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Author Topic: Basket-case Benjamin 317  (Read 802 times))

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #20 on: September 15, 2021, 11:06:16 PM »
  Thanks all, for the tips and pointers.  Rick offered to sell me an adapter with the Hy-car rubber cup when I spoke to him the other day but I had decided to try this piston with the modern Benjamin cup.  I'm going to try the new leather cup just out of curiosity.  The original piston with leather seal was just clearing the intake hole when it was in the gun.  If that doesn't cut it , I'll try something else.  I think the check valve seat is alright but will double check again, should I pull the valve one more time.

  I made an improvement on my makeshift bolt handle.  Got a stainless steel screw and sleeved it with a bit of stainless 1/4" tubing.  Easier on the finger (and eyes) than the bare screw.

  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline c801tfd

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Re: Basket-case Benjamin 317
« Reply #21 on: September 16, 2021, 12:01:50 AM »
Your bolt handle may actually be stronger than the original, the old bolts are a bit of a challenge to find and if you do people ask as much or slightly more than your purchase. There is a person that sells vintage Benjamin parts on ebay, I dont know he is but wherever he is I hope to find him as he is somewhere within a 15 mile radius of my house because I want to ask for all the brass and wood he does not sell and possibly sells for scrap metal.
  • Montana, USA
Springers:
.177 Beeman San Rafael FWB 124 Sport Deluxe JNC Stamp (77/78)
.177 Weihrauch HW55 MM
.177 B.S.F. Model 55N
.177 B.S.F. Model 35
.177 Marksman Model 70
.177 Diana Model 25 Late 20's early 30s Smoothbore
.20 Beeman R1 Santa Rosa
.22 Falke Model 70
.22 Winchester Model 427
.22 Diana/RWS Model 35
.22 RWS Model 34 T06
.22 Ruger Impact Max Elite

Co2:
.177 Crosman Model 113 1950-1955
.22 Crosman Model 99 X 2

 Pumpers:
.20 Sheridan Model C "Silver Streak" (53 or 54)
.20 Sheridan Model C "Blue Streak" (52or 53)
.22 Crosman 101 1947
.22 Crosman 101 1927/29 Disc Logo
.22 Crosman 101 - 1924/25 Straight Logo
.22 Crosman 102 - 1926/27 Checkered Stock
.22 Benjamin 312 1940's
.22 Benjamin 312 1956
.22 Benjamin 392PA 1995
.22 Benjamin 392S
.22 S & W Model 77A 
.22 Rochester - DT Fletcher

Pistols:
.22 Benjamin 132 early 40s to 1952 no serial #
.22 Crosman 1322 Medalist phase 1
.177 BB Umarex 1911 Colt Commander Co2

Offline eeler1

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Re: Basket-case Benjamin 317
« Reply #22 on: September 16, 2021, 12:31:30 PM »
Curious where you found a new leather seal for that gun?  At one time, leather seals were pretty common for all kinds of uses, not so much any more.  I once used a leather seal for a Coleman lantern (remember the old pump up lanterns?), but I don't think those are available now.
  • West Sacramento, CA

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #23 on: September 16, 2021, 09:25:16 PM »
Curious where you found a new leather seal for that gun?  At one time, leather seals were pretty common for all kinds of uses, not so much any more.  I once used a leather seal for a Coleman lantern (remember the old pump up lanterns?), but I don't think those are available now.


