No4 Scope mount holes misaligned and drilled too deep?

[Thunderbox]

Could anyone advise on suitable scope and mounts for the BA20/21 combination to give lowest line of sight in order to avoid adding a cheekpiece on a No4.

Parker Hale mounts and a straight-tube scope. There is a whole thread about faux sniper scopes, and most of those scopes mentioned are a good choice.

[jmoore]

The sheer notion that you can screw a telescope front sight base to a No4 receiver ring and expect it to remain tight and soliud is the stuff of fairy tales. It ignores the basic schoolboy physics of rotational forces that you learned in your first year physics lessons at school. You know, clock and anti clockwise moments and all that stuff

Even more intriguing to me than the mounting stability is the affect of the deflection of the action upon firing would have on a well clamped scope tube over a fair number of cycles. The No.32 bracket's rear contact surfaces have some built in fore and aft "slippage" and it's robust construction would prevent transference of most strain to the scope tube proper.

BTW, it's more than a purely theoretical concern, I've seen more than one commercial scope that's failed through it's turret! (One piece designs-not so much, but I THINK Pecar tubes are assembled to the turret like most of the time period.)

[Peter Laidler]

There is no in built 'slippage' with the No32 bracket JM because the bracket is fixed onto the dowel-like spigot on the front pad. So fore and aft movement is limited to NIL! Just a small point because it is the front spigot and rear dovetail that ensure that the sight will always correctly re-align on reassembly. We had a wall chart to test for this.

Incidentally, the front spigots could and did shear off during recoil but there was a repair procedure in place. The spigot had to be a stonking good fit (that's another REME technical phrase for PERFECT mechanical fit) into the corresponding hole in the bracket.

[Bearclaw]

Pete, nothing wrong with he Leyland P76 collectors item now, you woulld have to trade an enforcer, maybe two now for a good one.

Myles

[Peter Laidler]

Go on, what's a Leyland P-76? That's not the Rover 3.5 litre that the poms called the SD-1 is it. When I was in Australia, we thought that BMC (for British Motor Corporation) stood for bloody mooka crap. Happy days............. I saw Rockhampton mentioned in the recent flooding and thought to myself, after having spent many weeks there and Canungra, that it couldn't have happened to a nicer place

[jmoore]

There is no in built 'slippage' with the No32 bracket JM because the bracket is fixed onto the dowel-like spigot on the front pad. So fore and aft movement is limited to NIL! Just a small point because it is the front spigot and rear dovetail that ensure that the sight will always correctly re-align on reassembly. We had a wall chart to test for this. Incidentally, the front spigots could and did shear off during recoil but there was a repair procedure in place.

I reckoned that the rear dovetail might slide fore and aft a few thousandths under recoil, but return when the load was removed. However, if the rear is locked from movement (dang, I can think of a fairly simple hydraulic test stand w/ a dial indicator that could test it, IF I could afford to potentially tear up a rifle!!) it would load the front spigot- leading to possible eventual shear failure...

[BushyFromOz]

I saw Rockhampton mentioned in the recent flooding and thought to myself, after having spent many weeks there and Canungra, that it couldn't have happened to a nicer place

[jss]

No4 scope mounting to Aussie Leyland P76???.
The P76 was indeed a great tool for towing a 3 ton yacht down to Scarborough marina!. Shame about the sharks and sandbanks in Moreton bay though!.

[spinecracker]

So True - thank God for that, I thought I was abnormal, but I must be normal as I have the same problem.

You and me both, Alan. Every time I shot the blooming thing, I'd get a crick in my neck, and that isn't good for a chiropractor....

I think I'll save my pennies for an L42A1 (who am I kidding....)

[Surpmil]

I agree with Peter: a Mickey Mouse setup if ever there was one. However, if you get the steel bases, not the laughable pot metal ones, and solder the front base onto the barrel ring, and solder the screws in too, you're as well set as most other cheap commercial scope mounts.

Collimation? Forget it. Zero at one range and be thankful for that!