Just unwrapped a virgin HW95

[Mark 611]

I understand completely! I'm just pointing out my and others experiences with the workings of these rifles, I know from allot of tuning of HW guns that this seems to be the norm anymore with HW so sorry to hear you need to address these issues but I'm just tryin to help

[GunnerAl]

Hopefully that 12-15 pounds of weight to move your piston in that cylinder doesn't transpire into some energy sapping numbers at the muzzle. If that sort of weight is needed to push the piston through the entire length of its travel, well, you have to think of what a foot/pound is don't you - the energy gained by dropping a one pound weight from a height of one foot..!! Your cylinder might have less than half a foot of travel but that 12+ pounds of weight under friction over that distance may certainly show up as lost energy... Food for thought..!!

I see that you have the situation under control but it's worth bearing in mind for the rest us...

[Trigger man]

Hopefully that 12-15 pounds of weight to move your piston in that cylinder doesn't transpire into some energy sapping numbers at the muzzle. If that sort of weight is needed to push the piston through the entire length of its travel, well, you have to think of what a foot/pound is don't you - the energy gained by dropping a one pound weight from a height of one foot..!! Your cylinder might have less than half a foot of travel but that 12+ pounds of weight under friction over that distance may certainly show up as lost energy... Food for thought..!!

I see that you have the situation under control but it's worth bearing in mind for the rest us...

I haven't bothered to pencil the numbers, but,.. it is well establish dynamics that state, that undue piston friction will negatively effect available FPE @ the muzzle due to reduced piston velocity. We have a known amount of spring loading, pushing a known given mass, over a known distance. Dial-in extra friction and available energy @ the muzzle is reduced (and converted to heat within the piston and cylinder wall). Just how much FPE loss this problem caused in this gun, is unknown without testing. This very subject is a key element with those individuals that resort to low friction buttons installed on their pistons... specifically aimed at reducing friction.

What's interesting, is that this particular HW95 was allegedly inspected and fire-test (5 pellets). I have the AoA chrono printout (w/tester's initials). But after opening this gun, I seriously question the validity of that 'test'.     

I did manage to repair the piston - all I did was gently and incrementally pinch it in my well padded bench vise. It now moves freely by gravity alone (without the seal of course).  The 're' build continues.


   

[jdub]

What's interesting, is that this particular HW95 was allegedly inspected and fire-test (5 pellets). I have the AoA chrono printout (w/tester's initials). But after opening this gun, I seriously question the validity of that 'test'.     

I know it's disappointing but I seriously doubt the guys at AoA would fake a test and send you a bogus chrono printout.   It's nice to think of these rifles as precision engineered pieces of German goodness but it's obvious that they're mass produced and corners are cut to save money, and that they can perform remarkably well even before all the production defects are corrected.

It's very likely that for a lot of people the rifle you received would have eventually worn in to a state they're happy with.  The folks that are knocking down coke cans at 20 yards and pleased as heck.  And most of us have heard the stories of rifles continuing to shoot fairly well even with broken mainsprings.    As Mark attempted to point out there's nothing particularly surprising here.  He and a lot of other guys have tuned a large number of these and are just trying to offer some tips to get you back to shooting.   

I've only worked on half a dozen HWs and almost all of them had an abundance of burrs and rough machining.  All of them had forks that looked the same as yours and a couple had badly cut piston seals.  But despite the tight pivot bolts and grinding and scraping noises every one of them shot fairly well before tuning and extremely well after.

I'm sorry you have to experience it and I know it's disillusioning to drop $400 and have problems but give Mark and the guys here a chance and they can help you know what has to be addressed and what can safely be left alone and they really are pretty easy to work on as you're discovering.  It sounds like you're already well on your way to having a sweet shooter. 

Good luck!

[Trigger man]

Appreciate the encouragement jdub (and others too),

So someone please enlighten me. What approximate velocity can one expect from an out-of-the-box (no after market tuneups) HW95 throwing .22 cal RWS Hobbys?

Again, thanks all

[Mark 611]

with those pellets you should be on the low end of 650fps and as much as 700+ on the hi end, Hobby's are pretty light pellets!

[nced]

Nice looking, but unimpressed with both the very stiff cocking (unusually tight breach pivot), and mild but audible ratcheting sound (as though the spring was rubbing against something internally during cocking). Undecided whether to return it... or open the tool box.

 

My latest R9 (rebadged HW95 without sights but with muzzle break and scope rings) bought last year was also extremely rough cocking when new, but now after a home tune and a few thousand shots the action is "slick as snot"  ! By the way, if you exchange it I'm betting that the replacement will be the same.

