Looking at getting a 22 squirrel gun.
Looking at an auto. Local store has a 5.5" barrel on sale, but Id like a longer one if accuracy would be better.
Any thoughts on 22 rimfire pistols and barrel length?

I do not believe the barrel length has a material effect on the accuracy of the pistol. However, if you will be using open sights, a greater distance between the front and rear sight may add to your ability to shoot the gun more accurately.

I agree with wtroper...

As do I......you may shoot the longer barreled gun better because of the longer sight radius, but it is not necessarily a reflection on the accuracy potential of the firearm.

The only difference you will find is sight settings. One click with a short barrel will move POI more then on a long barrel.

You should get a little more velocity with a longer barrel, but not so much that it should define your opinion. If it handles well and the price is right, give it a whirl.

Lovin' the 4.5" Ruger...I posted elsewhere in here somewhere.

The slab sided government model Ruger MKIIs are very sexy. It would be my pick for that task and someone hide my wallet if I see one for a good price. I own a 5.5" MKII and squirrels are in trouble out to about 25yds with the factory sights. I assume we are talking head shots... I hate shooting squirrels in the body.

As far as the original question, practical accuracy will be better with more distance between the sights, but the gun itself may be capable of the same accuracy regardless of barrel length.

I have a 6" std MK-II and a 5.5" BULL MK-II both are open sights (plan to add a scope later--maybe)

I had a Ruger Govt Target MK-III it shot very well you could put 10 shots under 1" @ 50 no problem --sometimes better with very good ammo(scoped)

I also had an older MK-I 5.5 bull it was also scoped best I ever got it to do was 1.5" @ 50

I also had a 5.5 " bull 22/45 very cool gun had a scope on it too best it ever shot was 1.5" or so @ 50
It had a little more recoil then the others--keep in mind the Govt Target did not move on bags--so when I say more recoil we are talkin just slight movement of the gun.

To get the most out of a 22 auto a scope will help--If you go open sights I would try to stay with a 5.5-6" gun more can be better but it will add weight and make it a bit more to lug around.

JMHO
Fixed sight MK-III 6" Std
Scoped --Can not go wrong with the Govt Target Ruger
Cool factor the 22/45 Ruger is a Cool gun

The best--
Walther GSP
41 & 46 S&W
Hi-Standard H-D or Supermatic
Colt Match Target
SIG (Trailmaster --I think)and Beretta also made nice Target pistols--can't remember the models

a red dot on a pistol adds to the fun when squirrel hunting but as you go past 25-35 yards the dot/actually squirrel becomes much smaller because of not having magnification as compared to a scope but the red dot is a lot of fun.I have a mini-mag tasco red dot on my Contender 10 inch match barrel,my longest shot was at 53 yards on a squirrel with this combo.

You'll need this for squirrels and such....

What I've found out after shooting several barrel lengths in 22 Lr is the length of the barrel doesn't matter as much as finding the ammo your firearm likes the best. Good luck with your choice.