New P938 owner with questions

[JBrady555]

Hello I finally got my hands on a P938 Nightmare, been wanting one for awhile. I made sure to check the serial number, the ones below 88XX have problems and need to be sent to sig for upgrades. After purchasing from my local indoor range/gun store I shot 50 rounds of speer lawman 124gr round nose. They shot flawlessly with no hiccups. I didn't bother with 115 gr because I heard that sig says the 938 needs a heavier bullet. Once I got home I cleaned the gun and shot 5 rounds of federal hst 124gr to make sure they cycled fine since that's what I had on hand for defensive purposes. Once again the gun cycled fine. I then preceded to load the gun to 6+1, I loaded the mag full and racked the slide but the hollow point took a nose dive straight into the feed ramp and jammed. I pulled the slide back and let it fly again and the round loaded like normal. I was able to recreate this problem several times in a row. After having it loaded I hand cycled all 7 rounds flawlessly. It only does it while trying to hand cycle the first round into the chamber.

Anyone experienced this before? Do you think it might be the ammo? It hasn't had a jam during firing in my short possession of the gun, do you think it needs more rounds through it before becoming my carry piece? Thanks for any info in advance that you may have on the 938.

 

[needmorecowbell]

My 938 SAS has been flawless with 124 and 115gr. I too have shot with the 124 Speer and 0 issues. I think sometimes hand cycling can be the issue as you can ride the slide too long or in some other way obstruct it. I wouldn't worry about it if there's been no issues when shooting it.

 

[JWH321]

I can make mine do that sometimes when I'm hand cycling it. I've never figured out why, and it has never done it unless I'm just hand cycling. I've even made it happen with snap caps.

 

[Tirod]

Hand cycling is apparently at too low a speed, which allows the round to joggle out of position. I've done it with mine and HP's tend to do it more than round nose.

A lot of other firearms have the same tendency. They are designed for the high speeds and timing of the propelled slide or bolt. Hand cycling slows that down immensely, which allows gravity to interfere with the normal function.

Magazines also tend to have the first round under a lot of pressure which also interferes with normal operation. We only need enough spring pressure to elevate the column of rounds quickly enough to have them stripped off. As we load more, we also create more friction under the feed lips, that additive pressure is at the highest with the top round. It's why some makers don't use a spiral wound spring that adds it's tension every inch. They use a clockwork spring that winds and unwinds at a steady rate, which eliminates a lot of the excess pressure. That pressure is why first rounds pop out, magazines swell, or the feed lips distort. Magazine makers keep using spiral wound springs because they are cheap, and mostly work. Clockwork springs easily double the cost of a magazine.

So, as we have noted owning these, the little chromed mags have heavy springs, simple feed lips, and it's a 1911 design type feed ramp, too. Those have always been known to prefer round nose over other bullets. It's an obstacle for the HP makers as they can't always do what they know works because the round has to reliably feed regardless.

Most of the early reports I have read of the situation include that the problem goes away after the gun is broken in - a few hundred rounds - or if the owner tries out a larger variety of ammo and picks the ones that the gun feeds better. Nothing new there.

 

[JBrady555]

Great replies, thanks

 

[SC Shooter]

My Sig P938 has functioned falwlessly at the range with 115 gr range loads. Right now I have about 500 rounds throughit, and so far not a single jam or FTE. About 200 of these rounds have been reloads.

 

[AFDavis11]

The 938 pre-stages rounds in the magazine. The second, third etc. feed easy. The first one might be harder to chamber. I find the 938 loads much easier than other small autos, except for the stiff mag spring.

Load the first round and pull out the mag. You'll see what I mean by pre-staged.

 

[JBrady555]

Yea I noticed the round will be half out of the mag when I remove a full mag.

 

[Old Dog]

Nothing to worry about. Good springs in the 938 7-round magazines. I'm really liking my 938 Extreme ... the trigger is finally feeling lighter and smoother, and the accuracy and reliability thus far has been impressive.

 

[Lucky Derby]

Mine runs flawlessly with everything from 115-147grain, and I haven't tried anything else.
As others have said, hand cycling is often to slow. And if you don't have one, get the 7 rd mag. So much nicer to shoot/handle the gun.

 

[The Lone Haranguer]

It only does it while trying to hand cycle the first round into the chamber.

I would check your slide racking technique and be sure you're drawing it back forcefully for its full travel, releasing it with the full power of the spring behind it and not trying to "ride" (i.e., leave your hand on) it as it does so. The gun shoots fine because the firing cycle operates the slide with much more force than you can exert with your hands. This gun also has a small slide with not much to hold onto.

The real concern I have here is not with hand racking that first round, which is done in a place of safety with no time pressure. It is with reloading from a locked-back slide. A gunfight is no time to be fiddling with a round hung up on the feed ramp. Try this: take your empty gun, draw back and lock the slide open manually, insert a loaded magazine (as you would if reloading) and thumb down your slide stop. That round had better chamber then.

 

[KTXdm9]

No issues with mine. I've shot plenty of 115gr through it too.