Nelson Unit; phantom source of problems!

I decided to make this a separate post rather than attach it to my “mainspring housing polish” post and I’m posting this to shed some light on an experience I’m having with a 1911 22 conversion unit in hopes that it helps others that may face or have faced a similar situation. 

I shoot a Nelson for a 22 gun. I have all year and I’ve had great success with it inuding shooting my first 50 yard clean, and a personal best of 891. Not only that but the support that I’ve gotten from Larry and his business is second to none when it comes to a purchased product, and resolving issues. 

In the beginning, I bought this unit used. The previous owner said it was purchased as a backup piece but was never really shot much and he needed funds for a separate issue in his life. I got it, and it was a jam-o-matic. It would go bang, extract, eject, cock the hammer even, but went into battery without picking up a cartridge. 

Over many phone conversations with Larry we exhausted a lot of ideas and had not come to a solution yet. The only thing left to do was to send it back so he could examine it in person and make an corrections, or adjustments as he saw fit. When I got it back, it has been the most reliable 22 I’ve had. 

Over the year I’ve had four hammers in the frame the Nelson was married to. A stock Springfield Armory hammer, a Wilson Combat Value Line hammer, a KC Roll Trigger Kit “Battle Axe” hammer and now an EGW hammer.

Side note: early on in the year, I had the frame and it’s bigger parts (grip safety, MSH, thumb safety and magazine release/catch) cerakote finished black to match the units color. Came out nice. But emediately I had malfunctions of all sorts. I striped the finish off the rails and it came back to life. 

Now about a month or two ago, I put in an EGW hammer. I started getting the occasional failure to pickup a cartridge like in the beginning. I went over the gun trying to find an issue somewhere. Couldn’t figure anything out. I asked myself: why has it worked all season and just now started doing this? What’s changed? I’ve been in touch with Larry a lot too over this and it’s left us scratching our heads. 

Nothing seemed worn or broken. “What have I changed....?” The hammer. I did the trigger over (again). 

How could that be? How could the hammer make any difference? 

I put the conversion on my 45 frame and it wouldn’t work on it either. It also has an EGW hammer. So I went back to my parts box and pulled out that Wilson Combat hammer and threw it in there. Bingo! It cycled. 

Now, I also have a marvel. And it cycles reliably on the frame with the EGW hammer. Why though? What’s different? In comparing the two units I noticed one difference that may lead to an explanation. On the marvel, where what you might call the firing pin stop plate on a 1911, it’s radiussed. It’s radiussed with no edge or seem. It’s a smooth transition from curvature to flat. On the Nelson, there is an edge. 

So my thoughts are this after talking with one of our fine gunsmiths on this forum: hammers are not all equal. Some have a hammer strut pin located in a slightly different place, making the effort needed to cock the hammer more or less than a different hammer - comparing manufactures. So could it be that my slide from Nelson may not have been intended to have such a hard edge on the slide lug radius? I don’t know but I’m fixing to have another one of those phone conversations with him to see what he says. 

In solving my issue - or what may seem a solution, only time and rounds down range will tell - I found that using a very fine stone and just barely breaking the edge a little on the slide lug, and lightly polishing the face of the EGW hammer seemed to allow the gun to cycle with more ease and allows it now to pick up the cartridge when it’s susposed to. Could I have put in a different hammer that works? Sure. But I like the trigger the way it feels with that EGW hammer. So I’m gonna make it work. 

Food for thought guys. I’m no gunsmith but I can tinker with the best of em. 

I’ll add that despite my battles recently with reliability and the Nelson, it’s been an exceptional unit, and I still stand by it. If a gun doesn’t work I believe it can be made to work. For those that give the conversion option some distance in their decision for choosing a 22 I’ll say this: it’s a conversion. You’re building a 22. Expect some minor issues until you have it tuned to run reliably. Kind of like a 41. Some don’t work right until they’ve been worked over by a professional and we see that plenty. It’s not uncommon to see guns tuned in this sport because we demand such high performances in reliability and accuracy from them. 

Thanks for reading.

Jason, it all comes down to knowing how that firearm works and why. I'm with you, I like to try and troubleshoot it myself as much as possible. What my skills allow me I'll do myself, the skills I don't have will be sent to a good gunsmith who does.
 I notice another area on the slide that should have a slight radius is the other end on the face where the disconnect could rub.
Stan

Jason,,


I had a similar problem with my old Marvel this past year.

IE: "It would go bang, extract, eject, cock the hammer even, but went into battery without picking up a cartridge. "  

 funny thing it would always do it on the 4 round in the mag..  drove me nuts till I simply put in a new 7.5lb ( model 41) spring.. Been perfect since.   seems the issue is something to do with the cycle speed?

fun stuff

I am having this problem with a Nelson, using the stock recoil spring.  I have the Nelson Conversion on a Springfield RO lower.  Using both the Nelson magazines and GSG magazines, I get occasional failures to pick up a cartridge, usually the second of the 5 in the magazine.  The Nelson standard spring is a 9 pound.  I will try their 8 pound for my next range trip.

