Need machinist to make a Marauder breech
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Need machinist to make a Marauder breech
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Topic: Need machinist to make a Marauder breech (Read 1978 times))
Tonykarter
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Real Name: Ray
Need machinist to make a Marauder breech
«
on:
June 26, 2018, 01:47:02 PM »
I am considering using the full length of a HW barrel blank rather than cutting it off to stock Marauder barrel length. I want to put the extra length inside the breech for greater barrel to breech mating, hopefully to promote greater accuracy. To do this I would need a new breech machined that extend the front of the breech by the difference in the HW barrel blank length and the stock Crosman barrel length. Has anyone tried this and did the increased mating surface contribute to greater accuracy? If so, please point me in the direction of a machinist that might consider making one. Thanks!
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
shorty
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Real Name: Tim
Re: Need machinist to make a Marauder breech
«
Reply #1 on:
June 26, 2018, 05:32:27 PM »
I have never tried this and can never machine a part like this but, you made me think about and breech extension that may do it (possibly 3d printed).
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Palm Coast, FL
ChapoChoo
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Real Name: Doug
Re: Need machinist to make a Marauder breech
«
Reply #2 on:
June 26, 2018, 05:57:07 PM »
You're going to be hard pressed to find someone who will do it and you're going to pay a pretty penny. I'd start contacting local machine shops and expect to pay several hundred dollars. That's if you do all the 3D design work.
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Spanish Fork, UT
Tonykarter
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Re: Need machinist to make a Marauder breech
«
Reply #3 on:
June 26, 2018, 06:08:38 PM »
Thanks guys. Hoping a machinist on here has the breech already scanned to file with which to modify and produce. I'll check with a friend of mine down the road too.
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
Rob M
GTA Senior Contributor
Posts: 6308
Re: Need machinist to make a Marauder breech
«
Reply #4 on:
June 26, 2018, 06:10:10 PM »
maybe Vash would take it on , he has cnc access and a good understanding of what youd be after
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Louisiana
YEMX
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Re: Need machinist to make a Marauder breech
«
Reply #5 on:
June 26, 2018, 07:09:18 PM »
What's the O.D. of the HW barrel? The largest barrel a Mrod breech can handle is .5". Maybe slightly bigger. But that's because of those breech screws. What's wrong with having the barrel machined down to .5" from the breech screws back? The front 1.25" (maybe 1.20"?) of the breech's bore can be opened up all the way to 18mm, or a hair over .708"... machining the breech and barrel that way would be far less inexpensive, and something a tuner here might be willing to take on. Just a thought.
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Silver Spring Md
PCPhack
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Re: Need machinist to make a Marauder breech
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Reply #6 on:
June 26, 2018, 07:32:27 PM »
It's already been done and called a WAR WARP.
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Texas, USA
Bill G
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Re: Need machinist to make a Marauder breech
«
Reply #7 on:
June 27, 2018, 11:13:49 PM »
How much longer does the breech need to be? Or better asked, how much longer is the other barrel?
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Nicholasville KY
Engineering is the art of modeling materials we don't wholly understand, into shapes we can't precisely analyze, so as to withstand forces we can't properly asses, in such a way that the public has no reason to suspect the extent of our ignorance.
Tonykarter
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Re: Need machinist to make a Marauder breech
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Reply #8 on:
June 28, 2018, 08:25:09 AM »
16mm x 495mm on the barrel blank. I am not sure about how much shorter the factory barrel is , but it is somewhere around 2-3 inches shorter. Extending the breech would be somewhere between 2-3 inches.
«
Last Edit: June 28, 2018, 08:27:13 AM by Tonykarter
»
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
rsterne
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Bob and Lloyd
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Re: Need machinist to make a Marauder breech
«
Reply #9 on:
June 28, 2018, 01:09:10 PM »
495 mm is 19.5", shorter than the stock MRod barrel at 20"....
Bob
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Coalmont, BC, Canada
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1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).
Tonykarter
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Re: Need machinist to make a Marauder breech
«
Reply #10 on:
June 28, 2018, 05:06:39 PM »
Thanks Bob. I didn't have a stock factory barrel to measure, so I couldn't tell: I had cut the fronts off both mine trying to get the gouged places in the rifling off, so I was going on memory regarding length, which apparently does not serve me well. Intent is to leave the barrel as large of OD as possible in front of the front breech screws, have about 2 inches of extra breech/barrel mating due to the extended breech.
