No more scope adjustment?

[RichardinDorset]

No, 600fps @ 16gn = 12.7ftlb so FAC, 570fps = 11.4ftlbs which is a good safe level.

Download Hawke chairgun for air rifle trajectory, if you zero at 28yds you can then just use holdover at longer ranges, but from about 10-36yds you will be aiming bang on the "+" to be within 1/2" of POA.

If you only ever shoot at 40yd targets then it might make sense to zero at that, but it gives a very steep & high trajectory curve so all other ranges will need to be inch perfect to get the pellet close.

Just dl'd Hawke Chairgun. I see what you mean now. A zero at 40 yards is a very high trajectory (like a howitzer!). Zero at 25 or 28 as you say makes more sense and I'll hold over.

Thanks for pointing me to that!

[air-tech]

If you have run out of adjustment - considering ideally you don't want to be anywhere near the extremes - I'd not shim but buy adjustable, or tapered mounts, whichever is cheaper actually, the tapered are one piece.

[angrybear]

Just dl'd Hawke Chairgun. I see what you mean now. A zero at 40 yards is a very high trajectory (like a howitzer!). Zero at 25 or 28 as you say makes more sense and I'll hold over.

Thanks for pointing me to that!

My pleasure,
the whole point of the BBS forum is to enlighten those who need help,

even at my angriest I'm still trying to get a helpful point across .

[jonr]

Ended up raising the back of the scope with tin foil shims. If you are careful and start large then smaller as layers go up wont damage the scope or mpunts and as foil is metal wont compress over time. 5 layers and the scope was almost centered so not at edge of adjustment.

Jon

[RobF]

Shiming is a cheap fudge that can damage the scope.

[xbow]

I've heard of folks lapping scope mounts - not just to true them up but also to put a slight slope in the setup. Adjustable mounts are fine as long as they don't "adjust" themselves at some point.

https://www.amazon.co.uk/WHEELER-INC.../dp/B001Q8IKOS

[krisko]

I use 2 layers of beer can stripe under the rear mount. never damaged the scope, you cut a long band, fold it half, make it flat, cut it to size.
it needs to be narrow rather then wide.

[Geoff555]

Hi, I had the same problem and as the amount of packing was, to me, huge at over .010 then I thought that a decent pair of adjustable mounts would be better. Pair because I could not use a single mount. Now it took a long time principally because I kept on forgetting which adjustment I had made, I really could do with more than one brain cell, but it is now zeroed with all the scope adjustments at zero IE: in the middle.
Job done, no possibility of scope damage and all the adjustment and more than I will ever need.
Cheers.
Geoff.

[Artfull-Bodger]

Take the O-Ring out of the barrel band (assuming you haven't) then check again, there should be plenty of adjustment in the scope unless the barrel is being tensioned by the band.

Next job is to check the barrel is set correctly, simply loosen the barrel retaining grub screw set the rifle in a vice or on a table with some weight to hold it and use either a DTI on the end of the barrel or put a pointer like a wooden kebab skewer in the end of the barrel with a little electrical tape to make it snug and mark a dot on a piece of card held where the pointer is, rotate the barrel slowly whilst keeping the rifle steady and check to see how much the pointer moves off the dot, most barrels have a little bend in them, if there is set the barrel so the highest point is vertical in line with the scope and nip the grub screw back up, this way any bend in the barrel works in your favour and no more arsing about with shims (adjustable mounts should be used anyway not shims).

[krisko]

your problem is very common.

even on a FX impact, the line of sight of a perfectly optically centered scope and the pellet trajectory never meet, should do.
so you need adjustable mounts or scope.

or a 10moa or so scope rail etc. it depends on the model/gun.

shimming works. does not cost a thing.

[RobF]

No but it does bend your scope.

[PCPShooter]

If you look at specs on Panamax you'll see very small moa range of adjustment -often 30
Optics warehouse and Uttings have heavily discounted these scopes

Nikon have a massive moa range Hawke have improved there's too now on most models

There are solutions but the best one is get another scope (after checking barrel been bedded in straight or not bent knocked), mind you most airgun makers will blame customers or shop if it came out of factory a lemon anyway ....

Yep, a scope with enough adjustment for 'THAT' rifle is best solution, I use taper mounts on several springers too, of course if they are germanic downward angled barrel design .....

[Gecko]

No but it does bend your scope.

On a PCP with the mounts only just ligthly nipped up with a one peice scope tube i dont see a problem with a couple of peices or film negative.

On a springer or a field target setup then yes its not ideal but i bet theres loads of big nikkos out there with 3 shims in the rear mount.

[RobF]

On a PCP with the mounts only just ligthly nipped up with a one peice scope tube i dont see a problem with a couple of peices or film negative.

On a springer or a field target setup then yes its not ideal but i bet theres loads of big nikkos out there with 3 shims in the rear mount.

Yes. And compare the wheel movement with 3 shims to that when they're not. There's a noticable difference because the parallax tube runs along the inside wall of the scope.

It bends the scope.

[Rickenbacker]

On a PCP

3 bits of bicycle inner tube, one under the front / two under the rear.

Elevation is easily adjusted by altering & balancing the screw tension fore & aft. I.E. Half a turn on the rear screws = 11mm @ 6 yards (or something).

Only thing is (and its a big thing), with all this rubber-mountedness, the reticle just loves to go off plumb while you're messing about with it. And you have to loosen the bugger right off to correct it and start over again...