HW35E Accuracy change from excellent to terrible.

Jump to latest Follow Reply
Over the years, I have found out, that if your first shot shoots lower than your second, or even third or fouth for that matter, then the outer rim of the piston seal hasn't expanded yet, or as I would otherwise put it, it hasn't set in and taken the excess air out of it just yet, which in turn means that it's time to replace the said piston seal. If the gun isn't used for a while, the seal will contract and will therefore need some time/force of a couple of shots, to set in properly. Of course, I didn't mean DRY shots! Never dry fire a springer, because you'll not only damage the mainspring, but further deteriorate the piston seal as well. One more thing, it could also be the breech seal at fault. Tightly cover and wrap the breech with a paper towel or a piece of tp and shoot the gun. If the air bursts open the paper, then the air is leaking out of the breech - then you need a new breech seal. Also, if you have a chronograph, you can leave the gun alone overnight and the next day you can shoot the gun three times through the chrony and see if the numbers vary from one shot to another, that would indicate an issue with either of the seals or even the mainspring wearing out (which I don't think is the case in your example). I hope this helped a bit, and as others have pointed out already, it could also be barrel droop - spring-piston driven Weihrauch break-barrels sort of have a reputation for that, or it could be the stock coming loose or even swelling, the breech assembly loosening up on you (check the securing screw on the cylinder), the mainspring guide breaking... et cetera. Once again, I'm sure some of the others or even yourself have come to these conclusions or have perhaps considered any of these problems to be occuring with your HW, but these are all of the issues I've ran into over the years with my springers - and I only have springers, no gas-piston guns, just traditional break barrels and one springer sidelever; I didn't really have the time to check all of the other posts, i've checked a few in this thread and that's it.
Really hope this helped some.
 
  • Like
Reactions: Frogy and Mcrafty1
Upvote 0
JDR said:
Ok, ran the chrony with JSB Exact 10.34 gr at 5 yards.

1. 687 fps
2. 686 fps
3. 688 fps
4. 697 fps
5. 695 fps


Below is 5 shot group with UTG bugbuster 3x12 set at mid range elevation and UTG Piccany droop mount ( I checked the mount screws and scope rings, all torqued down good and no movement. Do not have a scope to try on the dovetail but do not think the mount is the problem.). Gun had a vortex spring installed when purchased. Yardage was 10 yards with JSB Exact 10.34 gr. Got 1" group that was 5" low. I think, from some of the comments, the problem is I may have over-tightend the pivot bolt and bent the forks holding the barrel thus adding a little variability in the lockup. Is it possible to do that with a screwdriver? The forks are very thick. Maybe I destroyed the shims. I could not tell if they were even installed by shining a flashlight on them. Had to take the barrel off to verify. Maybe I should try new shims if you guys think that may be the problem If I bent the forks, I will need a new receiver, The big increase in barrel droop also probalby happened after the over- tightening. Was never this high when I shot it last year. The barrel droop problem happened after I did the over tightening I think. Still rattles but the chrony says notihng is wrong inside. Like I said, it shoot great with irons and the chrony says the power plant is working. Please advise. Thanks so much with sticking with me on this problem. Only thing I know to do now is drop it off and Airgunwerks and let David Slade look at it.

View attachment 347302

View attachment 347303
Click to expand...
Oh, I'm sorry, I didn't notice you've already ran the gun through a chrony.
 
  • Like
Reactions: Mcrafty1
Upvote 0
I am still thinking scope....reason being..look at the groups, you will see two shots touching then a shift, two more shots touching then a shift, typical issue of scope not maintaining zero !! My other concern would be...did the jaws/ shims/ breech block, get burrs on them from overtightening ?? Might have to stone/ smooth/ polish the faces, add new shims and set barrel tension properly. Unless the barrel is loose...wouldn't cause this type of impact shift.....my two cents anyway....
 
Upvote 0
The barrel link up seems loose epecially when cocked open. I think the lockup not being exactly consistent is the reason for the poor grouping with a scope. Since iron sights are on the barrel, accuracy is not affected; just with a scope. I got new shims and breech seal coming from Airguns of Arizonia. I tried 3 different scopes with same result. Airguns of Arizona thought it would be impossible to bend the forks by over tightening the barrel pivot but maybe as you said the shims are damaged. They said the gun has a life time warranty for defects but only 1 year for normal wear and tear. I am going to shoot 5 shot group with iron sights as a final check but past groups with the iron sights have been good. The rattle I said I heard inside the gun was just the trigger jiggling around. I did order another pair of shims just in case if barrel is still loose after the first pair of shims are installed. If it still does not shoot with a scope, going to send it in to Airguns of Arizonia hoping I did not damage it enough to void the warranty. It only has about 200+ shots thru it so far. Thanks for the reply.
 
Upvote 0
JDR said:
The barrel link up seems loose epecially when cocked open. I think the lockup not being exactly consistent is the reason for the poor grouping with a scope. Since iron sights are on the barrel, accuracy is not affected; just with a scope. I got new shims and breech seal coming from Airguns of Arizonia. I tried 3 different scopes with same result. Airguns of Arizona thought it would be impossible to bend the forks by over tightening the barrel pivot but maybe as you said the shims are damaged. They said the gun has a life time warranty for defects but only 1 year for normal wear and tear. I am going to shoot 5 shot group with iron sights as a final check but past groups with the iron sights have been good. The rattle I said I heard inside the gun was just the trigger jiggling around. I did order another pair of shims just in case if barrel is still loose after the first pair of shims are installed. If it still does not shoot with a scope, going to send it in to Airguns of Arizonia hoping I did not damage it enough to void the warranty. It only has about 200+ shots thru it so far. Thanks for the reply.
Click to expand...
I would not be concerned at all that you damaged the gun by over tightening the jaws. The shims either. If the lockup is loose or wiggles at all, then that would explain the accuracy loss. I have seen shooters aggressively break open the barrel and if this was done on a 35 without unlatching the barrel catch it could have bent it or caused a bit of slop in the lock up. If you know that never happened then it sounds like a warranty issue.
 
Upvote 0
Sent the HW 35E back to AOA in 2 pieces. Could not fit the barrel to the reciever. Just got off the phone with technical support. They put it back together and shot it and got inconsistent groups with their scope. Inspected the barrel and said it was very dirty and cleaned it. Took the gun apart and inspected the components. Saw no issue but did lube the spring. Put it back together and shot it and got factory spec groups at 20 yard. Barrel droop was not an issue as they said it zeroed on right away. They are not sure what the issue was., maybe the dirty barrel but somewhat puzzeled. Sounds strange to me that a dirty barrel would get sporadic groups and very low point of impact I was getting. Maybe both my scopes are bad but I do have a brand new one to try. Anyway, no charge saying it is warranty work. Shipping it out today. AOA is a great company. I think they could have got away with charging me since they only found a maintenance issue with the dirty barrel. Will buy from them again.
 
  • Like
Reactions: Hateful McNasty and Sqwirl57
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu