Marauder pistol troubles - help needed 🙁

I have a Marauder pistol in .22 caliber that I haven't used much in the last couple of years. Yesterday I pulled it out to shoot a bit and realized something was wrong.  Accuracy has gone downhill - can't reliably get 1 inch groups even at 20 yards with what was it's favorite pellet. And, velocity is way off.  So - of course - I started messing with the tune. At this point I have the hammer spring at maximum (7 turns clockwise from its fully counter-clockwise stop) and the hammer throw at maximum (all the way counter clockwise). I'm only able to get around 570 FPS with a 14.3 CHP pellet.  I was getting up in the 640's with this earlier using 5 1/2 turns on the hammer spring and 1 1/2 turns on the hammer throw.

Could something be worn out inside or maybe partially disintegrated?  I don't know how old the pistol is really as I bought it used.  It does still hold air indefinitely so no air leaks.  As far as I know its stock inside.

Ron

maybe a bad o-ring part number 10 

do a tissue test and see if it is leaking at the breech 

Tried the tissue test. No evidence of a leak around the breech.

Hmmmm, bought used...  Have you looked inside for something like a “bstaley” mod ?

Only other guess would be valve stem/seat or maybe hammer draggin’?

Bon Chance

It was performing better than this a couple of years ago I think. When I got it out yesterday it was cocked so it had been cocked for several months. Could the hammer spring have become weak or damaged because of that?

I’m thinking I’ll end up rebuilding this P-Rod or getting someone to do it. But, I have no idea who. Any recommendations?

They are pretty simple to work on. Online videos of tear down. I would replace the hammer spring first. That does not require a lot.

Posted by: @pluric

They are pretty simple to work on. Online videos of tear down. I would replace the hammer spring first. That does not require a lot.

Yeah - I'm going to start looking for parts today. I assume Crosman/Benjamin is the best place to get things like that. If anyone knows of a good place for parts let me know. Last time I ordered parts was a seal kit for a Marauder rifle years ago.

If you want to get a stiffer after market spring ebay can hook you up.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=benjamin+marauder+pistol+hammer+spring&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=benjamin+marauder+pistol

Confirm with Seller if it fits a pistol. If I recall right they are different between the pistol and rifle.

Crosman has always been fantastic to order from.

Found this, they are different size.

Benjamin Marauder Hammer Spring Replacement ... use a .48” OD 2.5” free length, and .054” wire diameter; for the P-rod, use a .30” OD 1.75” .

@pluric Thanks! I'll probably be ordering today.  Aside from leaks (can't find any) the hammer spring would be my first suspect.

Try the hammer spring before you start adjusting everything. I have found that to be the culprit on mine. Cheap and easily replaceable.

Posted by: @johnny366

Try the hammer spring before you start adjusting everything. I have found that to be the culprit on mine. Cheap and easily replaceable.

Just ordered a hammer spring from Crosman a few minutes ago. That'll be the first step. ?