Lathe turned surface finish.
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    Default Lathe turned surface finish.

    I'm usually pretty particular about surface finishes since the shaft is going into a bearing or bushing.
    Now I've got to produce a rough texture for a dummy gun barrel.
    U.S. G.I. gun barrels, especially around WW2, were pretty rough, almost had a super fine-thread look to them. Some of the bigger tubes were actually threaded because you screwed the trunnion up or down to get your elevation... don't think I need to go that coarse.
    I figure increasing my carriage feed and taking light cuts, maybe even as if I was single-pointing threads so one pass doesn't mess up the previous one.
    Anybody got an old Garand in their closet to give me an idea of a starting point; 30 t.p.i., 60 t.p.i., 48 t.p.i.,

    Intentionally producing a rough finish?!? Probably has the old journeyman machinist I apprenticed with spinning in his grave so fast, he sounds like a dynamo.

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    Just looked at my M1 and would not call it rough turned at all. Even with my 3.5 power glasses on you'd be hard pressed to see or count any grooves without much higher magnification. Granted it's not polished, but it's not rough either.

    I only looked at the last 4" or so of the barrel beyond the wood stock. Said Blue Sky, Arlington up there and Springfield Armory back at the bolt. Not sure if those things make any difference or not.

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    Quote Originally Posted by JonesL View Post
    ...Some of the bigger tubes were actually threaded because you screwed the trunnion up or down to get your elevation... ...
    I have not shot a Garand since 1963, but do not remember the barrel looking like it was threaded. Of course, there is only a very short part of the barrel not hidden by wood.

    But I have to wonder if you know what a trunnion is. The quoted statement makes no sense to me. I built a muzzle-loading circa 1776 field cannon in 1953 and made a rookie mistake with the 3/16" one-piece pressed-in trunnion being intersected by the 3/16" bore. The first and only shot blew the bisected trunnion halves out of the barrel, taking a couple wheel spokes with them. The trunnions are the short crosswise shafts on the side of the barrel that provide a pivot for adjusting elevation of the gun. My first model used a quoin (wedge) under the breech to adjust elevation. Other commonly used designs involved a coarse screw that could raise and lower the breech, far back from the trunnion.

    Larry

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    Found a very short section of my Garand barrel(0.125”) that has turn marks corresponding to 120/“. Looking at other areas and I can convince myself there is that same but extremely faint pattern under the parkerizing.

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    Rickyb, 120 sounds like a good jumping off place. I'll turn a few samples to see how they look. The marks I'm trying to duplicate are not "threads" as such but have a very fine spiral appearance to them. Could be because U.S. companies were turning out rifles so fast that they were rushing the cuts between areas that had to have a machined finish / press fit for gas sealing, front sight alignment, or so that a component could be "dialed in" with a go, no-go gauge.

    Gee Larry... I'm pretty sure I know what a trunnion is. It's the little round, stickie-out things on either side of the two Gatling gun frames I built, or did the final machining on a couple of muzzle-loading cannon tubes. Done correctly, those trunnions are cast as part of the gun tube, not added later. And yes, they're a bear to machine so that they are on the same elevation, in alignment with each other and are the same distance from the muzzle.
    Your statement likewise makes no sense-- That the first and only shot of your muzzle-loading cannon blew up. How did you manage to get it loaded in the first place with your one-piece trunnion in the way?

    The mortarmen I was around (MOS 11C - Indirect Fire Infantrymen) alternately called the piece that clamps mortar tube to bipod a; Collar, Saddle and Strap, or Trunnion. Since the 11 Charlies were already pretty busy making the VC keep their heads down, I didn't think it was my place to interrupt and correct them on their nomenclature.

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    Re grade of finish, .............with all the talk of cuts / inch etc etc, bear in mind the finish is only applied on the final cut, so tool wear shouldn't be a problem, ......and as it's only 1 cut nor should ''picking up the thread''

    IME tool tip radius can have as much effect as feed rate, and if ground from HSS easy enough to modify / experiment with until satisfied.

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    Forgive them, JonesL, for they know not whom they are dealing with

    If you guys had a clue about the quality of false-antique work Mr Jones here does, you would not be so quick to make dumb comments.

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    Thanks for the kind words and vote of confidence, Emanual.

    Here are a few pictures of my latest, a Commercial Model of 1885 and its tripod (also my handiwork). Doing the final tuning on the cartridge feed then it's ready to test fire.

    Also a shot of my 5 year restoration / build of a 1921 Harley board track racer. I decided I didn't like the handling so I took the springer front end apart and machined new down tubes 2" longer. That little tweak to the wheelbase keeps it from searching out ruts and pot holes and makes it much more fun to ride.

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    Quote Originally Posted by JonesL View Post
    You need to make a new timing cover some day .... that part sticks out like a sore thumb Maybe next winter ?

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    I know what you mean.
    I was at this shop, where the owner was buying these WW2 cast offs, and putting sporting
    stocks under them.
    He showed me, when he took off the full covering stock, the finish was quite rough.

    So he would mount the barrel between centers and polish with a sanding cloth.

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    I have some kind of old Russian rifle stock and barrel that my kids play with as a toy. It looks like it was turned with dull HSS at a feedrate double the nose radius.

    Want pictures/measurements? or do you need them from a specific weapon?

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    Nice work!

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    Jeez, Emanuel... and I'm just now getting the right side looking this good. The close-up of the timing cover just shows more detail.
    In truth, all it does is cover the points and condenser but I wanted it to look "vintage" to match the bike.
    Bike doesn't sound half bad either, even with the short pipes. see pictures and video. Yes, its got a 1971 ironhead Sportster motor; but I modified the engine to fit the frame instead of hacking up the frame to take the engine. I cleaned, preserved and packed all the original parts away so in about a day, I can have it back to completely stock anytime I want.

    Garwood, a picture or two would be great. maybe a ruler beside to show relative scale. I just want a handle on recreating the finish for any future projects / restorations. Not working on any particular weapon. I have a collection of faux finish processes in case Ive made a new, replacement part and need it to look like it belongs on the vintage what-the-heck-is-this that I'm working on.

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    Quote Originally Posted by JonesL View Post
    The close-up of the timing cover ....
    Oh, sorry. We used to call the whole camcase cover the 'timing cover'. Ironhead is too streamlined, 1917 should have lumps all over. Anyway, you'll get around to it I'm sure ....


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    Yeah, for us kids and our new-fangled iron head toys, the right side is a "cam cover" "timing cover" fits over the points.
    The original pocket-valve motor I have put away-- now THAT'S lumpy.

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    Quote Originally Posted by 13engines View Post
    Just looked at my M1 and would not call it rough turned at all. Even with my 3.5 power glasses on you'd be hard pressed to see or count any grooves without much higher magnification. Granted it's not polished, but it's not rough either.

    I only looked at the last 4" or so of the barrel beyond the wood stock. Said Blue Sky, Arlington up there and Springfield Armory back at the bolt. Not sure if those things make any difference or not.

    It appears that your Garand is not WWII mfg. Does it say Springfield "Armory" or "Arsenal"? Blue sky was a mark required by the ATF to damage military arms brought back to the states after being sent to allies such as Korea.

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    Quote Originally Posted by JonesL View Post
    Yeah, for us kids and our new-fangled iron head toys, the right side is a "cam cover" "timing cover" fits over the points.
    Points ? Eeeuw ! Those are supposed to be in the mag

    See, this is a case where I think a tracer could be great. Trace the cover's shape on a piece of hardwood, knock it out with a bandsaw and belt sander, then drop 'er on the tracer and reproduce in aluminium. You could go into production ! 1917-look sporties

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    Whose side are you on Emanuel? I figure I'm gonna have to live to be about 120 just to get caught up on the projects I currently have going on.
    Besides, have you checked with the folks in Marketing? Just how big is the demand for parts to make an H-D Sportster look ancient?
    To that end; I wanted my primary cover to look more like the early stamped tin ones with the raised "H-D" enclosed in a diamond, so I tackled how to emboss an aluminum casting. Only after I'd done it was I told that embossing cast aluminum couldn't be done.

    A lot of early race bikes were pretty rough since riders were often working with what they could find or cobble together.
    I wanted the fill and clutch adjustment plugs to look more "vintage" so I whittled two "pipe plugs" out of aluminum, single pointed threads that matched the primary cover and textured them to have that rough cast texture. The filler plug even has the felt filtered breather cannibalized from a junk plug I had.

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    Quote Originally Posted by tdmidget View Post
    It appears that your Garand is not WWII mfg. Does it say Springfield "Armory" or "Arsenal"? Blue sky was a mark required by the ATF to damage military arms brought back to the states after being sent to allies such as Korea.
    Yes I always thought it was just one that got thrown together from pieces, or that it wasn't necessarily one of the "good" ones per say. Anyway... it says Springfield Armory. Serial 671279. Just one of the firearms I got from my gunsmith Dad after he passed. I got lucky considering I'm 1 of 5 brothers. Thanks for the info.

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    garand-bbl.jpg

    Springfield Garand. CMP rifle. SN 1.86 mil. SA 9-43 barrel. Note "threads" stop at about the .5" mark along with a diameter increase just prior to the rear gas cylinder band. Going toward the muzzle the "thread" depth seems to gradually decrease over .5" or so to smooth at about 1/16" before the front sight mount/gas cylinder. Hope this helps. Nice works.

    Thank you,
    Mr.Smith

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