While many people talk of slide to receiver fit, one of our resident THR experts asserts that said fit would reasonably account for not more than approximately 5% of a 1911's accuracy. This resident expert maintains that the critical link for the 1911 is the barrel to bushing fit.
In my own experience, having owned more than a couple dozen 1911s, I too have found this to be the case. The most accurate 1911 that I own is a rattle in terms of the slide to receiver fit. However, the barrel to bushing fit feels more like a steel monolith, than two pieces of steel fit together.
So, here is my request: post a picture of your most accurate 1911's barrel, showing the wear pattern that should be indicative of the barrel/bushing fit, and consistency of the fit (contact).
Feel free to add comments, for example, about the slide to receiver fit, the make, model, or other as you see fit. This thread is not intended to serve as a slam against any pistol manufacturer. I am looking for excellent performers, regardless of the make, model or caliber.
Edit to add some measurements just for the heck of it:
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November 30, 2007, 08:54 PM
Wow! :confused: Did I create a dud of a thread or what?! :uhoh: There have been 69 people read this thread, and not one, single, solitary person has added anything. :scrutiny: Not even an insult?! :o
Wow...just wow. :(
November 30, 2007, 09:01 PM
My cameras not home, but I have a picture of a very accurate gun barrel, bushing:) Bushing has no slop in the slide, and has .001 clearance to the barrel. The slide to frame fit isn't so tight.
November 30, 2007, 09:15 PM
The clearance is a mere .001?!?!?! Holy cow! I thought my lock-up was tight! I haven't sent mine to be hard-chromed because I think it gets applied to .001, and I only have .004 available.
How does your group? I have been considering some subsonic, hard-cast lead bullets in hand-loads.
Thanks for the post,
November 30, 2007, 09:29 PM
I haven't done any shooting off a good rest, but heres a before and after pic, at 30' offhand. I posted the best before target group, and with much frustration, decided to buy an EGW angle bore bushing and matching plug. The difference was night and day. I should have stopped at 4 shots on the after target, but I was so estatic and not believing my eyes at the much improved group, that I pulled the last shot:mad::D
November 30, 2007, 09:54 PM
Wow! That is great! Do you have a link for the parts? I want to buy upgrades for my one Colt. The one has almost zero contact to the barrel. Super-sloppy. Thanks.
The best thing to do is call them with your gun measurements. Mine took a little time to fit the bushing to the barrel (1HR) A little elbow grease, with some wet/dry paper, and a wood dowel, to open the bushing a bit. The bushing to slide fit was perfect as delivered, dont need a bushing wrench, but its way tighter than the factory Springfield bushing.:)
November 30, 2007, 10:58 PM
I have the original 'Accurizer' Barrel and collet bushing in my 70 series Gold Cup and it has given me excellent service and accuracy.
Where slide to frame fit really matters is if you use a scope or red dot sight with a mount that attaches to the frame instead of the slide.
December 1, 2007, 10:02 AM
That makes sense. Thanks for the tip. I have seen two different types of mounting system for 1911s: frame mount and slide mounted. I imagine the slide-mounted type would be consistent with using iron sights. I would worry about a scope or other electronic sight mounted to a slide. I don't recall where I saw that...some after-market company I ran across. I should have bookmarked it.
December 1, 2007, 10:30 AM
The slide mounted red dots work very well, but are rather expensive -- $200-250. I've had good results with the J-Point. Just added a Burrus Fastfire, jury is still out. Initially the Fastfire has a clearer dot, but it also picks up reflections of anything bright behind you which often obscures the dot.
Frame mounts are expensive ~75-150 + drill and tap costs, but cheap red dots generally work well witih them. See my thread on the EAA Witness Limited, http://www.thehighroad.org/showthread.php?t=316306
Its not a 1911, but does cocked and locked with a very tight slide to frame fit and a "cone barrel" for very solid barrel to slide lockup.
