FWB300 Dovetail Size?

[brent375hh]

I have had a Beeman/FWB300 that came with a Beeman/Williams rear sight. I thought I could swap my Anschutz rear sight and it did not fit. Next I tried a "Chinese clone" FWB rear sight, no fit again.

On the top section of my Anschutz and Weihrauch "11mm" dovetail, the measure .410, the FWB measures .455. Are there any experts out there that can tell me if there are two different sizes of FWB dovetails, or if they are all a special  "11.5mm" size?

Secondly, does anybody know of a quality rear sight that is readily available that fits on these?

[Yogi]

The Williams Airgun sight uses two small allen screws,0.50 allen key, to set the dovetail width.  When backed all the way out, I can not image it not being wide enough.

-Y

[brent375hh]

The Williams Airgun sight uses two small allen screws,0.50 allen key, to set the dovetail width.  When backed all the way out, I can not image it not being wide enough.

-Y

The Williams fits fine, its the Anschutz and FWB clone that does not fit.

[dtdtdtdt]

An expensive but the best solution would be to hunt down a FWB300 sight set on eBay or Amazon. 

If you have access or skills to do so, milling the SIGHT dovetail to fit would be a second solution.  TRY IT ON THE CHINESE CLONE!!!  Don't mess with the Anschutz one!!!

[brent375hh]

Can anybody out there confirm that their 300 has a wider dovetail than "standard" 11mm? I will look for an original sight, but don't want to find out it won't fit either.

Thanks.

[dtdtdtdt]

Just to make it more complicated for you.  There are two dovetails in question. 

Dovetail 1, measures 11.01mm and is on the permanently mounted rail on the receiver
 
Dovetail 2, measures 11.3mm and is on a clamp-on-rail that clamps to dovetail 1.  It is about 1cm high and has the grooves used to elevate and position the mechanical sights at eye level.  My scope is mounted on an aftermarket clamp-on rail that attaches to Dovetail 1. 

I don't have time to photograph these for you right now but will try to do so this evening.

[dtdtdtdt]

Just to make it more complicated for you.  There are two dovetails in question. 

Dovetail 1, measures 11.01mm and is on the permanently mounted rail on the receiver
 
Dovetail 2, measures 11.3mm and is on a clamp-on-rail that clamps to dovetail 1.  It is about 1cm high and has the grooves used to elevate and position the mechanical sights at eye level.  My scope is mounted on an aftermarket clamp-on rail that attaches to Dovetail 1. 

I don't have time to photograph these for you right now but will try to do so this evening.

[brent375hh]

Thanks Dave.

Now I am getting a glimpse of my problem. I was totally unaware that there was an intermediate dovetail involved. I only have the one that is machined into the top of the tube, and nothing I have for RWS, Anschutz or Weihrauch will slide on. Perhaps there are many variations. For all I know Beeman specified a unique size to sell more adapters!

I just checked web images. Some of them have an intermediate adapter, and some look like the sight is clamped directly onto the rear of the receiver tube.

[dtdtdtdt]

Mine is is the universal SU model that has an adjustable checkpiece for offhand shooting.  It apparently requires the intermediate rail. 

I haven't looked at many 300s on-line or in the flesh except mine.  The permanently mounted rail with the small dovetail will work with US 3/8" clamp on scope mounts.  I had one that way for a while.  I got a somewhat bigger scope and went to an intermediate rail not made by FWB  piece works with US Weaver-style bases too. I like to have the scope as close to the bore as possible to reduce parallax concerns. 

I rarely use the iron sights but have the complete set including 2 different front sights.  The guy I bought it from was on the UK National Air Rifle team for a time and used it there. 

If you now understand the arrangement, I won't do the pictures unless you really need them.  I'm off to see the eclipse this weekend so am a bit short on diddling time. 

Looking at Google pictures, I saw many sights attached directly to the first dovetail.  These are the 300S models rather than the SU.  I saw one set up in which the guy had TWO intermediate rails and a very high positioning of his scope. 

I googled FWB 300 sight images and found quite a few that might help clear things up for you. 

