Opinions

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Dave Sample

Moderator
There are always people who offer their expert opinions and are very adamant about their being right. This is the curse of the Internet and I am as guilty of this as anyone else and perhaps more so.
The folks who claim to be experts on the 1911 semi-automatic pistol have made a accuracy pie and I have heard about this percentage deal for years and years. "XYZ accounts for 8% of the accuracy. ABC accounts for 13% of the accuracy. EFG accounts for 81 % of the accuracy" and on and on. This is repeated all of the timne on forums and now it seems to be "The Gospel According To Who Today"....................................

How do they KNOW????????

Here is what I have found out from building High End 1911 Guns from parts for over 20 years.
I fit every part as if it were 100% responsible for the accuracy of the finshed pistol. I fit them tight, but friendly. After the slide to frame fit, I fit the barrel and there is no play anywhere but fore and aft. It then has to pass the gravity test where I tip the gun forward and it goes into battery by it's own weight and then when I tip it up, it unlocks and the slide goes all the way back and I do this a few times and then fit the rest of the parts. The Beaver Tail is next, then the trigger group, thumb safety, slide stop, etc until it is complete.
When it's finished, it has a very tight repeatablity which makes it accurate. It locks and unlocks exactly the same way every time it is fired. If you do everything to these guns that needs to be done. they have no choice but to work. The slide to frame fit is good for at least 75,000-100,000 rounds and the finished guns carry my NO BS Lifetime Warranty and don't come back much.
So I don't care about that slice of pie at all. I care about everything. One of my students, who built his PATRIOT My Way, put it in a Ransome rest and got 2 1/2 inch groups at 50 yards with 0 fliers. Pretty good for a first time builder! He never heard me mention the slices of that pie because I think the guys that invented it are just guessing about the percentages they created. That is just my opinion, of course!
 
Dave,

It could be that someone took how many times they read on the net that loose is bad, and tight is good and then figured out what tight was being mentioned and found out that according to the "net" 8% of the accuracy was due to the barrel and 28% was due to who bought the back page ad of handgunner magazine and the reset just logically has to be evenly distributed between the other parts.

Just kidding by the way.

To me, tight is good and I like my 1911's to be tight, not rattle. Probably more of a personal thing, but when I handle a loose gun it never seems to shoot as well "for me". Tight guns seem to shoot better "for me" so therefore tight is good.
 
One of the Kunhausen books has a chart showing how he believed accuracy was distributed.
While the percentages allocted may differ among folks, the basic concept that all the fits come into play but not to the same degree is probably the most important thing to take away.
 
Dave,

Your post would make more sense if you weren't a little guilty of it yourself:

You've described how you've taken stock guns and improved them with a new link and bushing - without consideration of other improvements you could have done instead. This certainly makes it appear that you feel certain improvements are more valuable than others (are bigger pieces of the pie).


It also strikes me that people like Kuhnhausen may well have created those percentages through trial and error - trying each and individually and recording their results. There's a thoroughness to his work that goes with such an exercise.


What I think is actually getting your goat is the WHY of the pie chart. I think any good 1911 smith wants to do a whole package, not just pieces/parts. To this end, the pie chart actually is there to DISCOURAGE single point jobs. By showing a faily low percentage for rail fitting it keeps people from getting lackluster results by attacking this more obvious condition without attending to the barrel fit. So really, it is a sales tool for gunsmiths, not a guide to avoiding certain jobs.


The pie is a rough guide to what is important, and serves primarily as a warning to do the types of fitting that are actually most difficult - like lug fitting. I really think it is more of a boon to gunsmiths then you give it credit for.
 
Beavertail pie ??? .... Actually the 1911 should come apart without wrenches or hammers! I have used mine for target,hunting and carry so it's accurate ,reliable ,easy to take apart [and has no gimmicks]. :)
 
The question when working on less than perfect factory guns is more one of "What can You Afford?".
It has been my experience that Joe will call and say. "I want thus and so!" OK! Then................."What will it cost?" OK.............then "How long will it take for it to rise to the top of the pond?" OH..............Dear, that long?