I was looking at your dissembled pic and it appears that it still had a piston liner, whereas my R9 had no liner in the piston and the cocking shoe was designed to ride the receiver cocking shoe slot onlike my older R9s that had the cocking shoe riding a piston liner. Here's a pic of the new style R9 cocking shoe.......
Uploaded at Snapagogo.com

LOL.......just for grinns I even added an old R9 piston liner to the new piston and the new style cocking shoe worked perfectly!
Uploaded at Snapagogo.com

I have seen R9s and HW95s come from the factory with OVERLY tightened pivot bolt screws which can lead to galling if not properly lubed. Also, the two barrel shims do "seat in" with use and the point of impact will shift as the barrel tension changes with this "seating in". Myself, I readjust my R9 barrel pivot tension till the cocked barrel just falls of it's own weight in any part of the swing (LOL.....obviously be careful no to touch the trigger or safety button when adjusting the barrel tension). Folks always advise that it takes a couple tins of pellets to "break in" a springer before serious accuracy testing begins. I personally believe that MOST of the "break in" is due to the barrel shims and latching detents "seating in". As mentioned by other replies......my R9 came with a COPIOUS amount of factory grease which I stripped and then relubed.

Anywhoo.......after a few thousand shots my R9 really shoots smooth, however it contains a home rolled tight fitting guide and top hat in a good aftermarket spring. While I've never had any accuracy issues with my R9s in "factory twang mode", they can't be expected to shoot without twang and vibration with the loose fitting factory spring guide and no top hat. Here is a 50 yard target I shot with the new R9 after a home tune testing the accuracy of different pellets............
Uploaded at Snapagogo.com
Notice the CPL group in the upper left hand corner of the target.

Here is another 50 yard group shot during a variable breeze.......
Uploaded at Snapagogo.com

And a couple "bug bustin" targets.......
Uploaded at Snapagogo.com
Uploaded at Snapagogo.com
Uploaded at Snapagogo.com
By the way.....all groups were shot hunter class field target style (sittin' on a bucket using cross sticks), not bench rested. Hummmm......not too big of a deal since I haven't found that my springers take well to bench restin' in the first place!

Anywhoo.....the HW95/R9 is my favorite springer and I shoot the R9 MUCH more than my HW77k even though the heavier "77" is a bit easier to shoot accurately!
 
 

[Sfttailrdr46]

  Wow now I have to get my nerd buddy hooked on air guns he has a nice shop and his (nerd ) buddy had a complete machine shop in the basement. Otherwise I'll have to buy another very large roll around for my air gun only tools!

[nced]

What caliber is yours?

.22

Not to be overly critical of Weihrauch, but I'm not impressed with the machining of this example. Perhaps it's my picky nature, but IMO, this isn't representative of $400 worth of German manufacturing....

Course machining evident on both pivot tabs. This is typical of dull and/or worn out tooling or broach cutter 



The red arrows show holes with sharply raised edges protruding internally - a.k.a. 'seal eaters'. Likely why the piston seal has noticeable damaged areas, as previously mentioned. Obviously, I need to chamfer these before reassembly.

IMHO.....the coarse machining is intentional to provide a "grease reservoir" for the shims. Notice that the rest of the surfaces are nicely machined.

Yes.....the punch outs ans dowel holes can be a "seal eater" and one of the first things I do is to deburr all holes and slots. This is especially important for use with my home rilled oring sealed piston caps, however I don't think they are much of an issue when properly lubed factory (or aftermarket) parachute seals are CAREFULLY installed.

[Trigger man]

with those pellets you should be on the low end of 650fps and as much as 700+ on the hi end, Hobby's are pretty light pellets!

Thanks Mark,

I realize that it's purely a guess, but... Based on numbers you just posted, what change in FPS would expect to see with a binding piston requiring a minimum of 12-15 pounds pressure to slide in the bore?

[Petey]

Trigger man,
Your 9 exhibits a lot of the same issues mine had. The piston was out of round the and the compression tube was pitted deeply. So I contacted the company that  provides "warranty" for Beeman.
After all is said and done I have nice little 12 pound shooter that loves 13.43 AA Falcons .

Good Luck & HAppy Shootin,
Petey.

[Trigger man]

IMHO.....the coarse machining is intentional to provide a "grease reservoir" for the shims.

