Is this a candidate for barrel bending...3.5" low at 10 yds.

[JD]

I'm thinking I have enough droop (RWS 34) that I'm going to have to do some barrel bending. Even using the RWS droop mount it's shooting 3.5" low at only 10 yds. (Yes, the mount is aiming in the right direction) That's a bit much for the elevation knob to deal with. My scope is optically and mechanically centered using a mirror and V Block and I'd prefer to keep it close to that if I can.

I also have a Sun Optic adjustable ring mount but I don't think it can take care of that much droop either. It possibly could but the rear ring will probably be cranked as high as it can go which won't be real stable.

Before I head into the bending project (which I'm highly nervous about) I wondered if some experienced shooters could weigh in on this and let me know if that's the best solution.

Are there other one piece droop mounts with a higher rear elevation?

[1959 Moggy]

I have used the crook of a tree to bend a couple of airgun barrels...one of them a Model 34, and it worked great.

[BenjiHunter]

Maybe this will take care of the problem.
http://www.deben.com/rings-mounts-bases-2014/1-1pc-38-or-9-11mm-droop-compensating-mount-matt-black.html

[SagaciousKJB]

I have used the crook of a tree to bend a couple of airgun barrels...one of them a Model 34, and it worked great.

I used my front door, just resting the muzzle in the door jam and bending against the door. Was easier than finding a tree with a crook for me

[robertr]

 Try zeroing at 25 or 30 yards first and see how much droop you have there. I think ten yards is too close for zeroing your scope.

[redcobra04]

On my 34 in .177 it was shooting 6 inches low and 5 inchs right at ten yards. At 20 yards it was even worse. Tryied 1 pc droop compensating mount and two piece mounts. Either shooting high or low no matter what. And always shooting to the right. After spending around $150 on different set ups just bit the bullet and bent the barrel. Just bend a little and shoot 5 pellets at a time until i had it with in a inch of POA at 10 yards. That leaves a lot of adjustment left in the scope. Bending up is not noticable at all. Bending right or left is more noticable. Went a different route with both of my model 48,s. But thats a different story. Oh by the way when  i tried it at 20 yds before i got around  to bending the barrel shot out 2 of my garage windows. Had enough at that point.

[Jeff Marshall]

On Diana's the breech face is the stop for the barrel. Filing a small amount from the breech face will correct droop. It must be done carefully and slowly; .002" of material removed will correct a lot of droop.

This method WILL NOT work on many or most other brands of break barrel guns.

[stevemag]

http://www.gatewaytoairguns.org/GTA/index.php?topic=49873.0
barrel bending 101

[anuthabubba]

A slight bend is reversible. Removed material is permanent.

[Jeff Marshall]

A slight bend is reversible. Removed material is permanent.

Yes, but why would one want to reintroduce droop?

[anuthabubba]

A slight bend is reversible. Removed material is permanent.

Yes, but why would one want to reintroduce droop?

And how would you correct the removal of too much metal at the breech as it continues to wear over many thousands of cycles?

[Methuselah]

Oh by the way when  i tried it at 20 yds before i got around  to bending the barrel shot out 2 of my garage windows. Had enough at that point.

I was aiming a 1911 looking one-cock bb gun aiming at the little chrome trimpiece between the headlamps on my 65 Bonneville from maybe 15 feet away and didn't know how little power those things had.  Hit smack in the middle of the bottom headlamp.  Couldn't help it, laughed myself silly 

[JD]

I've read about filing the breech and a few have claimed success but as nervous as I am about barrel bending, it seems safer to me.

I tried my Sun Optics mount last night and with the rear ring WAY up, I did get the elevation right. However that high it was unstable and came loose after one shot. All the screws were tightened as much as I could. The rear was more than 1/8" higher (almost 3/16") than the front and that's only in 4".

So unless there's a mount that extreme I guess all I've got left is bending.

On the bending, it seems like there are several schools of thought. There are those who use the door jamb/tree trunk method and those who say you must bend it right where the barrel inserts into the breech. Both have success but the bend is in different places. I doubt you can bend at that precise point when using a tree trunk.

Any thoughts about the different methods?

[Methuselah]

Any thoughts about the different methods?

Purely spitballing and zero practical experience ... I'd check things out first;

1.  Use a straightedge against the barrel, is it straight

2.  If #1 is yes, does the breach block machining look uniform and sensible

3.  Could too much, or too little (none) shimming, or a detective breach seal account for the droop

4.  Is everything concerning the barrel pivot/pin assembly seemingly 100%?

If the barrel looks straight and is mounted true in the breach block my personal choice would be filing the lockup surface, if too much you can still bend the barrel.  My only worry is getting the angle good enough for maximum contact between receiver and breach block ... a wrong angle/minimum contact will wear and put you right back where you started.

Just my thoughts and $·02

[Jeff Marshall]

And how would you correct the removal of too much metal at the breech as it continues to wear over many thousands of cycles?
[/quote]

First of all, do not remove too much material, and breech faces do not wear down after many thousands of cycles.

[robertr]

 Definitely bend the barrel over filing breech. Bending a barrel is simple and any mistakes can be easily fixed and you won't be taking the chance of screwing up your breech alignment.

[JD]

I'm wondering about the 2 different methods of bending per my post above. I've pretty much sidelined the breach filing idea. Not something I'm willing to try at this point.

[R1]

Put a small level on the receiver and level it in a gun vise.  Put the level on the barrel and see the difference. I also check the level of the breechblock.  This should give you an idea where to start. 

[JD]

That was an excellent suggestion. I leveled the compression tube then checked the barrel and of course it was off (drooped). But then I checked the breech block and it was off the exact same amount as the barrel. That told me the droop problem is caused by the breech, not the barrel. So maybe I have to revisit filing the breech.

Is Diana completely unable to machine a breech that's square to the matching face?? Or is it a pivot pin placement problem? I've seen comments that the droop is intentional because the rifles are set up for shooting with sights not scopes but I don't buy that. Both sights are on the barrel/breech so the breech face could be off by a whole lot and you'd still hit what you're aiming at with sights.

I don't know how many thousands I'd have to take off by filing but even with the breech seal being well proud of the surface I'd think the connection might become loose. I still don't like the idea even though it seems logical.

[robertr]

 Or you you could just by a set of FX adjustable mounts, that might be the easiest solution.