Yes, I have made minor improvments when time and cost was a factor. Yes. I have done major renovations on Factory guns after advising the Client he would have a very nice Expensive Sow's Ear at the end of the Job. Yes. I have told numerous clients that I could not build them a gun that would make them a Champ. I advised them to spend $1000.00 a year on primers and then we could build them a gun worthy of their skill.
There is a thing about 1911's that we cannot explain and you see it here time after time. "I bought such and such a gun and sent it to so and so and they did this and that to it and now it is just Wonderful! Man O Man!
Here is what I am asking all of you to consider. How do you know if you are going to get an 80% improvment by installing a new barrel? How do you know that tightening the slide to frame will only give you an 8% improvement? How do these people arrive at these percentages? I was building guns before Jerry was writing books. I have a gun with a 2 LB trigger pull here that has withstood 50,000-60,000 HOT 38 Super rounds in 18 years and still has never dropped to half cock or followed. Is this a 16 % improvment in accuracy? 25% improvment? Would this gun still be a tackdriver with a 8 LB pull? I am afraid that I don't have that answer. I just would like to know where these people pull these figures out of the air and then I am supposed to believe them. I DON'T. Maybe all of you do. That is fine with me. I do not believe that 95% of the people that own 1911's can shoot well enough to tell how much these things make any kind of improvement in accuracy. Interesting to think about, Huh? How much does your shooting stance improve your accuracy? 3%? Danged if I know!
I know this. If you can't shoot, it makes no difference what you do to that 1911!
 
I think opinions are only true facts when evidence based. Where is the evidence ie. scientificly valid study(s) for the accuracy opinions expressed on TFL? It seems to me this is an easy study to do but who has done it for one pistol let alone 50 for good evidence to base an opinion.

I met Jim Clark Sr. years ago at Camp Perry - it would have been interesting to ask him. Who are the high volume expert bullseye pistolsmiths? There must be some. I wonder if any of them have done any studies?

All my pistols shoot better than I do. They run in blowing sand and driving rain.

I believe in evidence based medicine not opinion based medicine.

Dean
deanrtaylor@att.net
410-952-7848
 
Dave,

Your last post really makes me think that you have grossly misunderstood the logical basis of the pie.

Those percentages are sighted as mechanical improvements. Trigger pull is not one of them - or is at least put in its own class as "shooter assistive features".

Kuhnhausen goes on to say that "this is an over simplification". He is not saying the numbers are precise, and he is certainly not saying that the first class of mechanical improvements will be demonstrated in the targets of any shooter. For you to say that means that you don't understand the question.


So I don't understand your beef, since it doesn't sound like you believe in testing mechanical accuracy BY ITSELF. Until you spend the time trying each area in a methodical, scientific way I can't understand how you can make it sound like Jerry was lying when he says a bushing is twice as important for accuracy than a match barrel. He is only stating a relative value, and you have not put that value to any sort of test.


Please stop presenting this information like it was ever designed to relate to shooter performance.
 
I don't know, but I'm allowing that Kuhnhausen likely did have a mechanical justification for his round numbers. It certainly wouldn't have been hard to come by that experience if you are doing a variety of accuracy work on many guns.

Dave sounds like he might know him, but hasn't said that he knows what "Jerry" used as his basis. His rejection doesn't include a denouncement of procedure, certainly.


Personally, if a respected technician offers numbers with his opinions, I ask HIM how he got them, rather than first asserting they are false. Personally, those percentages generally 'ring true' with much I have read about 1911 accuracy work, including the writings of Mr. Dave Sample.


But like I said previously, I think the misunderstanding isn't where the numbers came from, but what they represent.
 
I have no disageement with anyone, including Jerry. I am just asking that we consider the veracity of the "Pie."
I take a Colt 1911 and redo the link, pin and bushing. The rest of the gun is nicely fit. Before I do the work the owner test fires it and the best he can do at 50 yards is 6 inches.
After it I do the work, he goes back to the range, shoots some groups, and can now do 3 inches at 50 yards.
Is this a 100% improvement? A $ 35.00 job.
Is this a mechanical improvement?
Let us take that same Colt. It comes from the factory with a terrible 7 LB trigger pull. The best group the owner can shoot is 12 inches at 50 yards.
I do some trigger work, a $75.00 charge in those days, and he returns to the range, shoots some groups, and wow! He can now do 6 inches at 50 yards all day long!
Is this a 100% improvment?
Is it a Mechanical Inprovment?
Can I say I improvend this 1911 200%?

