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ian · New Member

tuning.
need to modify brocock .22 hunter from 10.7 over 11.5 thanks

broommaster2000 · Moderator

Do a search on google.

AirGunEric · Site Admin

That's a useful reply, Broom. That's probably how he got here.

The Brocock Hunter .22 is a PCP gun- so the power output is all in the regulator. Are higher output regulators available for it to swap in, or does one have to modify the existing regulator? I will find out.

Next question- what pressure is Ian putting through the gun? 1500psi, 2000psi, 3000psi? If you try putting more pressure into the air reservoir (do not exceed 3000psi no matter what) will this change how the regulator meters air? One way to find out... Mr. Green

AirGunEric · Site Admin

After looking into it a bit: Apparently the Brocock Hunter has a regulator that can be modified and there are versions of the rifle with a 40fpe regulator that sell in Mainland Europe and Australia.

I don't know where Ian is located- but seeing as how he wants to keep it around 12fpe- let's assume he's in the UK for the sake of argument.

I will attempt to locate some diagrams of the Brocock regulator. If they are not available- I will see about some "generic" regulators to give people an idea of what can be looked at to increase power output.

AirGunEric · Site Admin

After doing a bit more investigating on the Brocock .22 Hunter:

I re-read my first posts and realized I was being a bit unclear. Let me start over:

The Hunter has a built-in regulator assembly- which almost certainly also houses the valve components. Upping the reservoir pressure a bit might (might) allow the output to go up a very small amount- but not the 9-13% you are looking to achieve.

If I could find a parts diagram or description on the Hunter- I could be more specific- but for a small gain of roughly 10% in muzzle energy- just adding weight or pressure to the hammer may get you there. Adding weight by attaching something heavy to it- i.e. lead, or pressure by using a tighter hammer spring- which may also result in a heavier trigger pull. Another possibility is to put in a weaker valve spring- but this may change its overall shooting characteristics- quite possibly making them worse, not better. And lastly- there is the idea of drilling out the valve ports. As the gun is supposed to stay around 11.5fpe- if this is the route being followed, I might suggest only drilling out one port at a time, reassembling and testing to see what is gained before drilling another.

Also- based on the information I could gather from Brocock's own website- the Hunter is not actually made by, or for, them. It is, based on the structure of their website and the guns they explicitly state they do manufacture, quite possibly a gun from another manufacturer that they re-package and distribute. Alot of airgunners in Poland seem to have the Hunter (I don't read Polish- so my understanding of their topics was nonexistent)- leading me to suspect it may be a Czechoslovakian or Russian-made gun. I could be dead-wrong on this and the only reason alot of Poles own them is because they are relatively inexpensive as far as PCP guns go.

But if my idea is correct and anyone knows who might be making the Hunter, and under what name/model it might otherwise be sold outside of the UK- please fill us in. If I've read this right, perhaps the manufacturer has parts diagrams and lists available for it.

ian · New Member

thanks Eric.....very informative...i am in uk but don't think i'll be drilling ports out so will probably leave as is ..........thanks again....Ian