doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com MV vs. lead

I thought I posted this before, but any proportional change in velocity will result in about the same proportional change in lead to a first order approximation.

So, 10% faster will result in about 10% less lead. Nothing terribly surprising there.

When trying to kill something a little more velocity may make the difference worthwhile in terms of penetration, but that's always somewhat subjective as well.

Brent

Sounds like the old wives tale that cold water will boil faster than hot water. People will believe the damndest things and it seems the more incredible, the more willing people are to accept it. Just a thought, there was a statement that one shooter said he could tell the MV by his scores. If this is true, perhaps the score difference was due to one load patterning better than the other rather than the lead difference?. I don't shoot suppository shotguns but with muzzleloaders, the quality of the pattern can change dramatically when powder charges and/or shot charges are changed. This may not be the case with suppository guns as often, the blown pattern is due to the cushion wad blowing a hole in the pattern.

Cody

Another example of things that sound plausible but don't survive closer inspection is the just mentioned concept of a wad blowing a 'hole' in a pattern. Some feel the need to slow down or 'strip' the wad off the shot column at muzzle exit to prevent this.

Can't, never will, and hasn't happened. Acceleration stops at muzzle exit. The wad isn't pushing feathers, it's pushing Lead. Very quickly, the wad falls away from the back of the shot cluster. There is simply no force applied to the low density wad that can possibly cause it to interfere with the high density payload.

Note that in the above figures I popsted that 1330 fps is 17.2% faster than 1135fps. The resulting increase in lead for the lower velocity is 12% for #7½ size shot & 12.8% for #5's. Thus again lead is "Not" inversly proportinate to MV, but is directly proportinate to time-of-flight. As the inefficent shot pases the speed of sound, drag becomes far out of proportion to it's increased velocity. Thus most of the indrease in V is lost over the first few yds.
The problem with the old wading was not in it "Catching up with & blowing a hole through the shot patern" but rather on it's being caught in the rapidly expanding gases being expelled from the muzzle & being "Tipped" into the rear of the pattern. Fortunately this was not the rule, but could & Did, on occasion happen. This occured just at exit & not some feet down range. When it did happen it caused a loss of "Cohesion" of the shot mass & a disrupted (blown) pattern.
PS: Love my litle Casio Calculator.

Shotgunjones, I understand what you're saying but have you considrered the following. I'm refering to ML'ers with a lubed cussion wad, not a plastic wad/cup. A lubed wad is fairly heavy compared to a dry one. When the "payload" leave the muzzle, the shot is no longer a 1 1/8oz (or whatever) projectile. Each pellet becomes it's own projectile with it's own BC therefore, the enertia difference is that of a single pellet vs the wad, not a 1 1/8oz lead projectile vs the wad. Perhaps the most compelling "proof" that the wad blows through the shot charge is that with a full 3/4" thick lubed wad, you get a donut pattern with a huge hole on the middle and by splitting the wad in half to 3/8" thick with all other thing being equal, the pattern has no hole in the middle. I'm not saying you're wrong, just throwing out some things that are perhaps worthy of discussion before any conclusions are reached. Besides, anyone that quotes Frank is OK in my book

Miller,
While I agree that 50mph is pretty fast for a clay, there are a number of birds that fly 60 + mph. Routinely, pigeons fly paralell near my truck at freeway speeds. The Calif Valley quail can fly well above 50, probably more like 60 and up. I've seen chukar that I'd estimate were coming downhill (their favorite direction) at probably 70 + mph. These are all just estimates, but I did sleep at a Holiday Inn Express. Back in my RC model airplane days, my good friend bought a radar gun, and I also had a telemetry device which included airspeed among other data. So, I have some perspective, although admittedly eyeballing speed can be pretty far off. It'd be interesting to irradiate a few wild birds for real data.

Uh oh....

My stars dropped from 5 to 3 during the course of this thread.
That tells me one of the world's oldest juveniles voted me one star. If the other one catches on, I'll be at 2 soon. I'm recoiling in horror.

Hey, if everybody piles on...sort of a Star Wars attack..... maybe we can make them go away altogether (the stars, that is; not the juveniles). That would be an improvement.

A bird, clay or feathered, moving at 50 MPH, is moving 880 inches per second. A load of #8 shot, starting with MV of 1155 fps takes .1367 seconds to the 40 yard mark. Start it at 1255 fps and it takes .1449 seconds to get there. During the time of flight difference between the two loads the bird moves 7.2 inches. That's the difference if lead required.
The difference between MV is about 8%, time of flight difference is about 5.6%. Difference in lead required is 5.6%. As 2 piper said, it's the time of flight that matters, not the muzzle velocity. I though everyone knew that. Obviously not. The point of this thread was, and is, that hiking up the MV does not make the drastic difference in leads that many people think. It is also a fact that the difference in TOF is less at 40 yds than it is at 20. Of course I used a calculator, and verified the answers with a slide rule made by S & R Enterprises and sold for just this purpose. That's the way facts are established, not by a shooter's perception, or old wives' tales.

Mr. Brown,
Yes, but. The important factor here is the shot size.
As you said, the retained energy of big shot is much greater than that of small shot. Also, big shot carries its speed much better. Its mass overcomes the friction of the air and the gravety much better than the small shot.
It is the 71/2 and even the 6s (in hunting)that get the great reduction in speed in the fast vs. the slower loads tests. A high velocity 4 hits damn hard way out there. If you use 71/2 or even 6s a big pheasant will almost shrug it off at 70 yards. With 4s you will kill it dead.
All the, as you put it, "famous example[s]that loads with faster MV slow down quicker" with the conclusion that the force is nearly the same at distance that I am aware of have used 71/2 shot or even 8s in their tests.
The big stuff carries its momentum.
Jake

2piper and Legg, it's close enough to proportional to me. I don't take long shots either. But whatever works for you works.

Brent