.22 vs. .25?

[Vincine Fallica]

.22 or .25?

I'm thinking to try 100 yard shooting with a PCP air rifle next spring, my first. I want a repeater so probably a BT 65 QE. I've read that the .25 bucks the wind better, but .22 is a LOT more available. Having been burned by the drought of .22lr recently, I'm hesitant to go with .25 which would only be available for me by mail even now, let alone in a scarcity. I see that there are HEAVY .22 pellets the same weight as .25s.

So, all things being equal, would there be any difference in the drop and drift between .22 and .25? Does anyone here have any experience with both at the same fps? The search didn't come up with any direct comparisons without variables.
 
Edit: This is for paper punching only.

[PlanB]

First remember all my info is based on Fx air rifles, ive hread nothing good about the heavy 22 and i read mostly good on heavy 25. Jsb makes a 34 gr 25 cal. of course the 22 will be cheaper. if you will wait on the specials and order  $150. worth of pellets  to get free shipping, pa is as cheap as i know of.
And as far as i know the 22&25 jsb are nearly always available.
Maybe somebody will tell us an even better place to buy um?

[rsterne]

I have recently purchased some of the 34 gr. JSB Beast .22 cal pellets, and will be building a gun to shoot them over the winter.... When you have two pellets of the same weight, the larger caliber one should, in theory, slow down faster, meaning the smaller caliber will retain velocity and energy better downrange.... The PROBLEM is that it is much harder to launch the smaller caliber pellet at the same velocity, for exactly the same reason.... The smaller cross sectional area that means it slows down less, also gives the HPA less area to push on, so it's harder to accelerate it to the same speed.... In fact, with any given powerplant, you should always be able to get more velocity with a given pellet weight in .25 cal than in .22 cal....

When you stretch out to 100 yards, accuracy is everything.... If the 34 gr. Beasts don't shoot well in my new gun, it will be changed to a .25 cal in short order....

Bob

[Habanero69er]

The 34g Beasts shoot great out of my Rainstorm, but then again that rifle shoots just about everything well. Plus, the Beasts have a pretty good BC, so shooting out to 100yds should be good. As always, your mileage may vary.

[Vincine Fallica]

@rsterne: That's the answer I'm looking for. Your explanation makes sense, but I'm wondering; even though the cross section of a .22 is smaller than a .25, wouldn't the pressure on the .22 be greater for just that reason? Not to mention there being less friction on the .22 cal. because it has less surface contacting a barrel then a .25 cal.? More pressure, less contact, equals ... what?
Building a gun over the winter? I look forward for your results.

@habanero69er: I'm sorry, it's not clear to me whether you're shooting the .25 cal. 33.95 gr., JSBs, or the .22 cal. 34 gr. JSBs. A difference of .05 gr. Which is it and what do your 100 yard groups look like?

Thankx to both of you for your replies. Vini

[Habanero69er]

Beasts are .22. I haven't had a chance to really stretch them out, but at 50yds, they are shooting .50" out of my .22 Rainstorm-I. Like I said, that rifle shoots just about everything well.

[rsterne]

The pressure in a PCP is the same, regardless of caliber.... Pressure times area equals the force available to accelerate the pellet.... Larger calibers have more force....

Bob

[Vincine Fallica]

Uh-oh. Science!

I still can't figure out why block & tackle pulleys make lifting things easier. Vini