My Tach Ops 40 at around thousand rounds thru it is doing the proverbial slide not staying back. Shot it yesterday single handed(to confirm)and all four mags are affected. From time to time (I have my own range in my back yard)I have had this problem. Yesterday, it malfunctioned probably 40% of around 30 rounds through it weapon. Sig says change the mag springs.
I have always kept two of the magazines full but I have changed that out a few times and don't know what two I have always kept full. I don't keep track of it. Do the springs wear out that fast. That's the gist of what I'm getting from Sig. Weapon is less than two years old. My next door neighbor and I took the slide off and tested putting empty mags in and watching the mags come up and seat under the slide catch lever and they needed a tiny hair push up to catch. With the slide attached, inserting the four mags and racking the slide back, most of time, the slide would not stay back.
Could it be the slide catch lever?
I shouldn't keep the mags stacked full with rounds? I need your expertise.
Thanks for your help.

No, the magazine springs shouldn't be wearing out that fast.

Emptying the magazines before storage or loading fewer rounds in the magazines won't help prevent the spring from wearing out. Magazine springs wear out from repeated cycles of being compressed and released, not from sitting fully compressed.

You could try swapping the magazine springs to see if it helps, but it sounds like you may have a mechanical issue with an out-of-spec part, either with the slide lock lever, the magazine followers, or even the magazine catch (causing the mags to seat just slightly too low, although that would likely result in feeding issues as well).

quote:

Originally posted by ds1962:
My next door neighbor and I took the slide off and tested putting empty mags in and watching the mags come up and seat under the slide catch lever and they needed a tiny hair push up to catch.

Possibly the followers are gummed up and not moving freely inside of the magazine tube.

Disassemble the magazines, clean them thoroughly and assemble them dry, no lube whatsoever.

HUGE sticky on the topic:

https://sigforum.com/eve/forums...50601935/m/749101723

Agree with both of the above posts.

I've always kept my mags loaded for all my defensive pistols over during over 50 years of shooting. I've NEVER had a mag spring on any brand/model that needed replacement.

Same for range mags. My 1995 P229 has about 45,000 rounds through it. Same 10 mags. All draw/fire, drop mag, reload drills. Bounced off the concrete range floor every time. Still in use with no malfunctions.

Only mag problems I ever had were broken welds on a few Colt 1911 mags. After 20 years of range use, they earned the right to retire to the parts bin.

BTW, with failure to lock problems. Generally, the dynamics are completely different between live fire and manual cycling. Usually doesn't tell you much. However, the slide should lock back with a mag in after being slowly pulled back to full rear position.

Finally, I presume you've checked the possibility of the strong hand thumb contacting the slide lock lever during firing.

I think we need some more information...did you buy this new or used? Did it always do this or just start now? Was there a long period of time since firing it last? Maybe some of the lube gummed up the works. How many rounds total through the weapon? Are you using factory ammo or reloads?

Not sure what's going on but I'd try this:

I'd thoroughly clean both the weapon and the mags. Disassemble the mags completely and clean thoroughly inside and out. Reassemble the clean weapon and lock the slide back and store it with the slide locked back for a few days.

I have a P226 X-5 .40 and when new the slide would not lock back. I feel the recoil spring is really stiff, stiffer than my Glock 22. I know they are two different weapons but the Sig felt over sprung to an extent. After I locked my slide back for a week it shot fine and I never had a problem. I guess it helped break-in the spring to a certain degree. Also, try shooting with a strong two-handed grip...the .40 has a sharp recoil and shooting single handed could sorta lead to limp wristing and preventing the slide from cycling properly.

Edited to add one more thing to try: try your mags in another weapon...if anything that will confirm/deny the mags causing the issue.

Hope that helps, keep us updated.

SB

I agree: First look at the sticky, then don’t blame the magazines unless the followers aren’t moving freely (clean the mags regularly; they’re part of the gun).

Years ago I had some German made magazines that I used extensively for training. Their springs got so weak that I’d sometimes knock the top round loose during reloads. Despite that, however, they continued to feed the rounds fine and I never had any slide lock failures.

Had a similar issue with a 227 I used to own. Ended up being out of spec mags. The hole where the mag latches on to was cut too high.

Thumb not in way
Going to clean now
Just tried all four mags(not shooting) When I press up with my finger the bottom of the mags, the slide stays back.two seem to work better than the other two.
Cleaned the weapon before both of the last two sessions.
Goin to clean everything thourghly and leave one mag totally dry and try that one.
Then shoot and report back.
I agree, I don't think it's the springs. It's not like I shot a lof rounds and left weapon stored up for months and months and not used it.

Also, just recently got Slip2000 gun lube and have been using that on my weapon.

You could try to put an upward bend in say the 3rd coil of the recoil spring to make the front of the follower poke up more and possibly engage the slide stop. These types of spring tweaks are a fact of life with the main platform I shoot.

20 to 1 your thumb is touching the slide lock lever under recoil, Even if for just a fraction of a second. This happens quite a bit with sigs. It is a easy bad habit to pick up. Tucking the thumbs helps.

Update. I cleaned everything thoroughly. I switched to the lubrikit oil instead of the slip 2000 which is thicker viscosity, and I don't know if that will make a difference.I will try that. New I checked all mags and number one through three work perfectly.Number four,the slide did not stay back. I stretched the spring out a little and now it works perfectly. It's raining so I have to wait till it stops to Go try it.

All mags working great. Thanks for input.

Glad you resolved the problem. Thanks for the feedback.

Interesting. I just noticed the Tacops mags are extended cap with 15 versus 12 round capacity. I wonder if the extended are more sensitivite to dirt buildup and/or spring longevity issues.

I have never used extended capacity mags for any of my SD pistols. Prefer to stay within the original design parameters.

I would agree to the long spring possibility.

I have a very early P225 has to be 30+ years old, not sure when they first started imported, I think not long after the haws imports of P220's. I have kept it loaded since day 1, every year I take it out and shoot a couple mags through it have never had a problem.