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Hi Everyone, judging good checkering should be rather simple, all the diamonds should come to a perfect point with the tops of the points barely measurable, they should look like a perfect pyramid, all lines straight vertically and horizontally. (The vertical line being the long lines that run from mag-well to the trigger guard, the horizontal is the short line running around the radius from grip panel to grip panel). One line should not be deeper then the other where they intersect in the root of the V, the whole front strap should be uniform; there should be no high and low spots. If the checkering is machine cut you may see a burr hanging on the sides of the diamonds if it was not properly de-burred. If the tops of the diamonds are elongated like a blade in the direction of the vertical lines this means the vertical line was cut to deep. To correct you would have to cut the horizontal line deeper. If the direction of the blade runs in the horizontal direction the horizontal line went to deep. Mainspring housings: Wilson and Brown’s are examples of machine cut checkering. Smith Alexander’s checkering is cast in the mould and cleaned–up with a file. The Brown’s are pretty clean and are machined correctly around the radius (4th axis) horizontally and vertically proper. On the Wilson if you look close at the depth of the V on first and second vertical lines you’ll notice one side appear to be deeper than the other (the pyramid longer on one side than the other). To cut the vertical lines properly (concentrically) the cutter must be located in the center of the housing and then the housing is rotated for the correct spacing. The Wilson’s horizontal lines are machined correctly around the radius but when they do the verticals they are not rotating the housing around the 4th axis. They are using a flat set-up raising the mill table for the correct spacing to cut the vertical lines. The only correct vertical line on the housing is the one located in the center. Look close and you will see what I’m talking about.

99% of the frames out there have low spots buffed into them, they are finished by hand so it depends on the skill of the operator to provide a uniformed finish, low spots of .005-.010 are not uncommon, as much as .030 or more in the extreme. To put this into perspective consider the average F/S to be .068-.075 thick in the center at its thinnest point. 30 lpi checkering will run about .021-.022 deep, 25 lpi .028-.029, 20 lpi .034-.035, spacing is .0333 for 30 lpi, .040 for 25 lpi, .050 for 20 lpi. this is for 60 degree included angle cutters or 3 square files. If your frame has a .010 low spot you will lose the top half of a 30 lpi diamond, the smith will most likely have to fudge these low spots in, don’t blame him, he didn’t carelessly buff in these low areas, if you want a good looking job he needs something uniformed to work with. The checkering should be laid out squarely on the front strap, if the checkering fixtures are not set-up squarely or the frames are off it will not layout squarely. Easy way to check for squareness is to look at the first and last vertical lines, this is the first line that is next to the grips, there should be a full diamond the entire length, not start out with a full diamond at mag-well and taper to a half a tooth or worse at the trigger guard, this may be the reason why some smiths border the sides. Some frames can be difficult to layout squarely by machine or hand. There are a number of reasons for this: most magazine wells are not broached through the center of the frame straight or in the actual center; they are offset and may be on a slight diagonal. If the smith is using a checkering fixture that locates the frame through the mag-well this can be a real chore to set-up squarely but it can be done. There are ways to compensate for some of these defects, split the difference and shim, etc…. The radius on the F/S’s are not true as they look and should be indicated before you start so you know what you have to work with. They are usually off-set in line with the off-set mag-well, to check this off-set: mike the thickness of the sides of the frame flats in the mag-well, one side may check .115 and the other .090, this is extreme but not uncommon. Most flats on the sides of frame are finish ground by hand, this depends on the skill of the operator to keep the flats a uniformed thickness, if you check the thickness of the frame with a micrometer it may measure .762 at the mainspring housing, .745 at the F/S and .751 at the plunger tube, .005 to .010 variation is not uncommon. Some after market manufactures use a Blanchard or surface grinder to finish grind the flats and these are very uniformed. These flaws in the F/S may explain why some jobs turn out better than others. I think a nice relief cut under the trigger guard is proper, giving a higher grip and leaving the first line of checkering protruding. These last few rows are tough for some smiths to get perfect so check there for perfect diamonds. A poor example of this is Kimber’s, look at the first 2 or 3 lines under the trigger guard and you will see the vertical lines don’t cross the horizontals and a true relief cut is not made. All this is cosmetic and does not detract from the function of the pistol. Perfect looking checkering is nice but not absolutely necessary. Of course you don’t want your pistol butchered either. Keep in mind NOTHING IS PERFECT and you can find fault with anything if you look hard and long enough. It all depends on your personal standards, what looks good in my eyes may not look good in your eyes and vise-versa. Checkering is there to provide traction on the F/S. Some may find this hard to believe but I don’t own a checkered pistol, my first custom gun was a “Clark Long Slide” (which I extensively modified through the years) and is “Tiger Tooth Stippled”. It’s my workhorse. It has great traction and it works so why mess with it. I sharpened the teeth and had silver Teflon put on the frame for ease of cleaning.

