FWB 124 specs

FWB 124 specs

Joined: March 26th, 2012, 3:22 pm

July 12th, 2017, 1:22 pm #1

Looking for a few specs on the FWB 124. Anyone know the piston diameter, piston weight, piston stroke?

Thanks!

M.
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Joined: May 20th, 2013, 12:46 am

July 12th, 2017, 6:06 pm #2

Are you just doing some research, or are you considering purchasing an FWB 124/ or you already have one?

You can make your FWB 124 a much nicer rifle with the addition of the ARH spring/seal kit, AND the right lubes. By installing the ARH spring and seal kit the velocity goes up, while the vibration upon firing noticeably decreases. That's a win-win. The cocking effort slightly increases compared to the factory set-up but barely enough to notice. After you've shot 100 rounds you won't even notice the difference anymore, unless the only springers you are willing to cock are an R7/HW30 or a CZ630.

(BTW, my memory says the OD of the piston seal once installed in the compression chamber of the FWB 124 is VERY close to 1.100" (plus or minus a few thou), but my memory may be playing tricks on me because it's been a while since I tuned one).

Here's the ARH spring and seal kit I mentioned:

http://www.airrifleheadquarters.com/cat ... 265467.htm


For the best results you'll want to get some moly paste and spring tar if you don't have some already. Easily done! ARH also sells a lube package that includes both of those (and another useful lube ) for $24. It's here:

http://www.airrifleheadquarters.com/cat ... 169286.htm


Like I said, if you're only doing research and don't need any parts or lubes for the rifle maybe the links will be useful to someone else.


Last edited by ekmeister1 on July 12th, 2017, 9:30 pm, edited 1 time in total.
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Joined: January 24th, 2009, 5:47 pm

July 13th, 2017, 2:29 am #3

Looking for a few specs on the FWB 124. Anyone know the piston diameter, piston weight, piston stroke?

Thanks!

M.
I haven't had mine apart for awhile, so I hope someone else chimes in too. What I have in my notes; 28mm piston diameter. 310 grams piston weight. Transfer port is 3mm X 10mm long. Stock spring .118"

I don't remember carefully measuring stoke, but I have seen it listed as 77mm. Seems short to me. A bit mad at myself for not having a good measure in my notes, but gun well buttoned up with Macarri kit inside and loctite, so I don't want to take stock off.
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Joined: May 20th, 2013, 12:46 am

July 13th, 2017, 6:06 pm #4

Other air rifles with the same seal diameter produce more velocity with even a slightly longer stroke. The R9/R10/HW95 and the Beeman Kodiak/Webley Patriot all owe their high performance to a high diameter-to-stroke compression chamber ratio. Still, when you add a Maccari kit to the FWB 124 the performance is noticeably increased--it adds a nice amount of knockdown power and more yardage to its effective range.

For those who have yet to add an ARH piston seal: The fit of the piston seal will probably seem a bit on the tight side when you first install it compared to some other rifles, but if you retest the velocity in a couple of days you'll see an increase because the seal will have fit itself to the ID of the chamber. The circular valley in the face of the seal is a little wider than on some other seal designs so it takes a little time for it to reduce to the ideal size. It's not a defect--the OEM seal was/is the same way.

Sometimes it pays to turn down the ARH piston seal a few thou if the fit is VERY tight in the chamber when you try to install it. As with some other models out there, even though FWB was a high quality manufacturer, the ID of the chamber in their air rifles can vary from one specimen to the next. However, if in doubt it's better to leave the seal a little too-tight than too-loose. Like I said, it will adjust itself after a little shooting, or even after a week or so of sitting undisturbed in the closet. If you're going to adjust the OD of a piston seal, always leave the leading edge of the piston seal a little larger than the trailing edge to guarantee an airtight seal in the chamber.
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Joined: March 26th, 2012, 3:22 pm

July 13th, 2017, 8:51 pm #5

I haven't had mine apart for awhile, so I hope someone else chimes in too. What I have in my notes; 28mm piston diameter. 310 grams piston weight. Transfer port is 3mm X 10mm long. Stock spring .118"

I don't remember carefully measuring stoke, but I have seen it listed as 77mm. Seems short to me. A bit mad at myself for not having a good measure in my notes, but gun well buttoned up with Macarri kit inside and loctite, so I don't want to take stock off.
Thanks Steve!! That's what I was looking for. NT
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