Foot pounds of energy discussion

[WN0912]

Ok, when you hit a varmint at 80 yards and it looks at you and facts in your general direction, its time to get educated.

As I understand it, FPE is a simple calculation of feet per second divided by pellet weight.

Then of course, you have to factor in distance.

And pellet configuration?

Ok. My question.

I. Moving up from a Benjamin Maximus, 22 cal to a Marauder 25 cal.

Online calculators tell me the FPE difference is basically 20 vs 42.

And, as I go out to maybe 80 yards, the Marauder is triple the fpe of the Maximus.

Ok, now my question really.

Is FPE really that simple?

Does that mean every pcp rifle has the same "hunting" ability if the fps and pellet weight is the same?

Am I pushing the limit at 80 yards to expect humane kills of things like raccoons , etc.

Thanks!!!

Oh. One more thing.

Will someone please start making pellets? I lived through the powder ammo shortage, now there's no JSB pellets either!

 

[Kevin23]

FPE is the energy a solid object dumps into another solid object. As you talk penetration, the measure of FPE is a bit misleading. 

Specifically talking pellets and hunting here...

something like a non-lead round nose pellet will penetrate very far into the animal (often right through) and cause little damage (called pinhole effect). the 25 cal with this pellet may be worse for hunting than your current 22 with a hollow point. 
A round nose lead diabolo pellet (like JSB) is kind of the middle man, they will dump energy into your target but will also penetrate quite a bit. You only need enough penetration to get to the vitals of the animal, any more is wasted in hunting. 
A hollow point is going to expand and dump its energy into your target, while penetrating less. As long as it still penetrates to the vitals, this is the ideal outcome for hunting and where you will see the instant kills and graphic results most people are looking for (good ethic kills). 

Theres two ways to go about this. You can go for the most accurate pellet you can find for your gun, and as long as it has adequate penetration you should be able to put it right in the brain or other vitals of your target and kill it. Birds flying three or four wing beats and falling dead, squirrels falling and kicking for a few minutes but brain dead the whole time, racoons running 5-10 feet and falling over dead, these are the type of results of the round nose style pellets from my experience. 

Or you can go for the expansion and fast kills, even if its not quite as accurate. (polymag, cphp, hades, hunter/hunter extreme, etc). This will give you that graphic squirrel flipping over backwards stone dead, bird making a loud pop and falling with half its crop shot off, raccoon laying over with its feet straight up dead, and so on. 


Then we have slugs, but that is a whole different ball game. 


On your other subject of range, raccoons are the toughest "small game" animal out there and are usually pushed into the "medium game" category with coyotes and foxes. It takes a heck of a lot to kill one of these devil trash pandas.. I wouldnt even expect a stone dead kill with a 20fpe 22cal from 25 yards away let alone 80. Even the 25 mrod will probably struggle for instant kills at that range, but it will definitely kill them if you put that pellet where its supposed to go.. they just might run 10-20 yards first. A raccoons skull is extremely hard, almost as hard as a wild boar's head.. you may find it best to put it right in the lungs/heart like a deer and just let them do their thing to expire. 

 

[Guest]

Until you know your actual FPS at the POI, you're guessing at energy, that's why I do all my chrono reading right in front of the target

 

[Kevin23]

I guess my reply might have gotten a bit off track there.. the moral of my story is that higher FPE is only better if your ammo is matched correctly to your situation. a 70FPE gun shooting a jsb 18gr pellet at a squirrel 30 yards away isnt any more deadly than a 20fpe gun shooting that same pellet because the energy is wasted.. so FPE is really not a great way of measuring a guns "killing power", its really a balance of gun and ammo. 

It is a good way of measuring a gun's POTENTIAL though. That 70 FPE I just referenced has the potential to do a lot more than the 20 FPE gun has... if the situation and ammo dictates it. 

