In praise of the old leather seal

[eyebull]

I must confess to a soft spot for the phosphor-bronze piston rings in some webley and FWB guns. They feel 'future-proofed' to me.

[45flint]

I must confess to a soft spot for the phosphor-bronze piston rings in some webley and FWB guns. They feel 'future-proofed' to me.

Yikes! I forgot, my old Webley pistols are those piston rings!

[Hsing-ee]

I like them but when manufacturers ditched leather and 'O' rings and took up nylon parachute seals like the Feinwerkbau Sport had been wearing since the early 70s power went up 25% and the running-in time dropped to a tin of pellets instead of 20,000.....

[45flint]

I like them but when manufacturers ditched leather and 'O' rings and took up nylon parachute seals like the Feinwerkbau Sport had been wearing since the early 70s power went up 25% and the running-in time dropped to a tin of pellets instead of 20,000.....

What is the life expectancy of the Nylon? Will it deteriorate with age?

[Hsing-ee]

What is the life expectancy of the Nylon? Will it deteriorate with age?

I think if you are careful with fitting them and don't go too mad on the sizing they will last for several years. The Feinwerkbau Sport ones will definitely turn into cheese after 10 years. So, no, they are definitely not as durable or forgiving as leather but they are far more efficient and they are not much money to replace when the time comes. A leather seal can be forced past razor-sharp edges, endure heavy dieselling, seal an out-of-round cylinder and last for decades on no lube (provided the seal has been well lubed at the beginning of its life) and can be replaced with a substitute cut from an old belt, so they have advantages. If they go hard and dry they can also be refurbished with a roughing up with a file and a soak in oil overnight. The smell of a leather-washered springer that is 'on song' and combusting oil at the right rate is delicious!

[bill57]

I converted my Webley Vulcan to a leather seal over thirty years ago; it's still on the same one, and is smooth and very consistent. My Ospreys are similarly converted.
As Hsing-ee says, leather is very tolerant of cylinder wall irregularity, but they need to be sized to a good fit. Usually a relatively loose fit works best, it should be very easy to push it down the cylinder. Too tight will rob it of power.

[eyebull]

I converted my Webley Vulcan to a leather seal over thirty years ago; it's still on the same one, and is smooth and very consistent. My Ospreys are similarly converted.
As Hsing-ee says, leather is very tolerant of cylinder wall irregularity, but they need to be sized to a good fit. Usually a relatively loose fit works best, it should be very easy to push it down the cylinder. Too tight will rob it of power.

This is intriguing. I'd be curious to know if other modern springers could be converted to leather, and how it would affect their real-world performance.

[45flint]

This is intriguing. I'd be curious to know if other modern springers could be converted to leather, and how it would affect their real-world performance.

It’s been interesting for me going back in time with my vintage airgun purchases. I’ve been fortunate to buy some old but virtually new guns. It’s like a time machine seeing what it was like to airgun in 1959? Yesterday it was finally warm enough to take out my BSA Airsporter MK2. The lubricated leather seal gave me 575 fps with a 14.5 grain pellet for 10.5 FP. Did some close target shots, so nice. Yes we have “progressed” to more powerful rifles but I could care less? Do I really need more power? What is amazing to me is that with this technology and craftsmanship a Airgun made it 55 years with no degradation. My Beeman R1 couldn’t make it 15 years without losted performance.