SP20 problem

220 · Post by **220** » Sat Jul 19, 2014 3:15 am

Purchased a SP20 about 2 years ago but have done very little shooting since.
When I first got it seemed to function fine with a variety of ammo, used it a few times in the past month and it is failing to pick up the first round about 2/3 the time.

Load 5 in the mag, drop the slide, fire and it fails to pick up the next round. Empty case is ejected fine, trigger reset but nothing in the chamber, cycle the slide manually and it will run the rest of the magazine without issue.
Same story using either magazine. Thought it may be related to magazine spring pressure so tried loading 6 and 4 shots in the magazine and the failure to pickup is about the same.

I did find an old thread where recoil spring weight was found to be the cause of failures to feed in some SP20's but not sure if the failures to feed were the same issue Im having and strange that it is always the first shot.

Any suggestions and what to try.
I might run some HV next trip to the range just to see if it is related to the recoil spring weight or ammo power level.

Spencer · Post by **Spencer** » Sat Jul 19, 2014 3:44 am

220 wrote:...I might run some HV next trip to the range just to see if it is related to the recoil spring weight or ammo power level.

Arggh!

Step 1 - clean pistol and THOROUGHLY clean the chamber.
Step 2 - clean the magazines

220 · Post by **220** » Sat Jul 19, 2014 4:23 am

Spencer wrote:Arggh!

Step 1 - clean pistol and THOROUGHLY clean the chamber.
Step 2 - clean the magazines

I'm not keen on the idea either but from the old thread it appears some were shipped with recoil springs a bit stronger than needed. Have an old browning that does a similar thing with ammo that is a bit lighter powered it ejects cocks but doesn't cycle the slide quite far enough to pick up a round. Ammo with a bit more oomph and it runs quite happily.
Should be a simple test and less permanent than cutting springs if the issue is elsewhere.

here a link to the old thread
http://www.targettalk.org/viewtopic.php ... =sp20+22lr

My gun is the same age as those that were having issues, might even try my 32 springs, haven't had an issue with the 32.

Gun had a thorough clean prior to the previous range trip, thought it would be worth letting it get a bit dirty to see if things improved.
No trouble ejecting or feeding into the chamber the only issue is failing to pick up from the magazine

Tycho · Post by **Tycho** » Sat Jul 19, 2014 5:38 am

Could be an extreme buffer setting, too.

deadeyedick · Post by **deadeyedick** » Sat Jul 19, 2014 5:46 am

Hello 220. We purchased seven new sp 20's for Club members and all exhibited the problem to some extent. As I had stated in an earlier post I installed two matchguns mg2 slide return springs that were shorter and had less compression force. This overcame the problem completely so we eventually went to a spring maker and had seven sets of springs made with the same compression force as the mg2 springs but made to the same length as the original sp20 springs.
This immediately solved the problem of not picking up the second or third round in every pistol.
I also felt that if we had trimmed a little from the buffer length the problem would have also been solved...however that path proved not to be needed.
On later model sp20 pistols the ability to adjust the buffer has been removed.

220 · Post by **220** » Sat Jul 19, 2014 7:03 am

Mine is the later model without adjustment on the buffer.
Looking at the one fitted it looks good from the rear but like it may be a bit oil impregnated on the front.
I wonder if it has absorbed a bit of oil if it may increase the resistance. If the recoil springs are a touch stronger than needed a little more resistance from the buffer might be enough to start causing problems.

I have a spare and would change it out but having trouble removing the rear sight retaining pin that also retains the cap over the foam buffer.
Doesn't seem to want to move.

deadeyedick · Post by **deadeyedick** » Sat Jul 19, 2014 7:32 am

To remove the pin correctly you should press it out. The pin is characteristically difficult for the first removal but is a piece of cake after that.
Changing the buffer may not be the answer by itself.

David M · Post by **David M** » Sun Jul 20, 2014 2:02 am

My sp20 did the same thing, turned out to me a tight slightly tapered chamber.
Gave it a hone and polish, used the correct recoil springs and volia......

220 · Post by **220** » Sun Jul 20, 2014 4:34 am

deadeyedick wrote:I installed two matchguns mg2 slide return springs that were shorter and had less compression force. This overcame the problem completely so we eventually went to a spring maker and had seven sets of springs made with the same compression force as the mg2 springs but made to the same length as the original sp20 springs.
This immediately solved the problem of not picking up the second or third round in every pistol.

Wouldn't have a spare set you are willing to sell?
Had a play today, weather was a bit warmer so ammo may of had a little more oomph.
Fed Std failed to pick up 3 of 4 mags tried
CCI Std failed to pick up 1 of 4 mags tried
Lapua centre-X failed to pick up 3 of 4 mags tried
Fed HV 1240fps worked for 8 mags in a row.

