Slide; inside or out?

[Quincy12]

Are there any real advantages of having the slide of a semi-auto pistol mounted inside the frame (i.e. CZ 75) versus outside like most other sidearms? Or for that matter, disadvantages?

 

[JTQ]

Disadvantage, but only by a small bit, there is less slide to grasp when racking the slide.

 

[Walt Sherrill]

It's always been argued that the CZ (and SIG P-210) slide riding inside the frame allowed greater accuracy -- because as the gun heated up, it got a bit tighter. I've had both, shot both extensively, and never noticed any change in accuracy. (Some of the Stars I've owned -- Firestar and Firestar Plus -- also had slides inside the frame.)

That said, a tight frame/slide fit apparently accounts for a very small part of a gun's accuracy potential, while barrel/slide fit and consistent lockup is far more important.

CZ designs do give the shooter less to grab, but it's not a lot less, and if you use the hand-over slide method to move the slide (using the sights as something sticking out!), the difference is almost meaningless. If you try to use the slingshot method to rack the slide, it can be more of a problem. (I gave up on the slingshot approach long ago, and it had nothing to do with slides inside the frame.)

 

[Drail]

I think that if mounting the slide rails inside the frame was a "better" method it would have been adopted by most manufacturers a long time ago. Maybe different - but not better.

 

[tark]

Walt, you're quite right about the importance of consistent barrel lockup, and the fit of the barrel and slide being more important the slide/frame fit. In the years I worked for Les, I saw an occasional gun that had a bit of wiggle in the frame/slide fit. But the gun would put em' into one hole at fifty yards, from a Ransom, because the bushing, barrel lockup and the lugs/slide stop fit were all perfect.

I read a piece years ago in one of the gun mags, where the author was raving about the CZ75, and extolling the virtues of the slide being inside the frame. In his last sentence he solemnly wrote "I would not go into battle with a pistol employing an outside mounted slide" Or something equally moronic, I don't remember exactly.:banghead:

I smiled ant thought of the 1911. Yeah. Right. I'd really hate to have to go into battle with that one!!

 

[FROGO207]

That is the reason the Ruger MK series of .22s is so accurate. The sight and barrel are fixed to the frame coupled with a long sight radius that does not move. Most .22 semis that are fairly accurate are built the same way from what I have seen shooting small bore bullseye around here. You have to step up some in quality/cost to get it with an outside slide type .22 I am told. Can the casual plinker tell the difference between them when shooting at something though???? YMMV

 

[shooter1]

One advantage to the inside slide design is the lower bore axis. All I can say about accuracy is that I've never seen a CZ that wasn't better than average for a production gun when it comes to accuracy.
str1

 

[Walt Sherrill]

One advantage to the inside slide design is the lower bore axis. All I can say about accuracy is that I've never seen a CZ that wasn't better than average for a production gun when it comes to accuracy.

I'm a CZ fan, so don't take this wrong... I've had a bunch and still have a couple -- plus a couple of other CZ-pattern guns.

I think the fact that the CZs have a lower bore axis arguably has more to do with how the mechanism inside the frame was designed to interact with the slide than how the slide is mounted to the frame. Mounting the CZ slide outside the frame wouldn't make the bore axis higher -- but it would make the slide a bit wider. It could possibly be done without much slide width increase. A number of new designs from other gun makers also have low bore axes, and their slides are mounted outside the frame.

I think one of the things that contributes to CZ's accuracy is the lockup design, which focuses on the rear of the barrel and ignores the front (i.e., doesn't use a barrel bushing) -- and that continues to change with newer models. The latest models (CZ-40B, CZ-97B, and the CZ-P07/P09) use a lockup design like that used in SIGs, which jams the rear of the barrel/chamber back into the slide, rather than using barrel lugs as in the original CZ design.

 

[PO2Hammer]

CZ's are nice, had a 75B, but recoil and accuracy was no different than a Sig.

Also with gloves on the 75's slide was harder to rack because there's much less to grab onto.

