TargetTalk

I've been asked to re-chamber Walther .22short rapid fire pistol to chamber a long rifle, for use in bullseye and standard international. Don't remember if he mentioned the model, but he said the magazine would be no problem, so I assume it's been blocked for the short, and can be altered, or replaced with a LR one..

This brought a question to mind, regarding barrel twist. Is the twist the same for the .22LR as for the .22 short? Wouldn't the "ideal" twist be slower for the shorter 29gr. bullet than for the 40gr.? I'm referring to the Greenhill Formula here, which is used for determining the optimum bullet length/rifling twist, for the lead bullets we use in Schuetzen shooting.

Anybody converted these "obsolete" RF pistols?

Paul

In theory yes the shorter .22short projectile would need less twist to stabilise. But I would be very surprised if any manufacturer bothered to make special barrels for them.

1 in 16" is standard for .22 rimfire I think.

Don't forget to that you will need to block the ports to make it legal for Standard Pistol. And, add some weight to the bolt to slow it down.

Absolute waste of effort and money. Use the OSP as a plinker and fun gun, and buy a used GSP, they are a dime a dozen presently in Germany.

Alexander