I have an HW 100K in .177. It's a great rifle, and I shoot it a lot in the yard. It's FAC power level, so it's shooting 18-20 fpe, as it should. Since most of it's use is in the yard, I'm considering tuning it down, My question, can it be de-tuned to the 12 fpe level with the current components, and end up with a well balanced tune? If it's practical to do so by adjusting the reg down and backing off on the hammer spring tension, then I might do it. But my assumption, the 12 fpe rifles are probably assembled with a different hammer, spring, valve spring, regulator, etc. If anyone has knowledge about this, I would appreciate your input.
Tuning HW 100 tuning question
- Thread starter elh0102
- Start date
hey, I have the same rifle. the easiest way is to down reg pressure until 80-85 bar. it will be nearly 12fpe. of course you can play with hummer, valve and etc. but this last on is very complicated
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I did this to a full length HW100 177 I found at 12 fpe the gun sounded a bit sick but at 15 - 16 fpe it was sweet. On a KT 12 fpe might be fine.
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85 bar and free flight on the hammer to just barely get a gap. That should put you close to 12.
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Thanks to all for your responses. The rifle shoots so well, I'll probably keep it as is, and just look for a good 12 fpe rifle. It sounds like the 12 fpe rifles probably have a different hammer and/spring, and maybe valve spring too. The rifle is quiet enough now, and for my use, shot count isn't critical. And on the pesting side, a bit more power and flatter trajectory are fine. Too bad the US market isn't more receptive of the milder rifles, but it seems we always want bigger, faster, stronger in everything.
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HW100 is one of the best made mid powered PCPs.
A jewel from Germany.
Internals are built to last long.
One of the best triggers, best magazine indexing.
Easy to tune.
Best of luck.
Bhaur
A jewel from Germany.
Internals are built to last long.
One of the best triggers, best magazine indexing.
Easy to tune.
Best of luck.
Bhaur
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I just tuned my .22 FAC HW100k down to about 20 fpe. As an experiment, I tried dropping power down to 12 fpe. It worked, but the adjustment was overly sensitive. I did not feel confident that the setting was permanent.
I also ordered a replacement hammer spring and rear hammer block from the UK, in case my gun had the 'anti-tamper' device. The new spring was noticeably softer, probably intended for the 12 fpe market. It turns out that my gun did not have the anti-tamper device.
It's very easy to adjust power with a good regulator gauge. But I would stock up on o-rings. Two rings failed during the process. The primary intake oring (the very small one the air cylinder screws onto) and the regulator gauge port oring.
I also ordered a replacement hammer spring and rear hammer block from the UK, in case my gun had the 'anti-tamper' device. The new spring was noticeably softer, probably intended for the 12 fpe market. It turns out that my gun did not have the anti-tamper device.
It's very easy to adjust power with a good regulator gauge. But I would stock up on o-rings. Two rings failed during the process. The primary intake oring (the very small one the air cylinder screws onto) and the regulator gauge port oring.
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Yes, I've been expecting that small O ring on the intake valve to fail, but mine is still good. I always remove the barrel to clean it, so I probably take the air cylinder off more often than some folks. But getting a pull-through into that small breech opening is awkward, and replacing the breech seal isn't as easy on the HW100 as many others, so I figure I'd rather stress that intake O ring.
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Can anyone elaborate how to tune one (FAC in .22) down a bit, not down to 12 fpe, just a down to about 20 fpe, via the hammer spring? Thanks.
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Hi Serdac,
I'll give it a try.
Of course verify the airgun has no pellets.
There is no need to de-gas the airgun to adjust the hammer spring.
1.) Remove the stock.
2.) Remove the 2 screws that hold the cover on the back of the receiver. Remove the cover.
