Is this gap normal? (Sig Sauer 1911 STX)

Posting this for a friend. We've searched the internet and seems other forums have posts for other 1911's that say this gap is normal.

Friend says it's the first firearm he's had that has this gap. He noticed it by chance over the weekend at the range and was shocked considering the high price paid.

Normal.  I have it on two out of 5 1911s I have made by Colt.

Yes its normal. Needs to be there so slide doesn't drag on it. When building new pistols or tightening frame/slide fit it needs lowered in most cases for smooth cycling without frame interference.
Jon

Thanks for the responses.

He'll be happy to hear it. Nothing nastier than that sinking feeling when a new toy has something unexpected about it your gut thinks is wrong.

https://forums.1911forum.com/showthread.php?t=643321&highlight=

Is it Normal? Yes  all the 1911 style pistols have it some more, some less. As far as I'm concerned it's not good! Eventually it leads to vertical stringing. The 2 set screws Jimmy Clark put on the end of the dust cover was done to over come that issue. I use something similar on my 45s

Sorry Froneck, that's not correct. Clark screwed up when they added the screws to the dust cover to lock up the frame/slide. I've seen several dust covers that cracked because of it. Using a thin dust cover for a bearing/lock up surface wasn't smart. Frame rails alone provide more than enough vertical lockup. Vertical stringing is 95 + % from poor barrel fit. I can build sub 1.5" pistols with loose frame/slide fit: because barrel fit can compensate for loose frame tolerances. If Jim Clark were still alive I'd love to discuss it with him. In my opinion it was a short cut because it takes less time than refitting a frame/slide correctly. 
Jon

Th rails end a short distance in front of the slide stop pin. All weight forward of the rail exerts forward pressure. Momentum of the forward travel of the slide again exerts pressure in front of the rails, That is evident especially when letting the slide go with no magazine and dips downward. Add a scope base and scope to the top of the slide that downward force exerts quite a bit of pressure in front while the rails are almost all behind the slide stop pin. After a bit of shooting the rails in the back no matter how well fitted will wear and allow the slide to pivot at the slide stop pin!
 I don't care for Jimmy's cure and discussed that with him at Perry. I showed him my cure and he did agree it was better.
 The photo is not good but best I can do. It is again of Adam's gun that was tested by the AMU and impressed them. It was tested after Adam shot the gun for 3 years after I replaced the barrel because he shot it every day after school and wore out the barrel. The gun was the 45 he was using when he was 10 years old. He has a couple of Junior records of 884 with it. After all that shooting (10 years) the frame is still in excellent condition, no cracks anywhere and still shoots X ring accuracy. I put the tabs on the dust cover so that when the slide moves back it completely disengages from the slide and allows it to go back without interference that Jimmy's set screws do. I've done it on my other son's gun with the same success!  In addition to my gun and a few friends that still work great! I will post another photo of one I'm currently building but using set screws with rolling balls on the ends. Furthermore I have a few friends and know of a few shooter having guns build by some of the best yet after shooting for a while begin to pivot at the slide stop pin and require a tune-up.

I have a full length dust cover gun. Does that support it anymore or less?

The dust cover breaking is a sign of abuse.  Perhaps the users over tightened the screws.  Not like that never happens.

But all that aside, in a properly set up gun the fitting from the dust cover, no matter who's version, is unnecessary.  Back in the awl'd days a lot of smiths only fit the forward and aft rails thinking that the fit during lockup was critical.  The fit needs to be the whole length.  Also a lot of frames and slides weren't the best for hardness.  Some smiths wanted only a Colt Commercial gun to start with for that reason.  

And we should know better to drop a slide on an empty gun.

