Scope mounting problem.

Shooting Supplies : Ammo - Reloading - Firearms - Optics - Accessories
So an ex military K98 receiver that probably requires the alternative set of bases to fit snugly.

I know that some shooters criticise this type of Redfield/Leupold mount but I have always found them to be very solid and the ability to centre the windage without resorting to the scope's internal adjustments can be useful. I have a similar set on one of my rifles (Mauser M18) and they have remained rock solid since I set them up 5 years ago.
 
8x57 said:
So an ex military K98 receiver that probably requires the alternative set of bases to fit snugly.

I know that some shooters criticise this type of Redfield/Leupold mount but I have always found them to be very solid and the ability to centre the windage without resorting to the scope's internal adjustments can be useful. I have a similar set on one of my rifles (Mauser M18) and they have remained rock solid since I set them up 5 years ago.
Click to expand...
I like the setup (apart from the fact it's not quickly and easily removed and replaced in the way the original P-H rings were).
It looks good and feels solid, and allows me to use a 30mm tubed scope.

So, with the consensus of opinion shifting towards the possibility that they're the wrong bases, can anyone tell me if there's an identically styled set available that are correct, and will accept those Weaver rings?
 
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Yes I added the part number in a previous post but you probably missed it as I did it as an amendment.

I think the Leupold part number that you require is probably 52370. I'm sure that if you went into Norman Clark's he would have a set on hand to confirm it.
 
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8x57 said:
Yes I added the part number in a previous post but you probably missed it as I did it as an amendment.

I think the Leupold part number that you require is probably 52370. I'm sure that if you went into Norman Clark's he would have a set on hand to confirm it.
Click to expand...

My next question:
Does anyone know of any available in the UK?
A quick Google search shows plenty available elsewhere in the world, but a distinct lack closer to home.
 
Who says it’s not the scope?

Did you check the rifles action screws? Check the scope screws?

Bases look correct to me. FN / commercial bases are the same, just designed for a flush rear bridge - your PH is either a commercial or ex military (yes, they did use them at one stage) that’s had the charger hump milled off, and in that case, the milling and polishing work will likely explain the tolerance gap.

I doubt very much the gap will be the issue, best to bed it, but it’s not affecting a huge amount of surface area, I suspect it will be fine left as is. I’ve had many narrow bases with no more mating surfaces than you see.

I would not start filing the rear base!

I would suspect the weaver rings in Leupold bases to be the culprit. How did you turn in the front base and align it dead on with the rear ring before dropping the scope in? How tight was it?
 
triggertrix said:
Who says it’s not the scope?

Did you check the rifles action screws? Check the scope screws?

Bases look correct to me. FN / commercial bases are the same, just designed for a flush rear bridge - your PH is either a commercial or ex military (yes, they did use them at one stage) that’s had the charger hump milled off, and in that case, the milling and polishing work will likely explain the tolerance gap.

I doubt very much the gap will be the issue, best to bed it, but it’s not affecting a huge amount of surface area, I suspect it will be fine left as is. I’ve had many narrow bases with no more mating surfaces than you see.

I would not start filing the rear base!

I would suspect the weaver rings in Leupold bases to be the culprit. How did you turn in the front base and align it dead on with the rear ring before dropping the scope in? How tight was it?
Click to expand...

That's all food for thought, thank you.

The tiny gap would never have been noticed if I hadn't gone over the whole set up with a fine toothed comb looking for anything that might have moved. It really is fag paper thin.

I turned in the front base, and aligned it, using a piece of dowel of the correct dimensions.

It is possible that the scope itself moved forward under recoil, but no more than 1mm.
 
VSS said:
That can't be done. The front and rear bases are completely different.

That’s basically what I've done so far.

Norman Clarke is a good shout. I pass Rugby fairly regularly.

You're correct.
But the packaging also states that they're P-H compatible.

Agreed. That's exactly where I'm at with this.

That's helpful info, thanks. Bedding it is definitely something I could do myself, before resorting to more expensive options.
I might PM you for more detailed instructions, if thats OK?
Click to expand...

