Calculating shot energy..

[ElvisThePelvis]

Probably in danger of over thinking things, and accepting that due to manufacturer data the result will be incorrect, however sticking to one brand I am hoping that the relative difference will be the same, how can I calculate the energy of 5,6,7 (and half sizes) at a given range ( say 40 yards).

 

I am trying to clarify the actual difference in energy between shot sizes rather than relying on results which of course have many variables introduced by me, I'm sure it not the case that 10% heavier is 10% higher in energy...

[TONY R]

You cant go on anything the cartridge manufacturers say, they are quite often well shy of the mark on the muzle velocity of their ammo.

So even the initial data is flawed from the start of procedings, not a good way of drawing any accurate practical conclusions.

Chronographing ammo is the best way to start your calculations johny boys data on here is as good a [place online without haveing your own chrono to get some real numbers to start with.

Now you mention downrange!.. Here there are a few charts online listing downrange velocities of some shot sizes at certain speeds, but they seldom are relavant to what your load is doing or your shot size or shot type.

Guessing what your speed might be is not a practical way to go on and is as bad as the guestimates the ammo manufacturers put on the boxes.

About as close as you can get to callculating downrange shot velocity is with a shotshell ballistics programe.

ED lawerey did no and sadly he is dead it was for windows 95 and in quite sure it needs a 95 OS to run it wont run on 98 or xp win 10 etc.

The other one is KPY apparently its bassed loosely around lawerys programe and is about your best option to get reasonably accurate downrang shot speeds for various shot types loads sizes etc.

KPY is sold by Tosty off AW DHC Deep woods Gobbler nation aldeer forums, if you look online its there its not pennys but its not that expensive either. Good luck.

[seeker]

For this sort of info I would try Lyman Reloading Handbook 5th ed p104 ... It uses American shot size at 2% antimony, but there's sufficient info on pellets per ounce and pellet weight in grains to make comparisons ... Just don't ask a pheasants opinion.

Edited September 13, 2016 by seeker

[Guest cookoff013]

why would you want the energy levels of one pellet?

calculate the ftlbs from muzzle. that an be 2000ftlbs (i think for big loads.)

 

what you need to know the speed at 40yards.....

 

thats why the subsonics i make are minimum #4 which at 40 yards has the same energy as a #6 that started out at 1400fps.

 

nb, when changing from a #9 to a #1, 28 grams in both, they should have the same starting energy. but the #1 would have more energy at the start, and hold on to more energy over all distances.

[TONY R]

why would you want the energy levels of one pellet?

calculate the ftlbs from muzzle. that an be 2000ftlbs (i think for big loads.)

 

what you need to know the speed at 40yards.....

 

thats why the subsonics i make are minimum #4 which at 40 yards has the same energy as a #6 that started out at 1400fps.

 

nb, when changing from a #9 to a #1, 28 grams in both, they should have the same starting energy. but the #1 would have more energy at the start, and hold on to more energy over all distances.

Its knowing what the shots doing at 40 yards thats the problem, how you know what its doing?

Only KPY can tell you that and start bringing different shot types into the equasion and it gets even more complex.

I think it has to be that programe, unless there is a formulae or something. anybody know of any way of accuratly calculating downrange velocity of shot. ?

[Guest cookoff013]

wymberly...

 

we already did this and compared lead to steel with a 1300fps model for comparison. hence why the "go up 3" shotsizes to be comparable with the lead size....

 

1300fps @ 40 yards #6 lead = #3 steel.

[TONY R]

A model is all well and good but lowery used winchester balistics lab data to draw up his programe, winchester have or had the equiptment to measure shot downrange And KPY although not perfect is as close as i think you can get, I tried armouring a Chronograph at 40 yards it did not pick up reliable.

Shhot size for shot size comparability in different shot types is acchievable but the acctual downrange Ft LBS of eneregy calculations you need the pellets speed only way i can see to get that practicaly is toastys KPY .

[motty]

I would rather know about shot penetration than energy.

[dougall]

all the old books and Eley diaries have this sort of stuff.....can look up later.Importantly at 40 yards they will all work and kill normal targets which is probably the most important bit of info!

[dougall]

shots at 1200 ft/sec at 3 foot from barrel;

energy at 40 yards 7 1.4ft/lbs 6 shot 2.2 ft/lbs 5 shot 3.1 ft lbs...so a 5 pellet has more than twice a 7 pellet.Of course this makes no account for pattern etc...must be a good 25%+ more pieces of shot with size 7. For what its worth I favour the 7 over the 5 for pigeons etc at 40 yards,'patterns kill' and certainly a 7 pattern should be better than a 5 pattern and 1.4ft/lbs plenty enough.

[TONY R]

I would rather know about shot penetration than energy.

Yes and thats in the ballistics programes . They are the most practical thing to provide reasonable accurate downrange predictoions.

[ElvisThePelvis]

shots at 1200 ft/sec at 3 foot from barrel;

energy at 40 yards 7 1.4ft/lbs 6 shot 2.2 ft/lbs 5 shot 3.1 ft lbs...so a 5 pellet has more than twice a 7 pellet.Of course this makes no account for pattern etc...must be a good 25%+ more pieces of shot with size 7. For what its worth I favour the 7 over the 5 for pigeons etc at 40 yards,'patterns kill' and certainly a 7 pattern should be better than a 5 pattern and 1.4ft/lbs plenty enough.