... and permits easier access for contamination within those "reservoirs". The breach side-shims are there to inhibit lateral movement and prevent scratches to the side of the breach block.

Here's an image of my 'new' breach block... the visible circular scar you see, is approximately .003" deep. This is indicative of either contamination during assembly, and/or localized (read non uniform) pressure being placed on the shims - typically caused by rough, ill-machined mating surfaces.

 

Notice that the rest of the surfaces are nicely machined.

Notice that the "nicely machined" surfaces are external only. The rough machining is internal, and in most cases, the gun needs disassembly to see it.

Yes.....the punch outs ans dowel holes can be a "seal eater" and one of the first things I do is to deburr all holes and slots. This is especially important for use with my home rilled oring sealed piston caps, however I don't think they are much of an issue when properly lubed factory (or aftermarket) parachute seals are CAREFULLY installed.
[/color]

So how do you "carefully" install the piston without raking the seal across sharp, ragged burrs and avoid seal damage? My solution was to simply eliminate the burrs prior to assembly... a 5 minute fix the factory should have done.

BTW, the OEM seal in this gun WAS damaged, and the damaged areas aligned perfectly with the burrs... and the piston was still covered with a heavy coating of factory grease.

[nced]

".. and permits easier access for contamination within those "reservoirs". The breach side-shims are there to inhibit lateral movement and prevent scratches to the side of the breach block."
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"permits easier access for contamination"...well this hasn't been an issue with ANY of my R9. Some were used decades for all types of shooting with 10s of thousands of shots!

"breach side-shims are there to inhibit lateral movement and prevent scratches to the side of the breach block."
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Again I disagree a BIT........the barrel shim purpose is simply center the barrel pivot block in the receiver forks. If the pivot bolt tension is adjusted so tight as to "INHIBIT lateral movement" there is considerable thrust on the shims which will wear them quickly. The shims only minimize "lateral movement" with correct bolt tension, it's the spring loaded detent wedge that actually creates a repeated barrel registry after cocking.  However you are correct that doing so DOES provide about .005 clearance on each side between the pivot block and the receiver fork (determined by actually measuring a shim).

"Here's an image of my 'new' breach block... the visible circular scar you see, is approximately .003" deep."
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This is REAL puzzling to me because here is a pic of one of my barrels from an old Beeman R10 after THOUSANDS of shots.............
Uploaded at Snapagogo.com
This is the most worn side and there is hardly any detectable wear other than the bluing worn off. I measured the wear of the worst side and it's about .001, the wear on the other side is too minor to detect with the fingernail and not measurable with my dial caliper. Actually, of over a dozen R9s, a couple R10s and a HW95 I've NEVER seen a wear pattern like the one in your pic.  Just for grinns I removed the barrel from my newest R9 and here is a pic of the barrel shim area after shooting two cases of CPLs (about 10,000 shots). The "wear" is BARELY detectable with the fingernail and less than the .001 wear measured on the R10 barrel. Here's a pic I just shot.........


Notice that the wear pattern is similar to the old R10 pivot block wear pattern.

Again, I've never seen a wear pattern like yours and it SEEMS that it's a combination of excess pivot bolt tension and/or insufficient lube (or perhaps wrong lube), or perhaps the barrel shim was burred around the periphery. Even at that, the lack of bluing wear inside the "gouged circle" is a real puzzle! Perhaps you need to check out the shims for "punching burrs" and hone them off (if present) with an oiled Arkansas stone. Since the ".005 deep groove" is only on the periphery without even some bluing wear in the center, "good shims" will be perfectly adequate for proper function using proper lubes and barrel pivot tension!

"So how do you "carefully" install the piston without raking the seal across sharp, ragged burrs and avoid seal damage? My solution was to simply eliminate the burrs prior to assembly."
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I use a small round file to deburr the holes in my receiver tubes, however I haven't noticed where a new factory R9 seal performed any better.

"BTW, the OEM seal in this gun WAS damaged, and the damaged areas aligned perfectly with the burrs... and the piston was still covered with a heavy coating of factory grease."
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Yep.....I've had scored piston seals too like one in this pic next to one of my oring sealed piston caps that was damaged at the factory.................
Uploaded at Snapagogo.com
Ya see...the HW factory piston seal is a pretty soft compound and will endure a bit of abuse so I really don't think HW believes it's necessary to do a complete internal deburr. LOL.....it's the oring seal that has issues with cuts so I always do a thorough deburr for that mod.

