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AEA FPE vs Caliber

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As MysticalDragon said, the best choice will depend on other factors, such as what sort of game/pests and at what distances. And bringing in WorriedMan’s comments, the velocity of the .30 cal is dipping down into a region where inadequate penetration and/or a difficult trajectory may be an impediment to making clean kills. As such, I expect the .25 cal at 49fpe would be the better choice for anything except fairly close-range critters, perhaps no more than about 30 yards.
 
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In order to compare apples with apples you need to suppose both travel at same speed.

In two super accurate rifles, Daystate Wolverine for example, one in .25 Cal and the other in .30 Cal, both at 900 fps, one in 34 grains and the other in 44.7 grains, the .30 Cal will cause more damage in tissue, will deal better in wind and will loose less speed and inertia on distance.

Fpe IS NOT an adequate formula for killing power. Some years ago I propose a new formula for killing power that, as far as have chance to test, is more close to reality.

This is the thread:

Final formula for obtaining the Hunting Energy Units on Air Rifles.

Taking into consideration: a) That in Air Rifles (as it is when hunting with a bow and arrow) the killing power is related with size of damage (cut-hole) caused in vital tissues; b) That the damaged caused is related by a combinations of velocity (fps), weight (grains), diameter, density...
www.airgunnation.com www.airgunnation.com
 
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I think fpe is one valid way to look at the killing potential of a gun/projectile but only one. My biggest goal for my guns is to find a projectile they shoot accurately and then to get that projectile up to 800-900 fps. Whatever fpe that results in is OK. My P35-22 likes H&N Baracuda Match pellets which are 21 grain. It pushes them about 830 fps so it produces about 32 fpe. The regulator setting it came with produces these results and also a 200 on the 30 yard challenge. So I do not see a reason to change the regulator setting. I would mind if it went 40-50 fps faster but the trajectory is fine and the accuracy is great. My P35-25 isn't terribly accurate with any pellet I've tried but H&N FTTs which weigh 20 grains seem the most accurate. I reduced the regulator setting to keep them going only 875 fps. So also about 32 fps. Doesn't matter to me that the 25 fpe is not higher than the 22. But I got to this point trying to make both guns accurate, not tuning to a fpe level.

Between the two I've taken 24 squirrels, 18 with the 25 and 6 with the 22 (I've had the 25 longer). 2 squirrels with the 25 were the only ones that ran at all after impact and they went maybe 10 yards at most. Both were hit in the front of the chest and the pellet ended up under the hide at the other end of the squirrel. I think they ran because front of chest going lengthwise through is not a great shot for a quick kill. May only get one lung, Those two shots and one shoulder to shoulder with the 25 are the only shots of the 24 that did not exit. I think this performance is great. I don't think I need more fpe from either gun for squirrels. I also killed a 8 lb raccoon with the 22 with a head shot. I think it's kind of light for raccoons. For that use, I'd be more comfortable with the 25 tuned up to shoot 31 baracudas or 34 grain JSBs 800 fps or more. Should have more penetration with a bigger hole. I have a new barrel on order for it and when it arrives I might try tuning it for a heavier pellet.

But my primary point is that we need to pick a projectile that either is what we want to shoot to do what we want to do or is accurate in our gun or hopefully both. Then we need to tune the gun to give us decent trajectory. FPE is whatever it is. FPE shouldn't be the goal. The only exception I see to this is at the low end. We do need enough power to humanly take animals. There are different thoughts about what that level is. I want to see upper teens in fpe at the minimum. My Prod is pretty limited in what it can so with total air storage of 60cc. It likes H&N copper plated FTTs, 14.66 grain. I can get them up to about 800 for about 20 fpe but only for a few shots. So I've tuned it for 16-17 fpe and about 20-24 shots. It's taken 15 squirrels for me and the last 11 at the higher power tune were clean kills.
 
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well, ive found over the years that diameter of the projectile, given it has enough behind it to penetrate is the most important factor in anything less than a high powered rifle ..you cant rely on slow moving projectiles to 'expand' ... they usually dont ..it generally doesnt matter much on smaller critters though .. get up over 10lbs or so though and bigger smacks them down harder every time ... an airgun in no way shape or form even remotely adheres to the physics involved in a firearm rifle that can explode a fast moving small projecfile and make a massive wound, no, an airgun pushing a small projectile at 'high ft lbs' just makes a tiny hole all the way through, if its not in a perfect spot it wont incapacitate a larger critter ..
 
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MWS said:
What is more important, FPE or larger caliber? I have a 30 caliber putting out 40 FPE. Also have a .25 caliber doing 49 FPE. Larger caliber creates wider wound channel but smaller caliber travels much faster and hits harder. I'm thinking the .25 would be better over all but I could be wrong.
Click to expand...