 

[guod123]

Having both the guns you mentioned you'll find a huge difference in dropping power as the energy increases. For instance a .177 shooting a 10.3 @900 fps is about 20 fpe. A .25 shooting a 3395 at the same speed is about triple the weight and energy. The difference between the 25 grain and the 33 grain 25 pellets is minimal at say 40 yards and under, when stretched out to 80 you'll see a big difference on woodchucks. Shooting Raccoons I've taken many with a Disco and an 18 grain pellet. This was a very good combo all were closer than 30 feet. Shot placement with a 25 cal. Marauder gauging distance at 80 yards allowing for wind is a shot I would not take.

 

[Odoyle]

If you have a Labradar you can calculate actual energy at the target.

You can also risk SHOOTING your second chrony placed at the 80 yard target too. Ask me how I know (it was at 100 yards rhough).

Accurate enough gun and well placed shot may be good enough rather than being power crazy. 

On the other hand a Benjamin Bulldog might do what you need at 80 yards.

 

[dizzums]

you really need a bigger gun to take big coon size things at 70 or so .. your going to trade shot count to launch a bigger projectile at nominal pellet rifle speeds so trajectory is manageable .. past 70 it really gets iffy with any pellet gun unless you know the terrain and already have it sighted more or less, personal opinion, ive shot alot of sht in my time lol .. ..

 

[vmaxpro]

Dont worry about fpe. Get good enough to headshot something at 80 yards. Anything in my opinion in the 900fps range that is heavy for caliber will do the job. A 16gr .177, 25.4gr .22, 34gr .25 in the 900’s will all anchor a coon sized animal at 60-80 yards if its accurate. 

 

[LostinTejas]

This is fast, dirty and general. Velocity X Velocity x 1/2 Mass = KE Kinetic energy, FPE, ft-lb, ft/lb or how ever you want to relay it.

Energy moves things, drives things, and breaks things. There is no such thing as "knock down" power and "energy dump" or deployed energy in a target. If the pellet arrow, projectile stops in the target it doesn't have any more effect than the thing exiting, other than there are now two holes to bleed from rather than one, so tracking is much more possible. Arrows could be the exception since they are now pivoting and moving causing more damage if the broadhead remains in tact.

Muzzle velocity/fpe gives you a staring point. Someone already noted there is a calculator out there. Useful information, it is Air Ballistics Calculator

Now comes the fun part that is really confusing to many. Ballistic coefficient and sectional density. Almost impossible to compare apples to apples with different calibers in these, because weight can effect them and that makes for some fun calculations. In short BC allows the retention of velocity at longer ranges. It does it across the board, but the further out you get the more it comes to play. SD is the ability to penetrate and cause tissue damage. Weight is just that and the more the better, and long as the balance remains optimal. Heavies are better at short range, while a moderate weight can optimize performance.

80 yards with small caliber air is optimistic. Plenty claim to do it, and probably do, but are they making first shot hits and what are they shooting at. There is a lot of difference between a squirrel and a coyote. Even a raccoon can be rather tough to take down at range. For the raccoon, at 45 fpe /muzzle you should be OK depending on the pellet/slug choice, IF you can make a good hit at that distance.

I love air. I love hunting. I love LD shooting. My LD is hunting ranges, are more moderate, I prefer to keep things in moderate range for lots of reasons. There is plenty to do the job usually, but I have to hit it and at certain points the unpredictability of the field factors for me. Range? I'll step it out, but paper has no consequence other than bragging rights.

Air and center/rim fire have little in common in many ways. The theories and formulas are the same, but the terminal mechanism and performance is very different. Maybe that is why I like it so much, it isn't in my wheel house.

 

[Scotchmo]

...

As I understand it, FPE is a simple calculation of feet per second divided by pellet weight.
...

Energy = 1/2 x mass x (velocity x velocity)

For FPE, mass is in slugs and velocity is in feet per second.

When I say slugs, I mean unit of mass, not the projectile shape. There are 225218 grains in a slug.

 

[elh0102]

IMO, shooting raccoons at 80 yards is not what air rifles are all about. Whether 8 or 80 yards, to dispatch an animal that size humanely, you need to put a pellet in its brain, and forget about fpe. Many would insider a standard velocity .22 rimfire underpowered for such, yet it generates about 100 fpe. Tissue damage results from a combination of factors, but it's not going to be impressive with the air rifles mentioned here. 