Humm.....my R9s also came slopped up with grease which is why I only shoot them a few times to check out the actual function before doing a "strip down, deburr and relube". LOL......it's takes less than an hour to do a thorough job, and I'm sure that you've found out that HW95s ain't "rocket science" and easily owner serviced. 




 

[Trigger man]

".. and permits easier access for contamination within those "reservoirs". The breach side-shims are there to inhibit lateral movement and prevent scratches to the side of the breach block."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"permits easier access for contamination"...well this hasn't been an issue with ANY of my R9. Some were used decades for all types of shooting with 10s of thousands of shots!

The image I posted represents a 'new' gun - unfired by me. Clearly... not an example that endured thousands of rounds over decades.

"breach side-shims are there to inhibit lateral movement and prevent scratches to the side of the breach block."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Again I disagree a BIT........the barrel shim purpose is simply center the barrel pivot block in the receiver forks. If the pivot bolt tension is adjusted so tight as to "INHIBIT lateral movement" there is considerable thrust on the shims which will wear them quickly. The shims only minimize "lateral movement" with correct bolt tension, it's the spring loaded detent wedge that actually creates a repeated barrel registry after cocking.  However you are correct that doing so DOES provide about .005 clearance on each side between the pivot block and the receiver fork (determined by actually measuring a shim).

One can easily achieve ideal breach/receiver lateral alignment without 'shims'. But obviously, massive, visible scratches to the side of the breach block would result. So the designer simply dials-in extra side clearance and installs inexpensive shims...to reduce cocking friction and prevent the uglies. I guess we'll just have to politely disagree.    

"Here's an image of my 'new' breach block... the visible circular scar you see, is approximately .003" deep."
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This is REAL puzzling to me because here is a pic of one of my barrels from an old Beeman R10 after many THOUSANDS of shots.............

Why is it puzzling?... I already explained why. My HW95 example is NOT a decade old gun, so I assume it was manufactured under different conditions (and perhaps by different equipment, by different employees than your 'old' Beeman). Dunno. 

[Mark 611]

well that's part of the problem with HW they have lost part of their older staff due to retirement and their QC isn't what it use to be! we all know how the younger generation is today and I sure its no different in Germany + theirs such a demand for these rifles I'm sure things get over looked to keep up with the demand and to keep costs down which is no excuse! these were once fine rifles and it seems they have deteriorated due to the econmany JMO

[Petey]

well that's part of the problem with HW they have lost part of their older staff due to retirement and their QC isn't what it use to be! we all know how the younger generation is today and I sure its no different in Germany + theirs such a demand for these rifles I'm sure things get over looked to keep up with the demand and to keep costs down which is no excuse! these were once fine rifles and it seems they have deteriorated due to the econmany JMO

+1!

[Sfttailrdr46]

  After reading this thread, safe to say when I get my RWS 460 on Tuesday I'll be breaking it down and doing a basic tune and lube after a little homework on the breakdown process  and ordering a tune kit.  Now going to have to wait a few extra days to start shooting it.

[Trigger man]

So someone please enlighten me. What approximate velocity can one expect from an out-of-the-box (no after market tuneups) HW95 throwing .22 cal RWS Hobbys?

Again, thanks all

with those pellets you should be on the low end of 650fps and as much as 700+ on the hi end, Hobby's are pretty light pellets!

Interesting, Mark, thank you



And to think.. that my virgin, out-of-the-box HW95 allegedly produced mid 700's while suffering from a seriously binding piston, a damaged piston seal, and multiple helpings of thick 'axle' grease... amazing:) 

well that's part of the problem with HW they have lost part of their older staff due to retirement and their QC isn't what it use to be! we all know how the younger generation is today and I sure its no different in Germany + theirs such a demand for these rifles I'm sure things get over looked to keep up with the demand and to keep costs down which is no excuse! these were once fine rifles and it seems they have deteriorated due to the econmany JMO

Yup. The unfortunate decision to purchase this HW95, rests on my shoulders. Apparently, my expectations was simply too high. No disrespect intended to Weihrauch owners, but this recent HW95 acquisition will be my last.  Live'n learn.

[Mark 611]

pretty good #'s buddy!

[QVTom]

IMHO.....the coarse machining is intentional to provide a "grease reservoir" for the shims. Notice that the rest of the surfaces are nicely machined.

I don't agree.  Simply chatter from the side milling cutter use for the operation.  Fork shaped parts offer up many challenges for machining and side milling cutters are always a last choice.  My guess is that they don't consider the surface finish a problem in that area because of the use of shims to locate the breech block.

Tom