Sheridan C9 Silver Streak question about pump action

[quattroatl]

I recently acquired two Silver Streaks. They were owned by two brothers. Their serial numbers are within 3 final digits. One of the two rifles seems to have a much easier lifting action when pumping. I barely grab the pump arm and it opens. The other Silver Streak and my Benjamin 392P both require much more force on the initial pull. I hope I am describing this correctly.

Can anyone explain what might be the reason or issue?  I do not have pellets yet to test.

Thanks for any insight and help.

[19Sheridan57]

  May just need lubricating. Look for the oiling points in this manual, which is virtually the same manual as for a Sheridan.

https://images-na.ssl-images-amazon.com/images/I/817fEQ2tDCL.pdf

[Frank in Fairfield]

Do NOT put any oil in the chamber.
Oil only the hinge points.
The cup is synthetic and requires no oil.
The cup is worn out.
Replacements are available from Crosman.

[JPSAXNC]

The piston is adjustable, the gun that opens harder has it's piston adjusted further out so when the arm is closed the piston is pressing on the valve face causing the linkage to cam over. That's the force you feel when opening the lever. HTH

[bantam5s]

The piston is adjustable, the gun that opens harder has it's piston adjusted further out so when the arm is closed the piston is pressing on the valve face causing the linkage to cam over. That's the force you feel when opening the lever. HTH

I don't believe the pistons on these Crosman made guns are adjustable.
Sheridan had dropped the adjustable pistons at some point,  I don't know when but I know they were dropped by the time my blue streak was made in '79 and I see no reason why Crosman would add the expense of going back to an adjustable piston.

[Hoosier Daddy]

Do NOT put any oil in the chamber.
Oil only the hinge points.
The cup is synthetic and requires no oil.
The cup is worn out.
Replacements are available from Crosman.

I respectfully disagree.
Oil the snot out of it (within reason).. pump a couple times and shoot a "Dry Fire" a time or two then put it away a week.
Then try again... these guns will shoot out the excess oil with out damage short of being "Hydro-locked" from the pump cyl. being full.

[Frank in Fairfield]

Makes no difference to me.
Tim MacMurray is the expert..

[19Sheridan57]

  Scott,
     Thank you for the suggestion. I failed to mention that for older model Sheridans, I do add a few drops of non detergent oil to the pump cup area, especially if the rifle has sat for a while. Then a couple of pumps, dry fire it, then add 2 pumps & store it.

[Frank in Fairfield]

Just order a repair kit and install it.
It might take 30 minutes and…
You get to use your tools.🧰

[eeler1]

I always just took Tim at his word, never questioned the 'why'.  Thinking about it, seems oiling to excess (whatever that is) might stress the seals and linkages, as liquids don't compress.  Also, with very little oil migrating from the linkages, I suppose might be less inclined to pick up dirt particles and debris?

A fellow who interviewed some of the workers at the Sheridan factory told me that some variation occurred in placement of the compression chamber during the soldering process.  Some were soldered in a bit forward and others a bit to the rear.  A difference of 1/8", maybe more.  So some guns come from the factory with more headspace and others with less, assuming uniformity in the pump rod and linkages.  Keep in mind that manufacturing during that era was much less consistent than today.  Hence the OP may have 2 guns made within a few minutes of each other that have different pumping characteristics.  Probably wouldn't notice unless handling the 2 side by side, as he did.

[Van]

I always just took Tim at his word, never questioned the 'why'.  Thinking about it, seems oiling to excess (whatever that is) might stress the seals and linkages, as liquids don't compress.  Also, with very little oil migrating from the linkages, I suppose might be less inclined to pick up dirt particles and debris?

A fellow who interviewed some of the workers at the Sheridan factory told me that some variation occurred in placement of the compression chamber during the soldering process.  Some were soldered in a bit forward and others a bit to the rear.  A difference of 1/8", maybe more.  So some guns come from the factory with more headspace and others with less, assuming uniformity in the pump rod and linkages.  Keep in mind that manufacturing during that era was much less consistent than today.  Hence the OP may have 2 guns made within a few minutes of each other that have different pumping characteristics.  Probably wouldn't notice unless handling the 2 side by side, as he did.

  That makes sense about different head space due to the placement of the soldered compression valve. My 71 Blue Streak did not come with an adjustable pump rod. The cam over at the end of the pump after a reseal was not what I thought it should be, so I ordered Mac1s adjustable one and about 1/8" or so longer was what it needed. 8 pumps got about 55-60fps more than before the switch.  I thought the 392 pump cups that come with the modern seal kits may have caused less cam over, but the compression chamber placement may be more likely.  I do oil the cup, not the air hole, with a drop or two every so often when it looks dry and it pumps smoother. 

[quattroatl]

I appreciate everyone’s input and suggestions. I spoke with a technical support person at Crosman. He told me that my two Sheridan were produced in 2000 and my 392 was produced in 2004.

He suggested that I oil the three pivot points as well as the pump cup area with a few drops of Pellgun oil that I had. He’s said to work the pump back and forth a few mini strokes at first without closing. He then suggested that I dry fire the guns a few times. Since oiling the cup area, all three guns feel more similar now in terms of their pump action.

I cronographed the 392 with Crosman Premier 14.3 g hollow points. I am getting anywhere between 613 on the low side to 629 being the max fps. I am waiting on .20 caliber pellets to test the silver streaks.

I will post results soon.


Thank you!

[quattroatl]

I received my .20 JSB Exact Match Diablo 15.89 grain pellets and tested both Silver Streaks.

With the maximum 8 pumps I am getting 595 fps give or take.

Both rifles are extremely accurate giving half inch groups at 13 yards in my basement.

I am hoping that the power increases as the guns wake up from not being used for many years.

[Frank in Fairfield]

I just rebuilt my C9a bought from Cabela’s in 2001.
14.3 grain Crosmans/8 pumps:

[19Sheridan57]

  Good results.

[Hoosier Daddy]

Sounds very promising!
 Congrats!!!

[quattroatl]

Follow up question for the experts:

My Benjamin 392P had a serial number N040438. It has the rollmark of Racine, WI and is clearly marked as a 392P. When I called Crosman, they informed me that my 392P was made in November 2004. How can this be possible? Weren’t 392P models replaced by the 392PA models by 2004?

I’m a bit confused.

[Hoosier Daddy]

I don't understand your question... maybe your 392P is late production towards the end.
Replaced the same year with the PA?
where does yours have the Safety?

[quattroatl]

The safety pin is at the thumb. Push pull safety. Not the rocker safety or near the trigger. I thought the 392P models ended production long before 2004. Maybe I am mistaken.

[Hoosier Daddy]

A thumb safety ensures it is a "P"... one of my favorites.