try packing the scope under the rear mount, negative film is often used
Any advice would be most welcome.
Finally got around to doing up my old HW80 in .22. It used to shoot great with a rubbish old tasco4x40 scope on it but I recently picked up a Hawke Sidewinder 30 tc 8.5-25x42. Fitted a new spring and guides from TBT and put back together fine.
However, when zeroing (at between 10-20 yards all the shots land about 5 inches high! Swapped and changed the rings...no difference. Elevation totally topped out still had shots about 3" high of point of aim. Have googled it and followed instructions on optically zeroing the scope and setting the rings properly. Loosened the bolt in the rear mount (arrestor block) too. Still no joy. Any ideas?
One thing I should add is that the breech seal in knackered and needs replacing. Totally flat if not lower than the breech face and doubt it seals at all well (although it doesn't leak air above the join). Could this cause the barrel to point slightly skywards resulting in the high impacts? Got one on order anyway.
Other than that Im at a loss. Help please!!! :-)
try packing the scope under the rear mount, negative film is often used
Thanks guys. Yes, I had read about shimming. But have also heard that it should be avoided as can stress the scope tube. More importantly Ive read that many believe shimming simply masks the actual problem (which in this case presumably shouldnt be there). I'll try if owt else fails.
Also, just looked again at the rifle and there does appear to be an ever so slight uphill slope to the barrel as it meets the cylinder at the breech. Could be my eyes but wondering if the breech seal may be the culprit after all. Ever heard of this happening before?
Many thanks :-)
So how well does your old scope perform?
Don’t confuse luck with ability.
Yes that's it either the barrel is bent upwards (very common, if fired with barrel open - ouch!) or else - but not familiar with the 80 - if the barrel alignment is on the breech seal, and this is kaput, the barrel angles upwards. However I'd not have imagined the 80's barrel to align in this manner, perhaps someone can confirm or otherwise.
**WANTED**: WEBLEY PATRIOT MUZZLE END; Any Diana/Original mod.50 parts, especially OPEN SIGHTS
No bear trap on any hw80's I have seen either.
Anti bear-trap on a HW80?
It might be worth checking the barrel against a known flat surface. I had a BSA that shot a couple of inches high and the barrel looked perfectly straight. However it turned out that it was slightly bent up in comparison to the breech block. Hard to spot and made all the difference
My apologies. Not an anti-bear trap on the 80. I was under the impression they couldnt be fired with the barrel broke. By releasing the safety and holding onto the barrel I discovered I was wrong. Handy for de-cocking actually.
Anyway, just got back from a drive to collect a new breech seal & no it was not that. But at least I'm ruling things out. So if the barrel is inclined slightly upwards can it ben bent back without damage? TBH it looks straight compared to the breech block but does look a little 'pointy high' compared with the cyclinder.
Many thanks, P
At least you have a new breech seal, that can't hurt.
Yes they can be bent back but must be done carefully. It actually needs to be bent further than you would think to account for the spring back.
I've done it a couple of times and my process was:
- Use a straight edge to find where the worst of the bend is (the epi-centre of the bend I guess), and which direction it is bent in
- Lay a block of wood on the floor, with a smaller block in the middle to act as a pivot
- Lay the barrel down with the pivot at the epi-centre of the bend
- Ratchet strap both ends to the first block of wood and start cranking them up
- The barrel will bend about the pivot
- Measure how close the ends get to the first block. For example if your pivot is 20mm high, bend the barrel until the ends are 18mm from the first block
- Let it all go and test. If it needs more bending go to 16mm, 14mm etc
Second method is clamp the breech block in a vice and brute force it.
Best method is probably to take it to a gun smith but I like the DIY approach
Double check your scope with another known good rifle. Tick box.
Seal replaced. Tick Box.
Mounts correct, double double check. Tick box.
Stock, pivot pin, all screws good and tight. Tick box.
Air Rifle barrels are pretty soft and bend in wonderful ways. Moderators only add to the grief. Doesn't take much for a bend. Some of my well used air rifles have banana barrels; doesn't effect performance.
Bending them back is not easy. I've stamped and jumped on mine on occasions; not recommended. I use a meter long steel ruler to see where the have gone wrong. Really needs an engineering press to put them right. Wish I knew of one.