I tried a Leupold grip mount, It was a total POS. Interfered with ejection and was very uncomfortable to grip.
Some mounts let you use the irons as back up, others don't to get a closer to bore scope axis. The J-point and Fastfire mounts replace the rear sight. Check the mount carefully if this is important to you.
Here is a thread when I first got the J-point on my RIA. Its held up very well thru -- over 10,000 rounds wtih it mounted.
I recently moved the J-point to my double stack Armscor P14 clone and put the new Fastfire on the RIA as the standard GI dovetail mount for the Fastfire was easiest to find. They are making others now.
December 2, 2007, 07:40 AM
Wow, I am silly. When I measured the clearance between barrel & bushing, I should have clarified that I measured at the widest point of clearance, mid-way down the barrel. I'll have to measure the barrel at the lock-up point and post the tightness there.
December 2, 2007, 12:29 PM
'78 Colt Combat Commander 9mm.
KKM Precision barrel and unknown bushing fitted by Dave Sams. No measurements on hand but bushing is wrench tight in the slide, and there's the slightest resistance when I remove the bushing from the barrel.
Note faint wear line at top and bottom of barrel where it makes contact when in battery:
I tried taking a pic of my Kimber, but it just comes out to blurry. It has hardly any play and it gets great groups. It has a ring close to the end of the barrel, but I think it is too new to show significant wear.
I really like how the 5" "floats" when I shoot it. My old 4" compact Kimber did'nt have a bushing and the recoil was nowhere near as manageable. The 5' definately is more accurate for me.
December 2, 2007, 05:44 PM
I agree. Somehow taking pictures of the barrel is a difficult task. I had to take something like 16 or so pictures to get the 2 that I posted. :) Keep at if you can. It would be a great addition to the thread.
December 2, 2007, 05:55 PM
May explain my Kimber Match .38 Super problem with consistently inconsistent groups.
December 2, 2007, 06:09 PM
I don't have a picture, but I've got a EGW thick-flange bushing sized to about .001" clearance. I also kind of like the look because the thick flange extends past the end of the barrel.
December 2, 2007, 08:09 PM
Most of my center fire autos have Briley spherical bushings, which run right at 0.001" clearance.
My only "solid" bushing is also a Briley that came on my SW1911.
I've never bothered to measure it, but it seems to work okay.
December 2, 2007, 09:05 PM
I ordered one from EGW.
The specs on my pistol are:
Barrel OD .578
Slide ID .706
The "custom" EGW bushing is:
1 x Barrel Bushing (1044) = $20.00
Steel Type Blue
Select Model Government
Select Bore Angle Bore, .580 (Drop-in)
So one thousandth on the slide and 2 on the barrel. Not bad for twenty bucks. :)
December 2, 2007, 09:37 PM
One done for me by Bob Rodgers on a full house build. The full pistol is my pistol. The close-up is another pistol, but the bushing fit & crown is the same as mine.
December 2, 2007, 09:41 PM
Update, now that I am measuring the way it should be measured: :rolleyes:
Barrel external (mid-length):
Barrel external (at lock-up):
So, it looks like there is room for improvement through a custom bushing, but given that most lubricant's take up about 1/1,000", I likely would not gain much. But, in the future... :)
But, it also answers a question that I have had in the back of my mind...to hard-chrome or not to? The hard-chrome goes on around 1/1,000th" (so I am told). If the bushing, and barrel are chromed, and lube, that adds 3/1,000th in a 1.5/1,000 space...that won't work. I don't want steel removed, so no hard chrome. Anyhow, back to the thread's original thoughts.
December 2, 2007, 09:43 PM
In my experience, accuracy in a 1911 comes from several factors. They all relate to the ability of the bore axis to relign with the sight radius after recoil. Realignment in exactly the same position again and again is the key.
A close tolerance barrel bushing is only part of that equation. In addition, the barrel feet must be fitted propery. The hood must be fitted properly. The upper lugs must be fitted properly. Many of the older gunsmiths would build up barrels with welds to get them to engage more precisely. Some would build up the sides of the chamber decreasing the lateral movement.
