Nelson conversion misfires

Thought I'd share some info on two Nelson's I've been having issues with.

Issue. Rounds feed flawlessly but I have a "click, no bang" about every 20 rounds.

Trials and results
1) oil top round of mag. 90% improvement, but a pain in the butt.

2) narrowing the firing pin impact area to concentrate the force in a smaller area - 75%improvement (vs no oil)

3) 10 lb recoil spring instead of 9 lb. 95+% improvement (vs no oil, but with narrow firing pin) I say 95% because I only have about 400 rounds through it. This seems to be a major improvement though.

I spoke with Larry and he indicated they have two chambers. One for accuracy, one for cci minimags (action pistol guys) I obviously got the match chamber. What can happen is that the round engraves just a bit in the rifling for best accuracy. The dimension is based on the cci sv bullet profile, which after inspection of other ammo is considerably different. Sometimes, the round stands back a few thousandths and the firing pin pushes the round forward and absorbs energy when hit by the firing pin. Bullet profile or the amount of wax/lube can affect this.

The higher slide "impact" from the 10lb spring seems to be just a bit more effective in seating the cartridge in the chamber which allows more energy to be transfered to the priming compound.

I've had no malfunctions with the 10lb spring, but I hold pretty hard, and YRMV, but I thought I'd share.

Rob

How's the mainspring on the hammer, mine works fine with a 19lb.
Stan

chopper wrote:How's the mainspring on the hammer, mine works fine with a 19lb.
Stan

19 lb as well...

Were you testing with CCI SV when you got the misfires?  (Based on your experience with the 10 lb spring, I would assume not.)

hg401 wrote:Were you testing with CCI SV when you got the misfires?  (Based on your experience with the 10 lb spring, I would assume not.)

Ammo tested
CCI SV - "old dark blue box"
Aguilla Pistol Match
Federal Gold Medal Match (dimple primer)

there were no failures to feed with any ammo...

you might double check your mainspring weight. I received some batches of springs that were actually 17# springs but labeled 19#. 
Jon

I went through some persistent light strike issues with a Marvel, several trips to FCW. The 100% fix ended up being a stronger hammer/main spring, believe I ended up at 21#. Sometimes its not worth the hassle to try and make a 19# work.

Jon Eulette wrote:you might double check your mainspring weight. I received some batches of springs that were actually 17# springs but labeled 19#. 
Jon

I'll ck... can you advise on the displacement dimension to read the weight at?

Thanks

What frames are these Nelson’s mounted on.

james r chapman wrote:What frames are these Nelson’s mounted on.

Initially caspian, then Jem... both needed mag catch lowered to function properly.

My Nelson is mounted on a dedicated Fusion "combat" receiver. The only modification is a 3.5# trigger job that breaks like glass. 
The only ammo I use is CCI-SV! 

ZERO failures or stoppages of any kind in over 600 rounds!

Smiles,

P.S. this replaced a M41 and my scores improved 15%!

More Smiles!