John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) And, since I hate leaving a tutorial unfinished...and to keep the thread on-topic by addressing the original question... There's more to headspace in the 1911 pistol than simple chamber length. I'll try one from a little different angle. Suppose that you were to clean up the damaged breechface with .010 inch or so of material removal and install a barrel that required the chamber to be reamed to depth to get minimum headspace. If the barrel in question already has the ramp established...some call it the "throat"...and the barrel face under the hood didn't need any work at all in order to fit within the space available... the same condition would exist at the case head support area that would be present with excessive headspace. All you've done is to shift the whole cartridge case rearward. The breechface is moved rearward by .010 inch...which places it that much distance farther from the rear faces of the barrel lugs. The barrel ramp and face is still in the mid-spec position, even though the barrel is short-chambered. This means that the case will back out of the chamber by .010 inch farther to meet the breechface, and will lose that amount of head support at the bottom. It's the same condition as cutting the ramp deeper into the chamber, even if you follow the existing angle. The only way to make up for the relocated breechface is to go with a full semi-finished barrel. One that has not only a short chamber and a long hood, but one that has an overlength barrel face with no ramp/throat area. The hood and face must be cut to fit, including the slight clearance angle...the chamber is then reamed to depth, and then the ramp is cut to the correct depth and angle. So, you can literally have the slide barely close on a GO gauge, and still have a problem. My advice to the man is to ship that slide to EGW and let George install a hardened insert in it. That's really the only right way to make the repair. Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
benny hill Posted July 8, 2006 Share Posted July 8, 2006 The barrel hood is left long so as to cut to get no clearence between it & the breach face , next cut the chamber to the right headspace. The barrel hood lenght has nothing to do with the bottom lugs. I can only recommend watching a good smith fit one to understand. This is my final word on the matter. Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) Benny sez: >. The barrel hood lenght has nothing to do with the bottom lugs.< *************** I didn't say that. I referenced the breechface to the rear face of the slide lugs...not to the lower lug...which is where the zero-clearance hood fit pushes the barrel lugs. Again Benny...If you cut the breechface back by X thousandths of an inch and fit the hood tightly to that location...and ream the chamber depth to produce minimum headspace...you're still going to have an added gap between the breechface and the barrel face, (below the hood) and you're still going to have case setback past the point of optimum head support unless you start with a semi-finished barrel...A barrel that is overlength at the hood AND at the face, along with a short chamber, and doesn't have the ramp/throat pre-cut. It doesn't matter if the case setback comes from excessive headspace, or the chamber stop shoulder limiting its position forward into the chamber...the case will still sit further rearward than it should. Think about it... And: >I can only recommend watching a good smith fit one to understand.< Oh, I understand it perfectly, lad...I truly do. Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) Benny, in the interest of your continuing education...Let's hypothetically fit a barrel backward. Start with a hypothetically perfect barrel fit. Zero clearance at the hood and breechface. Full vertical engagement of the lugs. Fully equalized horizontal lug engagement with the slide. Minimum static headspace. Gap between the breechface and the chamber face is perfect, and so is the angle. Perfect! Take the gun apart and machine .025 inch from the breechface. You now have a gap of .025 inch between hood and breechface. Right? Okay...Weld the rear face of the hood and refit to zero clearance. Still perfect...or is there a headspace problem? How about the gap between the face of the chamber and the breechface. Still perfect...or is there now a .025 inch wider gap? Let's take it a step further and pretend that we know a gremlin who is one millimeter tall, and that he has a teeny tiny tig welder that he can use to shorten the chamber by welding up the shoulder. You use a reamer to again establish a minimum chamber depth, and the gun will once more just go to battery on a .898 inch GO gauge. You still have a headspace problem, Benny...and so will the guy who started this thread if he simply cleans up the breechface and fits a barrel hood to it. Think about it... Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
nvmichael Posted July 8, 2006 Share Posted July 8, 2006 John Travis, Thanks for the posts. I've been shooting 1911s for many years and always love getting to know them better. Link to comment Share on other sites More sharing options...
