Size difference between .177 and .22 Disco bolt



Author Topic: Size difference between .177 and .22 Disco bolt  (Read 667 times)

Offline Stefan

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Size difference between .177 and .22 Disco bolt
« on: December 07, 2011, 09:29:56 AM »
OK,
I have an extra disco breech, an extra disco .22 bolt and 10 inch .177 barrel.
I have to make this bolt to fit the barrel - whats the difference, besides smaller o ring used on .177? I measured 5,1 mm at the current bolt for 5,5mm (that mushroom head part), I suppose it should be smaller than that to fit the 4,5mm pellets bore.
Is there some difference in length perhaps?

Also, the end of the barrel that goes into the breech, does it have to be machined in some specific way, or just cut flat and inlet done properly? And what size of the hole should be made to fit the standard TP?
Thanks in advance
http://www.airguns-srbija.com
Benjamin Discovery .22, Mellon Air RVA, M-Rod trigger, MTC Mamba 4-16x50
BSA Scorpion .177, Altaros regulator, MTC Viper 10x44
Daystate Air Ranger .177, Hawke Sidewinder 8-32x56 20X Mil Dot
AirArms S410 FAC .22, Altaros regulator, MTC Viper 6-24x56

Offline rsterne

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Re: Size difference between .177 and .22 Disco bolt
« Reply #1 on: December 07, 2011, 01:59:09 PM »
The bolts are the same length.... The nose is a different shape and the O-ring is a different size.... The barrel port is the same size (0.134`` ID)and in the same location, and the recess in the bottom for the transfer port is also the same diameter and depth.... The barrel has a tapered lead to allow proper seating of the O-ring and to insure that the pellet is guided smoothly into the bore.... I don`t have detailed dimensions.... but they would be needed for what you want to do....

Bob
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal:
.177 Diana 34, 1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), .22 BAM B-26, .22 BAM B-51 (50 FPE), .25 Hatsan AT-4410 Long (70 FPE), .22 QB79 HPA (26 FPE), Disco Double .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, .308 & .357; Mk.III is .410 shotgun and .458 cal)

Offline Stefan

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Re: Size difference between .177 and .22 Disco bolt
« Reply #2 on: December 07, 2011, 03:35:48 PM »
well I hope some1 here has them :D
http://www.airguns-srbija.com
Benjamin Discovery .22, Mellon Air RVA, M-Rod trigger, MTC Mamba 4-16x50
BSA Scorpion .177, Altaros regulator, MTC Viper 10x44
Daystate Air Ranger .177, Hawke Sidewinder 8-32x56 20X Mil Dot
AirArms S410 FAC .22, Altaros regulator, MTC Viper 6-24x56

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