Nelson conversion light primer pin strikes

I have a Nelson 22 conversion on a Caspian frame with about 7000 rounds thru it.  I have experienced light primer pin strikes the entire time.  These light strikes often result in a failure of the round to fire.  The light strikes are usually on a dirty gun (300+ rounds) but sometimes within the first 10 rounds after cleaning.  I sent the conversion back to Nelson about a year and a half ago and they put a new barrel in.  The new barrel it worked well for several thousand rounds but the failure to fires slowly started coming back often times during a match.   After a recent alibi I decided that I have to fix this or get a new gun.   So I began examining fired cases from my Nelson and several other high end 22 target pistols. 
Three things I notices were:
1.  When I push on the firing pin from the hammer side until it hits its stop, it protrudes far enough into the breech area to give a deep indent in the case (even though it doesn't).
2.  The firing pin imprint the Nelson leaves is much larger than the other pistols.  The imprint is several times larger than the Walther and Clark custom.
3.  The fired cases from My Nelson have a bulge near the case rim.  The bulge is large enough so the shell will not fit back into the hole of the CCI plastic box. 

Are there any negative consequences in making my firing pin smaller so it will penetrate deeper?

Is the case bulge normal for a Nelson conversion?

DJW 1CAV

I purchased a lightly (if at all) used Nelson conversion kit sometime last year. I loved the look and the feel but sadly I had similar problems that you described. I couldn't get it to run right from the start though. My two biggest problems were 

1. Failure to chamber the next round after the fired case was ejected. So I ended up dry firing when I thought I had a live cartridge in the chamber. Alibi city! This problem was soon solved by have the correct springs installed according to what ammunition I was shooting. Hotter ammunition I use the 9# recoil spring, lighter ammunition I use the 8# recoil spring. 

2. (And this was the killer) I had light primer strikes. Constantly. And as time progressed the light strikes became worse. Fired casing looked scratched. From past dealings with a S&W M41 and help from others here I was told the chamber was over carbon fouled. So cleaned the Nelson well I did and everything was good - until it got dirty. Wouldn't go 90 shots with out an alibi. 

I finally got in touch with Larry at Nelson Custom Guns and sent it back for a go over. Cleaning, polishing, replacing the extractor, extractor spring, firing pin spring and something else I can't remember were replace or done. When it came back, it ran great. And has since. I make a point to try to keep it clean. I shoot a few times a week so every two weeks or so I clean it. I'm unsure of the round count. Maybe 250-500 rounds then clean it. I practice with what ever I have laying around for ammo, but compete with CCI SV. With cheap ammo I've had only one light strike failure to fire. It went bang on the second strike though.

I have not had it too long since I got it back from Larry. All of the winter at least. so I haven't run a ton of ammo through it but it's working great right now. 

Hope my experience sheds light somewhere.

DJW, I shot an 1800 today, the .22 900 with my Nelson. I don't have any problems with mine.

There is always some .22s that find its way into the net, even though I turn it for the .22 900, so I figured I'd look, and do some measuring.


I found 3 cases of my CCI SV, and checked them out. I don't see any bulge, they go back into the box grid.


For the firing pin dent, it measures .0410, pretty narrow.


The fired case running the caliper up and down the case reads .2235, no bulge.

An unfired round measures .2230.

Don't know if this helps.

Do you know what weight of mainspring (hammer spring) you have in your Caspian frame?  If you have a 17 or 18# you could try going up a pound or 2. If you don't know what it is, buy the reduced power kit that has 1 each from 18 to 23#.   Start with the 19#.  You might need an 8# recoil spring to get it to function with standard velocity ammo. 

You can also call Larry Nelson. I've talked to him a couple times and he's been helpful.

19# mainspring and 8# recoil spring with CCI SV and Eley target. I have shot 22 conversions and the 19# mainspring has always worked the best.
 I have 2 Nelsons and the above springs function flawless.
Tom Ginovsky

rreid wrote:Do you know what weight of mainspring (hammer spring) you have in your Caspian frame?  If you have a 17 or 18# you could try going up a pound or 2. If you don't know what it is, buy the reduced power kit that has 1 each from 18 to 23#.   Start with the 19#.  You might need an 8# recoil spring to get it to function with standard velocity ammo. 

You can also call Larry Nelson. I've talked to him a couple times and he's been helpful.

Thanks to all for the replies.  I have used a 8# recoil spring and a 18# main spring for most of the 7000 rounds I put thru the gun.   I had a some of failure to feeds or failure to strip a round from the magazine when the conversion was new but since then the gun has cycled flawlessly for 1000's of rounds.  Thats one of the many things I like about this gun.  It just has a light primer strike even when the round goes off. 
As far as my main spring, I used a 18# main spring for most of the 7000 rounds fired and just recently I changed to a 19#.  I did not see any improvement with the 19#. 
DJW

19 worked in mine but the strikes looked light even though they went bang. I run a 20 pound Wolff spring and it works and the strikes look a little better.

