Starting to look at adding a .22 caliber to my wall-o-pellet fun. Reading a bit on Nitro Piston and am interested.

For noobs:
A nitro piston air gun is a spring gun without the spring.
Instead of using a coiled spring as the power plant, it uses a nitrogen-filled cylinder.
The nitrogen in this cylinder is already kept under pressure and you put more pressure to it when you cock the gun.
The air is held under tension until you pull the trigger.

I also read where they may be quieter. Anyone confirm this?
Looking for accuracy - squirrels from 10-35 yards

Still shopping and have a budget of around $300 for just gun, will scope later.
Looking for something in synthetic just because.

Appreciate any experiences with this propulsion system.

Although nitro piston should be a very good way to make a spring airgun, most seem to be made to produce the most power rather than best accuracy performance.  A few gas springs are adjustable (the Theoben I have is one) which makes tuning possible.  However, those use air rather than nitrogen.

I do not own any nitro piston guns, but I have shot several of different varieties.  My take, is the spring noise (twang) is eliminated and can have a nicer firing cycle.  But, most seem to suffer the same problems as an overpowered lightweight steel spring rifle.  They are still rather hold sensitive.

So I might be better served funding a nice .22 Springer if my aim is to maintain accuracy?

I do love my R7 but would not mind a bit more termanal energy.

The step-up in power and shootability from the R7 is the Air Arms TX 200.  Of the spring guns I have, this one gets out to play the most.

I have a Benjamin trail NP in .22 that I bought about 10 years ago.  Really quiet. Quieter than my suppressed 10/22 with subsonics.  It is hold sensitive, same as spring guns.  It seems that if held right in front of the trigger guard, lightly, I get the best groups.  Accuracy was lousy until I got used to the hold thing.  Trigger sucked, BAD.  Lots of guns are the same gun with different branding.  Crosman, Benjamin, some Beeman are all the same gun with different stocks and stamps etc.  Same shitty trigger.  Lots of trigger DIY mods, or buy a Charlie da Tuna trigger.  Power is decent for what it is, about 740fps in .22.  Once you get the quirks figured out, it's good fun, and will handle some critter control.  Especially if you're not comfortable launching actual bullets skyward at treed critters.

I have a Hatsan(walnut stock) MOD95 springer while my stepson has a Crosman Nitro piston ?(plastic stock). Both are hold sensitive.

When standing beside either one, the muzzle sound seems to be about same, as both have more of a barrel protector that is more of a handhold for the break-barrels, than a modulator.

My Hatsan does have better accuracy from it's adjustable trigger and lesser 900fps compared to stepson's more powerful nitro 1400fps when using same weight .177 pellets.

I don't understand the hold sensitivity issue, can someone explain?

Spring airguns, whether steel or gas, use a fairly heavy piston that is driven forward rapidly to compress a column of air behind the pellet (at the rear of the gun).  This heavy piston movement initially causes a recoil impulse but well before the pellet starts to move.  The air is highly compressed as the pellet starts moving down the barrel, but due to the larger frontal area of the piston, it comes to a stop, and often rebounds which then causes a forward movement (anti-recoil if you will).  Due to the lightweight nature of many spring airguns, this back and forth motion (along with a whole bunch of other vibrations) causes the rifle to move quite a bit before the pellet leaves the barrel.

When such a gun is held inconsistently, the pellet will leave in a different direction due to the muzzle being pointed in a different direction all because the vibrations are different.  When a spring gun is well tuned, the vibrations are much more consistent even when there is more or less force holding the gun by the shooter.  This is the essence of what spring gun tuners try to do.  

@Sarge1400

I have a Crossman Fire .177 NP that easily takes out squirrels in my back yard.  I have killed them out to 25 yards (furthest feasible shot) no problem.  I’m not sure how it is as a target shooter, I zeroed it and have been keeping the pest population under control without a change to zero in the past year.

Shootability? Did you mean accuracy?
I didn't think any manually powered air rifle was more shootable than a R7 or HW30 or HW35.
I find side levers and underlevers to be a lot less fun to load and plink with than break barrels.

By shootablity, I am mainly referring to both accuracy/precision and hold sensitivity.  Also, there is an ergonomic factor as well.  The TX200 just gets most everything right.