What exactly is your question?
 
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WorriedMan said:
MWS,
Pyramyd Air's FPE calculator reflects a (.30) JSB 44.75 grain pellet @ 640 FPS equals 40 FPE, FPS seems low for optimal pellet performance. Let us know which PCP, members might be able to suggest power adjustments. WM
Click to expand...
AEA HP SS .30 which has an 8 inch barrel. Also have a Hatsan Bullboss .25 which hits harder. Got them for small game hunting.
 
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MWS said:
AEA HP SS .30 which has an 8 inch barrel. Also have a Hatsan Bullboss .25 which hits harder. Got them for small game hunting.
Click to expand...
@MWS For small to small-medium game I like a .25 caliber rifle with heavy domed pellets. The largest animal I’ve taken with a .25 is a beaver. My Brocock Bantam Sniper HR produces 44-49 fpe with 33.95 grain Diabolo pellets. For coyotes I go up to a .30, but prefer a .357.
 
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Emu said:
In order to compare apples with apples you need to suppose both travel at same speed.

In two super accurate rifles, Daystate Wolverine for example, one in .25 Cal and the other in .30 Cal, both at 900 fps, one in 34 grains and the other in 44.7 grains, the .30 Cal will cause more damage in tissue, will deal better in wind and will loose less speed and inertia on distance.

Fpe IS NOT an adequate formula for killing power. Some years ago I propose a new formula for killing power that, as far as have chance to test, is more close to reality.

This is the thread:

Final formula for obtaining the Hunting Energy Units on Air Rifles.

Taking into consideration: a) That in Air Rifles (as it is when hunting with a bow and arrow) the killing power is related with size of damage (cut-hole) caused in vital tissues; b) That the damaged caused is related by a combinations of velocity (fps), weight (grains), diameter, density...
www.airgunnation.com www.airgunnation.com
Click to expand...
This is not theoretical. I have 2 air guns that fire at different speeds. The .30 cal is much slower than the .25 cal which explains the .30 having less power. The question is simple. Would you rather hunt with a small light weight 40 fpe .30 or a larger heavier 49 fpe .25?
 
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Ezana4CE said:
@MWS For small to small-medium game I like a .25 caliber rifle with heavy domed pellets. The largest animal I’ve taken with a .25 is a beaver. My Brocock Bantam Sniper HR produces 44-49 fpe with 33.95 grain Diabolo pellets. For coyotes I go up to a .30, but prefer a .357.
Click to expand...

nervoustrig said:
As MysticalDragon said, the best choice will depend on other factors, such as what sort of game/pests and at what distances. And bringing in WorriedMan’s comments, the velocity of the .30 cal is dipping down into a region where inadequate penetration and/or a difficult trajectory may be an impediment to making clean kills. As such, I expect the .25 cal at 49fpe would be the better choice for anything except fairly close-range critters, perhaps no more than about 30 yards.
Click to expand...
LOL. 20-30 yards is what I hunt spruce hens at. I could take the longer shots but prefer to get up close.
 
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MWS said:
This is not theoretical. I have 2 air guns that fire at different speeds. The .30 cal is much slower than the .25 cal which explains the .30 having less power. The question is simple. Would you rather hunt with a small light weight 40 fpe .30 or a larger heavier 49 fpe .25?
Click to expand...
are you not able to increase the 30 cal any higher? or are you at the limitations or accuracy limitations of each rifle?
 
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MWS said:
LOL. 20-30 yards is what I hunt spruce hens at. I could take the longer shots but prefer to get up close.
Click to expand...
@MWS Just looked them up. Spruce grouse appear to be decent sized birds, but still on the small size. If your local laws permit hunting them with airguns, I think a moderately powered .25 caliber airgun shooting domed pellets would work fine within your stated range. If you can shoot them in the brain, you’re good to go.
 
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MWS said:
This is not theoretical. I have 2 air guns that fire at different speeds. The .30 cal is much slower than the .25 cal which explains the .30 having less power. The question is simple. Would you rather hunt with a small light weight 40 fpe .30 or a larger heavier 49 fpe .25?
Click to expand...
40 fpe for a .30 Cal is very few fps. You will have a lot of drop.

In all projectiles what kill is a combinations of mass and speed.

According to my formula of Hunting Energy Units, .30 Cal at 635 fps with 44.7 Cal gives 625 HEU's, and .25 Cal 34 grain at 807 fps gives 501 HEU's.......

So according to my formula, if you hit the same animal in the same place at the same distance with both, .30 Cal would cause more damage.
 
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