Sabot length

[Evil Dog]

When making wood sabots for use on solid ball shot, what should the length of the sabot be in relation to the ball?  For instance, if the ball is 2.25" diameter, should the sabot be 2.25" long.... 2.00" long... 1.75" long.... 1.50" long.... or even shorter?  These are made from good quality plywood and shot out of a smoothbore.  Would appreciate you opinions.

[GGaskill]

Here is a picture of a 12 pounder shot in a sabot without powder bag.  You should be able to scale from this.

[Artilleryman]

Sabots for 12 pdr (4.52 inch ball) were 2 inches long, and for 6 pdr (3.58 inch ball) 1.55 inches long.  The bore size is somewhat larger for windage.

Since the shot bounced in the bore you could extend the accuracy life of the barrel by using longer sabots so that the ball would hit a different part of the bore.

[mac_hunter]

Also, according to the Ammunition for Field and Mountain Service chart on page 266 in The Ordnance Manual For The Use Of The Officers Of The Confederate States Army (dated 1863); sabots for 12-pdr (4.52 inch ball) were 2 inches long (height), greatest diameter is 4.35 inches, diameter @ bottom is 4.15 inches, cavity for ball depth is 1.5 inches, cavity for ball radius is 2.26 inches, distance from middle (center) of lower groove of sabot to the bottom of the sabot is 0.4 inch. "The cartridge-blocks and sabots for shot (solid) and spherical-case shot for guns have one groove. Sabots for gun canisters and for the 12-pdr. howitzer or mountain howitzer shells, spherical-case shot and canisters have two grooves. All the grooves are 0.3 inch wide and 0.15 inch deep. They are 0.8 inch apart, from center to center, for guns, and 0.5 inch for howitzers. The corners and bottoms of the grooves are slightly rounded." Quoted paragraph taken from page 259 of same book.

Taken from page 260 of same book, "Straps to hold the ball to the sabot are made of sheet-tin. For shot there are two straps crossing at right angles, one passing through a slit in the middle of the other. For shells there are four straps fasted to a ring of sheet-tin, pierced with 4 slits, through which the ends of the straps are passed and folded down on the under side. This facilitated insertion of a fuse. The sheet of tin is first cut to a length equal to that of the straps, 12.75 inch for solid shot and 6 inches for shells/spherical-case and if the straps are for shot, a line is drawn, dividing it into two equal parts, to mark the place for the slit. The straps are cut with circular shears. If such be not at hand, the width of the strap 0.45 inch is marked on the sheet, is cut with tinner's shears, and straightened on a bench with a mallet. The slits are made with a cold-chisel on a block of lead, and a strap not slit is passed through, and set flat by a blow of the hammer."

I added the bolded sections to help with clarity. 12-pdr strap dimensions came of off same chart referanced at top.

[Evil Dog]

Managed to get out to the range for a little while yesterday.  Used a 3 x 3 piece of cardboard for a target at 100 yards.  It took 3 rounds to get on the cardboard, but after that the next 4 shots hit the cardboard.  All within a 2' circle.  This was using the 1 1/2" long sabot that was held to the ball by 2 strips of 3/4" wide masking tape.  I had expected the ball and sabot to separate very quickly after leaving the muzzle.  Masking tape must be a lot stronger than I expected though because I found 3 of the 7 sabots BEHIND the target !!!  To me that indicated that they never separated until the shot hit the ground.

If a major component of accuracy is consistency then I would want all of the sabots to either stay attached or separate at roughly the same distance downrange.  Much easier in my mind to just make sure they stay attached.... a #10 machine screw through the sabot into the solid ball pretty much assures that now.

I do want to experiment a bit with sabot length though.  So made up 3 different lengths.... 1", 1 1/2" and 2".... the plywood I use is 1/2" thick so those were the easiest options.  It will probably be the end of next month before I can get out to the range again to give them a try.



Also want to play a bit with the powder charge, but that will have to wait until I decided on which sabot length looks most consistent on target.

[GGaskill]

Judging from the picture of the original saboted shot, you should seat your shot deeper into the sabot.