Hw 57

[SuperSix1]

My HW 57 isn't grouping very well. I can normally get good tight groupings with other air rifles, but the pellets seem to go anywhere within 6 inches of the bull at 25 yards. Should I get the rifle looked at by a gunsmith?

[p.j.]

Did it once group and now doesnt?
With the 57 problems arise from the breech not being in line with barrel. Sometimes dirt gets under breech, or the breech not being pushed down far enough.

[SuperSix1]

Yes, it used group well. It has a bit of an odd history. I bought it of a friend from the gun club we used to go to after something went wrong when he fired it. I can't remember what he did, but I think he may have not pushed the breech down before firing and after that the breech popped up every time he fired.

I can actually pull the breech out completely when it pops up for loading and I'm not sure if you're supposed to be able to do that. I took it to someone who said he fixes air guns, but it's still not right. I would think like you, that the breech should align exactly with the barrel for the pellet to enter the barrel perfectly and produce an accurate shot. I can't be sure that this is the case after what happened or if what happened affected the accuracy or even if it can be put right.

There's a lot of ifs and don't knows there unfortunately.

[robs5230]

Regarding the breech, you need to make sure pellets are well seated. If not, when closing the breech it can shave / damage the skirt of the pellet. This will also do the rear breech seal no good.
The breech block needs to be firmly pressed down and closed correctly too. They can be stiff so best apply some moly grease to the post below the breech block.
The cocking linkage activates the breech block. If the breech is stiff to operate, it may cause the cocking link to gouge the cylinder in front of the cocking slot.

Issues after that are normal HW ones. If the rifle's new, its most likely dieselling. Strip, clean, relube and a delrin kit should sort it. A good deburr also helps .
Trigger needs to be adjusted properly to give you the best chance of consistency.

Assuming everything is in good order, its then down to pellet selection. I found JSB express worked best in my .177 57 with power set around 10.5

If the rifle's in warranty then you may wish to return to a gun shop. Personally I'd rather have someone conversant with tuning HW's sort it. Lots of talent on here.

[SuperSix1]

Hi Robs5230

I've just read all the posts on the Hw57 on the site and it seems to be a 'marmite' gun. Personally, I love mine even if at the moment its not grouping well. The rifle is third hand, so not new, and when bought by the original owner was tuned. 'V' tuned seems to come to mind from what my friend told me, then the second owner (my friend) bought it, fired it with the breech up (I now know this is not uncommon) and sent it for fixing at a local gun shop where they stripped out the tuning parts and replaced them with what my friend laments as inferior parts. After this, it hasn't really been 'right'.

I think I will try your suggestions with the grease and JSB express pellets. I would like to send it for tuning to someone who knows these guns, but I don't know any names or who does this yet.

Also, the first owner had a special walnut thumb hole stock made for the gun and for the wood alone it is worth keeping as its a beautiful stock. Call me a bit sad but sometimes I just get it out to look at it.

Thanks for the advice
Robert

[p.j.]

If the breech comes all the way out the o ring is missing off the breech stem. Are the breech washer good, they can break up and way be snagging the breech stopping it shutting correctly. The breech should be the right way round ie screw like indentations facing away from the shooter.
I know what you mean about marmite when I wrote an article on the 57 I called it HW Cinderella, alluding to the fact that its unpopular, but with a little polish it can be a bit special.

[robs5230]

Hi Robs5230

I've just read all the posts on the Hw57 on the site and it seems to be a 'marmite' gun. Personally, I love mine even if at the moment its not grouping well. The rifle is third hand, so not new, and when bought by the original owner was tuned. 'V' tuned seems to come to mind from what my friend told me, then the second owner (my friend) bought it, fired it with the breech up (I now know this is not uncommon) and sent it for fixing at a local gun shop where they stripped out the tuning parts and replaced them with what my friend laments as inferior parts. After this, it hasn't really been 'right'.