The answer is no, of course. I can say I made some improvments, but to what degree?
What I am trying to get across to you is that each 1911 I have worked on for 20 years is different. No two were the same. They each had their own personality, and some of them liked me and were easy to work on and came out great, others hated me and fought me every inch of the way. The +or - tolerances were either with me or against me.
I have the same situation with the single action cowboy guns that I still work on for clients. Every one of them is different and some love me and some hate me.
I guess this sounds really silly to most of you but I do this work for love, not money, and that is the way I have operated for most of the last 30 years. I do the work and the money comes.
So how can I tell someone that I can give him 8% more accuracy with the XYZ job when I really don't know what the outcome will be? Perhaps I am just a skeptic from being a copper.
I just don't know and I don't think the other guys know , either.
Anyhow, it is an interesting subject, isn't it?
 
Your last post confirmed what I thought, Dave.

You're misunderstanding those percentages. The percentages DO NOT refer directly to the change in group size. They refer to approaching the ultimate accuracy of the caliber from an unknown starting point.


If the pie referred to what you've been talking about, then I'd agree with you. But it doesn't. The pie compares the amount of improvement each job has IN COMPARISON WITH THE OTHER JOBS. It does not equate those to an amount of group size change, or whether those changes should be viewed as linear or geometric (vanishing returns).


I think if you looked at the information as intended you wouldn't be troubled.
 
At the very least the various upgrades for a tighter gun would act in an RMS type manner (square root of teh sum of the squares). This is a typical property of mechanical fitting with many variables. I do not have Kunhausen in front of me, but I do recall two seperte charts. One was intinsic mechanical accuracy and the other dealt with shooter related effects (lower trigger pull, cleaner trigger pull, hand hold repeatability, etc).
None of the items are the holy grail in isolation from the others. A zero clearance barrel bushing only anchors one end of the barrel. The other end is held by the slide and link. The bushing typically has more effect. Link play is usually not nearly as bad just because of the design.
If either is really bad, improving the other will not have as good an effect.
If the bushing is tight, the link is correct, the next item might be the frame rails. A loose fit will result in the back end of the barrel not being in the same position.
Many if these items have no practical impact except on a bullseye gun being used by a very good shooter. Some of the bullseye shooters I have met were very sure the first round fired after a manual slide release did not shoot to the same point as the subsequent rounds. They may have subconsciously caused the difference, the gun may not have been in the exact position desired till recoil 'settled' it into the hand, or maybe there really was a slight change.
Screw up any part bad enough (how about an 8 pound trigger) and accuracy goes to pot. Have an even decent distribution of mechanical error and accuracy can be very good.
 
Each gun is "a law unto itself".

I don't buy into the accuracy percentages, but there are some things that it just makes more sense to try first. I go at it like this:

Establish that you have a good barrel, and that it is well fitted at the lugs- top & bottom. See how will it will shoot and function with the stock bushing- this is your "yardstick".

When you're sure that you have established how well the gun is shooting, fit an undersize bushing per Kuhnhausen and see how well it will shoot and function again. When function suffers, ease off on the accuracy work unless you're building a bulls-eye gun. I have had excellent results with his "service" recommendation of .001 clearance at both the slide and the barrel.

I'd much rather have an honest "4 inch at 50 yards" pistol that works every time, than a "2 inch at 50 yards" gun that chokes every other magazine. The practical application of the pistol seldom involves a sandbag rest- which is about the only way I can consistently crowd three inches at the aforementioned range, anyhow. And even then, it has to be on a good day!
 
Like a lot of us I guess, I had to learn this the hard way.

Back in the 70's I "built" a Combat Commander. I was a young copper, and wanted the ultimate fighting handgun. It was actually pretty fair in slide/frame fit, and didn't work bad from the factory once a few "Colt-isms" were ironed out. I sent off to Bar-Sto and had Irv Stone build me a barrel, and split the diff between the SAMMI chamber and the match chamber. Think it cost me $65 dollars at the time. :eek: Mounted good MIcro sights. It was a shootin' machine. I actually had the eyes to be able to use a "2 inch @ 50" gun in those days, and the ol' Bar-Sto Commander produced a few of them with, as I recall it, Lake City Match hardball (68?). Wouldn't I love to have a case or two of that stowed away now!

