mainspring balancing act!

[G.T.]

Hi to all! Over the last 30 years or so, I have been walking a tight rope between balancing a mainspring with the ammo that is available, and of course, all the while, not cause any harm to the user or the pistol.
It is a tendencey of mine to to test with ammo that is relitively mild, such as the Winchester White Box Target / Range ammo. I've had good luck with the ammo as long as I had revised Mec-Gar magazines and good quality replacment springs. At first I had a considerable number of oeiginal armorers springs, mostly Mauser, but that pool has dried up long ago. So, any aftermarket spring could be just about any weight, or condition, or compression?
Just that variable alone makes it difficult to set perimeters that insure success!
Lately, I have been having good results with Wolff standard 38# mainsprings, althought it is too early to see if they stay in spec and keep their strength thru the recoil cycle?
Yesterday, I took two Lugers to the range, using WW White box, it had several short recoil james with each Luger. I was all set to leave, when I thought about some extra ammo I had just acquired that was labeled Winchester TARGET and came in a military style brown box. Both Lugers ran perfectly fine with it, and I ran thru a full mag thru both lugers without a hiccup! When I got home, I see where the ammo was listed at 1300 fps which is 100+ fps over te white box offering?
So, now I'm waiting on the Wolff springs, and will report the results after the next range visit. But, I'm starting to think maybe the new ammo might insure better function, without significent abuse on the Luger. The though being, if it was close to full recoil, the little bit extra will still be in balance and without beating the luger to death... More soon, best to all, til...lat'r...GT...

[Doubs]

G.T., I'm no expert on balancing recoil spring weights but 1300 fps seems somewhat hot to me. I load a 124 grain bullet to the original specs of 1090 fps which seems to work well in my Lugers.

Just my opinion but I think that powder burn rate is as important as velocity. A medium burn rate seems to give the proper pressure curve that functions a Luger well. Years ago I loaded 5.6 grains of Unique but now I use 5.8 grains of Shooters World Auto-Pistol which has a burn rate similar to AA #5. It's possible that the powder being used by Winchester has a burn rate that gives 1300 fps without excessive pressures.

Of course you're looking for a factory load that works properly as not everyone reloads. I'll watch with interest what results you have with Wolff springs. My experience with Wolff springs has been excellent and I've used a lot of them in various pistols.

[velodog455~]

G.T.:
I have discovered that Winchester is making their 9mm white box ammo in two locations now, one being the traditional U.S. made WWB that everyone is familiar with, and another WWB variant made in Bosnia. I most often see the Bosnian ammo at Academy Sports.

The two different ammo types chronograph differently, for me at least. The Bosnian stuff chronographs a bit higher and it subjectively feels like it has a bit more recoil.

The country of origin in tiny font is on both the U.S. and Bosnian boxes (which look pretty much identical) but is often covered by UPC or SKU labels applied by the ammo sellers. I'm just wondering whether or not you might have been using both U.S. and Bosnian ammo in your testing. I can see where it could cause excessive head scratching if you were using different ammo types without knowing it.

Of course, if you already know this then delete as you see fit.
-Bob