MORE POWER//SMALLER CALIBERS

I've recently built a .177 caliber Slug / Heavy pellet shooter. Currently shooting H&N Sniper magnum 15 grain @ 37 fpe

Yup it's Small - Fast - Accurate !!

You mean there's something larger than .177????

It is very plausible for sure. But I am no expert in ballistic coefficients or ballistic physics in general so I will leave that for others. I for one was thinking of getting larger calibers, but have since changed my mind and I think I will stay in .25 or less. I can tell you my next PCP will probably be in .177. 

Good to see you back and active in the forum again my friend. 

For general pesting I stick with 25 and under as you have mentioned the power output now is very generous. I am definitely looking at a 177 slug spitter. On the local permissions I have no reason to shoot anything larger than a 22 and have been in situations where a 177 would have been a much better option with a slug. Only time I have gone with a 25 was to take a pesky yote harassing the chickens etc. With slugs and the right shot placement he was DRT, farmer was happy and asked me to look out for more. Only reason I want a .357 is local hunting laws require it to hunt bigger game.

No.

"I believe caliber choice may become smaller".

Not unless the Earth reverses polarity!

 "I believe caliber choice may become smaller."

I agree.

Anything that increases power in a smaller caliber will also increase power in a large caliber...as well as bc...so all calibers remain in their rightful place. Just as you say there is a correct tool for every job, and you certainly won't be shooting a .357 inside a barn at rats, nor will you shoot a .177 slug shooter in a barn at rats...nor will you shoot a .177 at coyote from 100 yard...you see where I am going here? Chill out with the 'this caliber is going to replace this caliber!' talk...because it ain't happening chief.

I would love to see more in the smaller calibers just because there is opportunity for better BC's. One of the issues becomes diminishing return on power from a given pressure. It takes more pressure to move a smaller projectile since there is less area to push on. It takes more volume of air to push a larger projectile. The best balance I am seeing in airgun pressure levels seems to ba around the .25 cal. 

For example with most given tunes on my Impact, If I change barrels without changing settings I get the best velocities and sometimes even shot count in .25.

Is anyone having a different experience?

I got into PCPs for the lower power, as counter intuitive as that may seem. Less is more with PCPs for me anyway...

I have to disagree. Right now there is .177, .20, .22, .25, .30, .357, .45, .50. There's a choice for everyone and task. When I was a kid there was .177 and .22 - the choices only get bigger, not smaller. Unless a particular caliber (ahem .20 - don't hate me) that is really niche and it becomes hard to obtain (or have a decent selection of) ammo for it.

Power's fun but not everything. I got into PCP for simple, consistent and precise power. But just by grabbing any of 6 or 7 airguns I can go from 6fpe to 800+ fpe. 

One other to consider is energy transfer to the target and pass through (if you're a hunter). My guess would be if you put a 60 fpe .22 up against a 60 fpe .30, the .30 will be able to transfer more energy to the target.

edit:

I just thought to add that if we are talking purely longer range target shooting I'll take a smaller caliber that can push serious power.