Shortround6
Major General
if you are still puzzled and until a ballistics expert appears you might try the high school physics i used to check this. Starting 6 or 7metres call it 20ft short of the middle of the target calculate how far any fragment travelling at 2200 ft per second radially would get before impact (2200 was a figure i got from online source so a low credibility but it 'sounds right'). Result is about 40 or 50ft right? The area goes up by the square of the distance from target. And that is a 100% swept area as far as the aircraft skin is concerned until the pattern of fragments loses cohesion. Because the fragments take some time to acceelerate to 2200 ftpsec the real radius would be much less - as far as i can tell the 'delayed fragment' diameter of effect would be about - 88 to 100mm for a 88mm shell. Thats why 70 ft distance of detonation is much better than 6 meters or 7 metres
Something seems more than a bit off here. Or I am not understanding the situation. The Fragments spend about zero time/distance accelerating. They are moving about as fast as they will ever go within a few inches of the shell bursting. Fragments have really crappy ballistic shape, they make round balls look good and they slow down fairly quickly, a lot depends on size which is why so much work was put into optimizing fragmentation, matching explosive to shell body material/alloy and heat treatment. Too many small fragments and the lethal destiny of the "cloud" thins out pretty quick and lethal range is short. Too many big fragments (a sort of contradiction in terms, large size fragments means you won't have a large number of them) and the big fragments are dangerous to large distances but with few fragments the chances of a hit go down. The 2200fps figure may have been an average or average speed at a given distance.
Most extreme example is the old cast iron Pineapple grenades which, if filled with HE never split up along those grooves. They split up into 3-5 large chunks and a lot of cast iron dust/powder and while the large chunks were dangerous at over 100yds at times the dust was pretty ineffective at just a few yds.
Now a 70ft "miss" distance is way too far away to be effective. Please do the math. 70ft radius means a 219.8 circumference. even if you can get the large majority of fragments to stay within 10ft forward and aft of the center of the shell in a horizontal fan that is a 20ft high area and thus your fragments are going into 4396 sq ft area, At 70 ft how big does each fragment need to be in order to penetrate the aircraft skin and do damage behind it. Just poking holes in the skin does not bring the aircraft down.
or you may want to remember the effect of 'grape shot' (smooth bore cannon stuffed with bent nails, bits of chain, fragments) in the days of wooden ships at very close quarters.
Actually what you are describing was called scattershot (or other names) Grape shot was actually a cluster of identical sized balls often wrapped in canvas that resembled a bunch of grapes. While such expedients as bent nails, bits of chain, fragments were used on occasion they were much too unpredictable to be used by professional gunners as common practice. They also could jam in the bore and burst the gun on occasion and were much rougher on the bore (greater wear) than "standard" ammunition. Brass or bronze barrels being more common than Iron. Also in an era were nails were hand forged by blacksmiths bent nails were hardly the "scrap" they are considered today.
What gunners used for real ammunition and what non-gunners (infantrymen and cavalry men) wrote about in memoirs were often very different things. The famous quote by Zachary Taylor "A little more grape Capt. Bragg" actually went more like.
" What are you firing Captain?"
"Canister sir"
"Well double it and give them Hell"