Of course, give me a shout and happy to help
 
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Mounting scopes on older rifles will always require a degree of work and gunsmithing. Modern rifles are built on modern machinery, mostly with CNC machines so that are built to very close tolerances. Old Mauser actions were built on multiple machines, each doing a machining job with tolerances controlled by patterns and dies.

Doesn't really matter what shape the rear bridge is or if its it parallel to front ring when using open sights. Its one of the reasons why many earlier mounts were single piece attached to the flat side of the reciever (but these were enormously expensive).

So when mounting a scope to such a rifle there is either:

1) quite a bit of truing up work to be done on the receiver so that the bases and integral and inline with each other - one if the reasons why Mauser based custom rifles are expensive

Or

2) you need to take up the tolerances in the bases by either fitting carefully by hand and smoke, with scrapers, taking a tenth of a thou at a time. Or using an epoxy based bedding compound.

With two piece bases you still have the fun and games of making sure they are parallel in all planes. You might be better off using a leupold one piece base because then you at least know that the mounts for the rings are in line.

Mostly bases would be bonded onto the action so there is no chance of vibration and movement.

Then once bases are set up you need to

3) ensure that the rings are perfectly in line with each other. You will need a 30mm lapping bar and to lap
The rings so that they put full even contact with the scope with no stress.

If you consider basic geometry with a rifle with a yard long barrel, 1 thou of movement in the bases, translates to 100 thou at the target at 100 yards, so any movement, tension etc in the scope mounts can have a pretty significant impact down range.
 
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Could it be the reticule. It was zeroed but the adjustments you made for the first few shots didn't fully register, then the recoil made the reticule jump to where you had in fact adjusted it and the last few shots where true to that?

S
 
sh1kar said:
Could it be the reticule. It was zeroed but the adjustments you made for the first few shots didn't fully register, then the recoil made the reticule jump to where you had in fact adjusted it and the last few shots where true to that?

S
Click to expand...
I did also consider that, as the scope hadn't been used for a while so might have "stiffened up" internally, if such a thing is possible?
Certainly there was only one unexplained jump, and after that my shots were consistent to the new POI.

I might have a fiddle about with it later today, if I get time. Busy making burgers at the moment.
 
VSS said:
That's all food for thought, thank you.

The tiny gap would never have been noticed if I hadn't gone over the whole set up with a fine toothed comb looking for anything that might have moved. It really is fag paper thin.

I turned in the front base, and aligned it, using a piece of dowel of the correct dimensions.

It is possible that the scope itself moved forward under recoil, but no more than 1mm.
Click to expand...
I’d not be inclined to worry too much about the small gap. It is perfectly possible the scope might have slipped, especially if not moderated.

scope ring screws still as tight as when fitted ?
 
triggertrix said:
I’d not be inclined to worry too much about the small gap. It is perfectly possible the scope might have slipped, especially if not moderated.

scope ring screws still as tight as when fitted ?
Click to expand...
I do know that my previous scope, in P-H rings, did slip a bit initially, so it's not inconceivable that the same has happened here.
The scope tube is 124mm long, and the distance between the outside edges of the rings is 123mm, so the maximum it could have moved is 1mm, assuming I had the scope mounted as far to the rear as possible.

I don't think most people would even have noticed the gap under the rear base, but now I know I know, which is creating uncertainty.
 
Is it at the end of one adjustment range? The springs if pushed to the extreme, can behave erratically towards the far end of adjustment ranges.

If it stays where it is now, and all screws are tight. It has probably settled into its final position, hopefully! 😂
 
triggertrix said:
Is it at the end of one adjustment range? The springs if pushed to the extreme, can behave erratically towards the far end of adjustment ranges.

If it stays where it is now, and all screws are tight. It has probably settled into its final position, hopefully! 😂
Click to expand...
No, it's nowhere near extreme end of adjustment.
 
triggertrix said:
I’d not be inclined to worry too much about the small gap. It is perfectly possible the scope might have slipped, especially if not moderated.
Click to expand...

This is how far a cigarette paper will easily slide under the base. It's exactly the same both sides.
No amount of sideways pressure by me on the ring will cause it to move and pinch the paper.
1000010590.webp
 
Take them off, degrease action and bases, remount with a bit of devcon or similar. had similar happen with my PH1200C, and this solved the problem
 
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