Check your overtravel screw. If hammer half cock hits sear it will slow the hammer down and could light strike as well as damage hammer & sear.
Jon

Jon Eulette wrote:Check your overtravel screw. If hammer half cock hits sear it will slow the hammer down and could light strike as well as damage hammer & sear.
Jon

Jon,
I checked for sear hitting 1/2 cock by holding hammer back and pulling trigger.  Then I let the hammer down slow and felt for the sear hitting 1/2 cock notch.  The Caspian was OK (my Nelson is mounted on the Caspian).  Then I tried it on my Range Officer and felt the sear hit the 1/2 cock notch!  I fixed that by adjusting overtravel screw.
Thanks,
Doug

When you depress the trigger and slowly let the hammer fall, will the trigger move or get bumped if the sear is hitting the 1/2 cock notch?

CO1Mtn wrote:When you depress the trigger and slowly let the hammer fall, will the trigger move or get bumped if the sear is hitting the 1/2 cock notch?

CO1Mtn,
Its been over 4 years since I had this problem.   To the best of my memory the trigger does not move.  I felt the 1/2 cock notch when letting the hammer down slowly.  If you are having light hits and everything else checks out take a look at your firing pin face size.  Mine was HUGE compared to other 22's.  Once I reduced the size of my firing pin face the gun ran flawlessly.  I dont shoot it much anymore but whenever I take it out is functions perfectly. 
Doug W.

Thanks for the info sir! Haha, I just resurrected an ancient topic. I do not feel the 1/2 cock notch, and my trigger does not bump either. So I don't think I have that problem. As for the firing pin face, it looks normal compared to others.

1. #19 main spring. Adjust recoil spring weight as needed for complete ejection 
2. Use dental pick or tooth pick and make sure no crud is built on breach face, barrel face
3. After cleaning the barrel, look very closely from the breach end, down the barrel. There could be slight build up where the chamber meets the rifling. I take a used .22 bore brush, then wrap just a little bit of #0000 steel wool around the end. Gently, with my fingers and no rod, insert the brush into the chamber with a slow turning motion, in and out. With you finger tips only on the brush, you can feel when it is in too far. Simply clean the chamber gently in this manner. This will also, slightly polish the chamber, and will make some of those sticky extractions less troublesome. Again, gently with only finger tips and little bit #0000 wool on the brush. Some thin solvent may be needed too.
4. Depending on round count and conditions, you may need to remove the firing pin and clean out the firing pin channel. They can get pretty cruddy too.
5. Check FP nose for any chipping or roundedness.

My guess is that 1 - 3 are your culprits. Go easy with 3. 

~ Martin

One other thing to keep in mind is to make sure the magazine is not pushing up on the ejector. Which in turn interferes with the slide. When this happens, the slide may not go into full battery and most of the energy of the hammer is taken up by pushing the slide forward instead of igniting the primer. You will get what looks like light strikes in this situation

I just changed out the mainspring to a 20 pounder. The only problem with that is it took my trigger pull weight from 2.5 pounds up to about 4 pounds. It's decreasing my slow fire score. It fixed one problem and created another. And I already tried adjusting the leaf spring and there's nothing more I can do with that.

But I want to thank you all for your help and your advice here in this forum.

CO1Mtn wrote:I just changed out the mainspring to a 20 pounder. The only problem with that is it took my trigger pull weight from 2.5 pounds up to about 4 pounds. It's decreasing my slow fire score. It It fixed one problem and created another. And I already tried adjusting the leaf spring and there's nothing more I can do with that.

But I want to thank you all for your help and your advice here in this forum.

This sounds like a hammer/sear interaction issue. When a hammer and sear are properly tuned you should be able to have a trigger pull weight in the range of 2-4lbs without issue.

Chiz what pistol do you use for rimfire? I keep thinking that I am going to mothball this Nelson kit and buy a different type of pistol for bullseye. I only shoot rimfire anymore due to the cost of ammo. I think I would have fewer problems with a different pistol such as a Hammerli or S&W41.

Primary Guns are 5" Nelson with a dot on a dedicated lower for 900s and a 6" barrel Nelson on a semi-dedicated Springfield lower for 22 EIC. Both lowers are tuned to run the conversions (mags seat at the correct height, spring for function of the ammo I use, and an excellent trigger job).

Also have a non-lockback marvel, a 208, and a buckmark. All good options, but I shoot the Nelson's extremely well.

Should never be a reason to drop a Nelson conversion as a primary .22

Have the problem fixed.