cking Posted July 8, 2006 Share Posted July 8, 2006 Travis is correct in theory, Benny is correct that cleaning up the face and fitting a new barrel isn't big enough to make a difference. However I've another point I want to make. If the hood tore up the face that much, wasn't the orginal barrel fitted poorly? I thought the hood was just supposed to close the gap as the barrel made its final few degrees twist up into lock with slide. When slide comes charging forward to pickup the barrel after stuffing the cartridge in. You don't want the hood to be a contact point or it will get battered. You want the vertical lock points to pick up the barrel. You want the top lugs, side rails, hood all locked as link hits 90 degrees, then those last few degrees on link before feet hit the slide stop it acts as all once piece. You also don't want the ramps on link to hit the slide stop until your just a few degrees before 90, or you get bump feed problems. I like this, everybody gets to learn alot. So don't get peeved at each other. Link to comment Share on other sites More sharing options...
Larry White Posted July 8, 2006 Share Posted July 8, 2006 (edited) Bilski, clean up your breech face, fit your barrel, cut your chamber. Then go out and wear that pistol out again, that will take about as many rds as it did the first time. If you have a problem you can reach Benny at Triangle Shooting sports while he builds another couple thousand very fine custom, hand fitted, good running pistols.----Larry Edited July 8, 2006 by lkytx Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) cking, The breechface was damaged due to thrust forces when the gun was fired. Soft steel deforms faster than hard steel. That's why Colt introduced the steel inserts back in '36 and '37. After WW2, the slides were fully hardened throughout and the practice was abandoned. As to it not making much difference...it depends. Mainly on how much material will have to be removed in order to clean it up and get it flat and true...and the liklihood of being able to do it with a file is slim and none. It will require a mill and a machinist who can do a good setup. Also...the odds that it can be cleaned up...even in a mill...without removing at least a 64th of an inch are small, and it will probably be closer to .020 inch. A 64th is a bit more than .015 inch. The GO to NO GO limit is only .022 inch, which is about the thickness of a sheet of typing paper more than the required removal for cleanup. All that means that there will be an additional .0156 gap between the chamber hood and the newly-established breechface...which is about .010 inch out of spec, no matter how tightly the hood is fitted, and no matter how perfectly the chamber is cut. There's more to it than just chamber length and hood to slide fit. Much more. ********************** nvmichael...You're quite welcome, sir. I've had good success in this endeavor on various forums, under another name...and my main goal is to teach the guys how to fix their own pistols, or at least diagnose what's wrong so they can talk to their smiths on a common level. My theory has been that, if you can completely understand how the gun functions, you can usually figure out what's ailin' it...and a lot of the time, you can fix it. And...failing that...I've had several forum members bring their pistols to me to have them repaired. Most of the time, it's somethin' simple. Simple doesn't apply to the pistol that got this thread started though. This one will require surgery. In this case...and I repeat myself...the proper fix is to send the slide off to have an insert installed so that the slide will be within the specified tolerances...and the barrel fit will be good. The other way, one problem is (maybe) solved, but the other one remains. Cheers all! PS. For the record...Whenever a forum member or a friend does bring a gun for me to repair, the labor is at N/C. I don't do it for money. I do it for love of the breed. Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
EricW Posted July 8, 2006 Share Posted July 8, 2006 (edited) Benny, Since you "assembled" my gun improperly, will you build me a new one for free? If this thread keeps up, Brazos, Triangle, Kodiak, M2i, Bedell and god-knows who else are going to have to issue product recalls. (Looks like "hubris" just got an expanded definition in the dictionary.) Edited July 8, 2006 by EricW Link to comment Share on other sites More sharing options...
