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HW30 FPS Low?

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Bad News Beeman said:
I'm at pretty low elevation (>500') and yes, 7.9gr pellets.

Bummer, sounds like I gotta get into the guts of this thing and figure out what's the dealio. How may coils should I expect to see in the mainspring?
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How old is the gun? If it was made within the last two years I would just go ahead and order a tune kit from ARH and a piston seal from Vortek and call it a day. The factory spring has probably broken a coil and if I were a betting man the piston seal is likely partially melted
 
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Sqwirlfugger57 said:
How old is the gun? If it was made within the last two years I would just go ahead and order a tune kit from ARH and a piston seal from Vortek and call it a day. The factory spring has probably broken a coil and if I were a betting man the piston seal is likely partially melted
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Can't say how old it is for sure. Maybe within the
 
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Bad News Beeman said:
Can't say how old it is for sure. Maybe within the
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Can't say for sure the age, although not ancient as it sports the only slightly older hogback deluxe stock that predates the revamped toe and checkering.

QTaUs2Ih.jpg
 
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Bad News Beeman said:
Can't say for sure the age, although not ancient as it sports the only slightly older hogback deluxe stock that predates the revamped toe and checkering.

QTaUs2Ih.jpg
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Tear it down and check but I'm still going to go out on a limb and say spring kit and seals are a good bet. Obviously check the breech seal first. Thats the easiest one to get to and the cheapest fix. @Mycapt65 can verify if this is true or not but I believe he has stated that a loose lockup can relieve too much pressure on the breech seal and lose some power. 100+ fps seems extreme though.
 
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Bad News Beeman said:
Recently picked up a pre-owned HW30 that's dead nuts accurate, but potentially shooting on the low side. With CPHP's I picked up the following ten FPS readings:
452.1 | 472.4
444.0 | 457.6
421.0 | 465.2
422.2 | 492.4
460.0 | 488.4

Is this a little anemic for the platform?
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Definitely low and erratic. 60+ fps ES says bad breech or piston seal. Or broken mainspring. My R7
with 7.3 gr AA pellets averaged 685 fps last time I chronographed it.
 
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jccams said:
If it's a .177 and the CPHP's are 7.9g, yes it is on the low side. Should be around 600 at least. Now my .22 HW30 shoots 14.66 FTT at 500. What elevation are you at? Higher elevation will rob speed.
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My HW30 in .22 is shooting 14.66 FTT at 513, so it does look low especially for .177 cal. It has an ARH kit as well as ARH piston seal. Possible breech block seal like someone else suggested checking/replacing. Easy to replace at least.
 
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OEM Synthetic breech seals seldom leak on Weihrauch break barrels. I've tuned gun from the eighties that the breech seals while ugly, flat and brown were still working. When new Weihrauch breech seeks start off a little thick. This can hold the barrel of the proper lock on the HW30 and cause vertical stringing until the seal flattens with use.
Barrel pivot tension often affects accuracy on the HW30 but I've never seen it affect velocity greatly.
The gun as many said here before likely has a bad piston seal and or broken spring. Both easy to fix.
 
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Took the rifle apart yesterday (making a few mistakes and repeating various expletives along the way). That pin that holds down the cocking arm was a particular PITA to punch out. But I managed to get into the guts.

Outwardly, nothing stands out as apparent damage. Breech seal looks fine. The spring is intact with the correct number of coils (28). And the piston seal looks okay too, at least not visually torn up.

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Figured this is as good a time as any to install a new pistol seal regardless, so I'll order up a replacement. But as far as the other parts, does anything appear glaringly wrong?
 
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Slamming .. you see how many transfer port hole marks on the face of the seal..

Appearance overall aint bad outside that , now did you whip lube off or was it that "dry".

Breach looks fine like new ..

Anyway. If me id just clean it up real good ( seal, spring/guide, tube) do a proper lube job and try it .. you maybe surprised how a little tlc will do .

Then if it's good call it good . If no change or drops off again after a few 1000 . Just get a arh drop in spring snd a seal from him or vortec.... 40-60 bucks+/-
 
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Its hard to tell from the picture but the piston seal does look knicked on the left side there. Along with that the spring is definitely a bit worn. Pretty typical with how loose fitting they are on the guide and in the piston. I'd go ahead and just replace both.

I'll second the top hat as well. The ARH kit comes with one.
 
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