P08 Recoil Spring Ratings

unspellable · 04-20-2004, 06:31 PM

Both calibers used the same recoil spring in the old model with the flat spring. The new model has two different springs for the two calibers. Around the same time the 9 mm began to be loaded a tad hotter.

Cutting springs is more complicated than it looks at first glance. There are three important spring parameters, free length, per-load force, and loaded force. Spring suppliers, including Wolff, ten to provide only the last figure. Wolff springs have a free length much greater than the originals. While this is not desirable in itself it makes them the best candidate for cutting.

The pre-load force must NEVER be less than 25 lbf. This controls the final closing of the action and if the action stops just short of locked it is possible to fire the Luger with very unpleasant consequences.

For the 7.65 mm start with the softest of the three Wolff springs and see if the action will lock open. Trim a little bit off at a time until you arrive at this point. The 7.65 mm spring will want to be only 2 to 4 lbf lighter to match the original. You'll need to take a little more off for Winchester or Fiocchi loads.

I have the original factory specs for the 7.65 spring, I'll dig them out.

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04-20-2004, 06:31 PM	#2
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 769 Thanks: 0 Thanked 20 Times in 12 Posts	Both calibers used the same recoil spring in the old model with the flat spring. The new model has two different springs for the two calibers. Around the same time the 9 mm began to be loaded a tad hotter. Cutting springs is more complicated than it looks at first glance. There are three important spring parameters, free length, per-load force, and loaded force. Spring suppliers, including Wolff, ten to provide only the last figure. Wolff springs have a free length much greater than the originals. While this is not desirable in itself it makes them the best candidate for cutting. The pre-load force must NEVER be less than 25 lbf. This controls the final closing of the action and if the action stops just short of locked it is possible to fire the Luger with very unpleasant consequences. For the 7.65 mm start with the softest of the three Wolff springs and see if the action will lock open. Trim a little bit off at a time until you arrive at this point. The 7.65 mm spring will want to be only 2 to 4 lbf lighter to match the original. You'll need to take a little more off for Winchester or Fiocchi loads. I have the original factory specs for the 7.65 spring, I'll dig them out.