GTA
Airguns by Make and Model => Weihrauch Airguns => Topic started by: WyoMan on February 18, 2017, 01:19:29 AM
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The gun as modified in part 1:
(http://i.imgur.com/V4HZaOv.jpg)
(http://i.imgur.com/ZZJbYkQ.jpg)
Chrony results before and after the barrel change:
(http://i.imgur.com/TRImbcQ.jpg)
The longer barrel added 31 fps (an un-choked barrel would add even more). At 2.6 fpe, it’s now close to the published performance. You can gain another 5% or so by shimming the piston and using a 117 90D piston o-ring. However, those mods make it hard to pump and add undue stress. They’re not really worth it (imho) - after all, it’s still going to be a low-powered pistol, why make it hard to pump?
Weighing-in again for target shooting:
(http://i.imgur.com/tMn74UK.jpg)
Some 10-shot groups from 10m, rested… sighting-in and shooting groups:
(http://i.imgur.com/SPbdLvD.jpg)
(http://i.imgur.com/TcxC3h8.jpg)
In summary, it was just what I was looking for - a better-than-me gun that is fun to shoot. The scope, although not everyone’s cup of tea, makes it easier to operate the lever. I use the rear set of scope rings as a handle.
And a follow-up with several hundred down-range… the barrel shoulder is still tight to the frame:
(http://i.imgur.com/M43ZMFy.jpg)
After several thousand down-range… it’s settled in:
(http://i.imgur.com/YeqmovY.jpg)
This is a good check for barrel movement. Barrels on guns like these (with no bolt) can get a nasty impact load from the shot cycle. If the barrel is not secured adequately it can be pushed forward, and the breech seal will leak. So far so good…
Wyo
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Nice work!
-Y
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man that is a shootin gun :P!
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Thanks, guys. The HW 40 had a shoot-out today with an HW 45 (.177).
(http://i.imgur.com/MeJLhY5.jpg)
You probably already know - like I did - which gun would win...
10 shots from 10m:
(http://i.imgur.com/SZWaXXH.jpg)
But the HW 45 is still a real kick to shoot - one of the first I grab for pastime shooting.
Have four HW pistols now, .177 & .22 HW 45 - HW 40 - and a HW 75. The 75 would probably beat the HW 40 for accuracy... better trigger... But I'm not sure - need another shoot-out ;D
Wyo
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Did you get any gains in power from the longer barrel on the 45. I've been thinking of getting one in .22 for back up when hunting.
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I did, Denis - but it wasn't much - 14 fps ave. for the .177.
(http://i.imgur.com/iuMwiw8.jpg)
The .22 model did gain about 50 fps with a 12" LW barrel. Unfortunately, the oem setup on the .22 had a pretty bad breech leak, so that gain is meaningless. Fitting longer barrels to the HW 45 was a very difficult job (at least for me). There's no real tolerance or adjustment. If the barrel can move forward (and it wants to) by just a few thousands, the breech seal can leak.
(http://i.imgur.com/4wQGlpB.jpg)
(http://i.imgur.com/bg67G54.jpg)
Wyo
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Thanks Wyo, my Alecto suffers from the same fate. Slight movement forward and the barrel leaks like a siv. I'd go with the 75 or the 40 but the lack of power kills it for me .
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Indeed, the Alecto can suffer the same fate. Although it has a more robust retaining 'strap', it relies on clamping pressure (friction) to retain the barrel - just like the HW 40.
I think it helps if the turned down slot has a rough finish, for better friction, and the clamping screws (for all of them) are upgraded:
Alecto barrels:
(http://i.imgur.com/ezExtWH.jpg)
(http://i.imgur.com/d4HGBeT.jpg)
(http://i.imgur.com/muCi26L.jpg)
Oem vs. 5-40 x 3/8" screws:
(http://i.imgur.com/VOeDX2Q.jpg)
The HW 45 barrel cannot be restrained by clamping pressure alone (found out the hard way). The ‘strap’ has to withstand the impact load by direct bearing on the shoulder of the barrel slot:
(http://i.imgur.com/lvUWUvC.jpg)
I've never hunted with any of them, can't help you there, but you're right about the power comparison.
Wyo
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You can put a shim at the end of the barrel on these. I've done it to one of my P-17's and one of the Alecto's. If I recall correctly, there is a shoulder at the muzzle end of the barrel and a shim over that shoulder will more positively locate the barrel. It's been a long time since I did it but I think I did a plastic one on the P-17 and an aluminum one on the Alecto but either material should function fine.
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Did you ever consider a Diana/RWS LP 8?
I love mine..... ;) :-* :D
-Y
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Hi Yogi, I've never really seen or heard much about the LP 8... but now that you mention it I'll have to give it some thought. I does look pretty good - thanks
Wyo
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If you get one, don't forget http://www.galbraithbrothers.com (http://www.galbraithbrothers.com)
Makes them look prurdy too ::)
-y