I think I will try your suggestions with the grease and JSB express pellets. I would like to send it for tuning to someone who knows these guns, but I don't know any names or who does this yet.

Also, the first owner had a special walnut thumb hole stock made for the gun and for the wood alone it is worth keeping as its a beautiful stock. Call me a bit sad but sometimes I just get it out to look at it.

Thanks for the advice
Robert

Have a word (send a message) with Shauny on here. He knows his HW springers and will also be able to make a bespoke set of delrin guides to match the spring. Tell him I put you in touch.

[styggron]

Just a thought - ask your friend if the gun was fired with the underlever unlatched i.e. not fully clipped home. It could in such a case have struck the foresight assembly with enough force to bend the (slim) barrel upwards. I bought an HW57 from this forum which an idiot had repeatedly abused in this fashion but it took me a while to work it out. Look for impact marks on the underside of the foresight assembly which correspond to the grooves on the underlever release catch. Also, try holding a good steel rule edge-on on top of the compression tube (take care not to scratch the metalwork) and out over the barrel - look for a slight slope upwards. Stripping the gun and examining the bore for straightness might be a good idea if the foregoing checks give you enough to go on.

[SuperSix1]

The gun wasn't fired with the under lever down and I've checked the barrel and it's straight. I've taken apart the compression chamber assembly and noticed that the spring was bent at one end. (see pictures). I straightened the spring so its as near perfect as I can get. I understand it needs a little grease inside but not too much, so I was thinking of re assembling it and trying the pellets suggested.

The breech washer looks good and so does the barrel one. Everything apart from the O ring looks OK on the pop up breech.

Inside the compression chamber was the spring, a plastic tube with a rim around the end and a large metal tube with a rod in the centre with a hook type arrangement on the end. It doesn't look particularly complicated as there aren't that many moving parts.

Robert

http://tinypic.com/r/21lj045/9

http://tinypic.com/view.php?pic=21lj045&s=9

[maximus]

Hi, I wouldn't put the bent spring back, it will only go again. Also I would be surprised if it was the cause of the poor accuracy. Was it consistent over the chrono? Clean the barrel and try different pellets. Finally, I am intrigued to see a picture of the thumb hole stock, never heard of a custom stock on a 57.

Regards Max

[dayglowfroggy]

Piston seal ! there I said it.
I have had two guns in last six months who whent from very accurate to not so, suddenly.
And the piston seal had small marks in one and the other had a massive knick in it.

If the groups are up and down or could be power of all over the place seal or scope.

[SuperSix1]

Hi Max

There are what looks like 'gouges' on the front of the white piston seal. I don't know what might have caused them or if they would have any effect, but I think its time to renew the seal and spring. It doesn't make sense to put damaged parts back. What I need is to buy the bits and pieces to replace them and find out where to buy them.

dayglowfroggy

I have taken pictures of the thumb hole and piston seal, but I haven't got 'attachments' enabled so I can't attach them to this post.

If there are any moderators reading this, would you mind enabling 'attachments' for me so I can show the other readers my thumb hole stock please?
Alternatively, if anyone can give me the name of a mod or admin, I will contact them directly to request attachments.

Robert

[maximus]

Hi Robert, the pictures you put links to earlier in the thread worked fine so may be you could do the same again? Definitely replace the damaged piston seal and don't over lubricate as this will cause dieseling and result in poor accuracy.

[SuperSix1]

Hi Max

Here are some pictures of my HW57 and one of the piston seal. The gun is nice to have just for looks alone, but it would be the icing on the cake if I could hit something with it.


Robert

[maximus]

That's very nice, a Custom stock of Sheffield CS700. Didn't know they did them for the 57. Could be a very nice custom gun if you could get a muzzle weight cum underlever catch like a 97. Definitely replace the seals and spring and start the accuracy quest from there. If it cures it invest in some fitted guides to quieten things down and it will be a very nice gun indeed.