Tuning SAM Hammer Spring Adjustment & Reliable Operation

[nugria]

Hi All,

I came into a SAM to work with for a few days.

Does anyone have experience in adjusting through the hammer spring adjustment and the changes in the function & feeding of the semi-auto Marauder? My very limited experience indicates it likes the high side of spring preload for reliable function. Lower preloads appear to cause a misfeed and something that sounds like a quick pair of discharges. I've been shooting the Crossman 14.3gr HP.

My Google-Fu must be failing me on another topic. Are there any tutorials on removal, cleaning, and installation of the breach assembly on the SAM? It appears this gun has a fair number of pellets through it and I don't have a manual for care of this specific airgun.

Thanks,

Nugria

ps. The gun came to me because you couldn't remove the magazine. Seems it blew the breech o-ring. I assume the 2-009 N674-70 would be an appropriate breech seal?

 

[FuzzyGrub]

The -009 O-ring is correct.

I've heard that that the HP don't feed that well in SAM. The crosman 14.3 domes do.

The breech comes off just like the Mrod, four breech screws. Make sure the charging handle facing the way it came off. 

Currently, there is not a way to remove the bolt. It is pinned at factory. No hole at the top of the breech to press it out.

The hammer and the bolt work independently. The bolt cycles from the back pressure of the pellet traveling down barrel and returns via spring.

The hammer latches based on hammer bounce off the poppet. It is a very heavy hammer and shorter throw than a "normal" mrod.

 

[nugria]

Hi FuzzyGrub,

Thanks for the reply.

It does make sense now. When I've lowered the hammer spring preload, the lower velocity/air-blast doesn't have quite the energy to push back the bolt & hammer. The bolt pulls the hammer but not enough to hook on the sear. Everything would try to come back to "battery". The hammer would have enough energy for a little pop of air. The bolt/probe would not have the pellet in the barrel when the valve is struck by the hammer. Hence the jam.

I am rather surprised the the breech o-ring stays in as well as it does. After the 10th pellet the probe is stopped by the rotor in the magazine. The 11th "discharge" is with the breech open. That is how the breech o-ring got blasted into the magazine on the 11th discharge (preventing the removal of the magazine) when I got the opportunity to work on this airgun.

Take care, Nugria

 

[FuzzyGrub]

On the SAM, the magazines take a beating. Watch for damage on the rotor from the bolt just clipping it. Also, cracks in clear Lexan may start from that small gold pin.

With the gun pointed at ceiling, one drop of FP-10 in the bolt cavity, then exercise the charging handle numerous times to work it in. I do this after every 500 tin of pellets. Also a drop of silicone oil on the head of the first pellet, if you are seeing low fps on that shot and you have verified that you are using the load assist on it.