I ran across a picture with three different rear sights for the FWB.  One looks like it is intended to attach straight the first dovetail (11mm) It's beam  that attaches to the rail is flat with no "slit" down the center.  The second one is just like mine with a cross screw and a slit down the center that flexes in to hold everything tight.  The third sight - picture bad - I think is called a diopter sight and appears to attach to the first dovetail. 

[brent375hh]

Thanks Dave. I wish you clear skies.

[Jason_Garvin]

I have had a Beeman/FWB300 that came with a Beeman/Williams rear sight. I thought I could swap my Anschutz rear sight and it did not fit. Next I tried a "Chinese clone" FWB rear sight, no fit again.

On the top section of my Anschutz and Weihrauch "11mm" dovetail, the measure .410, the FWB measures .455. Are there any experts out there that can tell me if there are two different sizes of FWB dovetails, or if they are all a special  "11.5mm" size?

Secondly, does anybody know of a quality rear sight that is readily available that fits on these?

If I recall correctly on all the ones I measured in the past, they run fat as 11.5 to 11.8mm on mine.

Jason G

[scrane]

The 300 will come with a second dovetail only as a riser block or an adapter. The 300s came standard with the grooved receiver and rear sight. There's a guy who sells diopter sights from Bulgaria on EveryBody's favorite Auction site who may be able to help.

[scrane]

If I recall correctly on all the ones I measured in the past, they run fat as 11.5 to 11.8mm on mine.

Jason G

I believe this is correct!

[brent375hh]

I saw the Bulgarian ones. They look a little rough. I am generally leery of adds that say " last one" but there are a dozen listings.

[dtdtdtdt]

I would keep an eye out for US Domestic.  No eastern bloc purchases.  There a city an Bulgaria that makes its living running scams on US purchasers.  There was a program on TV sometime ago about the town full of high end cars with no industry or businesses to speak of.

[dtdtdtdt]

Any luck finding the iron sights for the FWB300.  I occasionally look to see what's for sale.  I haven't seen much. 

The gotcha is that they generally don't come as sets of front and rear sights.  So you have two quests not one.

While puttering, I found reference to an AIRFORCE Adaptive Diopter Sight Set that includes adjustable front and rear sights.  It claims on the AirForce website to fit many different rifles.  Current new price at the factory is about $185.  If it works as advertised it might be a good alternative. 

Worth a call to the factory to ask.....




Dave

[brent375hh]

Thanks for looking. I have just kept an eye out for an original rear sight to show up on the bay.  My front sight is the one that looks to be riveted on.

[dtdtdtdt]

The front sight on mine has another dovetail clamping system. I got two front sights with it. Lower one for prone maybe higher for other positions.  Since I scoped it I don't use the sights although I tried them out a few times.

Good luck!

[Hoosier Daddy]

The FWB rear sights do come up for sale on "target talk" from time to time... But DANG they get top dollar.

[MDriskill]

Can anybody out there confirm that their 300 has a wider dovetail than "standard" 11mm? I will look for an original sight, but don't want to find out it won't fit either.

Thanks.

YES, the FWB 150/300/300S series definitely has a wider dovetail, about 11 1/2 mm. Anschutz, Diana, and Weihrauch sights will not work.  IMHO, FWB has some of the best quality control on the planet--rest assured, they do not send out guns with rogue-sized dovetails.  Buy one of their sights and it will fit.

The "intermediate" dovetail discussed above is not a standard fitting, it is used on the Universal and Running Boar variants of the 300S to give a higher sight line. The vast majority of 300's just mount the sight directly on the receiver rail.

Walther uses a similar dovetail dimension, and SOME, but not all, of their sights will fit FWB's--that's another long post in itself. But it's better to just find a proper FWB diopter rear sight. They are fairly common and not that pricey--keep an eye out on EBay, Airgun classified sites, gun auctions sites, etc.

I've seen a lot of ads on EBay etc.--some from well-known sellers who should know better--claiming other brands of sight fit FWB. I am amazed they don't get called on that more often!