Competition pistol barrel question

[JackO]

I'm thinking of a new barrel for my Pardini HP 32 (bulls eye centerfire competition gun).

For those who don't know, the original barrel is great for 25 yards (as it was originally designed for 25 meter competitions), but for 50 yards is somewhat marginal even with some hotter ammo. With the new barrel (higher twist rate) I have an option to go with the original length (4.5") or make it longer, say, 5.5" or even 6".

On the first thought, the longer barrel might have some advantage, but being an engineer , I researched a little the subject on barrels and factors affecting their accuracy. Unfortunately, all I was able to find, was related to the long gun barrels, nothing on the pistol barrels. The major factors affecting accuracy of the long barrels, besides the other ones, are vibrations associated with internal resonance frequencies, which are related to the material and geometry of the barrel.

Does anybody have any knowledge on this subject and/or any experience and can give me an advice on the optimal length of the new barrel? Any input would be greatly appreciated.

Jack

 

[Dan S]

Go with the stock length barrel. Pistol barrels don't have so much a harmonic problem, as do rifles, but, barrel time has more to do with it. Meaning, the shooter has more time to move while the bullet is still in the barrel. Your load might be in the 800 fps range? If so, that's slower than .22 long rifle.

 

[bpm990d]

I would suspect that the most important consideration with increasing the barrel length, would be how the gun feels in your hand and how it shoots out of your hand. I think the ergonomic factors will overshadows any potential engineering or mechanical problems of a longer barrel. You can also track down Greg Derr and ask him. I’m sure he will give you the straight scoop.

The other possibility is to post something on this list serv and ask specifically about your pistol and barrel lengths for use in convention pistol.

http://www.lava.net/~perrone/bullseye/

B

 

[JackO]

Guys,
Thanks a lot for your help.

Jack

 

[boomerang]

Here's a linkl on the accuracy of the 32 and info in particular to the HP.

http://www.targettalk.org/viewtopic.php?t=13941

 

[Greg Derr]

For 50 yard accuracy I've rebarreled my Pardini with a custom Barrel in .308 caliber. It is longer than stock by 1.5 inches. I've gotten very tight groups using the .308 with a 1 in 16 twist. You can contact me via PM for more info if you like. Greg