For some reason we aren't getting email notifications from the forum lately. I'll need to dig into our settings and see what's up.
Luke, there is something else going on with your 935 that we'll try to walk you through finding here. Our in-house 935 with the shortest available barrel (22") will now run 1200 FPS 2 & 3/4 bulk packs flawlessly and there is no reason yours shouldn't with the right parts and maintenance issues addressed.
Here are a few things to check on your gun to make sure that you are getting full gas to cycle light loads.
1) Remove your forearm and disassemble the gas system. Does your piston slide smoothly in the cylinder? Does the piston slide smoothly over your magazine tube? Once re-assembled, does the piston still slide smoothly as an assembly? Does the mere weight of the spring behind the pusher return the piston fully forward or does it bind? If it binds, your piston may have been welded to the barrel at a slight angle or your rings are packed with crud and need to be removed from the piston and cleaned separately. The rings are easiest to address. Also, run your gas system DRY, without lube and see what happens. Since you don't have a Marine Spacer Tube, keeping lube off of your gas system is critical. This is also the time to check for rust pitting, gouges or scoring on your magazine tube and check that your secondary gas system's ring is intact. If your secondary gas system or magazine tube under it is scored up or pitted, this is where all of your gas is escaping. Escaped gas in this area isn't available to help cycle the gun. Also, some 935s quickly develop cracked pusher assemblies and/or forearm retainers. If either of these polymer items are cracked or broken, they can create drag on the pusher assembly where it meets the receiver or potentially contacts the forearm.
2) What was the condition of your factory plunger when you removed it? Chattering on the plunger from a spring burr? If you have a spring burr you likely also have a scored recoil spring tube. It is important to remember that the 935 uses the same spring as the 930, but has to compress it another 3/4" and naturally runs a higher spring weight than a 930 as a result. There is also additional weight to the bolt and slide assembly working against it. If your recoil system is providing drag, it is an uphill battle. The CSP drops the peak spring weight of the 930/935, but it won't drop the 935 below the weight of a standard 930. Some 930s have issues running 1200 FPS loads reliably. The recoil system has to be running right to cycle 1200 FPS 2.75" shells in a 935.
3) Other things that are common culprits in 930/935 cycling issues include side saddle shell holders that attach through the trigger group pin holes. The receiver to trigger group fit is designed to be loosely fit in the 930/935. Cinching a side saddle down on the receiver will narrow the rails in the receiver and slow or bind the cycling of the gun up. Another possibility is that your barrel needs a good polishing. If an empty shell is tough to extract, the marginal amount of gas available to cycle a 935 with 2.75" shells is spend dragging a sticky shell out.
As stated in our recent email, specifics on the load you are trying to cycle and answers to the above check list will go a long way to figuring out why your specific 935 won't cycle light loads.
Thanks!
William
http://www.OR3GUN.com