Now, if you are lucky and the source of your gun didn't put an anti-tamper or non-permanent loctite on the hammer spring adjusting screw (the hex socket screw under the rear cover):
3.) Open the breach via the cocking lever all the way. Point the airgun toward the ceiling and the hammer should slide part way out the back of the receiver. Loosen or remove the tiny set-screw that comes in from the side. This set-screw locks the hammer spring adjuster screw. (There is a hole that comes in diagonally that can be used to access the set-screw also if desired.) Some folks don't put the set-screw back. I put it back when I'm done.
4.) Looking from the rear, turning the screw counter clockwise will reduce the hammer spring preload (reduce the velocity).
Reverse to re-assemble.
If the hammer spring adjuster has a mild thread locker (loctite) on it and it takes some torque to turn, I'd not make the adjustment w/o removing the hammer and cleaning off the thread locker. I've been told you can do damage if you force the adjustment and use the trigger parts to prevent the hammer from rotating. Removing the hammer is a bit touchy as you start driving out the rear pivot pin on the cocking linkage part way with a straight punch. Then you push it the rest of the way out with a curved "pusher". There are directions out on the interweb.
Hope this helps. Took my HW100 out today. Wife indicated it was the most quiet. I'm guessing about 6 fpe or so
Enjoy,
Nugria
I'll give it a try.
Of course verify the airgun has no pellets.
There is no need to de-gas the airgun to adjust the hammer spring.
1.) Remove the stock.
2.) Remove the 2 screws that hold the cover on the back of the receiver. Remove the cover.
Now, if you are lucky and the source of your gun didn't put an anti-tamper or non-permanent loctite on the hammer spring adjusting screw (the hex socket screw under the rear cover):
3.) Open the breach via the cocking lever all the way. Point the airgun toward the ceiling and the hammer should slide part way out the back of the receiver. Loosen or remove the tiny set-screw that comes in from the side. This set-screw locks the hammer spring adjuster screw. (There is a hole that comes in diagonally that can be used to access the set-screw also if desired.) Some folks don't put the set-screw back. I put it back when I'm done.
4.) Looking from the rear, turning the screw counter clockwise will reduce the hammer spring preload (reduce the velocity).
Reverse to re-assemble.
If the hammer spring adjuster has a mild thread locker (loctite) on it and it takes some torque to turn, I'd not make the adjustment w/o removing the hammer and cleaning off the thread locker. I've been told you can do damage if you force the adjustment and use the trigger parts to prevent the hammer from rotating. Removing the hammer is a bit touchy as you start driving out the rear pivot pin on the cocking linkage part way with a straight punch. Then you push it the rest of the way out with a curved "pusher". There are directions out on the interweb.
Hope this helps. Took my HW100 out today. Wife indicated it was the most quiet. I'm guessing about 6 fpe or so
Enjoy,
Nugria
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Fortunately, the hammer spring adjuster turns easily on my rifle. But, all things considered, I think I've talked myself out of re-tuning it. As is, the rifle is very quiet, accurate, and the chrono results are almost freakishly consistent. A higher shot count would be nice, but not really needed. And if I get the power knocked way back, then have an unexpected squirrel show up at 30 or 35 yards (which happens), then I have to stop and think, exactly how do I hold for this shot? Or worse, take the shot and get a bad hit, and then the squirrel goes flopping into a neighbor's yard. At some point, I'll probably get a 12 fpe rifle, but maybe leave well enough alone for now.
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I thought it over and talked myself out of it too. Right now it’s in the 840’s with 15.9 JSB, very accurate for what I use it and quiet enough.
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elh0102
True, you have to pull the barrel to clean it with a pull-through patch. And of course you need to unscrew the air cylinder to access the barrel retaining screw. That wears the cylinder to main inlet valve o-ring. It's #2665D on the HW100 diagrams.
Mine failed after about 20 cylinder removals. I think it would have lasted a lot longer if I had put a very thin smear of silicone lube on it.
