Airforce 357 max fpe how to?

Running the nsa 178 grain bthps in .358 w the best results on full power outta my Texan .357, it's bone stock btw

2 ways of adding power is:

1) Airforce CF bottle with 3625psi fill pressure + stiffer hammer spring, or go for aftermarket CF bottle at full 4500psi

2) Omit the valve closing spring (on the 45 Texan this will add @50fps)

http://www.africanairordnance.com/424820687/product/3535437/texan-9mm-357-super-valve-4500-psi-bottle-combo?catid=625616

https://www.pcptunes.com/airforce-gunpower-airgun-mods-and-spares/

How much power are you getting now?

You can do helium but it's going to be very expensive!

Helium normally comes in bottles with max. 3000 psi (and they're not cheap! $119 for 1000 cft) to boost that you need an Altaros booster or the like (another $800-850 minimum) and you can expect your gun to leak as it sits (since helium molecules are very small).

Do take a good hard look at African Air Ordnance.

His new .50 cal valve is rated at 1200ftlbs whereas Airforce TX2 is "only" rated at 800ftlbs.

So he knows a thing or two about tuning Texans!

http://www.africanairordnance.com/

In all fairness the man said: Max power!

Not 5 good shots from a fill.

So i dont think i landed to far off target?

You are both right. What’s important is you don’t need 1200 fpe. Well I guess you might need it if your going after a Hippo or Rhinoceros. But you better be a good shot cause one is all your gonna get. These gun’s niche is really subsonic suppressed medium sized game hunting. These are not plinckers. Think of them as a Texas Hog rifle.

Really I'm just looking to get the full potential out of the gun. no I don't need 1200 foot pounds but I would like to be able to hunt Larger game I've seen on YouTube where people have took a dragon claw and shot cape buffalo in Africa I would like to have confidence that if I come across a black bear while hunting in the woods of Virginia I will be able to place a nice head or even shoulder shot and kill the animal humanely

Click to expand...

We don't have bears so I don't have a base line here. I have a question, would you hunt a bear with a AR-10 shooting sub-sonic rounds? That's the equivalent. If that would be ok with you then your good, but remember, if you go shooting a bear remember it is the same as shooting a rhino, you only gonna get one shot!

I hunt the plentiful feral hogs in Texas and some are in the 300 pound range. Pretty tough and smart animals but are a scourge here! I also have a .257, .357 and .457 Texan (and a 7mm custom barrel on the way) and every one has the Doug Noble mods of pulling the inner valve spring and the spring retainer (it's a big flow choke point, by doing this you gain 50 FPS BUT below 2000 PSI you can get bottle dumps) that AirForce adopted from him on their TX2 valve and they all have either a 3600 PSI TalonTunes bottle or a Chinese 500cc 4500PSi CF tank that I only fill to 3600 (because I don't totally trust them at full pressure... AND) because I get good power and shot count at that pressure. I find I prefer the .357 for hog and deer hunting as I simply don't need the smashing power of the .457, the .357 is perfectly adequate.

I've looked at the pros and cons of going up to 4500 fills and the increase in performance is simply not that much, there's some diminishing returns at much above 3600 fill. Note that operating above 3000 PSI REQUIRES a different hammer spring or you get valve lock. Doug has a tested spring(s) and I bought one for each rifle suitable for its caliber. I did buy the AAO springs at first but didn't get the FIT or performance I wanted so replaced them with the ones Doug tested and stocks.

Now, I want to mention that before I went entirely to airguns for the challenge I hunted for years with firearms and I would have disparaged using such low FPE weapons to hunt with back then. Remember, a .357 air rifle (or even some of the .40 and .457 rifles) is has lower power than a .38 Special revolver round and not many people pick a .38 Spl to hunt with. So any particular air rifle is going to have a limit on FPE it can develop, no matter what the weight of bullet, lighter bullets shoot faster and develop more FPE as speed increases , heavy bullets shoot slower but STILL develop about the same FPE range in the same rifle (easily seen on a chart of the various bullet weights, full power tune in that particular rifle and the FPE developed). of course that's using the same pressure for all bullets so its apples to apples comparison.

So then I considered what other factors besides bullet weight that effected my hunting and I think everyone would prefer a flatter trajectory. Here the slower heavier bullet is going to have a more arching trajectory and that forces you to be MUCH more precise in range estimation and absolutely know your drop at each range for SUCCESSFUL and humane hunting.. Also, the aerodynamics physics is such that best accuracy is achieved at LESS than 950 FPS so the bullet doesn't get into the higher drag and chaotic air flow transonic region. A lighter bullet will use less air usually, giving more shots and because it can attain a faster FPS it will have a flatter trajectory. Note that I use an 85 yard zero because at 950 FPS my bullet in ANY air rifle is approximately 3" high at 50 yards and 3" low at 100 yards and this vastly simplifies getting a vitals shot and reduces the need for exact range estimation.

Given all that I went with bullets in the 150gr range because Texans, modified Bulldogs (the Veridium Air and Pitbull conversions), Slayers, etc can do 950 FPS with that weight. This weight gives 300 FPE at the muzzle, 253 FPE at 85 yards and 246 at 100 yards. I have had shots as far as 200 yards so I have the trajectory tables for up to that 'in my mind' and the drop at 200 yards is -51" with a remaining FPE of 202, plenty good enough for a precise shot and lethal for that size North American game. I'm NOT going to hunt elk or moose with a .357 air rifle, no matter what bullet weight, in fact, having hunted both species with firearms, I'm not going to hunt them with any air rifle yet produced!

I hope my explication on why going to the heaviest bullet automatically isn't always the best choice and this long discourse might give you something to consider.

P.S. - I love the NSA 142 gr BTHP for it's accuracy but it hasn't expanded that well for me in gel or actual flesh, especially at longer and slower distances. I cast and so I have found that these two bullets do very well in delivering their energy into the target when launched at air rifle velocities, even down as low as 800 FPS at the muzzle.

https://noebulletmolds.com/site/product-category/358/358-152-hp-cf4 Casts around 148gr in 2% tin alloy

https://noebulletmolds.com/site/product-category/358/359-174-fn-ce2-bt Casts around 152 in 2% tin alloy... If you don't cast, HiKal bullets sells this one (I don't have any affiliation with them either) at https://hikalbigbore.com/shop/ols/products/renegade-hp-357