Brilliant, thank you, this is all I need, in answer to your point about shot count..

 

Imperial game in 28grams show 7 as having 350 shot, 6 has 255 and 5 has 198.

 

Driven grouse in 28 grams show 6.5 as having 297 and 5.5 having 224.

Edited September 13, 2016 by ElvisThePelvis

[ElvisThePelvis]

Yes and thats in the ballistics programes . They are the most practical thing to provide reasonable accurate downrange predictoions.

This brings up an interesting point that I have overlooked, which is more important, energy or penetration?

 

If it makes a difference let's say it's on a high ( but not stupid) 40 yard driven pheasant, 28g cartridge through 3/8 and 5/8 choked gun.

[TONY R]

Well the two are related obviously and you can complicate things even more with shot density and thus size frontal area

And again even more complex if you like with wound chanel , and dare i say it on an open forum out loud .... SHOCK

And CVT cadio vascular trauma .

Penatration just by itself is variable gel tests show gel birds are not made of gell they got feathers bone flesh fat tissue even different skin thicknesses in different parts of the body, the list is endless, i did once see some research done on frozen chickens which were interesting. but again its not conclusive.

This is the Point george youngs get out and shoot them with the gun and load theory gains momentum, theory is all well and good but terminal ballistics in shotguns is variable as are patterns they are just as variable in apparent same guns.

Its handy to know pattern % at your expected range then if you chose muzle energey or penatration you chose but you need both suitable pattern and penatration causing hopefully all or at least some of the above damage terminaly.

The writer and former forum creator and admin eric begbie in his book fowler in the wild lists a simple table with predicted patterns and penatration and where one or the other fail. Its as basic as it comes and acctualy near enough in practical terms.

This may or may not be enough for you, all people are different some strive morew info some others not so much.

Whichever you are i dont know, but a quick look at erics chart in the back of that little book could just satisfy your curiosity adequatly.

[ElvisThePelvis]

Brilliant, thank you, I will track one down. Unfortunately I'm one of those people who likes to know how things work, trust gut instinct but back it up with research.

 

I'm becoming convinced that no5 is the shot size I need for my shooting, but getting a 28g cartridge to pattern well at distance is difficult... Anything more than 28g through my sxs gets a bit tiring.

 

Back to penetration, do you think copper coated shot penetrates better as advertised by sellers?

[motty]

Why do you think no.5 is the shot size for you?

[ElvisThePelvis]

Why do you think no.5 is the shot size for you?

It just appears to be more terminal on the majority of shooting I do (rough, walked up, driven pheasant) by which I mean less runners, although I have noticed this week that copper coated 6 (hellfire) have been very effective on running rabbits, even at good distance, hence my question above.

[Stonepark]

Have a gander at this, : -

 

Edited September 13, 2016 by Stonepark

[motty]

You may get slightly better patterns with copper plated shot, but penetration is unlikely to be too much better.

I think this shot size thing is in your mind. Maybe you shoot accurately with 5s now and then, and makes you believe it is the cartridge giving the better results and not you.

[motty]

Stonepark - they are not US sizes.

[ElvisThePelvis]

You may get slightly better patterns with copper plated shot, but penetration is unlikely to be too much better.

I think this shot size thing is in your mind. Maybe you shoot accurately with 5s now and then, and makes you believe it is the cartridge giving the better results and not you.

Quite possibly, this is why I asked the question and referred to removing variables, just looking for data to prove or disprove and the responses have been really helpful. I'm sure a difference of one shot size will not turn a hit into a miss but if it can reduce 'runners' then happy days!

[Stonepark]

Stonepark - they are not US sizes.

 

Oops, too many tables open at once.

Edited September 13, 2016 by Stonepark

[TONY R]

Brilliant, thank you, I will track one down. Unfortunately I'm one of those people who likes to know how things work, trust gut instinct but back it up with research.

 

I'm becoming convinced that no5 is the shot size I need for my shooting, but getting a 28g cartridge to pattern well at distance is difficult... Anything more than 28g through my sxs gets a bit tiring.

 

Back to penetration, do you think copper coated shot penetrates better as advertised by sellers?

Nawt wrong with that at all.

[wymberley]

Have a gander at this, : -

 

Up in Lochinver so will by necessity be brief (internet speed) is it not the done thing to acknowledge the source of someone else's work?

[Walker570]

I have just done some practical tests on some 410s. I set a target board at a measured 35yrds. Then I soaked newsprint in water until fully saturated and then compressed it until it was 3/4 inch thick. My idea being that this well represented the breast meat of cock/pheasant etc.

I then fired a shot of each size and examined the results. My home load non toxic ITX 6s ploughed through and buried themselves a pellet depth in the hard ply backing. Lylevale fibre 5s patterned well but only about 50% of the shot made it all the way through the paper.

Eley Bismuth did well and all but a couple of the shots made it through and stopped at the ply backing. One can assume that the performance would be better still at the shorter ranges.

You can read all sorts of detail in issued charts but in my view you need to walk the walk and devise something which will give a definitive result and I think this wet newsprint goes a long way to doing that.

Edited September 13, 2016 by Walker570