I found an old .177 B1 in the back of a closet we cleaned out, I had bought it and another (Don't know what happened to the other) for my kids when they were 13- 14 or so for $15 each at a gun show. It is the only springer I have ever had any experience with, and was probably 30 yrs old or so. I put about about 50 or so pellets through it after cleaning the bore, and it seemed to shoot pretty good. It had a tight breech (not seal, there was a bit of lead flashing that looked like thin aluminum foil in the breech after a few shots) and a good barrel, so I undertook a rebuild as per Mr. B.B.'s excellent writeup of a B1 rebuild. I broke it down, cleaned all parts with brake cleaner, and ordered a 25 mm piston seal conversion to replace the deteriorating leather seal, moly gun grease and heavy tar from Vortek. The piston seal was too loose, so they kindly swapped it for a 26 mm seal kit, which fit perfectly. I found a couple of grade 8 washers at Lowes that were about the right size, ground and filed them to fit the piston and spring guide, and polished them to a mirror finish. Also polished the ends of the spring to a mirror finish and fitted the polished washers inside the piston and on the spring guide. Deburred all the internals, honed the compression tube, fitted an aluminum shim from a 20 oz Red Bull can (don't know how anybody could survive 20 oz of that) in the piston so the spring was tight, it must have taken 3 wraps of the aluminum can to fill the gap betweeen the spring and piston. Fitted a new breech seal using a 1/4" faucet washer, and put the whole thing back together using a thin layer of the moly in the compression chamber and at each end of the spring where they bore against the polished washers, and on the trigger. Also slathered the heavy tar on the spring. WOW! I was AMAZED at the difference! I had not realized it, but the B1 rang and vibrated like a bell before the rebuild, and was smooth as silk after! After adjisting the front sight (dovetail) I can reliably hit a 12 oz soup can at a measured 33 yards with open sights. It has a smooth receiver, so can't mount a scope. It is shooting a bit faster than my 880 Crosman at 10 pumps, (don't have a chrony) so guessing at around 600 fps, maybe a tad faster. It likes Benjamin 7.4 grain pellets. This has led me to get back into shooting, so I have ordered a .22 Benjamin Prowler and am rebuilding my old Crosman 1377. I plan on taking the Prowler apart before shooting it and doing the deburring, honing and moly thing with it. Also cleaned up my old cap and ball Remington 1858 (manufactured in 1977), modded it a bit and will be headed to a range after I find some sheep tallow and beeswax.