 

[L.Leon]

@elh0102, I have to agree. Raccoons at 80 yards is pushing it even with a rim fire. Unless you could confidently get a killing head shot. I personally don't shoot anything bigger than a woodchuck with my PCP rifles. Bigger than that? .22 LR or .223. 

 

[Odoyle]

OP could bait him in closer Hansel and Gretel style

 

[Guest]

A simple rule I was taught at a young age was to shoot at an empty soup can at a given range. If you can't shoot through both sides, don't be shooting small game at that range.

At 50 yards my Huntsman .25 will not.

 

[Odoyle]

At 50 laser rangefindered rangefounded rangefound yards my 18.5fpe Daystate CR97 shooting 10.5gr Brown Box Crosman Premiers will shoot through both sides of a #10 can filled with sand type media (kitty litter-?) which was used as an employee ashtray.

 

[Odoyle]

Sorry that was 18.0597fpe NOT 18.5fpe. 

Shooting 880x880x10.5÷450240

 

[Guest]

I've been doing a lot of testing in my shop at 50' on various .22 pellets, in my nitro break barrel and two PCPs, the best I've found in terms of energy, and accuracy, is the JSB Exact Jumbo 15.89gr

 

[GBGUNNER]

I DIDN'T READ ALL OF THE THREAD BUT I'D SUGGEST TRYING SLUGS IF YOU ARE HUNTING AT DISTANCE OR EVEN CLOSE IN. I'M A LITTLE PARTIAL TO FX SLUGS IN 25. YOU COULD TRY A BOX AND SEE WHAT YOU THINK. YOUR BARREL MAY BE OR MAY NOT BE AS ACCURATE WITH THEM. PERHAPS OTHERS CAN GIVE YOU THE BENEFIT OF THEIR EXPERIENCE WITH OTHER BRANDS.

 

[Vetmx]

I personally don’t give a crap about FPE with an airgun. Common sense and shot placement are what it’s all about. If I hunted large game with an airgun, I would then start looking at FPE. I just took a raccoon an hour ago with my .25 at 60yrds. I shot it in the back of the dome. Just like I would at 20 yards with any of my 22’s or 25’s. I can’t tell the difference between pellets or slugs on raccoons because it takes a head or head/neck shot to drop them no matter what you’re using. Raccoons will suck up a boiler room shot from a .22 magnum and run off. No back yard airgun is coming remotely close to what a .22 mag brings to the table. I feel I can consistently take a raccoon with my Impact shooting a slug out to probably 70yrds. I would be nervous going further because I’m shooting at night, the kill zone is small and the animal can move as I squeeze the trigger. The only reason I cleaned that raccoon out at 60 tonight is because I have a white one inch spinner on that tree by my bird feeder. I have shot that spinner at least 50 times at night with my red light and my scope on 10x. I didn’t just decide to send a Hail Mary tonight. That’s the common sense part.

 

[Odoyle]

Ok, when you hit a varmint at 80 yards and it looks at you and facts in your general direction, its time to get educated.

As I understand it, FPE is a simple calculation of feet per second divided by pellet weight.

Then of course, you have to factor in distance.

And pellet configuration?

Ok. My question.

I. Moving up from a Benjamin Maximus, 22 cal to a Marauder 25 cal.

Online calculators tell me the FPE difference is basically 20 vs 42.

And, as I go out to maybe 80 yards, the Marauder is triple the fpe of the Maximus.

Ok, now my question really.

Is FPE really that simple?

Does that mean every pcp rifle has the same "hunting" ability if the fps and pellet weight is the same?

Am I pushing the limit at 80 yards to expect humane kills of things like raccoons , etc.

Thanks!!!

Oh. One more thing.

Will someone please start making pellets? I lived through the powder ammo shortage, now there's no JSB pellets either!

TRENIER and AOA usually have JSB pellets unless you know something I don't-?