Barrel/Breech Wobble

[ak27]

Hello fellow Airgunners,

I present to you yet another opportunity to share your knowledge and pool your expertise!

Have noticed an issue with the barrel/breech block of my IHP 35 and would appreciate your help on the same.

When the barrel is broken, there's a significant amount of side-to-side play in the whole barrel-breech block. This, I believe, has been present since the time I purchased the rifle back in 2009. Yes, I have been rather impudent in addressing the issue then. But in my defence, I was too excited to shoot the damn thing and hence overlooked it.

In the locked position however, there was no wobble at all. I used the rifle very sparingly and put just over a 1000 shots through it ever since I got it. More recently, Have noticed a slight wobble in the barrel even when it is locked. Now, this started to bother me!

My common sense suggests that I should just slam a couple of thin washers at the breech hinge and see how it goes. But, I am no expert and would seek your advice before proceeding. Hence, Please pour in your suggestions.


Thanks!

[AnandNair]

Just tighten the screws holding the barrel and breach. if required shim it

[ak27]

Thanks for the revert, Anand!

Just tighten the screws holding the barrel and breach.

Have already tightened the screw to its extreme.

if required shim it

This was what I was thinking too. But no idea as to what kind of washers to use.

The problem is that one of the forks that hold the breach is actually slightly deviating outwards and there's an apparent gap between the breech and the fork

Will post pictures tomorrow to make a better case. Cheers!

[Basu]

Take the receiver/chamber to any automobile garage.
Ask the person to reduce the gap of "H" part by 0.5 mm so that it fits snug with barrel part.
He will load it on vice and give a measured pressure.
Measured pressure is most important.
It should take 2-3 attempt to get to the exact gap.
Once done , then tighten the screw as per requirement.
Mere tightening of hinge screw, does not slove the issue.
Caution- One must not overdo ,that may lead to another issue.

Basu

[aadhaulya]

Take the receiver/chamber to any automobile garage.
Ask the person to reduce the gap of "H" part by 0.5 mm so that it fits snug with barrel part.
He will load it on vice and give a measured pressure.
Measured pressure is most important.
It should take 2-3 attempt to get to the exact gap.
Once done , then tighten the screw as per requirement.
Mere tightening of hinge screw, does not slove the issue.
Caution- One must not overdo ,that may lead to another issue.
Basu

Being from the automobile sector and running big workshops for 28 years, I feel this is not a good idea. The fellow working on the vice will do it in 2 to 3 attempts but will eventually overdo it and then try to file off the excess part.

It is better to go in for shims and get the accurate size by trial and error. There will be no chance of permanent damage. You can get different size shims from any automobile parts shop.

Regards

Atul

[ak27]

Take the receiver/chamber to any automobile garage.
Ask the person to reduce the gap of "H" part by 0.5 mm so that it fits snug with barrel part.
He will load it on vice and give a measured pressure.
Measured pressure is most important.
It should take 2-3 attempt to get to the exact gap.
Once done , then tighten the screw as per requirement.
Mere tightening of hinge screw, does not slove the issue.
Caution- One must not overdo ,that may lead to another issue.

Basu

Thanks for the suggestion, Basu. But, Can the pressure be precisely regulated?

Being from the automobile sector and running big workshops for 28 years, I feel this is not a good idea. The fellow working on the vice will do it in 2 to 3 attempts but will eventually overdo it and then try to file off the excess part.

It is better to go in for shims and get the accurate size by trial and error. There will be no chance of permanent damage. You can get different size shims from any automobile parts shop.

That's exactly my fear, aadhaulya. Think I should try different shims and zero-down, as you suggested.

Guys, Please refer to the attached pictures that may help elaborate the issue notwithstanding the shoddy image quality. Have stripped down the breech from receiver for better visibility.

P.S.: I'm thinking of putting the receiver in a bench vice myself and giving the forks a controlled squeeze, What say?

[Basu]

Bench vice should be operated by someone who uses it regularly.
Like shock absorber or car bush changing mechanic.
To my mind , this is the only way ,though you make try other's suggestion also.

Basu

[AnandNair]

That is clearly bent.
put it in a vise and straighten it. let the barrel be in its place (fixed to the cylinder) so that you dont over tighten it. just tighen the vice slowly so that the barrel is snug and then leave it there for some time. it may straighten the bend without bending toomuch towards inside.

[essdee1972]

Quick and dirty suggestion..... sell the damn thing on OLX and buy a new one!!

[ak27]

Quick and dirty suggestion..... sell the damn thing on OLX and buy a new one!!

On a serious note, I have plans to overhaul the darn thing right down to the bone. Its gonna be a Guinea pig of sorts!