Any Suggestions

2yr old Nelson conversion on a dedicated frame built for the Nelson with GSG mags.  The gun had worked flawlessly until about 3 months ago when it started failing to chamber the 2nd round in the magazine. Sometimes it will be more than just the 2nd round but mostly the 2nd round.

I have replaced the recoil spring, all mag springs and even purchased a couple new GSG mags and the problem persists. Dirty chamber, breach face not the problem.

Problem occurs with all brands of SV ammo.  I don't shoot HV ammo in the gun.  I have an Nelson with iron sights and the problem occurs with the slide from that unit also.

Some times I can prevent the problem by keeping the mags in my pocket but cold should not be an issue at an indoor range and the problem stated outdoors when the temps were in the low to mid 70's

Any Suggestions?

It will do that to me if I don't push the magazine in hard. It almost seems like it is being held in place just by pressure and not really all the way up. Just my .02

Len

any reason you are not using Nelson mags?

failed to chamber? did it strip the round and then jam trying to feed the round or did the round simply not  chamber fully.

what lb recoil spring. Most folks run an 8lb

spring guide rod bent?  roll it on a flat surface to check

be sure the ejector is not bent and hitting the mags.

I find Eley ammo to be insensitive to cold weather compared to most std ammo.

for starters use the the nelson factory mags, is the slide rubbing on your 1911 factory ejector ?which springs do you have installed?

LenV wrote:It will do that to me if I don't push the magazine in hard. It almost seems like it is being held in place just by pressure and not really all the way up. Just my .02

Len

I wondered if maybe the mag catch was wearing out but it doesn't look much different then in my other guns

JGlenn & Chris 
The lower is a KC lower and he recommended the GSG mags 
9lb is the recoil spring - I don't know what the main spring # is KC puts in.
no bent guide rod
ejector is not bent or contacting the mags or the slide from what I can tell - there is zero missing finish and no signs of even a rub in the areas where those
parts could possible come in contact with each other

What has me stumped is that it ran flawless for 2yrs with the 9lb spring and all.  No impact to the gun i.e. dropped of impacted by something else.
When It gets warmed up good - during practice it will function ok for the most part.

Mine started doing the same thing recently, the only thing I can attribute it to is the colder weather causing the ammo to have weaker ejection.

I run a 19 lb mainspring and a 8 lb recoil spring and it has ran great up until just lately when it has gotten colder.

Kurt

"failed to chamber? did it strip the round and then jam trying to feed the round or did the round simply not  chamber fully." ??


I think you'll find the 8 lb spring runs much better overall.

what ammo do you normally run

jglenn21 wrote:"failed to chamber? did it strip the round and then jam trying to feed the round or did the round simply not  chamber fully." ??


I think you'll find the 8 lb spring runs much better overall.

what ammo do you normally run

most of the time it doesn't even pick up the round the slide goes home with no round

For me the round fires and then the next trigger squeeze will be a click.
I sometimes find the fired case in the chamber, but usually the fired case will eject and it will not pick up the next round in the magazine.

Its done this recently with CCI SV, Norma, FED Auto Match and Aguila SV.

how clean is the chamber.. will a round drop in freely by hand with the barrel vertical... sounds like the gun is short stroking but automatch is fairly hot compared to the other rounds.  look at the chamber closely for any peening if you dry fire a lot

I'm getting that occasionally with mine and CCI SV. I'm using a 17# mainspring and an 8# recoil spring. I bought a case of Agulia SE to practice with over the winter. It runs 100% with that and Ely Target. I'll probably switch back to an 18# mainspring for warm weather. 

Try some HV ammo. Bet it will run with that. Notice how these little problems always show up in the winter?

Jim

jglenn21 wrote:how clean is the chamber.. will a round drop in freely by hand with the barrel vertical... sounds like the gun is short stroking but automatch is fairly hot compared to the other rounds.  look at the chamber closely for any peening if you dry fire a lot

Yes rounds drop into chamber.  I use a dry fire plug

JKR wrote:I'm getting that occasionally with mine and CCI SV. I'm using a 17# mainspring and an 8# recoil spring. I bought a case of Agulia SE to practice with over the winter. It runs 100% with that and Ely Target. I'll probably switch back to an 18# mainspring for warm weather. 

Try some HV ammo. Bet it will run with that. Notice how these little problems always show up in the winter?

Jim

It started the problem in warm weather.  Problem exists in side in a heated range.  It rain for 2 years with 0 issues as presently configured in temps as low as 22 degrees

You've run this by Larry Nelson no doubt?? 

Sorry. Should have re read your original post.

Jim

Might also try cycling the slide by hand  but without the recoil spring installed to feel for any drag.. with and without  the mag in place( just hold the slide stop down)


also don't over tighten your spring rod.   just snug it up, then maybe a quarter turn from there. it really doesn't have to be farmer tight..

the slide stop  is another area that can be dragging on the slide

all else fails just for fun take your old 9lb spring and cut 3 coils off and then flatten the end square again.. and try that spring.. it'll be close to an 8lb

really just sounds like the slide is not retracting far enough to feed the next round but far enough to eject.

farmboy wrote:

most of the time it doesn't even pick up the round the slide goes home with no round

It's short stroking. Try the 8# recoil spring and see if that doesn't fix it.

jglenn21 wrote:Might also try cycling the slide by hand  but without the recoil spring installed to feel for any drag.. with and without  the mag in place( just hold the slide stop down)


also don't over tighten your spring rod.   just snug it up, then maybe a quarter turn from there. it really doesn't have to be farmer tight..

the slide stop  is another area that can be dragging on the slide

all else fails just for fun take your old 9lb spring and cut 3 coils off and then flatten the end square again.. and try that spring.. it'll be close to an 8lb

really just sounds like the slide is not retracting far enough to feed the next round but far enough to eject.