Merlin Orr Posted July 8, 2006 Share Posted July 8, 2006 Benny,Since you "assembled" my gun improperly, will you build me a new one for free? If this thread keeps up, Brazos, Triangle, Kodiak, M2i, Bedell and god-knows who else are going to have to issue product recalls. (Looks like "hubris" just got an expanded definition in the dictionary.) TROLL is the word that jumped to my mind..... Link to comment Share on other sites More sharing options...
blackdragon Posted July 8, 2006 Share Posted July 8, 2006 Lighten up Francis! Ivan ( From Stripes, The movie) Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) Benny,Since you "assembled" my gun improperly, will you build me a new one for free? If this thread keeps up, Brazos, Triangle, Kodiak, M2i, Bedell and god-knows who else are going to have to issue product recalls. (Looks like "hubris" just got an expanded definition in the dictionary.) ROFL Eric. The issue is basically nothing more than specs and tolerances. In this case, the breechface to first lug dimension, which allows a plus of just .009 inch from nominal on an ordnance-spec gun. (1.809 + .009 inch...and that's just to the first lug wall.) Slides selected for match purposes are held to just .004 inch over nominal print dimension. If the slide in question is at mid-spec...or about 1.814, which is "iffy" since it's been shot a bunch, and the rear face of the slide lugs have doubtless worn and/or deformed slightly...that doesn't leave a lot of material to remove and keep the slide within acceptable tolerances. Even .010 inch will take it .005 inch out of spec...and if it weren't critical, the allowable print tolerances would be much looser. Also...The breechface isn't dead perpendicular...or it shouldn't be. It's machined at a nominal angle of 89 degrees, 8 minutes...with an allowance of +/- 5 minutes. The chance of filing the breechface to square within tolerance from side-to-side, and stay within the specified vertical angle AND keep the dimension from breechface to lug walls within acceptable tolerances is practically nil, especially for someone with limited skill and experience with a file. Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
EricW Posted July 8, 2006 Share Posted July 8, 2006 Dammit Benny, now I'm really P.O.'d. Give me my money back or I'm a coming to TX and gonna give you the nougie of a lifetime. I cannot believe I was ever led astray by your reputation and bought one of your "assembled" heaters second-hand. Heavens to Betsy! What shall I do?! Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) Well...I'll stop now. Seems that I've ruffled a few feathers by tryin' to keep wsimpso1 from screwin' up his gun with a mill file. My advice stays the same though. This one needs corrective surgery...at least if he wants the problem corrected. If he's okay with a cobble-job, far be it from me to bust his chops. Cheers! Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
EricW Posted July 8, 2006 Share Posted July 8, 2006 Oh man...just when I was going to nominate this for the thread of the month. I can't believe it's over so soon. Please don't go. I haven't laughed this hard in weeks. This is way better than all the "how many angels can dance on a compensator?" threads, and we haven't even invoked the Raelians or the 24 hour Church of Elvis yet. Link to comment Share on other sites More sharing options...
blackdragon Posted July 8, 2006 Share Posted July 8, 2006 Oh please keep it up! This is good stuff! Ivan Link to comment Share on other sites More sharing options...
John Travis Posted July 8, 2006 Share Posted July 8, 2006 (edited) Hey Ivan! Good to see ya, buddy! Kinda...chilly in here...dontcha think? Eric...Since you seem to have descended into veiled insults and condescension...which surprises me, since I had rather expected a more relaxed, open atmosphere here...I'll toss this out and see what we get. As stated previously, the breechface isn't supposed to be perpendicular, but is rather set on an angle of 89 degrees, 8 minutes...+/- 5 minutes. That's a critical angle. The small allowable tolerance confirms that much. That angle is so specified for two good reasons. The first is pretty obvious...or maybe not...but it's to allow for the barrel tilt in-battery, along with the small angle on the chamber face. I'll let ya ponder on the other one. Stay tuned, flamewar fans! This one could go hot. Edited July 8, 2006 by John Travis Link to comment Share on other sites More sharing options...
Flexmoney Posted July 9, 2006 Share Posted July 9, 2006 Relax folks. CLOSED. Link to comment Share on other sites More sharing options...
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