46m sparks on firing... twice noticed now

[Gerard]

I've been shooting my 46m since mid-April, and it apparently had only about a couple of tins of pellets through it by the original owner, so probably around 6,000 pellets so far. I've been putting a drop of Crosman oil into the cylinder every in or slightly more often depending on how dry the piston head looks through the opening on the bottom while cocking. A drop into the transfer port as well, almost as often. Frankly I might be over-oiling, though I wipe off some excess from around the breach seals during the next ten shots or so when also cleaning the barrel with cotton patches. There's always a bit of oil showing around the whole trigger assembly area and transfer port, which I figure is okay...

Anyway, to my point, the other day while practising I was quite surprised to see a spray of very fine almost-white sparks flying up and to the left from somewhere just above my trigger finger on firing. I fired a couple more times paying special attention to this area but saw nothing further... then later in the session, just once, I again saw sparks exactly the same. So I carefully oiled here and there, cleaned again, and haven't seen any sparks since. This is somewhat alarming as really there shouldn't be any metal-on-metal impacts, right?

I tore down the cocking lever and removed the piston last night just to get started overhauling and to get to know the guts. Cleaned out a bit of 'fish grease' or whatever was stuck in the bottom of the cylinder, so now it's just a bit of Crosman Pellgun oil. Reassembled it and everything seems working fine up there.

If it's any help in answering, I've been finding the by now familiar problem of the breech block not staying up on cocking the lever all the way forward just for the past 1,000 shots or so. Figured that might be because of my trigger adjustments a few weeks ago, perhaps the sear engagement not quite sufficient as suggested in a 2003 thread here on TT. But I've played with that adjustment a bit this week and it still dropped down about half the time. So instead of worrying about this distracting inconsistency, last evening I removed the stamped metal bar which auto-cocks the trigger by tossing up the breech block. One less noise while loading anyway, so I won't miss that function. As I also filed and polished the sharp edges around the transfer block it's easy enough to raise that manually before cocking. Just a new part of the ritual, easily adapted to by the time I'd shot 20 shots this evening. Thinking of adding a small brass knob on the left maybe to make this even easier.

Anyway, the gun functions wonderfully well besides this stuff. Removal of the barrel clamp and my nicely fitted maple grip with rake adjustment bolt make it oh so natural in my hand. It could be my imagination, but it does seem the gun is louder now than when I bought it. Could it be that an O-ring in the valve has worn down or broken? If so, would anyone be able to offer an O-ring size I should be shopping for? There's a great O-ring shop just about a mile from the range I'm joining, and I'm sure they'll have 90 durometer (if I recall right that's what's wanted, correct?) rings of any size for me provided I can name the dimensions needed. Thanks in advance, and sorry for the long ramble. I seem to have lost my built-in editor somewhere along the way.

[philip_T]

Just an amateurs opinion Gerard. You probably have more on the
ball than this old duffer. Could the "spark" actually be oil spray in the light/sunlight?
I use mac-1 oil on all pivot points , two drops in the cylinder each
500 shots, and one drop in the transfer port each 500 shots.
I stand the gun up overnight to ensure distribution.
Mac also has a rebuild kit with the good O rings and "secret sauce oil".
HTH - Phil

[Gerard]

Thanks, someone else here has sent me a private message suggesting the Mac seal kit as well so I will order one and install it.

I doubt it's sprayed oil. No bright light nor significant changes in light around those particular shots, and as someone who's done a lot of grinding of metal in my time, I kind of recognize sparks. Good suggestion, I just really don't think so.

[plinkster]

I've noticed tiny flecks of pellet "dust" on the loading port area of my fwb103. I wonder if what you saw was pellet "dust"? Perhaps the crown has a bur and it shreds a small piece of pellet..Or the rifling is so caked flecks come out ocassionally?

[Gerard]

That's a good thought. But the way it looked so bright, the direction it came from down by the trigger, and the way I keep my Izzy clean make me doubt it. And no, no sharpness nor burr around the pellet skirt. The rifling on mine is very sharply defined but I clean that regularly with cloth patches after oiling.