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A point of interest (perhaps) on bore guns and their shooting!

I have been re-reading WW Greener's "The Gun and It's Development" again, for perhaps the upteenth time as a refresher. The London Gun Trials of 1883 on pages from 682-on, give the results of a trial of double rifles from .400 up to and including the bore rifles. Of particular note, is the poor shooting of some of the 'best made' guns in smaller Express Calibres. The bore guns were shot at Numhead 50 yards only. The bore guns all appeared to use round balls and except as noted, were rifled.

Holland and Holland's 12 bore, a 13 1/2 pound gun was fired with 7 drams(191gr.) fo black powder and produced 141 pounds of recoil. It managed a pattern with a deviation of .993"- meaning less than an inch average from centre, each shot - considerbly better shooting than the Express guns shot at the same range.

The 10 bores shot, weighed 12 and 12 1/2 pounds repectively, with 8 drams 5gr. (223.4gr.) black powder and 8 drams (218.4gr.) made deviations of .1092" and 1.843" respectively. Recoil was 163 pounds.

The 8 bores were represented by Messrs. Holland, weighed 17 pounds 8oz. and fired with 10 drams (273gr.)black powder, "a very light charge for this calibre as some of the more renowned elephant hunters using as much as 12(327.6gr.) and 14 (382.2gr.) in this bore". The mean deviation was 1.452" at 50 yards, or all in a square of 4.2" x 5.0". The recoil was 185pounds.

The 4-bore, weighing 23 1/2 pounds and and fired with 12 drams only (full charge 16 drams) made a higher recoil than 200pounds, so could not be registered, and made a beter diagram than the 8-bore, the mean deviation being only .782".

"The 12 bore smooth-bore ball gun of Messrs. Holland was fired, but the diagram was so outrageously wide that we cannot think of publishing it as a standard. A smooth-bore shot-gun, choked of cylinder, should make a better diagram in good hands."

You can see the 4 bore rifled gun made an oustanding target. Cheers to the intrepid fellow who managed it for the requisite 10 shots! WOW!

Compare these 'bore rifles' to the Express rifles. The best express made deviations of 1.139", 1.052",1.056", a .400, .500 and .577. Since these guns shot elongated bullets, at that range, it is quite evident they did not do as well as the 'bore' rifles. Many of us today are cranked on guilt edge accuracy, the accuracy we derive from scoped modern guns - spoiled we are, when we're used to shooting 1" or better groups, and expecting our century and more-old rifles to do as well. It was a rare shooter/gun combo back then, that could do as well as we've found we can with the same guns they used, using the kowledge, practise and skill at loading to our disposal today.

To find the deviation as noted by Greener, find the centre of the group by scribing a square or rectangular box around the group to encompass all the shots. Scribe a line corner to corner, then measure from the centre dot to the centre of each hole, recording the 'string', then add and divide by the # of shots. That's the mean deviation as Greener figured it.

All of the guns shot & diagramed(potographed), show spreading as well as crossing & high and low shots within a single group. This means you cannot judge a double's shooting characteristics by a single shot from each barrel.

Multiple shooting must be done to determine regulation. We, as humans are not infallible and will shoot a bit high, a bit low, to one side or the other within a group. Also, the gun itself is not capable of printing one on top of the other - this also must be taken into consideration. They are hunting guns, not target rifles.

How about that recoil boys? I'd guess my estimate that smokeless kicks over 1/2 less and closer to 1/3 the recoil of black powder was pretty close.

Martin - your WW slug target, just a rough estimate, would go around .7" for deviation & of course, is excellent for a smoothbore - about normal for many shotguns today with the same lightweight slugs. Unfortunately, they aren't very good for heavy game - lack of penetration, which is why we have laws here about using shotguns on moose, elk and grizzlies, but OK on deer and black bear. With rifled sights, any shotgun becomes a smooth rifle by definition and therefore is legal - it behooves us to use them with appropriate projectiles.

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Daryl

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

Edited by Daryl_S (07/02/10 06:04 AM)