Here is a example of a extreme case and how I would correct for the defect: about 20% of the Series 70 Colts I see have a low spot buffed into the center of the F/S at the base of the large radius under the trigger guard, approximately .030 to .035 of metal is buffed out leaving you with about .050 thickness, the rest of the F/S will run .080-.090 which is nice and thick. The same production operator, maybe the guy on 2nd shift or a replacement operator, most likely did this. This is too thin to fudge. If you stop checkering short of the low area you’ll get gypped out of about a ½” of checkering. MEASURE BEFRORE YOU CUT OR YOU MAY BE SORRY. There are a number of ways to measure the thickness of the F/S in a vise, mill, lathe etc…without buying a expensive instrument, try this: take a piece of ½” drill rod about 12 inches long and chuck it in the lathe, leave about 8 inches sticking out, set-up a dial indicator on a mag-base and put it on the cross slide, center the stylist on the rod and zero, now lift the stylist and slide the frame on through the mag-well, as you slide the frame up and down the rod keeping the back of the F/S tight to the rod the indicator will give you the exact reading at the point of the stylist.

To correct low spot: First I would lightly true the F/S radius to the checkered length and this will clearly show the low area, it will be about .250 to .400 in diameter. Now we are going to tig weld the low spot: next make a copper backer ½” o.d. to go inside the F/S, use a jack bolt and nut to hold it tight to the back of the F/S, this will act as a heat sink, it will keep the welded area from blowing through, keep it level on the inside and help the weld to cool slowly. Next remove all the bluing from the area to be welded, with a propane torch warm-up the copper backer to 600 to 700 degrees and the frame to about 400 degrees, if the frame starts to turn brown stop, its hot enough. 70S rod is ok, you don’t need a fancy specialty rod, hold the electrode away from the job, tap the pedal to start the gas flow, hold the electrode at the spot and give the gas time to enrich the area so when the arc strikes you don’t get carbon or splatter, you must have the gas shield in order for the metal to start mixing, if this is not done it may cause a air bubble in the weld. Do not start welding with a rod with a burnt tip. The burnt tip and bluing are impurities and a source of porosity, cut the burnt tip off to fresh rod, now melt in a nice droplet of weld in the low spot, when the hole is filled back off on the heat very slowly, you don’t want the molten metal to cool fast, now grab the propane torch and heat this area back up till it starts to get red, about 1200 degrees, back off on the torch slowly, should take 5 to 10 minutes draw back, longer the better, this will normalize the area welded. Most frames are probably around 1035 to 1040 carbon steel and are not heat-treated (that is.35-.40% carbon content in the steel, 10 stands for carbon steels). The carbon content in these steels are high enough to heat treat (will harden to about RC-38 max) but will not obtain a high hardness as in 1095 spring steel, .95% carbon content is about high as it goes in steels and can be harden to RC-68 . To put the Rockwell hardness into perspective RC-57 is considered good to perfect knife steel hardness for general use and can be cut with a good hard file, go 3 point higher to a RC-60 and most files will glide over it not cutting. RC-42 can be machined fairly well with good high-speed steel, go a few points to RC-45 and the high-speed may stop cutting, then you change to carbide. On the low end of the scale it’s difficult to tell the difference when machining because the steel is mild. If you weld on heat treatable steels cold the coldness in the steel will suck the heat out of the weld quenching it rapidly and making your weld hard as a rock in some cases. This is the reason for backing off on the heat slowly. If you form a hard spot you will have a tough time cutting through it and this hard spot can be seen when the steel is refinished. This is the purpose of the copper backer and the pre-heat, to hold the heat and normalize it. When complete checker as usual and you should not be able to tell it has been welded if done properly.
BROWNING HI-POWERS: BETTER MEASURE BEFORE YOU CUT OR YOU MAY BE SORRY. Hi-Powers are very thin where the F/S meets the grip panels, average .025 to .032 not counting for a low spot. I once had a customer that had to have a checkered Hi-Power, he sent at least 10 before I measured one that was .038 not counting a .005 low spot. Lets say you have .030 to work with and put 30 lpi on it at .022 deep. Well, what’s left of your F/S is about thick as a beer cans, a whopping .008 at best. Go with 40 lpi at .017 deep that leaves you with .013, big deal, sheet metal on cheap car is thicker then that. BEWARE if it is a newer Hi-Power with a cast frame, these are the ones coated with black epoxy paint and serrations at mag-well opening. I’ve heard of people checkering these and when finished giving the grip a good squeeze and the F/S crack and fall out. There are way to correct all these deficiencies above and are easier said then done. To correct the Hi-Power it will set me back the better part of a day in labor. In short, to correct: You will have to fabricate a new F/S, if you are going to do this modification and make a new F/S do what I do and make a bar of them while you have the machine set-up so you’ll have 2 or 3 extra. Make them extra thick so you can checker them any lpi you wish. I make an aluminum backer the size of the mag-well with removable copper shim plates to back the weld, V out the welds joints for 100% weld fill. If the F/S has a serial number in the center you have more problems, you will have to get the BATF involved to relocate the serial number, good luck and hope you get a very understanding agent.

