LUBRICATION QUESTION = 300S

[yellow boy]

I am about to reassemble my 300s with a new Maccarri spring.  I have Maccarri's grease but I am not sure of the proper application.  Any suggestions?
Sky

[chuckinohio]

  The 300S is designed to run with very light lubrication. Some say that the piston is supposed to run dry, no lube whatsoever.

  I personally used Ultimox and applied it very lightly to the metal compression ring on the piston body, inserted it into the compression cylinder, and that was it for lube on the piston.

  Assuming that you are using the clear grease from ARH, I would apply a very very light coat of it in the same fashion and reassemble.
  You can use it sparingly on the OD of the compression tube to ease its travel in the receiver.

  The rest of the rifle should be lubed with a sparing application of light oil at most, with the exception of the cocking arm pivot, you can lube that with some grease to ease the cocking arm in its travel.

[yellow boy]

Thanks for the quick come back.  Sounds pretty straight forward.  I am waiting for a new compression ring to replace a broken one and then I'll be ready to go.
sky

[chuckinohio]

  Right on, the ring is supposed to be replaced at a certain pellet count, but I can not remember the exact number off of the top of my head. It is in the thousands though, like 5K or better if I remember right. The new ring should last you a good bit.
  There is a measurement to determine if it is in spec or not, and is used as a GO/NO GO guide.

  Remember to err on the side of too little when it comes to lube on the piston and compression ring, and you will be fine.

  The reasoning for very light lube, or basically running it dry on the rest of the rifle is due to the tight tolerances that they were manufactured to. The lube attracts dust and grit, and thr trigger will feel hideous instead of marvelous.

  Look in the member registry and pop off a message to MDriskill here on the forum. He has forgotten more about the FWB 300 and 300S than I will ever learn. He may have some insight or advice beyond what little I have come up with.

[yellow boy]

The finished product with a new Maccarri  spring, seals and compression ring.  JSB's 7.3 - 660fps  /8.4 - 620fps.  Almost a 100fps increase.
sky

[grauhanen]

Your velocity of 620 fps with JSB 8.4 grain pellets sounds very respectable.  Many FWB 300S bores favor smaller head size pellets in the Exacts, such as 4.50 or 4.51mm.

[chuckinohio]

 Cool deal, sounds like 'Mission Accomplished'!!

  You probably wound up with the sharp snappy shot cycle as well eh? I was pretty impressed with the one that I kitted with a Maccarri spring during it's resurrection.
  My kitted up Match L model prefers the 7.8 JSB pellets, and it figures, as they are more expensive than the other popular JSB pellets............