Model 6M has arrived.... And its actually a Hyscore (plus pics) + an unexpected bonus

[nige346]

Hi all, just aquired 6g and 10m pistols. These are my first pistols apart from a hw45 i had years ago. Do they both have the same power output ? From memory the hw was very accurate and powerful, but the dianas seem very under powered by comparison. For example at 6m i am aiming way above the target just to hit it. The pellet visibly dives after it leaves the barrel. I am assuming they will need re sealing. Is it likely the springs are u/s or more likely the seals. read the previous on resealing but am a little concerned with the washers at the end of the cylinders. Is it pointless using the old ones in a reseal . I have no way of measuring their thickness accurately, and would not be able to make or refinish them. Both guns are in great condition and from all the searching, everyone says they are accurate and great to shoot so i am willing to get them as they should be.

The 6g and 10m pistols are designed for 10mtr target shooting so would probably be less that the HW45, That said you should not be able to see the pellet and they should shoot spot on target at 10 mtrs, It is most likely the the seals have gone, most certainly if the original O/E seals are still fitted as this will likely be long gone. Chambers sell the seal and compensation washer either separately or as a set, I have purchased these for a 6g, 66 rifle and 75 rifle and never questioned the size of the compensation washer, all 3 shot superbly after the reseal.

[thirdwheel]

Regarding balancing the two pistons, when I resealed mine I thought the same as I have access to all sorts of useful stuff. They were only 0.05g apart so I did no balancing. I did moly the lot after a clean and light polish - I use powderd moly from the US and acetone as a carrier and a buff afterwards. The manufacturer did not originally recomend lubrication of the seal as the oil available then would break up the seal. Glad you found the rebuild guide useful.
Stop worrying, and get it shooting asap and join us in the MPL.

George

[TheWilding]

Regarding balancing the two pistons, when I resealed mine I thought the same as I have access to all sorts of useful stuff. They were only 0.05g apart so I did no balancing. I did moly the lot after a clean and light polish - I use powderd moly from the US and acetone as a carrier and a buff afterwards. The manufacturer did not originally recomend lubrication of the seal as the oil available then would break up the seal. Glad you found the rebuild guide useful.
Stop worrying, and get it shooting asap and join us in the MPL.

George

I weighed mine tonight on the wifes kitchen scales, ssssshhh , not the most accurate of beasts, and it showed a 1 gram difference weighed with the Orange washer and blue seal, I think your right, just get it built and get in the comp


Whilst on about the washers, I measured them tonight aswell, the Orange is 4.07mm thick and the red is 4.11mm thick, I'm guessing they are to do with the preload spacing that I've been reading about.


Anyhoo, project Model 24D is in the throws of completion, just requireing a trigger rebuild and paint and varnish applied to the stock and its done, though I might make a match trigger for it at a later date, hopefully looking at the weekend for a finish, sunday I pick up the Model 50, and then its project Model 6M

[andrewdorset]

Ok so i stripped the 6g, easier than i thought, and inspected the seals and internals. The compression washer looked good but i replaced it anyway, i left the compensation washer as it looked new and also the springs.
Looking into the cylinder revealed traces of old washer on the compression face so this was scraped out as best i could and the whole cylinder washed out and cleaned. I re lubed with moly and a smear of silicon on the washers and re built it, again easier than anticipated. On dismantling i revealed that the compensation washer was slightly proud of the cylinder end, and should be slightly inside the tube end i presumed this was causing the loss of power, ( no damage to racks or pinions was evident....phew ! ).

What a difference , the gun now shoots great, much more power and accurate and invisible pellet ! However, the fps is only about 250-280. read it should be 450 fps. also the first few shots fly high and erraticly then it settles down and is consistent. I am thinking it might be dieseling for the first few shots then settles when its clean, too much moly ? And i guess i should have changed the springs also and maybe the compensation washer.

Do the outside of the pistons need moly, maybe this is bleeding in front of the compression washer. thinking another strip and washers and springs renewed ! Any suggestions ?

[TheWilding]

Ok so i stripped the 6g, easier than i thought, and inspected the seals and internals. The compression washer looked good but i replaced it anyway, i left the compensation washer as it looked new and also the springs.
Looking into the cylinder revealed traces of old washer on the compression face so this was scraped out as best i could and the whole cylinder washed out and cleaned. I re lubed with moly and a smear of silicon on the washers and re built it, again easier than anticipated. On dismantling i revealed that the compensation washer was slightly proud of the cylinder end, and should be slightly inside the tube end i presumed this was causing the loss of power, ( no damage to racks or pinions was evident....phew ! ).

What a difference , the gun now shoots great, much more power and accurate and invisible pellet ! However, the fps is only about 250-280. read it should be 450 fps. also the first few shots fly high and erraticly then it settles down and is consistent. I am thinking it might be dieseling for the first few shots then settles when its clean, too much moly ? And i guess i should have changed the springs also and maybe the compensation washer.

Do the outside of the pistons need moly, maybe this is bleeding in front of the compression washer. thinking another strip and washers and springs renewed ! Any suggestions ?

Can I ask if you noticed whether your seal compensation washer is smaller in diameter than the actual rear piston? Ive been looking at mine and it looks as if the bottom of the piston has been running along the compression tube, wearing away the blacking. To my mind this cant be good for performance and longevity so I may fit 3 small buttons to the rear piston to stop this happening, did you notice yours being the same?

[andrewdorset]

Yes i did notice the compensation washer was smaller than the piston and mine also has its balcking rubbed away. ? Incidently i have just taken it apart again and cleaned all the moly off the pistons, racks , pinion wheels and reduced it on the springs. After rebuilding it shoots better ! FPS is up to 310 and the power is up but more importantly it is more consistent each time i pick it up . So i would say less is more on the lubrication front.

[TheWilding]

Yes i did notice the compensation washer was smaller than the piston and mine also has its balcking rubbed away. ? Incidently i have just taken it apart again and cleaned all the moly off the pistons, racks , pinion wheels and reduced it on the springs. After rebuilding it shoots better ! FPS is up to 310 and the power is up but more importantly it is more consistent each time i pick it up . So i would say less is more on the lubrication front.

From what I've read so far that seems to be the theme, someone said they buff their lube on, so its only just the tiniest of smears on the parts and that seems to work, like I mentioned in the other thread FWB assemble their 300 series with no lube, just some special lube to help bed in and thats it..... looks like that and highly polishing all mating surfaces are the way to go.

Sean