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
YEMX
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Re: Need machinist to make a Marauder breech
«
Reply #11 on:
June 28, 2018, 06:11:34 PM »
IMHO, it wouldn't be worth the extra expense... The factory barrel (if it's a .25) is .5". 16mm is .630" You could just enlarge the bore forward of the front breech screws, and machine down the remainder of the barrel from the front breech screws back... If you really wanted to, you could:
open up the breech forward of the breech screws to tightly fit 16mm
machine down the rest of the rear of the barrel to fit in the breech
possibly machine a ring to fit a c-clip (like a WAR airgun)
have a custom shroud made and use a WAR tensioning end cap that also doubles as an LDC mount
Overall, I think the above would be cheaper than machining a whole new breech.
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Silver Spring Md
Tonykarter
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Re: Need machinist to make a Marauder breech
«
Reply #12 on:
June 28, 2018, 10:44:32 PM »
Good ideas. Thanks!
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
rsterne
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Bob and Lloyd
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Re: Need machinist to make a Marauder breech
«
Reply #13 on:
June 29, 2018, 05:39:43 PM »
Something like this....
Hole in receiver is drilled to 5/8" almost back to the 4-40 breech screws....
Barrel OD is turned down to 1/2" to pass through between those screws and fit into the existing hole in the receiver behind that....
Bob
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Coalmont, BC, Canada
🇺🇦
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since! 🇺🇦
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).
YEMX
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Re: Need machinist to make a Marauder breech
«
Reply #14 on:
June 29, 2018, 06:36:06 PM »
Exactly- Bob, thank you. I don't have pictures of what I was trying to describe.
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Silver Spring Md
rsterne
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Bob and Lloyd
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Re: Need machinist to make a Marauder breech
«
Reply #15 on:
June 29, 2018, 07:16:00 PM »
If your receiver is from a .177 or .22 cal, I understand the receiver is only drilled 7/16".... not 1/2" as in the .25 cal.... You would have to turn the back of the barrel to fit either way....
Bob
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Coalmont, BC, Canada
🇺🇦
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since! 🇺🇦
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).
Tonykarter
Crappie Savant
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Real Name: Ray
Re: Need machinist to make a Marauder breech
«
Reply #16 on:
June 30, 2018, 09:25:16 PM »
Bob, thanks for the pictures! Would an extra inch or two on the end of that breech contribute to better accuracy?
«
Last Edit: June 30, 2018, 09:27:29 PM by Tonykarter
»
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East Texas: Snuff Gully, Surrounded by the Big Thicket Preserve
rsterne
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Bob and Lloyd
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Re: Need machinist to make a Marauder breech
«
Reply #17 on:
June 30, 2018, 10:03:53 PM »
I doubt it would produce a noticeable difference.... Sleeving the barrel to stiffen it, or using a larger OD barrel than the stock MRod one... or mounting the shroud solidly to the breech by turning the OD down back to the 4-40 screws and tensioning the barrel.... would probably do more.... I don't like the way the MRod shroud just butts against the front of the breech....
The stock barrel is already inserted about 5 diameters into the breech, and the stepped setup I showed above is about 2 diameters for the larger section (plus the smaller piece)…. With enough setscrews, anything over 3 diameters is unilikely to provide any improvement....
Bob
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Coalmont, BC, Canada
🇺🇦
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since! 🇺🇦
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).
Privateer
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Re: Need machinist to make a Marauder breech
«
Reply #18 on:
June 30, 2018, 10:32:07 PM »
Quote from: rsterne on June 30, 2018, 10:03:53 PM
using a larger OD barrel than the stock MRod one...
There's the reason I'm working the .32 barrel the way I am.
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Nevada, Ohio
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ken47
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Re: Need machinist to make a Marauder breech
«
Reply #19 on:
July 18, 2018, 03:17:15 PM »
I can help with that, do you have a 2d or a 3d part file?
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ken: Mechanical Engineer
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Need machinist to make a Marauder breech