Guys, I apologize for being MIA. For some unknown reason I am not getting emails when new posts are made here! I have been getting them since the beginning, now nothing.
Anyway, where to start?
Cvans, that extension and your other work looks amazing! Excellent job and equally impressive performance and shooting- got to hate those marauding sparrows! Recently the subject of
painting a Daisy black came up at Daisy Talk, some good info there.
Stork85, you do have a very nice 1938 there! Cleanest I've seen maybe ever. With your gun I would start by taking it apart and assessing the existing parts. Ask about them here if there's anything that concerns you or if you have any questions. Clean it out well- both the compression chamber side as well as the BB reservoir side. Oily BBs and oily shot tube will kill accuracy! The shot tube has to be kept free of oil. Which means routine cleaning since we add oil to the wiper and that oil migrates from the compression chamber through the air tube into the shot tube as the gun is shot. So at the first sign of any loss of accuracy, clean the shot tube. I use either alcohol or Goof Off citrus cleaner on a patch followed by dry patches.
As Hinz has ably advised you, a new spring, drilled air tube and a fresh piston from a Daisy plunger assembly if needed should put you right at your goal. I'm not sure what spring they were using in the No. 1938s like yours, but if it doesn't have ground ends, even the stock new production 1938B spring with a 1/2" to 5/8" preload spacer will make a marked improvement even w/o a drilled air tube. Like around 300 fps.
As for the piston and abutment seals needing attention, if this gun has sat unused for a few years what happens is the piston can take on the small dimples from the staking used on the shroud to hold the barrel/abutment seal in place. Not always, but often enough these dimples cause a loss of pressure when the gun's shot. So if you see the piston has become distorted on its edge it's good policy to replace it. If you have access to a chronograph, it will tell you the condition of the seals fairly well but it's not always the seals that cause a lower MV- the spring can also become distorted and if it has enough distortion to it, it can rub on the plunger tube which robs power. The newer guns seem less prone to this but the '60s guns were bad about it. A gun left cocked for extended length of time can distort regardless of the era it was made. Bottom line is the spring should fall off the plunger tube by its own weight. If it doesn't, it's distorted. Maybe not much but it's on its way out IMHO. Good idea to be proactive and replace it at the first sign it's going south than to wait until later. It'll save you taking it apart again, too.
