I,ll try to keep this as short as possible.Theres been alot of talk about getting the breech seal on the 460 to seal up.Heres how I fixed mine.First off the seal on a 460 is alot like the one on a 48,52,54 rifle in the fact that its a formed seal not a o-ring like the break barrels.


I never measured the thickness of mine before I added the shim two weeks ago but I believe it was thicker then.Okay,to remove your breech seal cock your 460 and slowly release the cocking handle and close the chamber about half way so you can see down into the piston face.I would suggest having someone hold the rifle and the cocking arm because you should never trust a mechanical devise!With a flashlight you should be able to look down into the breech and see the blue seal.If you take a small wire with a hooked end(I used a ice pick)you should be able to go through the center of the seal and put enough side pressure on it to dislodge it and pull it toward you.If it,s like mine it will come out easily.You can inspect the seal for damage while you have it out.The washers I use I got at Lowes,but I,m sure you can get them at any hardware store.

#8 brass washer fits perfectly into the breech opening and the center hole is only slightly smaller than the breech seal opening.Simply drop one washer into the breech opening and make sure it,s laying flat in the bottom of the breech.Place your breech seal back in the chamber and press it back into the breech.Close the action on the rifle which will compress every thing together.You should notice a different feel when you close the chamber,like its actually closing against something now.With one shim mine went from 750fps to 860fps.I hope this helps!John

That slighly smaller hole could be contributing to it.

I was searching around yesterday and saw a site with info on springers with actions like the 48 and your's. The fellow's advice was to store the gun unclosed, as the seals, if left compressed for a long time, can take a set. He figured that, for guns that have been left closed for a long time, leaving them open for a few days may let the seal re-expand. Could be why your initial measure was slightly thicker.

Back up the bus.......I'll be your gun didn't arrive opened, did it? How long do they sit closed after leaving the factory, going through inventory, leaving the dealer and arriving home? Guess that blows that bit of urban logic.

Anyway, good post. Quite a boost in performance for such a simple thing.

thanks for the pics and post. I will definately give this a shot as soon as I get my gun back from Paul

Thanks Again

it does make sense a simple breech seal that throws out of WHACK the whole firing cycle

I say, GENIOUS because it is a simple fix

warren

and remember "it's 30% the gun and 70% the shooter"

we overlook the solutions that are right in front of us, if you only would of posted in English the first time Rick

warren

Does the gun fire differently after the installation of the shim I.E. harsher etc?

Also, would there be any negative affects to doing this (long term or short term)?

Thanks

Thanks John
Ray

What is the ID and thickness of the washer.
Thanks Ray

The ID of the washer is 0.168 and the thickness is 0.031.I bored out the one I used because it is just slightly smaller than the ID of the seal.Since some had asked I placed a washer right from the bag and it showed no change,still 865fps with 14.3 CP.I doubt very highly that anyone would need to place two washers in there.I wish there was an aftermarket seal because the factory seal has a small raised rim around the top which seems useless.They should have just made the seal solid to that overall thickness.Thanks guys for the nice comments!

I guess I will be the first to post numbers with this shim and the power Maccari spring added to my 460 .22. I should post this coming week on my numbers.