The 75 is a very nice gun for the price, as are all CZ's IMO. I'm a big fan of their rimfire rifles.

 

[shooter1]

I've owned Tanfoglios and CZs, never been disappointed by either. Currently own just one CZ, an 85 Combat. Extremely accurate and 100% reliable to date. My problem is, I like all kinds of guns. The guys I shoot with never know what I'll shoot at the next match. The 1911s/CZ and my Hi Power are among my favorites. I'm even fond of my Glocks. There's something good to be said about almost all pistols.
str1

 

[ny32182]

I've shot a good bit of both, and there could be other factors, but I prefer the inside-the-slide design like CZ now. For me it seems like they just recoil, and return, and settle cleaner.

The only consistent difference that I think could possibly be responsible for this is that the slides are a lot lighter than most any popular slide-over-frame design.

I do wish classic CZs had more aggressive slide serrations.

 

[Walt Sherrill]

I've owned Tanfoglios and CZs, never been disappointed by either. Currently own just one CZ, an 85 Combat. Extremely accurate and 100% reliable to date. My problem is, I like all kinds of guns. The guys I shoot with never know what I'll shoot at the next match. The 1911s/CZ and my Hi Power are among my favorites. I'm even fond of my Glocks. There's something good to be said about almost all pistols.

That is pretty much my position, too.

I have a Glock 38, a SIG 228, two CZs (one a CZ-85 Combat), a Sphinx, a custom AT-84s, several Rugers, a BHP, two FNS-40s, a S&W M&P Pro, and an older Stoeger-imported 9mm Llama 1911 (it's a surprisingly good handgun). I've omitted my rimfire handguns. I've owned a number of Glocks, SIGs, and several other .45 1911s. (I've even had a SIG P210, a S&W 52-2, and a P226 X-Five, all three SA.) I'm predisposed to the guns that can start from SA, or to striker-fired guns -- the ones that make all trigger pulls the same. (I have only two decocker models at the moment.) But I do keep experimenting and exploring.

 

[jmr40]

CZ's are the only handgun I've ever owned that I simply couldn't make work and didn't like. The slide inside the frame was a big part of it. Like everyone I have my favorites and if I'm buying would choose those. But if being issued a handgun to do a job I can make anything I've ever tried work and feel confident in the gun and my ability to use it. But a CZ would be at the bottom of my list.

 

[kokapelli]

I don't know which is better, but the two most accurate pistols I have have the inside rails.

 

[Walt Sherrill]

I don't know which is better, but the two most accurate pistols I have have the inside rails.

The reason I think the frame-inside-the-rail isn't all that critical is that generally speaking, barrel-to-slide fit (and consistent lockup) plays a much greater role in a gun's accuracy than slide to frame fit. (Some of the top 1911 gunsmiths suggest that, at most, maybe 5%-7% of a guns accuracy comes from good slide to frame fit.)

I'd argue that if there's something about the CZ design that gives it better accuracy than some other guns, it's the lockup design, and that continues to change as CZ goes forward. The earliest CZs locked up much like the BHP or 1911, with barrel lugs connecting with indentations in the top inside of the slide; the newer designs are more like SIGs, in that the rear of the barrel (around the chamber) locks up with the corresponding area in the slide in front of the ejection port -- a different approach. CZ has used that approach with their newer designs: 40B, the 97B, and the P-07 and P-09.

Some of the special custom guns being done by the CZ Custom Shop come with a closely fit barrel bushing... like a NM bushining in a 1911, and some upgraded CZ-97s from Cajun Gun Works go that route, too. (The stock 97B has a plastic barrel bushing, it really doesn't seem to play much role in barrel lockup or accuracy.)

I had a SIG P-210-6, which was exceptionally accurate (it came with a proof target showing 1.75" groups at 50 meters, roughly 55 yards.) The P-210-6 had the slide inside the frame. I also had a S&W 52-2, with the slide riding outside the rails, and it seemed to be just as accurate. I couldn't shoot either of those guns with anything like that sort of accuracy, but some others who shot them could make those guns sing.
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