[Sticky] Tanaka K98 BGS hop set fitted!

For anyone who doesn't have a manual for their Tanaka K98, I've scanned the "exploded view" of the parts. I hope it helps!

I used my freshly upgraded rifle yesterday and today. The temperature was around 30 degrees c! All I can say is that I had people yelling "argh!" at 50m when they were hit, plus, and I kid you not, I got one guy, centre mass at just over 100m, boy was he shocked! Going to have to switch to .43g bb's, as I had to back the hop off all the way with .36's, just to get a level flight, which affected the range.

For the benefit of those whom I've just got BGS sets for, here's a quick "how to" for fitting the hop itself.

Step 1 - First thing to do is to fit the hop rubber to the barrel (which you should already have filed out to the correct shape using the jig provided). It's very important to do this right, ie, make sure that the rubber presses down through the barrel cutout EXACTLY in the centre. If you don't do this, your accuracy will be affected. Also, don't forget to clean the barrel thoroughly to remove any brass filings left in there from filing it out.
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Step 2 - Slide the barrel/hop rubber into the metal housing provided in the kit. Again, it's very important to get this bang on central. It's also VERY important that you are careful when doing this, I've known several people to tear their hop rubber from trying to force it in. A squirt or smear of silicone lube should help. On the photo, the hole through which you can see the hop rubber is where the nubbin pushes down an applies the hop to the bb. Push the barrel and hop assembly in as far as it will go and confirm you have it all lined up by using a matchstick or similar down the hole to make sure the nubbin is lined up correctly.-- attachment is not available --

Step 3 - Slide the brass collar down the barrel (or you could have pre-fitted it) and into the hop housing, with the cutout lining up with the cutout in the hop housing itself. (Note, on the photo, I have removed the barrel for clarity).
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Step 4 - Use one of the very small grub screws provided to fix it all in place. Again, it's worth a final check at this point to make sure everything is lined up correctly).
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That's it, your hop is assembled and ready to fit. You should be left with 2 parts. One is a long rubber cylinder, which is your new replacement for part 62, and the other is a small grub screw which replaces part 67 when you fit it all back together.
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Put the gun back together and away you go! Again, be very careful to fit the assembled hop unit dead centre into the plastic housing (part 65) before tightening it all up. You'll need to put a few hundred rounds through the hop to bed it in properly (I put 1000 through mine). You'll notice that your bolt is a bit stiffer to work for a while, due to the increased nozzle length and the better airseal in the hop itself. You'll soon get used to this.

I hope you find this useful. P.S - You're not allowed to shoot at me with a BGS equipped K98/G33!

Thread tidied and stickied.

Pete, did you have to cut down your replacement rubber cylinder? - mine is about 15mm in length which seems way too long the (old one is 6mm).

I'm not sure what you're referring to. I didn't have to cut anything on mine. The replacement rubber goes all the way into the housing. If you mean the cylindrical bit of rubber, I actually used the original one, not the BGS one but yes, I suppose you could cut it down if it were too big (you'd have to make a precise cut though, to ensure it puts an even pressure on the hop rubber).

Is there a knack to getting the old nozzle out as I can't shift the bugger?

Is there a knack to getting the old nozzle out as I can't shift the bugger?

You're just not pulling it hard enough Rich.

Thats the first time I've been told that but indeed I wasn't. All sorted now, cheers Pete. You weren't joking about the bolt being stiffer, it is going to take some getting used to. I'll see what it runs like in the morning and get some rounds through. I hope to give it a proper test this weekend.

Limited success so far...

The "small grub screw which replaces part 67" is a mystery to me - I see it on the diagram but I can't find the location on the real thing.

look at the underside of the hop unit housing, it's screwed in the hole on the bottom.

Is that the molded plastic thingummy?

Why does this require a replacement?

Thanks John. I managed to fit it all together in the end. Now I just need to find somewhere with enough space to test it.

The fire 1000 rounds through - to bed it in, take a while but needs to be done

I've had a couple of requests for more of these, so, does anyone else want one? It's only worth it to order 5 at a time, so if you do want one, please pm me. Don't forget I can also get spare hop rubbers as well.

Already PMd have you got them yet just shout when you need the money butty

The fire 1000 rounds through - to bed it in, take a while but needs to be done

Blimey, you're not kidding are you... I've spent hours putting rounds through mine this weekend and I'm still only up to about 600.

Another thing to point out is that the BGS gas nozzle thingummy that sits in the bolt (technical term) is a lot longer that the stock part it replaces. It looks like it would get damaged if you changed mags with the bolt closed.

You shouldn't change mags with the bolt closed, no matter whether it's a BGS hop or a standard hop. It IS a pain to bed the hop in properly but it's most definitely worth it (although if you've only got 1 or 2 mag's it may take you a while! ).