A year ago I bought a new HW50s in .177 and love it. However, it does have a twang which hasn't gone away in ~4,000-5,000 shots. I'm going to order a tuning kit from ARH, and I'm wondering if I need to replace the piston seal. I installed a Vortek kit in a used RWS 350 Magnum I have, and did replace the seal in that gun, but I bought this gun new. It has never dieseled or been dry-fired, this I know for sure. I'm thinking the factory seal is as good or better than an aftermarlet seal (which might also require sizing). Is there a known reason I should replace the original seal?
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HW/Weihrauch Tuning kit w/o seal replacement?
- Thread starter mozeely
- Start date
I'd get one, or maybe two. There's a good chance the OEM seal is fine...but ya just never know for sure. They are cheap relative to the kit, and you might as well be prepared to fix whatever you find In there.
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Being there is a VERY high likelihood the factory seal is already compromised due to factory assembly into the air tube that they do not deburr 
Yes get a seal as well. DEBURR air tube before installing & checking fit
Yes get a seal as well. DEBURR air tube before installing & checking fit
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I have a question about the Vortek seal... I get that they don't need sizing because they 'wear in' to the proper fit. But do they continue to wear after that to eventually become too loose?
I know, I'm over thinking again.
I know, I'm over thinking again.
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I put an ARH kit in a HW95 and HW50, I reused the OEM seal on both. Neither gun had more than a few pellets through them so the seals were new. I inspected them when I took them apart and I saw no seal damage. I do have vortek seals on hand to put in them when needed. So my opinion is you don't necessarily need to replace the seals if the OEM seals aren't damaged, again mine were basically new. At 4-5 thousand through it I would put a Vortek seal in it, they aren't that expensive and you are probably on borrowed time with your original.
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The Vortek seals don't wear in to their size. The material more or less thermally conforms to the bore size with use. They fit very tight initially and loosen up in a couple hundred shots. I've gotten as may as 10k rounds through the Vortek seals. They are far more durable than the OE and make more power.
I second what Motorhead said. Most of the factory seals I've found had installation slices from the sharp edges of the cocking slot. Deburring the comp tube is very important to ensure the new seal isn't damaged. Recently the factory seals often burn up from excess assembly lube.
You may not need a new seal but they're worthy having on hand. I keep several on hand.
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Respectfully, no.Being there is a VERY high likelihood the factory seal is already compromised due to factory assembly into the air tube that they do not deburr
Yes get a seal as well. DEBURR air tube before installing & checking fit
Deburr the air tube BEFORE you remove the piston if there is a chance you are going to reuse the seal.
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