, DRSS--
"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...
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gungadoug
.333 member
Reged: 13/08/12
Posts: 285
Loc: NM
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BTW, even when I protected the Chrony with 2x4, and believe me I did have things covered, those dam wads will go sideways and sneak in from anywhere! Even when very carefully being in a position where neither end is visible, one of those will sail in there! I think, however, that I have solved the problem in a reliable manner.
I'll let my buddy send some over the Chrony, with the proper admonitions, and he can fix it!!
Doug
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tinker
.416 member
Reged: 12/03/05
Posts: 4835
Loc: Nevada
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Doug I have trouble with the chronograph under the bore rifles too.
It ain't just you I assure...
Cheers
Tinker
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--Self-Appointed Colonel, DRSS--
"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...
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CommandCar
.333 member
Reged: 18/09/10
Posts: 292
Loc: East Coast, USA
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Don't know why I forgot this, but Mike Rowe has a cherry cut to make moulds that cast .734ish H&H ammunition paradox slug copies. He made the cherry for me a couple years ago, should be perfect for the Lancaster.
Edited by CommandCar (24/01/14 11:47 AM)
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gungadoug
.333 member
Reged: 13/08/12
Posts: 285
Loc: NM
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Final update- For some time now I have been following Ross Seyfreid's advise. Fed paper hull trimmed to 2.5", 22.5 Unique, nitro card, 2 hard waxed 1/2" wads, 750 Fosbery style bullet cast at .730, LLA lube, and garotte crimp. This is close to being the most accurate double I own! I can consistently hit a bowling pin at 100 m. offhand both barrels! Though not many times- not a lot left after 10 or so hits.
Best, Doug
Edited by gungadoug (06/06/14 10:59 AM)
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tinker
.416 member
Reged: 12/03/05
Posts: 4835
Loc: Nevada
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Good!
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CommandCar
.333 member
Reged: 18/09/10
Posts: 292
Loc: East Coast, USA
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Quote:
I have acquired a Lancaster Shot and Ball gun, and after taking some measurements etc. have the following: Bores both at .730, 6 groove polygonal, very shallow rifling. Seems straight and uniform up to about 8" from the muzzle, where it imparts a slow twist, and about a light mod. choke. All this is very difficult to see, and I have no clue as to twist rate.
Doug
Doug,
Do you mind making an attempt to measure twist on your barrel? I really have to know. I imagine you would use a cleaning rod with a tight patch. Insert rod with patch into barrel, mark start location on rod, also put a mark on the top of the rod that is sufficiently long to not disappear in the barrel as the rod is pushed in. Push rod in and record stop location for 1 full turn. Mark stop location, the distance between start and stop would be your twist rate. If it is slower than your barrel length, you would measure 1/2 revolution length and multiply by 2 or, if really slow, measure 1/4 revolution length and multiply by 4.
Sorry for the step-by-step, but just I went through step-by-step on the off chance that you were unversed in determining twist.
Thanks for your Help.
CC
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gungadoug
.333 member
Reged: 13/08/12
Posts: 285
Loc: NM
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I'll try- likely be able to do this tomorrow. It may not be too precise, due to the very short section that actually rotates, it may be difficult to determine where that twist actually starts! But, we'll give it a go.
Doug
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gungadoug
.333 member
Reged: 13/08/12
Posts: 285
Loc: NM
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OK, I tried! Using the technique described, I can see no rotation. Possibly because the rifling is so shallow, and very smooth. If I try to figure this, I come up with maybe 1 in 54"??? I could be way off! It looks like 1/4" rotation in 6", if the circumference is 2.3", that would be 1/9th of a turn in 6"? This is all kind of a guess, and my math could be way off.
Best guess! Doug
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rigbymauser
.400 member
Reged: 15/05/05
Posts: 2021
Loc: Denmark
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Quote:
OK, I tried! Using the technique described, I can see no rotation. Possibly because the rifling is so shallow, and very smooth.
Yes!.
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CommandCar
.333 member
Reged: 18/09/10
Posts: 292
Loc: East Coast, USA
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Gungadoug,
Thanks for checking. Your math looks good. Appears to be a situation where it is like trying to measure the speed of light with a wristwatch, yardstick and a flashlight...
I was interested because, at least the early Paradox chokes are reported to be 1 in 36". Most of the modern rifled 12's sabot guns are 1 in 34" to 36" too. I am wondering what twist it takes to stabilize a Fosbery slug.
Thanks again for your efforts.
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DarylS
.700 member
Reged: 10/08/05
Posts: 27490
Loc: Beautiful British Columbia, Ca...
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In 12 bore - a short Paradox slug would easily be stabilized by a 72" twist, I'm sure, and round ball, easily at 100".
Greenwells formula will show the slowest twist necessary - usually a few inch faster twist is better than what is given by the 150 constant.
Greenwells formula doesn't seem to work well with round balls, for some strange reason.
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Daryl
"a gun without hammers is like a Spaniel without ears" King George V
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