Sure looks like it is related to the strength of the recoil springs/ammo power level. Temp has ben lucky to make it to double figures lately around here so I guess if the ammo was boarder line to start a little less oomph in the cold could have brought it on.

Tried the 32 springs, wouldn't run with anything so they are obviously much heavier despite being a bit shorter.

David M · Post by **David M** » Sun Jul 20, 2014 7:32 am

Do not use American .22 ammo, they are bigger in diameter than european ammo and being tight in the chamber it delays the release and reduces the slide blowback.
Try some higher power European ammo, SK ,RWS or Geco.

deadeyedick · Post by **deadeyedick** » Sun Jul 20, 2014 8:05 am

David M

Joined: 24 Mar 2004
Posts: 658

Posted: Sun Jul 20, 2014 4:32 am Post subject:
Do not use American .22 ammo, they are bigger in diameter than european ammo and being tight in the chamber it delays the release and reduces the slide blowback.
Try some higher power European ammo, SK ,RWS or Geco.

This is good advice and probably should be applied to most European target pistols. While trying to find a fix with the sp20 problems we tried at least five non U.S. ammunition brands including the ones mentioned by David, however the problem remained.

David M · Post by **David M** » Mon Jul 21, 2014 12:38 am

I did trim a buffer about 25℅ but the thing that did work was to do the chamber.
I found that the chamber was tapered and under size at the front.
Using a match grade chambering reamer and then polishing eased the chamber, allowing the shot to cycle sooner and with more force.

deadeyedick · Post by **deadeyedick** » Mon Jul 21, 2014 2:58 am

David M

Joined: 24 Mar 2004
Posts: 659

Posted: Sun Jul 20, 2014 9:38 pm Post subject:
I did trim a buffer about 25℅ but the thing that did work was to do the chamber.
I found that the chamber was tapered and under size at the front.
Using a match grade chambering reamer and then polishing eased the chamber, allowing the shot to cycle sooner and with more forc

Doesn't say much regarding Walthers quality control David. I don't know where the problem 220 has is coming from however he now has several different options to explore.

220 · Post by **220** » Mon Jul 21, 2014 4:07 am

Thanks fellas, have a few things to try.
Not real keen on shortening the buffer as I run a 32 conversion on it and it is running 100% reliably with the buffer as is. Actually purchased it as a 32 and added a 22 conversion not that it makes much difference.
I'll try a bigger variety of ammo and see if I get any improvement.
Will you be at Wagga next month or Oct David? if I haven't had any joy sorting it I may be in need of a chamber job.

David M · Post by **David M** » Mon Jul 21, 2014 4:15 am

I will be at the states in oct, not sure about the bidgies as i am currently os.

fc60 · Post by **fc60** » Mon Jul 21, 2014 2:31 pm

Greetings,

I have owned both the Haemmerli 280 and SP-20. I found that CCI Standard Velocity would function the pistols reliably.

On a guess, I think I have perhaps two malfunctions in 15,000 rounds.

The barrel chambers do have a tight throat. Removing a round after chambering was difficult to do when we all had to unload to make the line safe for whatever reason.

Cheers,

Dave

220 · Post by **220** » Thu Jul 31, 2014 6:24 pm

Shot last weekend, given CCI std did run reliably previously and gave the best resultsof the std vel in my quick test I gave them another run.
Put 2 boxes in my pocket when I left home so by the time I shot they were close to body temperature instead of ambient temp of around 10c.
Still had 2 malfunctions but not the failure to pick up that I was getting.
One failed to feed fully into the chamber and the 2nd the empty landed back in the gun preventing it closing.
Shot the remaining ammo after the match and didn't have an issue.
Looks like the increased temp helps, can only put it down to it giving the ammo slightly more oomph.

On a side note another member was having trouble with his AW that previously ran flawlessly. Failing to fully chamber, a bore snake every 10 shots was needed to keep running. Looked like lube build up in the chamber was responsible. The problem only seems to arise in cold temperatures.

Spencer · Post by **Spencer** » Thu Jul 31, 2014 8:32 pm

220 wrote:...Put 2 boxes in my pocket when I left home so by the time I shot they were close to body temperature instead of ambient temp of around 10c...

Back in the days when .22Short was used for RFP, a lot of people kept their ammo tucked into an armpit until each 5 rounds were needed

TargetTalk

SP20 problem

SP20 problem

Re: SP20 problem

Re: SP20 problem

SP20 Ammo Functioning