Preventing barn roof holes from happening.

Jump to latest Follow Reply
Somebody mentioned purchasing a carbine version PCP and using it. It caused me to remember a Benjamin Woods Walker in .22 that I had. I tried it in my field on a piece of old metal roofing scrap I had. Even at 10 yards it did not penetrate at all. It always made a dent but I don't think a dent affected the integrity of the scrap. I then mounted a simple LED white torch onto the barrel with rubber bands and soda box wrap (the thin carboard a 12 pack come in) as a shim to get the light pointed where the scope is aimed. This was done to test if indeed the white light would keep the birds from flying out of the barn. I haven't had a chance to try that but at least I have a way to test it. The videos BobO referenced above are super fun to watch. I'll have another pesting job with the farmer as he has about 3 shelters that are covered with feces from Starlings who like to roost in the rafters. Never knew those things made so much noise. The remaining issue, which Nugria may have helped solve, is to slow down my FX WCII or my Veteran Shorty. The Woods Walker is nice but has a limited air supply and an 8 round magazine. WIth the pigeons, about 20 remaining, 24 rounds without reloading and recharging, should be enough. With the size of the cow shelters and the amount of feces in there I'll need the larger air capacity and several FX Dreamline magazines for the FX Dreamlite Tactical Compact with bottle that I am told will be here in a couple of weeks. I'll use that with the white light or go back to my ATN 4-12, tune it down and, I hope, lay waste to those Starlings.
 
Upvote 0
This question is like the opposite of those other discussions where we try to puncture some quarry's hardened skull.... 😄

So, to avoid puncturing — the opposite applies:



🔶 (1) Larger caliber spreads the energy out further, so a .25 spreads 20FPE impact energy at the target on a wider impact area than a .177 at 20FPE impact energy.



🔶 (2) Softer material will deform quicker upon impact, and by flattening, dissipates energy and increases impact area (see point 1).



🔶(3) Blunter projectiles like wadcutters (or even hollow points) will hit the impact area with the full caliber size, unlike pointed (or even domed) pellets where their impact energy is concentrated on only a small area, the point.



🔶(4) Lower BC projectiles will dissipate more energy on their way to the target than those with higher BC — that way they have less energy to puncture.



For all those comparsions to be valid, all other factors should be equal, of course.... 😄

Go, hit'em!

Matthias
 
Upvote 0
This has been an interesting thread as it has me curious about something similar, as we consider pesting some in barns and other buildings around our property. 

I know the OP specifically asked about .25 and I saw the threads saying to stay in the 500 FPS range, as well as that video that was just a bit higher. 

How would you translate similar advice into other calibers? What velocity or FPE make sense for a 22 or 177? Maybe it is some simple math that I should know as a fairly new airgunner, But I’m trying to learn too. So any advice on how to translate it could help too.

I don’t have a lower powered rifle, but it is something I have considering putting in the Arsenal after watching the 68 Whiskey guys with their lower powered crown. I’ve considered something like a 177 springer in 12 FPE if I go the field target route and pull double duty. Or possibly get a rifle for this purpose only and the FT rifle too. 
 
Upvote 0
This question is like the opposite of those other discussions where we try to puncture some quarry's hardened skull.... 😄

So, to avoid puncturing — the opposite applies:



🔶 (1) Larger caliber spreads the energy out further, so a .25 spreads 20FPE impact energy at the target on a wider impact area than a .177 at 20FPE impact energy.



🔶 (2) Softer material will deform quicker upon impact, and by flattening, dissipates energy and increases impact area (see point 1).



🔶(3) Blunter projectiles like wadcutters (or even hollow points) will hit the impact area with the full caliber size, unlike pointed (or even domed) pellets where their impact energy is concentrated on only a small area, the point.



🔶(4) Lower BC projectiles will dissipate more energy on their way to the target than those with higher BC — that way they have less energy to puncture.



For all those comparsions to be valid, all other factors should be equal, of course.... 😄

Go, hit'em!

Matthias
Click to expand...

Amen Brother! I agree with your observations. The only thing I would add is that the heavier the pellet the more it wants to retain its energy and therefore penetration. The 25 caliber has a larger diameter to slow penetration but since most of the pellets are heavy that aspect is offset. There are only two lighter weight pellets in .25 cal. I know of which are the Predator GTO at 16.54 grains and the H&N Baracuda Green 19.91 grains. However they are dome pellets which is a minus. I think the best caliber would be the .22 using the lighter weight pellets with a flat or hollow point nose. Bill
 
Upvote 0
You do not need much energy to cleanly kill pest birds at very close ranges. My first priority would be to keep the power low, as in 15-ish fpe. This would be in the 600fps range for .22 and likely 550 fps range for .25. My second priority would be to shoot a wadcutter pellet. Think of being hit with a frying pan versus a flying traffic cone. The energy isn't cincentrated in a single point and really smacks them hard. Softer lead would be an advantage. I don't see ballistic coefficient as having any significant effect at 10-12 yards.
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu