bamagreg
.327 Meteor
Woodstock, GA
Posts: 852
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Post by bamagreg on Apr 14, 2020 6:27:12 GMT -5
I got bored waiting on my cast bullets from Missouri Bullets (Still haven't got to shoot the new 480 Bisley) so I started checking out the chamber throats and then the barrel. The throats were consistent with a snug fit of a .477" pin gage. Then I checked the barrel. A .464" pin gage slips through completely but a .465" is snug through the barrel up to the frame then stops. See pic below. I still want to shoot the gun to see how she does but a little fire lapping may be in order.  |
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Post by bula on Apr 14, 2020 8:51:51 GMT -5
Nice job on the picture ! Have both barrel lengths here and similar to yours. Jacketed bullets by Speer and Hornady just fall thru the cylinders as you'd expect. The Missouri's hang a bit, gentle nudge from eraser end of a pencil and they go thru. Am approaching a 100 rds of fire lapping thru each and improvements seen. No pin gauges here and will be watching to see your fire lapping round count. Lapping rounds, the Missouri bullets on 8grs of TB n CCI350. My play load anyway.
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Post by wheelguns on Apr 14, 2020 10:40:27 GMT -5
After seeing your post, I decided to check mine. A .465” goes all the way through mine, and it shoots great. Barrel stays clean. I am anxious to hear your range report to see if that .001” makes a big difference.
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gman50
.30 Stingray
Posts: 191
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Post by gman50 on Apr 14, 2020 12:19:58 GMT -5
One of my SBH 44's had more thread choke than your 480 and was eleminated by removing the barrel and reinstalling without the Ruger pipe wrench. It was slugged as it came from Ruger then slugged again after removal. The steel sprang back and stayed when reinstalled. While the barrel was removed the bcg was tightened. Probably my most accurate 44 now. Just an option. Maybe I just got lucky.
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Post by bula on Apr 14, 2020 12:54:17 GMT -5
Now THAT is a most interesting thought.
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Post by bradshaw on Apr 14, 2020 13:13:58 GMT -5
One of my SBH 44's had more thread choke than your 480 and was eleminated by removing the barrel and reinstalling without the Ruger pipe wrench. It was slugged as it came from Ruger then slugged again after removal. The steel sprang back and stayed when reinstalled. While the barrel was removed the bcg was tightened. Probably my most accurate 44 now. Just an option. Maybe I just got lucky. ***** gman50..... I, for one, appreciate your excellent post. Aside from grouping a revolver before and after accuracy related work, your observation is the first description of elastic deformation from over-tightening. As opposed to plastic deformation, wherein a compression ring remains when barrel is removed. However, please explain how you re-installed barrel to Top Dead Center without compression. David Bradshaw |
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Post by willicd on Apr 14, 2020 13:32:23 GMT -5
One of my SBH 44's had more thread choke than your 480 and was eleminated by removing the barrel and reinstalling without the Ruger pipe wrench. It was slugged as it came from Ruger then slugged again after removal. The steel sprang back and stayed when reinstalled. While the barrel was removed the bcg was tightened. Probably my most accurate 44 now. Just an option. Maybe I just got lucky. ***** gman50..... I, for one, appreciate your excellent post. Aside from grouping a revolver before and after accuracy related work, your observation is the first description of elastic deformation from over-tightening. As opposed to plastic deformation, wherein a compression ring remains when barrel is removed. However, please explain how you re-installed barrel to Top Dead Center without compression. David Bradshaw Stating the BCG (barrel to cylinder gap I assume) was adjusted leads me to believe the barrel was possibly set back a thread and refit... |
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Post by wildcatter on Apr 15, 2020 10:18:11 GMT -5
I for one hate to assume anything when the facts can be made available. This is one thing I see a lot of on forums which can lead to much misinformation. It is always better to here from the OP to be sure instead of guessing at possibilities.
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gman50
.30 Stingray
Posts: 191
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Post by gman50 on Apr 15, 2020 14:31:47 GMT -5
Mr. Bradshaw,
I had Mike Brazda set the shoulder back and cut extra thread to tighten the BCG and to be able to hand tighten before TDC. I remember Mike telling me he has discussed this with you before he did the work. This was probably 3 years ago. Originally we had talked about doing the free bore like I believe he did on your one of a kind Ruger. You may correct me if I'm wrong. Since I wanted a tighter BCG and we were going to pull the barrel anyway we checked for thread choke before removing and after removing. It was also checked after it was reinstalled. I already knew the choke was present from the lead build up after 12 rounds I originally fired in the gun when new. Cylynder throats played part of the blame for the leading also. This gun is a real accurate shooter now and has zero leading issues. Other that the work mentioned above we opened the throats to an even .431 and Mike did a nice trigger job on it. It wears a set of nicely finished tiger stripe maple handles. I mentioned this as another option to firelapping. I've firelapped some other revolvers myself and figured it was worth mentioning.
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Post by willicd on Apr 15, 2020 19:08:08 GMT -5
I for one hate to assume anything when the facts can be made available. This is one thing I see a lot of on forums which can lead to much misinformation. It is always better to here from the OP to be sure instead of guessing at possibilities. Well, how bout that... |
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Post by bradshaw on Apr 15, 2020 20:40:47 GMT -5
Mr. Bradshaw, I had Mike Brazda set the shoulder back and cut extra thread to tighten the BCG and to be able to hand tighten before TDC. I remember Mike telling me he has discussed this with you before he did the work. This was probably 3 years ago. Originally we had talked about doing the free bore like I believe he did on your one of a kind Ruger. You may correct me if I'm wrong. Since I wanted a tighter BCG and we were going to pull the barrel anyway we checked for thread choke before removing and after removing. It was also checked after it was reinstalled. I already knew the choke was present from the lead build up after 12 rounds I originally fired in the gun when new. Cylynder throats played part of the blame for the leading also. This gun is a real accurate shooter now and has zero leading issues. Other that the work mentioned above we opened the throats to an even .431 and Mike did a nice trigger job on it. It wears a set of nicely finished tiger stripe maple handles. I mentioned this as another option to firelapping. I've firelapped some other revolvers myself and figured it was worth mentioning. ***** gman50.... perfectly fine option. I much prefer THREAD TIMING----timing the barrel threads to the frame----than FIRE LAPPING. Fire lapping as a means to smoothen LANDS & GROOVES and to iron out minor irregularity is fine. To remove a COMPRESSION RING, aka thread choke, by fire lapping----without timing the threads----might cause a loose spot, if, down the road, the barrel be pulled to correct BARREL FACE EROSION. My introduction to freeboard revolvers came through Rod Sward, who set up manufacture of the Virginian Dragoon in Virginia (for Sam Cummings, owner of Interterms). The Virginian Silhouette Dragoons I shot in .357 and .44 Mag were freebored and very accurate indeed. I do think freeborn may improve accuracy in the presence of excess chamber-to-bore runout, but the variables which make or break revolver accuracy are fierce and always in concert----which is why I call revolver accuracy an orchestra of dimensions. Threads in frame socket and on barrel tenon must both be timed for proper THREAD TIMING. When the factory substitutes a torque wrench for thread timing, the result is a loose barrel or, more often, an over-tightened barrel with a compression ring in the bore. To correct that, the barrel must be pulled, and the shoulder set back on a lathe. With Mike Brazda, I used THREAD PITCH and 12-degrees BTDC to calculate in thousandths-inch the amount to lathe-turn off the barrel shoulder. Barrels differ in how tight they may be turned into the frame before the bore distorts. Depends on steel and heat treatment, thread pitch, and wall thickness of tenon. Please give Brazda my greeting, until I can do it personal, David Bradshaw |
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Post by willicd on Apr 15, 2020 20:55:19 GMT -5
Mr. Bradshaw, I had Mike Brazda set the shoulder back and cut extra thread to tighten the BCG and to be able to hand tighten before TDC. I remember Mike telling me he has discussed this with you before he did the work. This was probably 3 years ago. Originally we had talked about doing the free bore like I believe he did on your one of a kind Ruger. You may correct me if I'm wrong. Since I wanted a tighter BCG and we were going to pull the barrel anyway we checked for thread choke before removing and after removing. It was also checked after it was reinstalled. I already knew the choke was present from the lead build up after 12 rounds I originally fired in the gun when new. Cylynder throats played part of the blame for the leading also. This gun is a real accurate shooter now and has zero leading issues. Other that the work mentioned above we opened the throats to an even .431 and Mike did a nice trigger job on it. It wears a set of nicely finished tiger stripe maple handles. I mentioned this as another option to firelapping. I've firelapped some other revolvers myself and figured it was worth mentioning. ***** gman50.... perfectly fine option. I much prefer THREAD TIMING----timing the barrel threads to the frame----than FIRE LAPPING. Fire lapping as a means to smoothen LANDS & GROOVES and to iron out minor irregularity is fine. To remove a COMPRESSION RING, aka thread choke, by fire lapping----without timing the threads----might cause a loose spot, if, down the road, the barrel be pulled to correct BARREL FACE EROSION. My introduction to freeboard revolvers came through Rod Sward, who set up manufacture of the Virginian Dragoon in Virginia (for Sam Cummings, owner of Interterms). The Virginian Silhouette Dragoons I shot in .357 and .44 Mag were freebored and very accurate