Beeman RX2 (HW 90) Questions

[peterdulux]

Just picked up a RX2 in .20 and it has quite a bit of barrel droop. So much so that two scopes couldn't site in. It may of may not be bent. Can I get some advice on what to do?

Also, where can I get a valve so I can increase the pressure in the gas strut? Anyone in north America have these?

[Petey]

https://www.pyramydair.com/product/sports-match-1-rings-high-adjustable-9-5-11mm-dovetail?a=3510

https://www.pyramydair.com/product/bkl-1-pc-adjustable-scope-mount-1-rings-3-8-dovetail-black?a=4134

[Nikoman]

Is it shooting slow?
Just wondering why you would want to increase the gas pressure.

[peterdulux]

I just got the rifle and don't know what it's shooting at. I want the valve to have the ability to adjust, if required:)

[peterdulux]

It seems as though there is a bit of movement in the lock up. So, when the barrel is closed, lock up should be solid, locked and take some force to crack the barrel.

On mine, with the barrel closed, I can push the barrel, with a little effort, then it seems to hit a lock point.

If this is happening, gun loaded, barrel locked to closed position, then fire, will the barrel move to the position it moved to with a little force as I described earlier? Could this be happening causing a low POI?

If so, who can walk me trough the sets to figure it out and fix it?

[Nikoman]

Sure sounds like a lockup issue to me but I can't tell without seeing it. As far as a pump goes, there's a GTA member (tjk, Thomas) who uses the pump regularly on his RX-1. He drops the ram pressure down to 14fpe to turn the gun into a real smoothie. He obviously uses the pump to get it back up to full pressure. That's the beauty of the Theoben rams, you can go up and down in power. You have to be really careful not to over-pressurize the ram, the seal can get cooked with too much power. I would like to try and drop mine down to 14fpe but the gun shoots so smooth as it is at 20fpe.
If yours is shooting in the 18-20fpe range, I'd leave it alone unless you love to tinker with stuff
As far as that barrel lockup/droop goes, it doesn't seem right to me. Can you post a video or something? Some way to show us here would help so more people would chime in to help you out.

[peterdulux]

I see by your inventory, you have a couple Beemans. I have just pulled off the barrel and degreased everything. Looks like to pivot bolt has some wear on one end. The breach block has shims. One if slightly frayed.
Trying to put it back together degreases and without the shims, seems like a no go. When I put the barrel into the action, it appears that the barrel has to be pointed down slightly to align the holes. Then, trying to put the bolt in, well it just won't go.

Is it possible that the barrel is not a match for this gun? The barrel has a Theoben stamp.

[Nikoman]

The barrel is the right one, all the rammed HW's have the Theoben stamp to identify the powerplant. So you're good to go there, it sounds like the barrel needs to be reset or something. Is the barrel loose in the breech block? I had to have my Webley's barrel reset recently because it was moving, it was definitely affecting accuracy.
The HW's have shims at the breech block so you'll need to put those back, I remember seeing them on my R7 when the barrel was off.

[peterdulux]

No, barrel is not loose in breech block. It looks like the holes don't line up when the breech block is inserted into the action, and thats without the shims. How much play should there be between the action and breech block? Not that I have calipers or anything, but there is movement for sure.

[Nikoman]

Not sure about how much play there should be but mine is VERY snug without absolutely no movement whatsoever. In fact, when the gun is cocked the barrel doesn't drop when I let go but that's easily adjusted to your liking by loosening the bolt.
Is the screw stripped?

[peterdulux]

Ok, cleaned and got the barrel back in, silly me, tried to get in in straight instead of cocked position. Curve.
It does lock up and locks up good. But, back together and out of the stock, it's clear as day I have barrel droop or bent barrel.

My screw is not stripped. I haven't put the shims in either.

[Nikoman]

Barrel might be bent but you should be able to bend it back to normal.
How's it look when align your eye down the barrel? Does it have the slightest curve to it? Maybe you can lay it across a flat surface to confirm.

[jdub]

If anything taking those shims out will *add* slop.  All the current HW barrels have those designed in to prevent galling of the breech block and if properly lubed (a touch of moly on both sides) they'll add to the smoothness of cocking.  Regardless of anything else you figure out I'd put the shims back. 

You my try smoothing the insides of the fork (where they ride against the shims) with an extra fine stone just to remove any obvious roughness.  My HW30 had a burr in the pivot hole that had caught on one of the shims and torn it.  I removed the burr and ordered new shims.

[peterdulux]

How do you remove the cocking arm from the breech block? Does the pin punch out?

[jdub]

How do you remove the cocking arm from the breech block? Does the pin punch out?

I understand they're a press fit but I've never removed the arm itself.  When working on my HW's I leave the cocking lever attached to the breech/barrel and separate it from the tube at the opposite end--where the shoe goes into the cocking lever slot.  You'll need to decompress the spring first in most cases.

[peterdulux]

Yup, punches out, one way only. Nice, now I can get my barrel checked without the cocking leaver sloping around.
http://www.airgunforum.co.uk/HW90strip.html

[tjk]

For starters, put the shim washers back into place on both sides of the breech block. They are put there for a reason. They should be lubricated on both sides before installing. Seems to be some  component terminology confusion here. These shim washers are important in keeping the breech block tensioned properly and horizontally aligned. They have nothing to do with barrel droop as far as I can tell.  The shims that can cause break barrel 'droop' are shims that can be or are placed under the breech seal at some point in time. You shouldn't  need to remove the cocking linkage from the breech block to check for droop either. Dont see the logic in that. A straight edge goes along way in diagnosing alignment problems if they are in fact the cause of your rifles low poi's. If your rifle is a newer model. Place the straight edge on top of the breech block extending over the barrel. Visually check the spacing of the barrel from the breech block out to the end of the barrel. You can also check the barrel assembly's orientation to the rifles action by placing the straight edge atop the breech block with the straight edge extending over the compression tube. Check this spacing the same way you did the barrel. Hth's.