JG Airguns has them.  This is only the second leather piston seal I have come across, the first one in a Crosman 102.
  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline pgritty

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Re: Basket-case Benjamin 317
« Reply #24 on: September 18, 2021, 09:54:48 AM »
Curious where you found a new leather seal for that gun?  At one time, leather seals were pretty common for all kinds of uses, not so much any more.  I once used a leather seal for a Coleman lantern (remember the old pump up lanterns?), but I don't think those are available now.
You can get them on ebay.
Pat
  • Houston Texas

Offline DanD

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Re: Basket-case Benjamin 317
« Reply #25 on: September 18, 2021, 11:20:22 AM »
Curious where you found a new leather seal for that gun?  At one time, leather seals were pretty common for all kinds of uses, not so much any more.  I once used a leather seal for a Coleman lantern (remember the old pump up lanterns?), but I don't think those are available now.
You can get them on ebay.
Pat
I think Mike Baker has them, too. You can probably find his email address if you search this site.
  • Binghamton, NY

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #26 on: September 19, 2021, 12:58:46 PM »
  Yesterday morning, I decided to shorten my bolt handle.  Thought it looked to long so I took just under 1/4" off.  This morning I decided to try a spyglass on the gun, popped on a vintage Weaver B6 using a Sheridan intermount.  The bolt handle just clears the scope.  I know it may make some purists cringe but, what can I say, this is how I roll.  Have to see how accurate they are.  Once dialed in, my first 5 shot, 20 yard group was right at 1/2".  Amazing.  Including a pic of my three old Benjis, a 342, 312 and now, a 317.

   

  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline Air Head

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Re: Basket-case Benjamin 317
« Reply #27 on: September 19, 2021, 03:06:24 PM »
Beautiful rifles, the stock on the one in the middle is exceptional. If you Blue the bolt handle you made,
only the purist's would know!  ;) Nice job!

Rich
  • Stalingrad, California USA
The best things in life are....
financially out of my reach...

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #28 on: September 21, 2021, 09:58:37 PM »
  I tried the replacement leather pump cup in the original piston.  Could not get it up to speed, was shooting worse than with the new rubber cup.  So, I put the modern cup and piston back in.
  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #29 on: September 24, 2021, 09:31:38 PM »
I worked up a fix for the velocity in this gun.  I took a nonadjustable piston from an 80s vintage 342 that I parted out a few years ago, with an old, hard pump cup on it.  Cleaned the inside surface of the cup and applied some silicone.  Used the pump tube as a form.  Coated the tube wall with a bit of Vaseline, dropped the piston in upside down just below the rim of the tube.  Don't know how long it will last, but I get around 570 fps with 5 pumps now.  6 pumps puts it around 620. 

  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline RBQChicken

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Re: Basket-case Benjamin 317
« Reply #30 on: September 24, 2021, 10:01:53 PM »
VERY interesting!  Keep us posted on how long that performance lasts!
  • U.P. of MI
The first time I hit it, I missed. The second time I hit it in the same place.

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #31 on: September 25, 2021, 12:03:06 PM »
  Shot some groups this morning.  This doctored pump cup slightly extended the piston length, plus I filled the front cavity with silicone, reducing the headspace.  3 Pumps=470 fps, 4 pumps 530, 5 pumps 565, 6 pumps almost 600 fps.  I tried a single shot with 8 and 10 pumps, 643 and 665.  All with RWS Basic 7 gr.   JSB 7.8 is more accurate, slightly slower.  50 or more shots this morning, hope this hybrid cup holds up.  I might try something similar with my Crosman 101.
  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline TerryM

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Re: Basket-case Benjamin 317
« Reply #32 on: October 09, 2021, 05:00:46 PM »
  Hybrid piston is holding up great after 200+ shots.  Experiment with Crosman 101 showed no gain.
  • TX
Crosman model#
101, 108, 110, 112, 113, 114 (x3), 118,
120, 140, 180 (x3), 187, 400, Mark II, 1377, 1322, 150, 122CG, Sears 126.19311, Ted Williams Match Rifle (2nd variant 160)
Benjamin model#
312, 342, 237, Discovery
Sheridan:
Blue Streak (x2: '64, '67)
F model CO2 Blue Streak (converted to bulk fill)

Offline sicumj

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Re: Basket-case Benjamin 317
« Reply #33 on: October 14, 2021, 12:42:39 PM »
You might consider a new hammer spring.  I noticed quite a difference in my 312.
  • NE Ohio