Buy a book titled The ABC’s Of Reloading, by Dean Grinnell.
And digest it, thoroughly. It won’t steer you wrong.
Been shooting and reloading for .357 Magnum for years.
My advice...have it put back to factory specs.
Don't shoot antyone else's reloads.
Pull the bullets, dump the powder and reuse the primed cases and bullets.
life, liberty, protection BUMP! 2A
Since you have a set of springs put in the next strongest one or two up and try it. Federal small pistol primers have a reputation of having a softer metal cup.
You must have sufficient striking power to ignite the primers uniformly in order for the powder to be ignited and burn uniformly. This is especially true if you use a powder such as H110 or Winchester 296, which really need a magnum primer.
I would put the factory spring back in the and try a lot of target practice using that. Maybe you will like it with the original spring. The original spring could be the baseline, after all, that spring is what the designer thought was a good solution. If you want to experiment, then try the next-weakest spring. You already know the limits, that the spring the previous owner put in is too weak.
I have Magtech and it's fine. I also reload and have been doing so for several decades.
Get whatever ammo you can and see if it works. Typically, light springs work better with primer ignition in trigger cocking, rather than hammer cocking, mode. (That's "single action" vs "double action" for you youngsters.)
But if the gun were mine, I'd get the trigger pull back closer to factory. I'd also want to know if the previous owner made any other modifications to the gun.
I own a GP100. You've made a fine choice.
I have/own 8 Ruger revolvers I would Put the it back to factory spec’s.
It is far more important that a gun goes bang then to have a light trigger.
Ruger revolvers are some of the simplest to do a trigger job on without messing with the springs or sears.
That said one has to know what they are doing.
That said one should find a instructor that knows double action revolvers.
They can instruct you on the proper technique in using. them.
Or read a couple of books on how to shoot them.
I have reloaded many 10’s of of rounds of 38spl and 357mag straight walled pistol cases are some of the simplest to reload for.
Good luck and enjoy your new handgun.
Get the trigger fixed.
They also have an Installation Video:
Just reload some touch hole ammunition. Do no carry rounds in your pocket.They’ll cook off at the slightest touch.
Change up that spring.
Put the real springs back in. A gun that constantly misfires is no fun at all. If the action feels stiff, try dryfiring a few thousand times - it will improve.
I don’t know about Europe, but here in the US reloading components are hard to come by right now, especially primers and powders. I hope you have success in your endeavors. Handloading is a great way to expand your knowledge and enjoyment of shooting, and saves money in the long run.
As far as equipment goes, some of the big names here are RCBS, Hornady, Lee Precision, and Dillon Precision. I have no knowledge of the reloading scene in Europe, so I don’t know what is available there.
Have a new factory trigger installed. Problem solved.
If you dont know what you’re doing, take it to a competent gunsmith and have him replace the springs.
Or just watch a Youtube like all the bubbas do, lol
A hair trigger on a .357Mag? No thanks! Good basic advice on this thread. Restore the gun to specs is the 1st order of business. Ive reloaded for over 25 years and look at anyone suspect who trusts the tiny explosives that I manufacture.
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I have a few surplus hand grenades with touchy, rusty spoons and one with a small but definite dent in the side, if you are interested?