[Higgins]

Apart from the skill of the shooter, what mechanical elements of the 1911 contribute to/govern accuracy?

I know that consistent lockup between the barrel/slide(sights) is central to repeatable accuracy, but what practical factors does this entail? Put another way, if you were building your own 1911 from parts and wanted to produce good/great accuracy, what areas would you focus on and what steps would you take? What's to most important single factor/step you could take? What's the simplest/quickest way to improve a 1911's accuracy from so-so to good/great?

Thanks for any insights.

[1911Tuner]

Howdy Higgins.

Good vertical lockup and hood to slide fit, along with a good fit at
the muzzle between barrel and bushing...bushing and slide, and
the fit of the locking lugs in the slide's recesses to limit fore-and-aft
movement.

Vertical lock is obtained with the lower lug and the slidestop pin,
not the link. Installing a long link is counterproductive and can do
damage over the course of 4-5,000 rounds.

Hood to slide fit limits barrel rotation, and should be fairly close,
but not so close as to cause functioning issues. I like about .002
on each side for accuracy tweaks, and looser for a carry gun. Some
match tuners will get this clearance tighter than .002 inch.

The barrel bushing is normally fit as loose as .005 inch or even more on
entry level production guns. Match grade pistols get this down to a
half thousandth, but about 001 to .0015 is a good working number
for good accuracy without compromising function. I normally set mine
at .002-.003 for reliablity.

Bushing to slide can be anywhere from slightly snug to requiring a wrench to turn it. I like snug and being able to strip the gun without having to carry a special tool along.

Slide to frame fit is responsible for about 5% of the total potential...or less.
I like .002-.003 inch clearance here for game pistols and range beaters.
.004-.005 is fine for a carry gun, as long as vertical play is held to a minimum...preferably none, bit .001-.002 is okay too. Again, reliability
is paramount. Snce I'm not a game player or bullseye competitor, I
take only a passing interest in a high degree of accuracy in a 1911.
If the pistol will shoot into 5 inches at 25 yards, it will do for what I
need it for. I'm almost anal about reliability, though.

The one thing to keep in mind is that accuracy means having to make things
tight. Tight means that the gun won't tolerate dirt or neglect as well as
a looser, "Ordnance Spec" pistol will, all else being equal. I've seen some
amazingly accurate National Match pistols that required cleaning as often
as every 50-75 rounds. It was an accepted consequence of those one
ragged hole 50 yard groups. Would I carry a pistol like that? Not if I
had a choice.

Cheers!
Tuner

[dsk]

Not to argue with 1911Tuner, but the truth is inherent accuracy is more a result of repeatability. Tight guns are usually accurate simply because the parts have to come back together in the exact same spot each time the gun cycles. However, you can have a tight gun that's inaccurate if the parts being forced together are stressed due to inadequate tolerances or inconsistent pressure. For example, if one lower barrel foot exerts more pressure on lockup than the other you're going to have an eight-shot group that looks like the Big Dipper. By the same token, parts that are more loose but which come together in a consistent fashion will display better overall accuracy. My older Series 80 Colt is fitted loose as a goose, yet it has always been accurate simply because the parts all fit together consistently. The barrel always unlocks at the same point each time, and goes back into lockup using the same contact points as before. This is why some guns actually shoot better after they've been used for awhile, as the high spots get worn down and the parts "settle in".

[VG]

If you get Kuhnhausen's shop manual he lists all the factors, their relative contribution, and how to check and remedy them.

FWIW I've found replacing the barrel bushing, barrel link, and link pin with drop-in parts improves the accuracy to acceptable levels on even the loosest of M1911's. $17 worth of parts cut the group size in a Sistema in half, and the slide and frame on that pistol are barely on speaking terms.....

[1911Tuner]

No argument there, Dana...Just giving a general overview instead of
going into a lot of detail about barrel springing, uneven lug contact, etc.
The devil's in the details, and details take up a lotta time and bandwidth.:D

Cheers!
Tuner

[bountyhunter]

A loose gun can be just as accurate as a tight gun.

And a poor man can be just as happy as a rich man...


But the odds are REALLY against it!:eek:

[308win]

Does a full length guide rod contribute to accuracy/reliability?

[1911Tuner]

.308 asked:
Does a full length guide rod contribute to accuracy/reliability?

Not that I can tell. About the only advantage that I've noticed is that,
on a pistol with worn or loose frame rails and a lot of vertical play,
a FLGR smooths out the cycle a little and helps keep the slide tracking
in a straighter line. Recoil springs also seem to last a bit longer with
a FLGR, but not enough to make a practical difference unless you go
through a couple dozen springs a year. There also may be some increased
life of the frame rails, but it would be tough to prove.

Shoot straight!

Tuner

[Sean Smith]

But the odds are REALLY against it!

It depends on what is loose. Loose slide-to-frame fit in very accurate guns is quite common. Loose barrel-to-slide fit in very accurate guns is alot less common.

Also, the quality of the barrel itself is a major contributor to accuracy. If it isn't machined precisely, you won't be able to get past a certain degree of accuracy no matter how perfectly you fit it.

[1911Tuner]

Sean said:


Also, the quality of the barrel itself is a major contributor to accuracy. If it isn't machined precisely, you won't be able to get past a certain degree of accuracy no matter how perfectly you fit it.

Very true. A well fit mediocre barrel will generally outshoot a high-end
match barrel that's poorly fitted. Bring a good barrel and a good fit
together in the same pistol, and they can be frighteningly accurate.

Tuner

[Sunray]

A good crisp trigger and highly visible sights are more important than a match barrel. Without them, all the rest is useless. Then there's good ammo too.