Studied and rationalized the numbers on paper, not thinking the .25 had any real advanatge over a .22 at the same energy level. It's easy to think of them as "even" from paper anaysis, which I honestly did belive...until I tried a .25.
Probably not at it's best with lighter weight pellets, but the resuls on game so far have clearly been in the .25's favor. Certainly, put any kind of hole though the "off button" and the game falls down (which could mean the choice should be between .177 and everything elce) but in the real world, are some shots that don't go exactly where you planned (and some that do, but you planned wrong).
But consider this. BC basically predicts how well a pellet will move though the resistance of air. IF the pellet doesn't deform, that smae BC seems a very good predictor of how well those same pellets will move though heavy resistance (like meat).
How fast would this hypothetical .22 be shooting to match the FPE o the .25?
February 7 2010, 12:48 PM
Instead of using a heavier(slower) pellet in the .22, use Predators in it.
If it can launch them at 800, they may well do more damage than a .25. See some of Harry's(Yrrah) posts show their destructive capability and someone recently posted results in gelatin blocks showed both fairly good penetration along with expansion. If you already have such .22, you might want to try a tin of Predators out before shelling out for a .25.
..both guns are shooting JSB's, so call it 25.4gr. for both the .22 and the .25. So you can also make the velocity even...somthing like (just picking a number) 780fps, so they both earn 34.3 foot pounds.
If both the .22 and .25 pellets were of the same weight, and shooting the same fps. the question is a good one.
The .25 caliber will definitelty impart the most energy upon contact with what ever it hits, but the .22 will give the greater amount of penetration.
So if your shooting reletively small game I would say the .25 would have a more noticiable effect while the 22 would be just as deadly but with less smack.
If it's bigger game, say groundhog, raccon, or maybe even nutria the 25 might not get in deep enough to do the job where the 22 may with its added penetration.
having said all that I am a fan of the 25 in the 50ft/lb range and the .22 in 30ft/lb area.
You can't talk aout this without stating muzzle energy.
February 7 2010, 9:14 AM
There will be a different situation for 10 ft-lbs a different one for 15 ft-lbs, yet another for 20 ft-lbs, whole different ball game at 30 ft-lbs and no contest at 60 ft-lbs.
25/25 rule applies if all esle is equal. The higher in ft-lbs you get beyond 25, the .25 rules. If you shoot a critter at 15 yards and 15 ft-lbs, grab the .25. If you change the distance to 35 yards, don't touch the .25, grab the .22.
No simple answers. With my Greg Davis .25 at 55 ft-lbs, I don't have to worry about it. Any airgun distance is good. The power is there and the penetration is there. You need both.
Bottom line, you have to use the caliber that would penetrate most and preferably not exit. The .25 at anemic levels (any .25 gun below 20 ft-lbs IMO) and distances of 30 yards or so would hit a crow on the wings and just tip it over, just to have it fly away.
Not enough frontal pressure to penetrate in that situation. Penetration is inversly proportional to the pellet's frontal area. The good thing about the .25, after it penetrates it slows faster inside the game, dispersing more of its energy where it counts.
..which did mention that they both have the same energy. Would be comparing a heavy weight .22 pellet with a .25 pellet of something close to the same weight.
Nice pair up would be JSB's, which can be 25.4gr. in either caliber, but are other comparisons that are close enough (.22 Kodiaks vs. .25 trophy / .22 EJ vs .25 Kodiak).
So could have about the same weight, moving along at about the same speed, with the difference being in striking area... .038 vs .049 inches of contact area,,, and a difference in SD. For the game i hunt, either one tend to come out the other side when impacting at a decent vel.
Think steve is right. The fatter pellet tends to both slow down a little faster after impact and penetrate a bit less, dumping it's energy faster and contacting a larger volume...basically giving a bit more "thump" for a little less penetration.
i have shot RX or HW90 in 22 and 025 , same pest (feathers), same conditions , typical range being 30-50 yards and for me 025 is better . Some critters are compact,boney or tight and would perhaps respond better to a better penetrating 022 . I still love 022 though , cheaper ammo , better selection and often plenty of power to get the job done . If I had to pick only one caliber it would however be 0177 or 022 .
Do run a .25 at 32 foot pounds (Kodiaks at 685fps) and have tuned down a 5mm Sumatra to that level in the past (23.5gr. at 800fps or 14.3's at 1012fps). Could tune the .25 up to about 40 foot pounds, and the 5mm sumatra to a little over 50, but they run happier at these speeds.
The closest in .22 I came to that power level was with a modded up Discovery that could manage 14.3gr. at 955fps for about 29 foot pounds (and as you could guess, the sweet spot was tiny-tiny and my current Disco is set to run at 17 foot pounds)
The largest critters shot have been 'possums, (had a 'possum family that were intent on some satsumas growing in my yard and one tree in my neighbor's yard). Range from 20-30yards. Exit holes for the 5mm.23.5gr/800fps, .22 14.3gr/955fps., and the 25 30.6gr./685fps. The .25 got a big flinch-reaction on impact while the other two only gave the smack sound of the hit. Dead is dead, so it made little difference in that respect.
Totally subjective, but the .25 impressed me enough to make it the go-to choice for that kind of shooting.
Little problem in hitting targets out to 40-45yards with the slow .25 if sighted in correctly (those .25 Kodiaks have a very good BC.. will be testing the JSB's); past that point better to have a real good grip on range and a drop chart taped to the stock.
Basically, yes it is worth it to me even at 30-32 foot pounds. But it's not going to be a good "do everything" rifle.
(And if any one ever does find a "do everything" rifle, please keep it a secret...if such a rifle is out there, we'd have no real excuse to own more than one air rifle.)
the .25 has devistating killing power even at low FPE. I didn't think so at first but a few yrs ago I gave my Dad a DAQ 25xx for squirrels but he's been using it to whack groundhogs large #s out to 35yrds.
"Nice work Robert"..your tests are very impressive,I
February 7 2010, 5:28 PM
dont think anyone can knock the .25 cal. Great caliber for sure. Looks like no matter the cabiler,the weight of the pellet needs to be up there and the results will be good on the penetration. What exactly were you shooting into?
we have the unlimited FPE at our disposal and come up with phony requirements way above what's needed.
a .25 caliber pellet shooting at 'only' 20 fpe is one fearsome hunk of lead. sure, more power is fun, but you don't strictly NEED it.
For several years shot a Stingray and a Exocet in .25. Not power houses, both of them about just loafing those big pellets along, but never had a problem at typical woods ranges collecting game. Noithing fancy, certainly not fast, but even at their lower speeds, were deadly tree squirrels guns.
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