One myth that I’d like to dispel before I go is this one I see from time to time in print, that you can tell a true pistol smith’s worth by his metal checkering or metal checkering sets apart the men from the boys when it comes to pistolsmithing. In my humble opinion this is a pile of B/S. Just what the heck does checkering have to do with pistolsmithing? To me pistolsmithing has to do more with the function & reliability, trigger work, barrel fitting etc…..of the pistol, not checkering, which is more cosmetic than the later. I know a few great pistolsmiths that never checkered a 1911 because they are wise enough to see before hand what’s involve in doing the job right and choose not to invest the time, money and absorb the loses to get started when there are alternates to checkering. Besides that, its not a big money maker if you count in the time and tools involved. On the other hand I know people that call themselves pistolsmith and don’t thoroughly understand the design and function of the pistol but do a good job of checkering, people rave about their checkering and the smith builds pistols that jam, break barrel links and drop to half cock etc….and the smith don’t understand why. And some people label him as a Master. So the “Master” calls the pistolsmith that don’t checker for help. Go figure! We have over 2542 words above, I hope this enlightened some of you on the subject. MetalSmith


[This message has been edited by Metal Smith (edited 03-24-2001).]
 
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WOW!!!....AWESOME post....it's a real pleasure to see something this technical explained by someone who understands all the "ins and outs"....Now I'm even more amazed by some of the custom work I've seen and handled over the years....mikey357
 

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Metalsmith,
Great post! Thanks for taking the time to share that. I cut and pasted it into my 1911 valuable and worthwhile information archive. I manufactured a weld on front strap a few years back. Had I guy tig it on for me. It is on there and about Rockwell 900. That was a very interesting point about the cool metal sucking the heat out of the weld to quickly. Never knew that and know alot of welders that don't either. Looks to me that you could just about get away with wacking the front strap off a gun in a vertical bandswaw, machine it flush and plumb, and then weld on a pre-manufactured frontstrap insert with close to the same amount of effort.
Also it seems that your half inch jack screwed round stock set up for surface indicating could be modified into a saddle jig for true-ing up the radius or machining a pocket for an insert. Great post! I live for this kinda of stuff popping up on this board.
ocie
 

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WOW, thats the most informative post I've ever read on any forum. I was fortunate enough to have Metalsmith work on my 1991-A1. He made it a good looker and a better shooter,too many things to list now. However, I had promised everyone that I would get some pics up, but its taking a while to get hold of my buddies digital camera. I'll post them soon.
 

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DITTO DITTO DITTO! Incredible post, which I'll have to re-read 6 times to absorb! It's a keeper, even if I never checker a frame. Stupid question: are you the person with the initials PS?
 

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Wow!
Great post by a great guy.
I'm lucky to have Metalsmith as one of my outside sources.

Chuck

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WOW again! Thanks Metalsmith for sharing with us awesome information that is not available anywhere, at least publicly.

Beyond the obvious technical merit, what impressed me was Metalsmith's putting checkering in proper perspective. Being "the man" on checkering, he could easily use this strength of his to pump himself up over others. Yet he is able to say hey, awesome checkering's great, but it ain't the whole enchilada, not even close. That speaks character to me.

[This message has been edited by Litespeed (edited 03-25-2001).]
 

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WOW again! Thanks Metalsmith for sharing with us awesome information that is not available anywhere, at least publicly.

Beyond the obvious technical merit, what impressed me was Metalsmith's putting checkering in proper perspective. Being "the man" on checkering, he could easily use this strength of his to pump himself up over others as some egomaniacs would do. Yet he is able to say hey, awesome checkering's great, but it ain't the whole enchilada, not even close. That speaks character to me.
 

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Wow
Had to read that several times to take it all in. Just wanted to say thanks Metalsmith for sharing a little insight into your world. I am a part-time hack and always appreciate anothers perspective.

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Chris from va
 

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Discussion Starter · #18 ·
Thank you gentlemen for taking interest in my post and all the kind words. I wrote it for you. I tried to write the post in a manner the average guy could understand. This was more difficult then I thought. I did some editing to make it easier to understand and clarify a few things. I posted a revised copy. So you may want to give it a re-read. If you want to down load save the revised copy, thanks, MetalSmith
 
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