Slide Jammed Bad on 1911

[polyphemus]

All depends on what you consider accurate. Never in my life have I heard any top notch 1911 smiff, that builds a pistol for accuracy, say slide to frame clearances don't matter

A poorly worded,misspelled non answer to a very specific question.
Needless to say what you have heard in all your life is of no relevance to anyone else.

[WVsig]

IIRC according to “The Colt .45 Automatic” by Jerry Kuhnhausen, the slide to frame fit accounts for 15% of total accuracy.

The other factors are as follows:

Match grade barrel 10%
Bushing fit 20%
Headspace 10%
Rear barrel side play 20%
Vertical lock up 20%
Beyond reach 5%

So it is not the most important part of the equation but it certainly plays a part. I personally think that people overstate its importance. I personally believe that bushing, rear barrel side play and vertical lockup are the most important parts of the equation. Get those right and the pistol will out shoot most shooters.

I think people focus on slide to frame because they can see it and feel it and they understand it. The other factors not so much.

[Walt Sherrill]

Originally Posted by Rinspeed

All depends on what you consider accurate. Never in my life have I heard any top notch 1911 smiff, that builds a pistol for accuracy, say slide to frame clearances don't matter.

Sure it's been passed around the erronet, for the last 20 years, that it doesn't matter but tell that to any number of top 1911 bullseyes smiffs and they will laugh at you.

Sometime the "erronet" gets part of it right. I think it matters -- but not nearly as much as other things, most importantly, consistent slide/barrel lockup.

If you're doing Ransom Rest tests, a tight slide/frame fit is very important -- because you're not using the sights! -- but if the slide and barrel don't link up consistently that tight slide/frame fit won't help much: there'll be slop and the gun won't come back to the same position for each shot.

We've all heard tales about 1911s with frames and slides so sloppy they rattled but were highly accurate. Were they all fairy taies? I don't think so. If you aim using the sights and the sights (i.e., slide) and barrel are consistently aligned with each shot, the gun has the potential to be very accurate if the shooter does his part. That same gun would might do badly in a Ransom Rest test.

One of those gunsmith talking about this topic attributed about 80% of a top 1911s accuracy to slide/barrel fit (which also implies consistent lockup), 7%-8% to slide/frame fit, and the rest to the other things that make for a good shooting gun -- the things that make the gun easier to shoot well. (I see that while I was trying to organize my response, WVsig replied above, using Jerry K's formula as a guide -- and I can go with that.)

Why WOULD the slide/frame fit matter UNLESS those other mechanical attributes aren't also top notch? And if the other things are top notch, and you use the sights, why would the slide to frame fit play that big a role in accurate shooting? You're aligning the sights, and where slide sets on the frame isn't a big deal.

Note: in a competition gun, where you're using the sights on the slide, slide/frame fit might not matter as much as if you're using a gun where the sights (optics,etc.) are mounted on the frame. But in either cases, we're assuming consistent slide/barrel/sight alignment.

[tangolima]

If I am a smiff, I certainly will tell you no gun is good until you pay me to work on it. If I'm the manufacturer, I certainly will tell you my guns are so tight that you don't need to pay your smiff to work on it. It is vanity. Customers are willing to pay and feel good about, vanity schmanity I will make it the way you want.

If slide and frame tightness is 15%, the hand holding the gun must be 1500%.

-TL

[Rinspeed]

Needless to say what you have heard in all your life is of no relevance to anyone else.

Really, you sound like quite the expert, maybe you reach out to some builders such as Jerry Keefer, Bob Marvel and such to let them know they don't know what they are doing.

[Walt Sherrill]

Originally Posted by Rinspeed

Really, you sound like quite the expert, maybe you reach out to some builders such as Jerry Keefer, Bob Marvel and such to let them know they don't know what they are doing.

His response was a bit SNARKY, but I think the lack of "meat" in your comment may have provoked it...

As I said, above, a good/tight slide to frame fit can be important, and I'm reasonably sure that any competent 1911 gunsmith won't build his best 1911 handgun with an intentionally loose slide/frame fit.