No additional support Chris. Slide free floats forward of the frame rails like 99.9% of all other 1911's out there. In my opinion its not necessary. If pistols without it are shooting sub 1.5" 45 groups and sub 1" 9mm groups then its not necessary. If it worked that much better everyone would be doing it. The forward weight of the slide has almost zero effect on lockup because the bottom barrel lugs are supporting it when bearing on the slidestop pin. When pistol is unlocking it doesn't matter because all slide forces are traveling to the rear (recoil) and up into the bottom of the frame rails (recoil is up and rearward). So basically slide is being forced up from slidestop pin pushing up on barrel in lockup, and the rear of the slide. Could be either up or down depending on fit. If a bending moment equation was performed the end of the slide would be cantilevered with upward force at slidestop pin and downward force at rear of slide. If the tip of dustcover was a bearing surface then the bottom barrel lugs would not be making contact with the slidestop pin unless loose. On a properly fit frame and slide there will be minimal movement horizontally or vertically and it just doesn't matter.
Jon

Yes the recoil is up and wears the bottom side of the rail, closing is also an upward force and increased when the the slide stop pin is riding the link or there is a large radius on the lower link, after a while the slide will pivot on the slide stop pin. Those hard steel that are fitted to the frame are intended for that purpose. But they too wear and have larger sizes to replace them with. Closing the slide on an empty gun is not the best thing to do but I was making reference to the dip that will happen, It will happen to a lesser degree when loaded. Plus breaking the dust cover is a sign of someone adjusting the screws too tight on the Clark modification. Unlike the Clark there is no adjustments on my version plus after a short distance back the support is removed. Natural slide wear is an upward force and  wear removes material. Also a friend of mine also has the extended dust cover like Chris has and installed the set screws on the very end so that when the slide starts back it's out of service. Works great and is just enough tension to stop the slide from dipping. As to wear, I don't care who make the frame it will wear, some faster than others. I Hard chrome my rails then use a surface grinder and Jig grinder with diamond wheels to bring them to size, I do not lap the slides, that not a good way. No Tool and Die machinist would ever fit anything similar to lapping a slide to the frame! What I do is build my 45's like a top of the line machine, when done correctly it will last for a 100 years. I use Jig Borers, Jig Grinders, Tool Grinders and Surface grinders to finish and have some of the Best lathes and Mills ever made to do the less accurate work. But on the other hand I have a complete fully set-up machine shop to tinker with.

Froneck wrote:Yes the recoil is up and wears the bottom side of the rail, closing is also an upward force and increased when the the slide stop pin is riding the link or there is a large radius on the lower link, after a while the slide will pivot on the slide stop pin. Those hard steel that are fitted to the frame are intended for that purpose. But they too wear and have larger sizes to replace them with. Closing the slide on an empty gun is not the best thing to do but I was making reference to the dip that will happen, It will happen to a lesser degree when loaded. Plus breaking the dust cover is a sign of someone adjusting the screws too tight on the Clark modification. Unlike the Clark there is no adjustments on my version plus after a short distance back the support is removed. Natural slide wear is an upward force and  wear removes material. Also a friend of mine also has the extended dust cover like Chris has and installed the set screws on the very end so that when the slide starts back it's out of service. Works great and is just enough tension to stop the slide from dipping. As to wear, I don't care who make the frame it will wear, some faster than others. I Hard chrome my rails then use a surface grinder and Jig grinder with diamond wheels to bring them to size, I do not lap the slides, that not a good way. No Tool and Die machinist would ever fit anything similar to lapping a slide to the frame! What I do is build my 45's like a top of the line machine, when done correctly it will last for a 100 years. I use Jig Borers, Jig Grinders, Tool Grinders and Surface grinders to finish and have some of the Best lathes and Mills ever made to do the less accurate work. But on the other hand I have a complete fully set-up machine shop to tinker with.

Would the acculock pistol accomplish something similar Frank? 

http://www.accu-lockpistols.com/

IMHO, the accu-lock is no better than a cone barrel pistol.  In many ways it's probably not as stable or reliable.

Wobbley wrote:IMHO, the accu-lock is no better than a cone barrel pistol.  In many ways it's probably not as stable or reliable.

+1

I would bet that the majority of the accu-lock's accuracy claims are due to the fact that he uses a custom made barrel (not factory "custom" like a Kart, KKM, etcetera) and not the system itself.

Jim

I haven't worked with or had much time looking at the Accu-lock. I'm not sure how the spring guide is attached or is it similar to other spring guides on the near slide stop pin side. I also know a group of top shooters (not to mention names) tested the Accu-Lock and it didn't preform as it was claimed to. The Briley Bushing is one of the best for simple application. I use them but don't use them as recommended. I taper the barrel a slight bit. Another issue I have with Accu-lock is how does the barrel pivot?