indeed. I do think freeborn may improve accuracy in the presence of excess chamber-to-bore runout, but the variables which make or break revolver accuracy are fierce and always in concert----which is why I call revolver accuracy an orchestra of dimensions. Threads in frame socket and on barrel tenon must both be timed for proper THREAD TIMING. When the factory substitutes a torque wrench for thread timing, the result is a loose barrel or, more often, an over-tightened barrel with a compression ring in the bore. To correct that, the barrel must be pulled, and the shoulder set back on a lathe. With Mike Brazda, I used THREAD PITCH and 12-degrees BTDC to calculate in thousandths-inch the amount to lathe-turn off the barrel shoulder. Barrels differ in how tight they may be turned into the frame before the bore distorts. Depends on steel and heat treatment, thread pitch, and wall thickness of tenon. Please give Brazda my greeting, until I can do it personal, David Bradshaw You find 12* before TDC to be the magic number to have sufficient torque to keep the barrel tight without distorting the bore diameter? |
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Post by bradshaw on Apr 16, 2020 0:13:24 GMT -5
willed.... haven’t got a straight answer from anyone. Steel on the late 1800 guns was softer and certainly less fine in grain structure, with heat and alloys less refined. I should think those guns would pretzel under torque applied by Gorilla Monsoon in barrel fitting. I like the front sight to stop about 12-degrees BTDC, hand tightened. Fine threads allow a larger fudge factor without compressing bore. I don’t know what degree-range works. Some people really crank em down, and you know what happens.
Both Ruger and S&W set back barrels on my guns to eliminate barre face erosion. We all referred to it as forcing cone erosion. Don’t know their degree numbers, but they sure timed the barrel to the frame.
David Bradshaw
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Post by buckelliott on Apr 16, 2020 7:25:18 GMT -5
All else being equal, the bigger the bore, the thinner the barrel wall. That's just one of those facts you have to live with.
One of the reasons I'm a mite leery of the .50 caliber conversions..
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Post by bradshaw on Apr 16, 2020 8:32:30 GMT -5
All else being equal, the bigger the bore, the thinner the barrel wall. That's just one of those facts you have to live with. One of the reasons I'm a mite leery of the .50 caliber conversions.. ***** Done right, they don’t seem to be a problem. The Python and Model 19 have a thin-wall tenon. Yes, a thin wall is weaker in the presence of high pressure, thinness more vulnerable when the tenon protrudes into the cylinder window. Dick Casull figured the protrusion caper early on, and so did John Linebaugh. Lee Martin has torture tested his big bore Blackhawks, adding the heat of continuous fire to the equation. Fit-up is part of getting a magnum or big bore revolver right. Once steels proper for the application are selected----with, in Bill Ruger’s words, “good heat treatment”----the experimenter must remember MASS has its place. There is no steel & heat treatment to offset arrogance & stupidity. The Peacemaker-style single action remains the strongest frame concept for POWER in a REPEATING HANDGUN. So strong, in fact, it challenges a single shot to match its power-to-weight ratio. A swing-out cylinder design of equal strength cannot be made as compact. Saddled with a 2-piece frame, strength if a tip-open revolver lags far behind the swing-out. CHAMBER PATTERN limits cartridge diameter. The chamber pattern, or hole pattern as Ruger called it, involves more than round-count. It involves where the hole fits between cylinder circumference and axle hole. It includes thickness between chambers. And it involves placement of the bolt notch. All these relationships factor in strength. If someone wants a 25-ounce .500 Linebaught, be my guest. There may be some super-exotic material to make it possible. You’ll need to bring King Farouk’s checkbook along for the ride. If the gun holds up, all that will be necessary is an orthopedic surgeon. We never ran into strength issues with the Blackhawk .357 Maximum. I was grateful for its mass, all the meat wrapped around the chamber, Ruger’s 4140 chromium molybdenum frame. Tough. Linebaugh and others have built the .500 Linebaugh Maximum on the Blackhawk Maximum frame. Lee has put these through serious shooting without stretch or warp. Now, to introduce sloppy fit-up of cylinder to frame, with poor chamber-to-bore alignment, imposes a whole new level of stress. Dick Casull was a brilliant machinist devoted to huge power in a 3-pound revolver. He achieved it with his .454 Casull. Along the way, he wrecked guns. Sloppiness was not in his nature. It is a tribute to Wayne Baker enabling Dick Casull’s revolver to make it into production----with strict adherence to proper alignment and fitting. PRECISION is the last detail of POWER, from which manufacture must not waver. David Bradshaw |
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