That said, how about giving us YOUR understanding of what you've "heard" from those top line 'smiffs, and explain why slide to frame fit is critical? And do you disagree with my point about aimed fire making it less important, if other things are fit as they should be?

[KyJim]

The other factors are as follows:

Match grade barrel 10%

In this week's episode of Shootout Lane, Clark Custom was building an "old school" bullseye 1911 for the NRA museum in the manner that Jim Clark, Sr. built them. One of the smiths mentioned that they thought standard barrels were about as accurate as "national match" barrels and therefore used standard barrels.

[polyphemus]

Kuhnhausen doesn't seem to place a great deal of emphasis on rail to slot clearance and how he came to that percentage is not explained but he seems to be fine with .004" to .006" for commercial pistols.
Barrel to slide fit is where he focuses to gain shot placement consistency and rightly so,aiming is done with the slide regardless of where it happens to be at the time so if the barrel's position can be made to repeat then the pistol can be expected to shoot accordingly.Absent any concrete proof,"tight"slides do not
offer more consistent POI than properly fit ones and if OP's is an example and
especially if they are SS then they are a potential source of trouble for nothing.
M1911's are not target pistols they are military weapons,I expect a commercial
1911 with no gizmos freestanding to put seven holes in the bottom of a small coffee can at 50'.

[WVsig]

In this week's episode of Shootout Lane, Clark Custom was building an "old school" bullseye 1911 for the NRA museum in the manner that Jim Clark, Sr. built them. One of the smiths mentioned that they thought standard barrels were about as accurate as "national match" barrels and therefore used standard barrels.

National match has become more of a marketing tool then anything else these days IMHO. The proper fit and crown of the barrel is the most important things these days. IMHO YMMV.

[Grizz12]

so how did it shoot?

[tipoc]

National match has become more of a marketing tool then anything else these days IMHO. The proper fit and crown of the barrel is the most important things these days. IMHO YMMV.

If true it's because barrels in general are better made these days than in the past. It was the case that "Match" barrels were more carefully made than standard production barrels. The chambers were tighter and bored concentric to the rifled bore, which was not always the case with production barrels. The tolerances allowed were less. If today standard barrels are no different than "match" barrels it is because the quality of the standard production tubes have improved.

tipoc

[WVsig]

If true it's because barrels in general are better made these days than in the past. It was the case that "Match" barrels were more carefully made than standard production barrels. The chambers were tighter and bored concentric to the rifled bore, which was not always the case with production barrels. The tolerances allowed were less. If today standard barrels are no different than "match" barrels it is because the quality of the standard production tubes have improved.

tipoc

I tend to agree I also believe that in most peoples hands it does not matter.

[Nathan]

Not sure why I'm posting this here, but if you look at 1911 geometry and barrel fitting principles, the gun can be fit to lock up tight with a loose slide.

That is the basic principle of the EZ Fit barrel. Basically slide to frame fit is sooo good on modern 1911's that you can fit a barrel to the slide only and with those nubs, you can get pretty good lock up and tight vertical fit.

So, forget about slide rail fit....if it locks up tight it will shoot. Now, there is some value in tight horizontal fitting...

[tipoc]

Here is a further discussion of the "galling" issue.

http://forums.1911forum.com/showthread.php?t=488212

tipoc

[Sequins]

Thanks for that link Tipoc.

[Aguila Blanca]

Originally Posted by tipoc

If true it's because barrels in general are better made these days than in the past. It was the case that "Match" barrels were more carefully made than standard production barrels. The chambers were tighter and bored concentric to the rifled bore, which was not always the case with production barrels. The tolerances allowed were less. If today standard barrels are no different than "match" barrels it is because the quality of the standard production tubes have improved.

It's all in the spin. If you pay attention to advertising spin, as I sometimes do for amusement, I think you'll find that none of the production 1911 makers claim to be offering "national match" barrels. The national match barrel actually has an Ordnance Department specification, and if a barrel doesn't meet or exceed that it isn't a national match barrel.

