A few bits and pieces about the Walther GSP






Fatigue cracks in .32 magazines

Can the .22Short OSP/GSP be converted to .22LR to meet the current ISSF 25m rimfire rules?

Assembling .32 GSP magazines

Adjusting .32 GSP magazines

Assembling .22LR magazines – to be added

Adjusting .22LR GSP magazines – to be added

OSP/GSP timelines – in progress, only partial



Fatigue cracks in .32 magazines

In all fairness to Walther, I have only experienced this problem in very old magazines that have had a LOT of use.



There are two symptoms:

·         First round does not want to feed properly when slide is released

·         Magazine is difficult to insert in magazine well when loaded with five rounds



Even when these cracks are quite small the magazine will exhibit the symptoms above – you unlikely to notice the cracks before the symptoms appear.

In fact, the cracks are easier to feel than see – simply run your thumb nail up the side of the magazine towards the wings at the top rear of the magazine.


How to fix:

1.     The best fix is to replace the magazine/s.  The good news is that the current series Walther .32 GSP magazines fit the earlier models without modification: there are differences in the old and new magazines (follower dimensions, the number of turns in the spring and the colour of the plastic base) but they fit and work!

2.     Silver solder.

3.     TIG welding


Can the .22Short OSP/GSP be converted to .22LR to meet the current ISSF 25m rimfire rules?

The short answer is ‘yes’; the long answer is below – but ask yourself, is it worth the trouble?


What is involved:

·         Re-chamber to .22LR.  Simply re-cutting the chamber with a .22LR reamer is the quick and dirty method – the bore of the original GSP .22Short rapid fire barrels is usually fairly sloppy.  Far better is to counter-bore from the front to within about 7mm of the rear of the barrel, sleeve with a piece of .22 barrel (soft soldering will fix it in) and cut the chamber with a .22LR reamer – this method has the advantages of a/ not requiring the slot in the breech face for the extractor to be re-cut and b/ the barrel vents are closed off.

·         Close barrel vents.  If you have not re-sleeved the barrel, these are already tapped to take metric grub screws

·         Magazines.  The Walther GSP .22LR magazines should fit GSP .22Short frames: older OSP frames may need the magazine well to be modified to allow the GSP .22LR magazines to fit.

·         Set trigger adjustment to ˃1000g.  For GSP trigger units, in most cases this is simply a matter of winding up the trigger adjustment.  For the older OSP triggers, the main trigger spring will need to be replaced.

·         Bolt weight.  This can be increased by using bob-weights on the ends of the bolt cross slide as on the GSP .32 pistols.

·         Recoil spring. Upgrade to a stronger spring.

·         Reduce sight radius to ˂220mm.  Moving the rear sight forward on the frame is possible, but a far better solution is to move the front sight back on the barrel.

·         Grip. The .22Short OSP/GSP pistols were produced in an era when wrap-around grips were permitted in the rules – simply remove any wrap-around parts.


Is it worth the trouble?

1.     Expect any of the original ‘round barrel’ OSF frames to be well worn and to have had lots of use.  Some of these OSP models are now over 50 years ols and many of these frames are already infected with fatigue cracks and are marginal with the .22Short ammunition they were designed for – for safety reasons I would not recommend converting these to .22LR.

2.     Given the price of second-hand .22LR target pistols from the same era – probably not.  It would be cheaper and less hassle to buy a pistol originally chambered for .22LR.


Assembling .32 GSP magazines

You might have thought that there is only one way to assemble the magazine after cleaning – wrong!  There are some points:

·         The follower fits in the magazine body with the hinge to the front of the magazine.

·         The cross pin must be above the follower base but below the hinged part.

·         The spring must be the correct end up and the right way round.  The ‘base’ of the spring is finished at right angles to the length of the spring: the top is finished at an angle  (30°) to the length of spring and the higher end goes to the front of the magazine.


·         Insert follower hinge forward into the magazine body – insert as far as the hole that takes the cross pin.

·         Insert cross pin so that it is above the base of the follower but below the hinged part of the follower.

·         Insert spring in the correct orientation.

·         Bring plastic base to the spring, ensuring the spring fits down over the boss inside the plastic base.

·         Use the plastic base to push the spring fully into the magazine body.

·         Insert the base retaining pin into the plastic base from the left side of the magazine.


Adjusting .32 GSP magazines

There are two areas that can get out of adjustment (dropped, etc.), a/ the vertical wings at the front of the magazine top and b/ the wings at the rear of the magazine top:

·         The vertical wings should ‘just’ grip the case as is passes through them.  The amount of grip will vary due to slight variations in outside case diameter with different brands of ammunition, and there can be differences in outside case diameter depending on the dies used for reloading.

They seem to work best with an interference fit of 0.xxxx”/0.0xxxxmm – measure case diameter of your ammunition about 4mm back from the neck.

·         The wings at the top/rear of my magazine (Geco cases) seem to work best with the following dimensions:

Inside measurement




‘A’ – front



Add drawing

‘B’ – rear




Assembling .22LR magazines

To be added



Adjusting .22LR GSP magazines

To be added


OSP/GSP Timelines – in progress





GSP .22lr

GSP .22sh

GSP .32


GSP Expert





















Round barrel discontinued










Matt nickel (MV variant) – one year







Safety omitted







2 stage trigger







25 Jahre Model (‘gold’ bolt) – one year







Atlanta Model (‘gold’ bolt) – one year






















Walther website downloads

Pilkguns 10P Files




© 2011, Spencer C Tweedie