It is a balance of penetration AND expansion!
I spent my first year big bore airgun Deer hunting frustrated with the lack of blood trails and pass throughs I was getting from my slugs. I tried all sorts of options to include casting my own ammo.
Reading all the info on the forums I kept hearing this mantra, "you want to dump all the energy into the game animal for maximum take down power". I have found this to be COMPLETELY false when it comes to big bore airgun hunting. Maybe for birds or rabbits or squirrels and other little fury critters, but Deer? NOPE!
One of the biggest lessons I have learned along this journey is chasing the crazy high foot pound of energy (FPE) numbers shooting ridiculously heavy ammo shot from big bore airguns was just an exercise in physics to show bragging rights numbers. What you really want is a flatter and faster trajectory COMBINED WITH the FPE needed to get a full passthrough on a Deer.
Based on the number of Deer I have shot, depending on the distance and angle of the shot - you want above 400-500 FPE (roughly). Again, this is going to differ based on the situation and where you hit the Deer because bone (rib / shoulder) impact changes things a bit with the terminal ballistics of your slug.
Using a clean broad side vitals zone shot, that 400-500 FPE number is going to get you through and through and get you the expansion you are looking for in your ammo if you can get your slug zipping up around 900 FPS. That additional FPE will also compensate for if there is a situation where you have to take a less than ideal quartering or even straight on shot (the worst angle possible in my opinion).
Based on my experience I have learned it is better to give up some upper end FPE and shoot medium weight slugs to gain velocity and get over or close to 900 FPS in order to get your slugs to expand as much as possible. Plus you will have a much flatter shot out to 100 yards. Doesn't 6 inches of drop sound better than 12 inches of drop at 100 yards? Takes a lot of guesswork out of your shot placement. Win - Win!
I started this journey with the Texan .357 and found it difficult to hit that magic number because at best the Texan .357 is a 300 FPE gun. I didn't have a single passthrough in the 3 Deer I harvested with that rifle.
This year, I worked with Airgun Depot and Airforce Airguns to find the ultimate Deer hunting combination and I think I have found it. I moved up to the new Texan .45 TX2 Valve with Carbon Fiber Bottle and EVERY single shot I have taken this year (4 Deer total so far) except for one crazy hard quartering shot have been through and through. Even that hard quartering shot resulted in going through over 20 inches of the Deer - liver - both lungs - broke through the back shoulder - and lodged in the backside hide of the Deer at 68 yards.
These entry and exit wound photos are from the small buck I harvested with a 116 yard shot and you can tell from the exit wound, there was awesome expansion going on even at that range. This was with the Nick Nielsen NSA 290 grains. I haven't had the chance yet to sling one of his new 302 grain BTHP yet at a Deer, but I am expecting similar results or maybe even better given the crazy HUGE HP in that new slug. They should be available soon, so keeping watching here: https://nielsenspecialtyammo.com/collections/45-cal
If you are thinking about getting into big bore airgun hunting for big game like Deer, my advice to you is this. Just get the AirForce Airguns Texan .45 carbon fiber series and TX2 valve with the full length barrel or LSS model which also has the full 34 inch barrel. This will give you the best opportunity to get the results you are looking for. Personally, I think the maneuverability the shorter barrels with the carbine and SS models provide isn't worth giving up over 100 FPE. Go big with the longer rifle. Just my 2 cents.
I spent my first year big bore airgun Deer hunting frustrated with the lack of blood trails and pass throughs I was getting from my slugs. I tried all sorts of options to include casting my own ammo.
Reading all the info on the forums I kept hearing this mantra, "you want to dump all the energy into the game animal for maximum take down power". I have found this to be COMPLETELY false when it comes to big bore airgun hunting. Maybe for birds or rabbits or squirrels and other little fury critters, but Deer? NOPE!
One of the biggest lessons I have learned along this journey is chasing the crazy high foot pound of energy (FPE) numbers shooting ridiculously heavy ammo shot from big bore airguns was just an exercise in physics to show bragging rights numbers. What you really want is a flatter and faster trajectory COMBINED WITH the FPE needed to get a full passthrough on a Deer.
Based on the number of Deer I have shot, depending on the distance and angle of the shot - you want above 400-500 FPE (roughly). Again, this is going to differ based on the situation and where you hit the Deer because bone (rib / shoulder) impact changes things a bit with the terminal ballistics of your slug.
Using a clean broad side vitals zone shot, that 400-500 FPE number is going to get you through and through and get you the expansion you are looking for in your ammo if you can get your slug zipping up around 900 FPS. That additional FPE will also compensate for if there is a situation where you have to take a less than ideal quartering or even straight on shot (the worst angle possible in my opinion).
Based on my experience I have learned it is better to give up some upper end FPE and shoot medium weight slugs to gain velocity and get over or close to 900 FPS in order to get your slugs to expand as much as possible. Plus you will have a much flatter shot out to 100 yards. Doesn't 6 inches of drop sound better than 12 inches of drop at 100 yards? Takes a lot of guesswork out of your shot placement. Win - Win!
I started this journey with the Texan .357 and found it difficult to hit that magic number because at best the Texan .357 is a 300 FPE gun. I didn't have a single passthrough in the 3 Deer I harvested with that rifle.
This year, I worked with Airgun Depot and Airforce Airguns to find the ultimate Deer hunting combination and I think I have found it. I moved up to the new Texan .45 TX2 Valve with Carbon Fiber Bottle and EVERY single shot I have taken this year (4 Deer total so far) except for one crazy hard quartering shot have been through and through. Even that hard quartering shot resulted in going through over 20 inches of the Deer - liver - both lungs - broke through the back shoulder - and lodged in the backside hide of the Deer at 68 yards.
These entry and exit wound photos are from the small buck I harvested with a 116 yard shot and you can tell from the exit wound, there was awesome expansion going on even at that range. This was with the Nick Nielsen NSA 290 grains. I haven't had the chance yet to sling one of his new 302 grain BTHP yet at a Deer, but I am expecting similar results or maybe even better given the crazy HUGE HP in that new slug. They should be available soon, so keeping watching here: https://nielsenspecialtyammo.com/collections/45-cal
If you are thinking about getting into big bore airgun hunting for big game like Deer, my advice to you is this. Just get the AirForce Airguns Texan .45 carbon fiber series and TX2 valve with the full length barrel or LSS model which also has the full 34 inch barrel. This will give you the best opportunity to get the results you are looking for. Personally, I think the maneuverability the shorter barrels with the carbine and SS models provide isn't worth giving up over 100 FPE. Go big with the longer rifle. Just my 2 cents.
