.177 extended probe

cheewee · May 16, 2012, 04:14:47 AM

anyone have dimensions for a .177 extended probe. i can only find the .22 using search and i dont have one i can measure.
thanks

cheewee · May 17, 2012, 02:49:37 AM

i know i have seen a pic on here before, this os what i need only for a .177

breakfastchef · May 17, 2012, 05:21:09 AM

Dimensions of the stock Crosman bolt should be the same except for the botl tip profile.

cheewee · May 17, 2012, 11:21:43 PM

thanks breakfastchef i wasnt sure because looking at the picture it looks like the 177 o-ring is slightly further forward.
might be just an illusion.

BDS · May 18, 2012, 12:05:41 AM

Quote from: cheewee on May 17, 2012, 11:21:43 PM
thanks breakfastchef i wasnt sure because looking at the picture it looks like the 177 o-ring is slightly further forward.
might be just an illusion.

No, that angle is longer on the .177. For an extended probe, all dims are the same as stock except... you need .100" more length at the forward end, not .110, or .125, but .100, max. If you make a bolt, you really can't continue that angle .100 longer, it will just be a pencil point. You need to transition to a diameter and extend that .100'

This will push the pellet in further and still allow about .032 of room to wiggle your pellet in place when cocked back.

cheewee · May 18, 2012, 12:38:39 AM

Quote from: BDS on May 18, 2012, 12:05:41 AM
No, that angle is longer on the .177. For an extended probe, all dims are the same as stock except... you need .100" more length at the forward end, not .110, or .125, but .100, max. If you make a bolt, you really can't continue that angle .100 longer, it will just be a pencil point. You need to transition to a diameter and extend that .100'

This will push the pellet in further and still allow about .032 of room to wiggle your pellet in place when cocked back.

thanks for the info, i understand the angle is longer and will have to end in a .100 pin. the thing i dont have is a standard bolt to measure i only have a .22 so i guess it will be trial and error.

BDS · May 18, 2012, 11:04:51 PM

Quote from: cheewee on May 18, 2012, 12:38:39 AM
thanks for the info, i understand the angle is longer and will have to end in a .100 pin. the thing i dont have is a standard bolt to measure i only have a .22 so i guess it will be trial and error.

Don't sweat it

, use the .22 dims for all but the probe end past the o-ring groove. The o-ring groove should fit a #003 o-ring for a .177 with a skosh of room so that the o-ring doesn't fit too tight on the probe. Those two angles on the .177 stock probe are actually different but, you can just make a 30 deg. angle ahead of the o-ring goove and about .060 past it, then, transtion into your diameter +.100" longer than stock feature.

cheewee · May 19, 2012, 05:28:26 AM

cool thanks

1377x · May 19, 2012, 06:38:22 AM

does this help?
http://www.network54.com/Forum/275684/message/1257935611/Re-+Extended+probe+bolt+questions

http://www.network54.com/Forum/275684/message/1257700897/LarryR+did+a+post+on+this

cheewee · May 19, 2012, 02:45:14 PM

good read thanks

arkmaker † · May 19, 2012, 05:04:29 PM

Try this if you have a chance. I haven't had the time to make one yet.
Rich

cheewee · May 19, 2012, 11:11:05 PM

Rich looks interesting i may just give it a try. im guessing the larger dia. at the end is to keep the pellet straight when loading.

arkmaker † · May 19, 2012, 11:29:06 PM

Quote from: cheewee on May 19, 2012, 11:11:05 PM
Rich looks interesting i may just give it a try. im guessing the larger dia. at the end is to keep the pellet straight when loading.

You got it. That was my thought anyway. The only draw back is it you shoot multiple types of pellets and then you would need to go with the smallest Inner Diameter size as the max on the probe head.