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Parker-Hale 5c "2" |
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Strangely Brown 
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 Topic: Parker-Hale 5c "2"Posted: October 25 2024 at 3:58am |
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This oddity turned up on an L39A1 owned by the Lee Enfield Rifle Association; we've had the rifle stored in the NRA armoury at Bisley for some years as part of our collection, along with Envoy serial number 1.
And nobody has noticed it isn't like other normal P-H5C's.
The MoA scale is in 6's which makes it very unusual, I mentioned it to Geoff, (britrifles) some weeks ago and in the meantime an identical sight was found in a box of bits by LERA's club secretary which is the one in the images. My first thought on hearing about was that the sight might be in 1/3 MoA and my second thought was that it could be in "small" MoA as used at various times by the Aussies. The way to confirm what a sight is graduated in is to measure the elevation scale with a vernier micrometer which if the sight is in normal (or big) MoA will give you 50 MoA per half an inch. If the sight is graduated in small minutes you will get 60 MoA in half an inch. This sight gives 66 MoA per half inch! What is it and what was it produced for? Well the jury is still out on that one, my own thoughts were that it might have been made for 300M shooting where every bit of accuracy counts, the downside to that theory is that Lee Enfield actions have never been in vogue for that discipline. Might it have been an attempt at metrification and given to the military to test? Given that it was on an L39A1 that theory might hold some credence. I've been in correspondence about it with a Queens Prize winner turned forensic scientist who would like to examine it. My current assumption, having been told that are others out there and no published information that I can find, is that it was probably a failed research & development project that escaped Parker-Hales factory when everything was sold off.   |
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Mick
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Shamu
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Posted: October 25 2024 at 2:33pm |
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Wild, off-the-wall suggestion. For MILs? (mrad)  The sniper community got into them heavily at one point? https://en.wikipedia.org/wiki/Milliradian |
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Strangely Brown
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Posted: October 25 2024 at 2:44pm |
Yes already discussed! I'm hoping that our forensic scientist can do the math better than I can; if it was an attempt at Mils than the British target rifle community (being very conservative) would have rejected it without question. It took some years to move on from .303 let alone moving on from minute of angle!
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Mick
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britrifles
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Posted: October 25 2024 at 5:17pm |
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Mick,
Based on a 29 inch sight radius, the back sight rise required for a true MOA is very close to 0.008 inches. The PH 5c2 gives something very close to this based on your measurement of 0.50 inches rise for an indicated 66 MOA (0.0076 inches per MOA indicated). The back sight rise required for 66 true MOA would be 0.53 inches. So, I suspect this rear sight gives very close to true MOA values. Perhaps the reasons the scale is marked in 6 MOA major increments is to distinguish it from the previous PH 5C “MOA” scale. I thought perhaps this sight was made for giving true MOA on the L39/Envoy, but not quite. Note that I’m using a 1 inch per 100 yards to define a MOA, which is not exactly correct, its more like 1.05 inches per 100 yards. I’m curious how the windage scale compares to the regular PH 5C |
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britrifles
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Posted: October 25 2024 at 5:23pm |
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Mick, did Bisley range change from yards to meters? Or are the targets still placed at distances of 100 yard multiples?
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Strangely Brown
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Posted: October 26 2024 at 2:33am |
Geoff, Many thanks for your technical thoughts on the previous post, I'll keep you (and the forum) informed when the rifle gets examined by our forensic scientist and whether or not he's able to make sense of it. Bisley is in yards except for a couple of notable exceptions; the 300m sheds being one of them where the shooters and monitors are under cover...not for long though as there is a plan to demolish them and put a 100 yard/metre?? shed in for zeroing and barrel breaking in...do people still break barrels in? I'm also told by those with laser range finders that the 200 yard Short Siberia range is closer to 200 m...but not quite! On some of the older military ranges the yardage signs have simply been swapped for signs proclaiming the range to be in metre's...given that the UK military have in the past rarely shot over 300 yards I can understand the cost implications. |
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Mick
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Sapper740
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Posted: October 26 2024 at 2:43am |
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I see rifleman.org has added your sight to their site and is requesting information from anyone with experience or knowledge of your PH5C2.
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Strangely Brown
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Posted: October 26 2024 at 2:54am |
Yes LERA's club secretary sent pictures to Terence Smith who owns rifleman.org; sadly the link between those who worked at Parker-Hale and those still living is becoming rather tenuous to ask.
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Mick
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britrifles
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Posted: October 26 2024 at 4:19am |
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I looked over my own notes on the PH 5C backsight. The windage and elevation movements measure 0.100 inches for each 10 “MOA” graduation. I put “MOA” in quotes because it is not a true Minute of Angle.
To calculate the elevation rise (or windage deflection) in true MOA of the PH 5C Backsight on the No. 4 rifle with a 29 inch sight radius: [Inverse TAN (0.01/29)] x 60 = 1.185 MOA This gives a linear movement of the bullet point of impact of: 1.185 x 1.047 = 1.24 inches per 100 yards Note that a true MOA angle subtends 1.047 inches at 3600 inches (100 yards) and is calculated by: [TAN (1/60)] x 3600 = 1.0472 inches To obtain a true MOA angular movement on the No. 4 rifle with a 29 inch sight radius, the backsight would need to move 0.0084 inches per MOA. The backsight would need to move 0.00806 inches for a 1.00 inch rise/100 yds. And that’s pretty close to what this PH 5C2 backsight gives. |
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Strangely Brown
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Posted: October 26 2024 at 5:29am |
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Geoff, your an absolute star!
The unanswered questions that I still face, why was it never marketed, and why is the scale in 6's? I suspect we will never know. I have done a cut & paste of your very erudite calculation and answer and sent it to the LERA secretary and Terence Smith who runs the Rifleman.org. website.
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Mick
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britrifles
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Posted: October 26 2024 at 6:02am |
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Mick, I can only guess that the different marking was to draw attention to the shooter that the backsight gives different angular movement per “MOA” than the more traditional PH 5C. It would be an instant reminder when looking at the elevation or windage scale.
As to why this was not more popular than the 5C? Perhaps these came out just prior to the new TR class with the longer barrels and 7.62 chambering, so never really caught on? Again, just my speculation. It is a most interesting find, something that would be highly desirable. |
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Strangely Brown
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Posted: October 26 2024 at 6:16am |
Geoff the range distance scale goes to 1200 yards suggesting that it was made in the .303 era so your theory could be right. Another thought I've just had; possibly for Match Rifle shooting coupled with a gallian foresight and "clearing lens" fitted to the rear sight. This was shot exclusively between 1000 & 1200 yards and the finer clicks would have helped?
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Mick
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britrifles
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Posted: October 26 2024 at 7:43am |
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Mick, is it 1/4 click “MOA” adjustment? I’d suspect so, looks like the cylindrical elevation and windage knobs fitted rather than the 1/2 click MOA knobs.
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Strangely Brown
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Posted: October 26 2024 at 7:46am |
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Geoff, yes 1/4 MoA and the knobs are marked the same, I counted the clicks for confirmation when it was handed to me.
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Mick
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britrifles
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Posted: October 26 2024 at 7:47am |
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I just noticed what looks to be a stamped marking on the elevation knob “1/4 Min”.
My PH 5c knobs don’t have this marking, perhaps an additional indication that this really is a 1/4 minute (1/4 inch per 100 yd) adjustable backsight.
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Strangely Brown
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Posted: October 26 2024 at 7:54am |
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That hadn't occurred to me Geoff; so yes, everything is pointing to this being "true" MoA as you suggested.
It's the finer details like that which are often missed!
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Mick
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