Jason, thanks for your post. Been having the same issue with my new Nelson. Was thinking it was just a tight chamber, as after 10 or so shots, the problem disappears for the rest of the session. You've given me something else to look at. One odd thing I've noticed, and I'm not sure if it's normal... if I put a spent case or fresh round in the chamber when the gun is cold, it will not extract by manually cycling the gun. I have to use a brass rod to push it out. I've been meaning to check the extractor, haven't gotten to it.

Dave

Common for conversions not to extract loaded cartridge when hand cycling. I push on the extractor with my thumb and it will easily pull it out of the chamber. No rod required.
Jon

Well, there you go. Thanks Jon.

There are a multitude of forces that act upon the slide in motion. Any of them may cause the slide to short stroke and not pick up a round.
Most common is the recoil spring.(weight)
Next is the mainspring(weight)
Next is the relationship of the firing pin stop to the hammer on the regular 1911.The radius of the firing pin stop and the distance/time of the firing pin stop to contact the hammer makes a difference in leverage to cock the hammer against the mainspring.
Next is the overtravel the hammer goes beyond the sear notches when the hammer is being cocked. This affects the friction of the hammer against the slide. The more the hammer has to rotate the greater the force of the mainspring. Failing to pick up a round can also be related the the magazine spring force or lack thereof.
 My story is a Dworak unit. It had a multitude of reliability issues. The two common were failing to pick up a round and the other lacking about a 1/16" from closing the slide. None were associated with the unit itself. 
 The frame had a problem in that the slide encountered more resistance in the last 1/16" of travel forward causing the slide to stay out of full battery. The slide was fine on the frame but when the unit was tighten there was some resistance in the rails. I never could find the problem. I put the unit on a different unit.
 On the new frame I ran into a couple other problems. In handling the pistol the action seemed smooth as silk. But if you tried to over cock the hammer(without a grip safety) the force was tremendous. I changed two times and I think both were responsible. The mainspring housing had worn in that it would mot allow free overtravel of the mainspring. The mainspring could be depressed some far and then it hit  solid resistance. The hammer in the frame would rotate  so far  then encountered resistance. Both these points was the extra movement of the hammer after the slide rotated the hammer. This resistance caused the slide to shortstroke.

Just an update on my issues... I'm happy to say my unit is fuctioning like clockwork. I'm using a lower with a spur hammer, and the hammer was making excessive contact with the bottom of the conversion slide/firing pin stop, even after fully cocking. Putting several hundred rounds through the units has polished both surfaces, and I've had no issues in the last couple sessions. I'm a happy camper!

Jason,

 Thanks for writing your summary on your Nelson conversion.
 I mount my new Nelson combo conversion on a SA A1 Gov.  this morning and head to the range to test fire and sight it in.  I have the same issue as you and other in this thread,  failure to pick up next round. I issue like some of the other is it is somewhat random.  
 To get to the question I have for you .  How big of a R. did you stone onto the sharp edge on the slide?
 I think the approach and order I'm going to take is ,  first polish the striking face of the hammer with a white glass stone and test fire another 50 rounds. Second step if the issue remains is go to an 8lb spring. Problem still exists then 7.5 lb. S&W 41 spring.  Problem still there polish R. to sharp edge of slide. 
 I too love this Nelson combo conversion.  Even though it has only seen 50 rounds of 5 different flavors.  So far it likes CCI Std. and Eley Prime .  Didn't like 711b or R50 which is odd as my SP 22 and 208s love 711b and R50.  I'm convinced it will like more flavors when it gets dialed in.

I am sick to my stomach on the couch right but when I’m feeling better I’ll get back in touch with you.

The hammer spring in your Springfield Armory Mil Spec is too heavy to reliably function the conversion. Change it out to a 19# hammer spring. I use a 9# recoil spring with high velocity ammunition and an 8# recoil spring with Standard Velocity ammunition. If doing this you still have issues I’ll discuss again some points of contact on the slide to polish slightly that should help.

Jason,

 Thanks for your reply , especially from the couch.  I'm putting the 8lb. spring in this morning and heading to the range.
 I've had had a 19lb. main spring in for awhile and the bore of main spring housing was polish quite awhile ago.
 I appreciate your input and will drop you a note on how it goes today.

If your Nelson still doesn’t work right then consider this: in the picture the knife is pointing at a seem or edge that the hammer has to rotate over or pass. It’s my belief that it can slow the slide enough to not run  efficiently. Sort of a speed bump. So if you were to slightly stone/polish that edge to round it some and ease the movement of the hammer over that spot then I feel your chances of greater reliability could increase. It’s what I did and it’s seemed to help some. I still have a little ways to go. 

If you have a Marvel to compare to, the Marvel is completely radiussed with no edge. My Nelson started having issues with the new hammer and the Marvel did not. What’s different? The hammer. But it works with the Marvel. So what’s different between the two units? That edge for one. Obviously there may be other things but that seems to be a major difference that I could change and see if the Nelson behaves better. So far it’s working. 

Alternatively, you could swap the hammer to a non spur hammer. Or just shoot around 1000 rounds to break it in. That did it for me. My unit now looks like Jason's, no stoning, just a lot of rounds.

Dave

Dcforman wrote:Alternatively, you could swap the hammer to a non spur hammer. Or just shoot around 1000 rounds to break it in. That did it for me. My unit now looks like Jason's, no stoning, just a lot of rounds.

Dave

I don’t have time for that lol. I needed it to work. Like.. yesterday.