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Legacy Member
I have a problem with the engineering of the sight mountings of these rifles or indeed, ANY rifle where the front sight base is screwed into a 4mm thickness of breeching up ring. I keep thinking of my engineering physics lessons - you remember them, the total clock and anti-clockwise rotational moments and all that. I wonder just how substantial the front mounting pad grip on the body can possibly be, being retained in place with 4 or 6BA screws threaded into a base of 4mm or so.
The recoil forces and rearwards rotating forces on the telescope must be substantial. (In fact, I could work them out mathematically if I had the weight of the telescope...) I remember that even with the old No32 on the No4 and L42 could and would rotate under torque and shear off the locating spigot on the front rifle pad. In fact we had a repair policy formulated for them.
These are my views. Any comments asto the mechanical sustainability of these front pads.
As for their strength when used in the sniping role, being battered and bruised during a long stalk across Salisbury Plain..............
Whilst I hav'nt fired off thousands of rounds thru' a rifle with the PH mounts used on the Enforcer I have fired in excess of 100 in one day and several 100s over a few weeks.
This was with the Enforcer clone I built.
I cannot argue with the theory / mathematics / metalurgy but in practice they have NOT shifted or screws loosened 'one-iota' (an 'iota' is a non-armourers term meaning an immeasurably small amount)
I'm not stalking across Salisbury Plain which may help.
Brian - they were used at the Iranian Embassy siege in London but I dont know if they were actually fired. If only we knew the serial numbers of those ones, what a story.
(NB - the Metropolitan Police had 45 Enforcers, the highest number held by any force, closely followed by Glasgow with 44)
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Thank You to Alan de Enfield For This Useful Post:
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11-11-2009 01:21 PM
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It's true of course Al, that the proof of the pudding is in the eating. It's just the not even 4mm (it's 3.75mm / .147") depth of thread that's worried me slightly. Hope that I haven't upset anyone...............
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Legacy Member
Hope that I haven't upset anyone...............
Not me !
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Legacy Member
They were used during the Balcombe Street siege as well.
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Sorry to get wound up a bit, but I've also given the local USMC M40 (not so much the M40a1) fans a bit of a hard time too, can't help myself sometimes.
BTW- Amongst other things I've watched my first M40a1 clone fall onto a linoleum faced concrete floor directly onto the Unertl's top turret w/ no loss of zero. Also had my real M85 ruin its modded P-H one piece mount (also w/ a Unertl 10x government issue- but not US...) when the quick release sling swivel failed after a day long hunt.The sling was packed away until it got dark; now slings are just for emergencies. Rugged is a major requirement for me!
Anyone know where to find the P-H one piece ring set? 1" would be best.
Hopefully, an Enforcer will follow me home one day- Maybe I can be a little gentler to it. Gotta keep the Samsonite gorilla caged sometimes.
What few Enforcers I've seen did not have a scope still on them. Did they get removed when sold from service?
Last edited by jmoore; 11-12-2009 at 03:18 AM.
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The PH 5C's use the same or a very similar mounting bracket and seem to shoot happily for decades without any hassles on rifle ranges.
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Have I missed something in the thread T-bone? I thought the PH5C. was bolted to the side of the rifle body. While there will be rotational forces, with the 5C set-up, you'd be trying to shear the bolts as opposed to pulling out a tenuous thread
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Advisory Panel
Surely the recoil forces on the PH scope blocks are forward and down: e.g. during recoil the scope slides forward and down, whilst the rifle body moves backwards and upwards.
The scope therefore pulls forward on the rear BA21 mount (to which it is locked by a stud), which in turn pulls on the No4 rearsight cross pin, but pushes the front block down and forward. Thus the two little BA screws are mostly experiencing a shear force and some compression, for which they are presumably more than adequate.
I think we also forget that, in the era these things were designed, 'scopes tended to be small and light, compared to the heavy monsters used today. The PH system seems to be sufficiently robust with a lightweight scope such as a Simmons Whitetail or the Enforcer's Pecar.
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Threaded fasteners are not designed to operate under shearing loads except in the unthreaded portion. Generally, for tension loads there needs to be at least three theads in FULL engagement which usually means at least five threads entering the hole.
Whilst the clamping forces exerted on most commercial bases holds things together fairly well (kind thoughts help, I reckon), I've seen plenty of U/S mounting screws on rifles that no longer hold zero. Plus, one of my L42a1's had its front pad screws severly joggled after an apparent solder failure. The initial firing session displayed rather poor shooting capabilities;the problem wasn't detectable until the screws were loosened-they were all so offset that it was difficult to remove from the pad. (Very rectified now!-Unfortunately a friend has it back after a convoluted trade.)
That's enough ranting from me... Back to Enfields!
Last edited by jmoore; 11-13-2009 at 02:56 AM.
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