Much as I loved that damn Commander, it was finicky. The extractor and everything had to be just absolutely perfect to get it to run with anything besides ball- and Stone had cut a nice throat in the barrel when he built it. I kept it a while and sold it to another cop, because I just didn't trust it. He was gonna just play with it as a target gun, anyhow.

Fast forward to 1998... I buy a brand new, ugly Old Roll Mark '91A1 Commander, expecting to have to do some work to get it to run OR shoot. Straight out of the box, the damn thing shoots into 3.5" at 50 yards with Federal 230 HydraShok. Two taps with a hammer & a little file work, and the sights are dead-zeroed at that distance. It runs and runs and runs for the whole 4 years I had it, and never, and I mean not once, does it jam.

These guns taught me that you don't have to have a tight fit between the slide and frame to get a 1911 to shoot well- and that a reliable gun can shoot plenty well enough for anything I'm gonna need to do with it.

By the way, I ain't knocking Bar-Sto barrels. If I was building a 100% bulls-eye gun, I'd buy another one today at four times the price.

I'd just have them cut the chamber to minumum SAMMI specs, this time.

Live and learn- it only takes about 30 years if you're lucky!
 
pistol guys...

I'm not much of a pistol fella myself, I've gotta chuckle when I hear you folks bicker. I just think that it's borderline hilarious to argue about 5" at 50 vs. 2" at 50. I wouldn't want to be at the receiving end of either one and that's what it's all about right? Granted, I do appreciate quality workmanship but it's how you use that workmanship that really matters. Either one of those groups will do the job that the 1911 is intended to do. Beyond that, and competition shooting, I say you don't really need it if you can't use it.
Enjoy your pistols fellas!
 
The tables in question are on page 108 of Volume one.

There are two of them.

I would scan them and post them, but Kuhnhausen is copyrighted. That makes a difference to me.

At any rate, you have the cite, above, so the claims Kuhnhausen makes are as follows:

The pie chart titled "Mechanical Accuracy [Repeatbility]" shows
  • Match Grade Barrel: 10%
  • Fit Accuracy Bushing: 20%
  • Headspace: 10%
  • Elminate Rear Barrel Side Play: 20%
  • Consistent Vertical Lock-Up: 20%
  • Beyond Reach: 5%
  • Remove Frame/Slide Play: 15%

The pie chart titled "Shooter Assistive Features" shows
  • Trigger Work (No creep, etc.): 50%
  • Sights: 25%
  • Miscellaneous, Ammo, etc.: 25%

In the discussion of the charts, Kuhnhausen makes the interesting observation that "...100% mechanical accuracy is unreachable." (page 108)

My observation has always been that it's obvious that the pie(s) are flawed, because it seems to imply that changing sights, alone, will increase accuracy by 25%.

If this were the case, the market would have cleared away all but the "correct" sight decades ago.

Dane Burns used to have a post on his board, pistolsmiths.com, about that chart, and that was where I first heard that the bushing was more important than the chart indicates, and the frame to slide fit less important. That observation also matches my own experience, and, in fact, I won't own a 1911 that doesn't rattle. Tight is for gamers, and I only own weapons.

The reason Kuhnhausen gives for separating the issue into two pies is precisely what you guys are talking about- he says "...machine rest accuracy isn't bothered by trigger creep, the machine doesn't notice it, but a shooter does."

So there you go, Sample, and Taylor, you can't simply quote a Ransom rest set of tests results, because the machine wouldn't care about a gritty, creepy, nine pound trigger.

That said, I agree with Burns- the pies are oversimplifications, and at best, are off. I trust his judgement, and I've seen for myself that slide/frame rattle just doesn't mean much, but bushing fit sure does.
 
Oh, I wouldn't call it bickering, John- but I agree with the basic concept you just stated. My daily carry gun is an XD40, box stock as it can be. It's plenty capable for fast work, and at 100 yards from a solid rest, it'll bust a 100 oz. laundry jug often enough to keep it interesting.

Mostly we fiddle with 1911's because we like 'em, and enjoy the challenge of making JMB's old warhorse shoot well.
 
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