I will give that a try until I can purchase an 8lb

rreid wrote:

farmboy wrote:

most of the time it doesn't even pick up the round the slide goes home with no round

It's short stroking. Try the 8# recoil spring and see if that doesn't fix it.

I will get one and put it in and give it a try. Why would it now need a lighter spring - just wear?

Larry Nelson told me there's just not that much energy to cycle the slide to begin with. Any drag that slows the slide down will cause the problem you're having. A small burr on the rail or 45 ejector. Even an increase in tension on the disconnector leg of the sear spring. I just put a 7.5# recoil spring in mine so I'd be ready for cold weather.

farmboy wrote:I will get one and put it in and give it a try. Why would it now need a lighter spring - just wear?

With the heavier spring you might have been on the edge of having this problem and something like changing the brand of oil you use or the amount you use could cause the problem.
- Dave

Here are some things I've seen over the years, not all may apply to your issues.  But the main idea is to look for issue where recoil energy is being used up more than it was before and causing function problems.  Even the cut end of a recoil spring can ride against the guide rod and take up some energy that needed for operation.  

This is a problem common to a lot of .22 conversions, including the Kart which is one that is really on the edge energy / operation wise at its best.  The second round in the magazine is the one that requires the most "chambering" action force and produces the most drag on the slide.

Be sure to check the inside of the feed lips where the rim of the .22 round sits when it's at the top of the magazine.  Many magazines develop a "notch" or wear point inside the the back edge of the feed lips there.  This little imperfection holds the rim of the .22 round just a little more than it used to and can cause these types of problems.  My magazines for the Hammerli 208 had this issue after quite a few years.  

Also check the position of the rounds to the rear of the magazine.  If the rounds do not come up high enough from issues with the back spacers in certain .22 conversion magazines, it can also increase the amount of force needed to chamber the round.  

Since your problem exists with new magazines as well, that reduces the possibility of the magazine issues above, but its worth checking anyway.

Since you have issues with the new magazine, there are a couple of other items to look at.  First the breach end may preen or have a little burr and its just enough to affect that first or second round on extraction which reduces the energy available to chamber the next round.  That handy little chamber swagging tool is great for all .22s that need a little burnishing now and again.   

Sometimes the firing pin stop on conversions becomes deformed a little as well.  It gets preened around the edge where the firing pin protrudes. Check it out and make sure that the firing pin can extend fully to the rear when at rest.  Also that extra preening around the firing pin stop can produce some extra drag on the hammer during recoil and sap away just a little more energy.  Same thing with the hammer itself, check out where the slide drags against it during recoil.

Just some thoughts.  Hope you can find out the problem.

CR

I'm having a similar problem with my Nelson conversion using SV ammo (higher velocity works OK).  I think the (my) issue is with the lower.  These appear to be very well designed and manufactured conversion units, but the lower is somewhat of a wild-card.  I've been using an older (20+ yrs old) Essex frame with mine along with a fairly new Range Officer.  However, mine has done this from the start (more or less) and not after two years. 

I don't blame the conversion unit, for reasons stated above, and Larry is very dedicated to his product.  Still, that doesn't necessarily fix the (these) problems.  These conversion units are a bit of a 'kit' that require further assembly. I'm still trying to figure out where the drag and friction surfaces are on my conversion unit. 

A big one is where the slide cocks the hammer.  Another is barrel chamber and brass drag.  The recoil spring rod can rub on the slide.  The slide itself can rub on the lower frame rails.  The recoil spring can also rub on the slide.

I'm looking at polishing the hammer face and checking the amount of force needed to cycle the slide with the recoil spring removed.  The next step in that process is to change the hammer mainspring (17lb vs 19lb) and see if I can perceive any reduction in drag or force when cycling the slide.  The next step is looking at reduced recoil springs; I already use the 8 lb spring but have some S&W 41 lower strength recoil springs that can be tried. 

Maybe all this will not help - but I really think the problem is with the frame to unit interface and not the conversion unit.  A methodical troubleshooting approach should fix the low velocity ammo feed problem - trying only one of these steps at at time.  It's been a bit cold and I haven't had much range time lately, but I hope to make some soon, maybe tomorrow on MLK day.


Edit: Made it to the range on MLK day.  Polishing the hammer face and making sure hammer contact was evenly distributed with the conversion slide appears to have solved my problem.  I shot CCI SV, Tac-22 (SV) and Aguila pistol match without a hitch.  In my case, it was the frame to conversion interface that was causing my low (standard) velocity ammo to not have enough energy to cycle the slide.

rreid wrote:Larry Nelson told me there's just not that much energy to cycle the slide to begin with. Any drag that slows the slide down will cause the problem you're having. A small burr on the rail or 45 ejector. Even an increase in tension on the disconnector leg of the sear spring. I just put a 7.5# recoil spring in mine so I'd be ready for cold weather.

Ralph,

Where did you get the 7 1/2# spring? I think that may be just the ticket for winter shooting. My Nelson is right on the edge with an 8# spring and CCI SV.

Jim

Wolff springs has S&W 41 springs in 7.5 lbs. They work perfectly in the conversion