HW100 tuning has the upgraded, red 'poly' orings. https://hw100tuning.co.uk/shop/ols/products/upgraded-cylinder-seals
However, I spotted a wonderful discussion about HW100 o-rings in this post: https://www.tapatalk.com/groups/weihrauchowners/hw100-tweaks-t5300.html.
He lists ALL HW100 o-rings.
That prompted me to get a lifetime supply of all HW100 orings. I went to oringsandmore.com and chose the minimum quantity of each oring, typically 25. Total cost was $21.60, delivered.
True, you have to pull the barrel to clean it with a pull-through patch. And of course you need to unscrew the air cylinder to access the barrel retaining screw. That wears the cylinder to main inlet valve o-ring. It's #2665D on the HW100 diagrams.
Mine failed after about 20 cylinder removals. I think it would have lasted a lot longer if I had put a very thin smear of silicone lube on it.
HW100 tuning has the upgraded, red 'poly' orings. https://hw100tuning.co.uk/shop/ols/products/upgraded-cylinder-seals
However, I spotted a wonderful discussion about HW100 o-rings in this post: https://www.tapatalk.com/groups/weihrauchowners/hw100-tweaks-t5300.html.
He lists ALL HW100 o-rings.
That prompted me to get a lifetime supply of all HW100 orings. I went to oringsandmore.com and chose the minimum quantity of each oring, typically 25. Total cost was $21.60, delivered.
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Thanks JJ, I saw that list and did the same. For what the dealers charge for a few O rings, you can buy about 10 lifetimes' supply.
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How’s the wood on y’all’s? Maybe it’s normal but the one I have has some nice wood. Mag index and trigger are perfect.
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That is a very nice stock! Mine is laminate, because I need the adjustable comb feature. And, I'm not concerned with scratching it.
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I finally found a parts listing, and the FAC model uses a different hammer assembly than the 12 fpe version. Best I can tell, it's the same spring, but a different hammer. If that's the case, then I assume the hammer is lighter and would utilize a lower reg setting, but just a guess.
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Hi All,
If anyone knows the different hammer and spring specs for the different flavors of HW100 it would make for an interesting comparison.
With that information, I'll be on the lookout for a 12 fpe HW100 in 177. My targets are paint balls on golf tees at known ranges.
I'm not sure of what the factory power level setting was on mine. It is an old HW100 (pre quick fill, Hunnington Beach Beeman marked) that does not have the moderator. The barrel is not threaded. I did shoot it over screens this last week and found it shooting 465 fps, 4 fpe. ES is large (20 fps) which is to be expected with this way below plateau velocity setting. I had backed off the hst when I received the rifle to make it yard quiet (and my chrono had suffered a gsw.) The hold over on 35 yard targets was significant. Really quiet at 465 fps. The previous owner indicated he set the regulator at 85 bar. I've since turned the hst screw in 1/2 turn to get 635 fps (7 fpe, Crossman 7.9gr HP). ES is much better at 5 fps. It is louder now but much easier to shoot 35 yard targets.
Nugria
If anyone knows the different hammer and spring specs for the different flavors of HW100 it would make for an interesting comparison.
With that information, I'll be on the lookout for a 12 fpe HW100 in 177. My targets are paint balls on golf tees at known ranges.
I'm not sure of what the factory power level setting was on mine. It is an old HW100 (pre quick fill, Hunnington Beach Beeman marked) that does not have the moderator. The barrel is not threaded. I did shoot it over screens this last week and found it shooting 465 fps, 4 fpe. ES is large (20 fps) which is to be expected with this way below plateau velocity setting. I had backed off the hst when I received the rifle to make it yard quiet (and my chrono had suffered a gsw.) The hold over on 35 yard targets was significant. Really quiet at 465 fps. The previous owner indicated he set the regulator at 85 bar. I've since turned the hst screw in 1/2 turn to get 635 fps (7 fpe, Crossman 7.9gr HP). ES is much better at 5 fps. It is louder now but much easier to shoot 35 yard targets.
Nugria
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