Norinco m93 woodsman clone mainspring tension?

[alpining]

Hi all - I just received an m93 and I am VERY impressed with the value. For the money, I don't think anything comes close to comparing. Finish was much better than I expected, frankly. After the requisite cleaning, two obvious out-of-the-box mods are to loctite and tighten the rear sight assembly screws (adjustment screw and set screw), and to work over those amazingly sharp edges on the magazines with some emery cloth. I also smoothed the edges of the slide stop lever (personal preference), and all of this was completed in less than half the time it took to watch Death Wish 4. Terrible film.

On to the range: 100% reliability with minimags, Federal bulk pack, and Blazer bricks. Zero fail to feeds and zero fail to extract on all ammo over approx 300 rounds. Many fail to fire (seemed like light firing pin strikes) on all of the mid-high-end Remington ammo I tried, though. So, in the interest of making this already amazing little package into a one-pistol-eats-all ammo plinker, I'd like to address the light strikes.

Hammer movement and firing pin movement are satisfactorily smooth, so I'm guessing it has more to do with the mainspring. In searching the forums on this topic, I've seen that several people have mentioned that they were able to increase the mainspring tension. How, exactly, can I do this?

Thanks in advance...

 

[super7]

When I had a m93, the only time I would get light strikes is when the chamber got dirty. The slide would then not close completely yet would close enough to allow the hammer to be dropped. The dropped hammer would then just push the round in that extra 1000th of an inch and cause a light strike.
Although I can't remember much of the guts of the m93, in general you could try putting in a heavier mainspring and/or a lighter firing pin spring.

 

[Wolfgang7]

My buddy and i both have a M93. It's weird he has the light strike problem all the time and mine doesn't unless it's really dirty. At about 700 rounds with no cleaning is where i started to have problems. Yeah that's not a normal habit of letting my guns get super dirty but i was kinda just trying to see what the M93 would do. Up to that point though it ran fine without any hiccups. Must just be whatever one you get!! Good luck!

PS- I only ran the federal bulk 525 and the blazer. I hadn't tried anything else. However on my buddies gun the ammo makes a huge difference. The blazer and federal bulk work far better than lots of other brands....

 

[paininthe10]

I bought one awhile back and extra mags for lots of shooting. I like the feel and finish of the pistol but that's it. It stove pipes and fails to feed continuously and takes the fun outta plinkering when you have to rack the slide just about every second or third round. Tried Federal, Winchester , Several brands of Remington and even CCI to no avail. I guess I should have sent it back to Marstar.

 

[Cammy7s]

Should be some posts here somewhere to help you out. I remember a few guys posting about increasing tension on the spring. Ummmmm, here it is:

http://www.canadiangunnutz.com/forum/showthread.php?t=580445&highlight=norinco+m93&page=3

I will get light strikes on about one in every 3 magazines. It gets wore as the gun gets dirty. But all in all I am still happy with this gun for $150. I am thinking of trying to increase the firing pin spring tension someday.

 

[alpining]

Should be some posts here somewhere to help you out. I remember a few guys posting about increasing tension on the spring. Ummmmm, here it is:

http://www.canadiangunnutz.com/forum/showthread.php?t=580445&highlight=norinco+m93&page=3

I will get light strikes on about one in every 3 magazines. It gets wore as the gun gets dirty. But all in all I am still happy with this gun for $150. I am thinking of trying to increase the firing pin spring tension someday.

That's precisely the info I was looking for, thanks!

Note that light firing pin strikes are only a problem with Remington ammo - CCI Blazer bulk and Federal bulk are firing 100%.

For those looking to do the same mod: Do the basic pistol disassembly. Disassemble the mainspring housing (remove the mainspring from the housing). Drop a suitable spacer in the bottom of the mainspring channel. Reassemble, and your mainspring tension has just been increased. The difficulty is in getting a spacer to precisely the right length. Too long, and the mainspring housing cannot be replaced into the frame.

To make the spacer itself you can use anything of the appropriate diameter and hardness, I used jb weld kwicksteel packed into a cutoff section of a 22 case. It just happens to be the correct diameter. I've got mine at about 5/32" long, but I need to take another hair or two off (reassembly is a real pain at this length). I would suspect that other pistols will require different lengths, as the internals are not exactly machined with precision.