What the current makers universally seem to claim is a "match grade" barrel. And since there is no industry standard for what "match grade" means -- it means nothing.

[Hunter Customs]

I was taught that slide to frame fit is less then 15% as a matter of fact my Mentor taught me it's more like 5%.
I believe Ed Brown done an article for one of the gun rags and came up with the same conclusion.

If you stop and think about it when a barrel is "hard fit" the vertical play in the slide is removed.
With a "hard fit" barrel there will still be a little horizontal play but it will be a small amount, I believe that's where the 5% figure comes from.

As for barrels, Jim Clark and many other smiths from that time frame realized the only problem with Colt barrels was they were cut with very generous tolerances, that's why we would weld them up and re-cut them to a "hard fit".
There's no need for that today as there a lot of top quality barrels out there that's oversized in all the critical areas so smith's can get a "hard fit".

As for guns being produced that manufactures are telling customers they need a 500 round break in really pegs my BS meter.
I would tell them to take the gun back and finish fitting the gun the correct way.

I'm building a Commander size gun for my oldest Grandson who turns 21 this year.
The frame is on my mill right now as I'm milling the oversized frame rails to accept the slide for the lapping process.

The lapping process will consist of hand lapping with several different grits of lapping compound the last being 1200 girt.
When finished the slide from it's own weight will glide fore and aft on the frame like it's on ball bearings.
There will not be any 500 round break in period for this gun and I'll be willing to bet it will be just as accurate as any that requires a 500 round break in.

[WVsig]

SOOOOO does the gun run now?

[buckhorn_cortez]

The lapping process will consist of hand lapping with several different grits of lapping compound the last being 1200 girt.

When finished the slide from it's own weight will glide fore and aft on the frame like it's on ball bearings.

There will not be any 500 round break in period for this gun and I'll be willing to bet it will be just as accurate as any that requires a 500 round break in.

I think manufacturers don't lap the gun as that process adds cost to the gun in terms of labor. Lapping has to be done with the frame / slide detail stripped so you don't get lapping compound into the working mechanisms of the gun.

To do it correctly, you have to thoroughly clean the rails between each compound. You spend more time cleaning the gun than you actually do in the lapping process.

It's easier for them to tell you to shoot the gun for XX number of rounds without cleaning it - which basically does the same thing - laps the slide to the frame.

It's also interesting that Wilson, Baer, DW etc. don't call it "break in." It's just a suggested operating procedure for the first XX rounds as recommended by the manufacturer before cleaning. "Break in" is the term used on Internet gun forums to describe shooting the gun without cleaning it.

There were no instructions included with my two, 2010 DW guns in regards to shooting without cleaning. My two Wilsons suggested 400 rounds while the Les Baer said 200 rounds.

My full custom, which had been shot by the gunsmith over 200 rounds, came with a bottle of gun oil and a letter suggesting keeping the gun well lubricated and shooting it for an additional 200 rounds before cleaning.

While it may peg your "BS meter" it seems to be a standard practice among gun manufacturers & even custom gun smiths to suggest shooting without cleaning for some number of rounds.

Frankly - I fail to see what the big deal is about this process. You buy the gun to shoot it - so what's the problem with shooting it for 200-400 rounds without cleaning it?

If you want to just look at the gun and rack the slide - then you don't need to worry about whether it's been shot without cleaning do you?

If you're going to use the gun as a self defense pistol, I would think it would only be prudent to prove the gun works reliably with at least 500 rounds before you carry it. Why would you take the gun out of its box, load it up and put in in a holster without shooting it first?

I think it's a BS criticism leveled by people who just want to complain about something to make themselves feel like they're truly a gun connoisseur.

Or you can do what I do. I keep lapping compounds in my tool box and that's how I address new 1911's - I run them through a series of lapping compounds from 400 - 1200 grit.

As noted in your post - when you're done lapping the rails - the slide glides back-and-forth under its own weight...

[Grumpy_Bottom]

I had the same problem with my cbob when I first got it. ran about 500 rounds through it very wet and dirty with wilson lube, cleaned after 500, keep it on the wet side, and its been flawless since