The sights must be tight.
The barrel must be of good quality, with clean rifling, no chattering, and a good muzzle.
Finally, it helps if the trigger does not cause the shooter to misalign the sights when pulled.
Slide to frame fit? Nah......I don't need it.
I think a lot of times folks place a lot of stock in a bushing, because they do help. The first time I installed a King's bushing in a Springfield Mil-Spec, I was amazed at the accuracy improvement. The bushing only controls one end of that bore axis though. If you want great, repeatable accuracy, you have to control both ends, and get them to return to the same place again and again.
I'm not sure what you want in these pics, but these are some of my 1911s that I can not out-shoot. I do not know what the tolerances are, but the Clark and the Gunsite Gold Cup bushings can be turned with the fingers.
You actually just answered much of what I have pondered for about 2 years that I have owned this Series 70...why is this thing so darned accurate? I try to pick up bits and pieces of info here and there, but I have not yet found a book that details target-quality 1911s. I'm sure such books exist, but I haven't found such a book...yet. :)
Thanks for the Info!
December 2, 2007, 10:35 PM
I forgot to add one more item to the equation..........Along with the bore axis and the sight radius, the next cartridge must return to the exact same location and position as the previous one. This is where match chambers and match ammunition come into play. The longitudnal axis of the cartridge in the chamber must be the same every time.
The rear of the barrel can be out of alignment up & down, left & right, or even a twist one way or the other if the lower lugs and barrel link are not fitted correctly. Rear alignment problems can be any combination of those movements as well.
A better fit at the muzzle end helps cover for rear alignment problems, but wear will be accelerated at the front if the rear is not right.
Now watch Tuner come blow Xavier's thinking out of the water.........;)
One more item in regards to slide/frame fit........Clark Custom (http://www.clarkcustomguns.com/scdetail.htm) installs an accuracy modification called the Slide Guide. It is an extension welded to the front of the dust cover with two set screws. By adjusting the screws with the gun in battery, all horizontal and vertical movement of the slide is eliminated. The advantage of the slide guide method is that the slide is tight in the locked position but is free in the cycle mode. This enhances the functioning of the slide and eliminates break in period. Obviously, it also helps reliability. Their accuracy guarantee is a 10 shot group measuring 2.5" or less @ 50 yards with match grade ammunition, including flyers. Obviously, they consider the slide/frame fit to be somewhat important, but then they first tweaked the barrel/slide fit for all it's worth.
December 2, 2007, 10:45 PM
One of my dreams is to enroll in a 1911 pistol smithing course. I have seen them listed. Anyone know of some really good 1911 technical books I could read? Seriously, my wife buys me firearms books for Christmas...now is the time to drop the hint. :)
December 2, 2007, 10:54 PM
The Colt .45 Automatic by Jerry Kuhnhausen Volumes 1 & 2 (http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=13805&title=Jerry+Kuhnhausen+SHOP+MANUALS)
The Gun Digest Book Of The 1911: A Complete Look At The Use, Care & Repair of the 1911 Pistol, Vol. 2 by Patrick Sweeney (http://www.amazon.com/Gun-Digest-Book-1911-Complete/dp/0896892697/ref=sr_1_2?ie=UTF8&s=books&qid=1196653552&sr=8-2)
The Custom Government Model Pistol by Layne Simpson (http://www.amazon.com/Custom-Government-Model-Pistol/dp/1879356163/ref=sr_1_1?ie=UTF8&s=books&qid=1196653640&sr=1-1)
If you can only get one or two, get the Kuhnhausen Volumes.
December 3, 2007, 09:03 AM
Thanks for those titles!
I just ran across this 1911 DVD about 2 minutes ago. I think it might be worth buying just to see how such precision 1911s are built. It's offered by Caspian for $69.95: