Browning GP Competition Won't Cycle

[armed_partisan]

Howdy all. Yesterday, I bought a Browning GP Competition (6" High Power target model) for $600 in a pawn shop in Like New condition. I saw it a few days ago, went home and researched it, calculated that I could afford it, and went back to buy it. My friend and I immediately proceeded to the range to see how it stacked up against my other 9mm's including a regular High Power from the same era (70's-80's, MK1) as well as a Glock 17L. I didn't have any CB, only some J-word reloads (80 grainers designed for .380's in a load I call ".380 Magnum") so they all shot poorly. I also had some RWS 124 grainers that the pawn shop owner gave me as part of our negotiations on price. That shot better, but not exceptionally.

All the guns worked except for the GP Competition. It would stove pipe every round. I don't know if the previous owner put in a heavier recoil spring, but whoever had it last, that's probably why they pawned it for such a low price. I figure it just needs a lighter recoil spring, or a much hotter load (although my .380 Magnum is definitely +P and designed to get the most velocity possible out of my 6" 17L just to see) even though all the other guns cycled fine with the ammo on hand.

Any suggestions as to which recoil spring weight I should try? Has anybody else had problems with this model?

[oldscool]

Why not just try some heavier bullets? I really do not think an 80grain .380 bullet is optimum for your gun.

[armed_partisan]

I also tried 124 grainers, RWS/Dynamit Nobel. They didn't work either.

I'm casting some 150grain round nosed bullets from a very old Ideal mold for .38 S&W. It looks like a Lee 356-125-2R, but it's 150 and perhaps a bit pointier. I'm also casting some 356402's since they seem to get the thumbs up on several threads here, and even a 150 will likely be trans-sonic with a hot load out of a 6" barrel.

[Multigunner]

I also had some RWS 124 grainers that the pawn shop owner gave me as part of our negotiations on price. That shot better, but not exceptionally

I'm guessing the recoil spring is too stiff, it may have come that way from the factory, but a replacement intended for heavier bullets like the 148 grain subsonic is not unlikely.

Many pre WW2 European milspec handguns in 9mm did not work well with civilian U S manufacture 9mm ammo. While this extended barrel target model is not milspec it is a development of a military sidearm, and likely will operate better if fairly hot cartridges are used.

A recoil operated system must have a minimum recoil impulse to operate efficiently, added mass in the system requires increased recoil impulse.

Caution though, as I recently read of Argentine military P-35 clones having worn out quickly when NATO Stanag 9mm ammo was first introduced. First I'd heard of this, the only Argie P-35 pistols I've fired were in excellent condition and seemed as strong and reliable as my old Belgian P-35. The NATO spec ammo damaged a lot of older 9mm pistols and the early versions of the Berretta now used by the U S. So its more likely an ammo situation rather than a pistol situation. Also its likely a matter of ammo quality, increased max deviation in pressure is my guess.

PS
The U S Army technical manuals list commercial level 9mm cartridges intended for use in non standard handguns and the M3 Greasegun converted to 9mm.

[oldscool]

Sorry, I did not see that you had tried the rws 124's. Looks like a 17lb spring is standard. You might try snipping a coil at a time off yours and see if it helps any.

[armed_partisan]

No worries Oldscool. My .380 Magnum's are no slouch either. I think this batch was 5.5 grns of Unique, which out of a 6" barrel (the Glock is the only one chrono'd of course) they run about 1400 FPS. I've loaded them to 1700+ out of the Glock, but I don't like to push 'em that hard unless I load on a single stage.

[armed_partisan]

Oh, and referencing my notes, they're 95 grainers, not 80 grainers. Got a box of 5000 from my former employer when they gave up reloading for production.

[MtGun44]

More powder, more bullet or less spring.

Bill

[Piedmont]

Nice purchase. I've never even handled one of these but they are supposed to have a flat spring t on the top of the slide that tensions the barrel. Maybe that is creating too much drag? That is where I would look first. You also said you went immediately to the range. Did you lube the pistol before shooting?

[armed_partisan]

I keep lube in my range bag. I took it apart and compared the mainsprings to my regular high power, and the spring on the Competition one is actually one coil shorter, so that means it's less powerful (in theory) than a regular one, but not enough to matter. I guess I'll just try out these reloads I've cooked up, and if they don't work, I'll buy a Wolff Performance Pack or something.

[oldscool]

a p, try the spring out of your regular hp. The spring power is supposed to be figured at maximum compression in the gun with the slide back. That is where the force is rated, pushing the slide forward. Often longer springs or a few more coils do not equate to more power. A variable power spring will load up quicker compared to a standard spring. Someone may have snuck one of those in your GP.

The other spring may not work, but it is an easy try. Good luck.

BTW, you did make a nice score on a nice gun, and once worked out, you should be very happy with it.

[MtGun44]

Wire diameter is MUCH, MUCH more important than length with springs. If one is even
.002" larger wire it is MUCH stiffer. Spring rate is extremely dependent on wire diameter.

Bill