TargetTalk

Hey guys, I was looking at an acquaintance's BSA Martini with PH sights on it. The rear had a Gehmann rear iris on it though... does anyone know if that is normal? I have read there is an adaptor and some say you just screw it in the PH rear. Anyway care to school me on this?

Thanks,
B

That is correct but no idea where you would get one where you are!

Martin Catley wrote:That is correct but no idea where you would get one where you are!

That these just screw in or you need an adaptor... or it depends on what Gehmann iris you have?

The ones I have seen are complete adapter with male PH thread on one end and female on the butt end. A Gehman Iris will screw directly into this.

As far as I know all the European Iris set ups ( Centra Anschutz Gehman) have the same thread and diameter (larger than PH) and would fit these adapters.

Years ago we had a Gunsmith who would cut off from the sight the threaded area and replace it with a block threaded for Gehman etc. Some were impossible to do depending on how they were put together!

You may find someone who sells Iris's who has adapters for the British sights.

Is this the item you need?

There is also an adapter available from customgunparts.co.uk that appears to be a bit shorter in the thread and neater, with a knurled grip, price £16.50 plus postage.

Gehmann have occasionally made irises with a specific PH thread, like this http://www.intershoot.co.uk/acatalog/Ge ... d-184.html

But yes to fit a Gehmann iris that has the standard 9.5mm thread to a PH rearsight requires an adaptor.

One of the problems that using a Gehman or other similar iris unit is size. I have a Fulton converted mauser K98 TR rifle with the AJ Parker rearsight. This is very similar in design to the PH ones. I also have thread adapter and use my Anschutz Iris/5 colour filter unit with it. I think this is actually an Anschutz branded Gehman unit. With the thread adapter screwed into the windage arm, and then the length of the unit it brings the whole lot quite a long way back compared to a standard PH multi hole aperture. Fortunately the 60's era stock design has quite a long butt, so that it actually places the aperture about right for a modern position when using the iris unit.

I mention this because the location of the rearsight on the action of my mauser is fixed, just as it is when using AJ parker/PH sights on a smallbore BSA Martini rifle. This can be an advantage or disadvantage depending on how you find the eye relief currently. I got my thread adapter for the Mauser from either the NSRA shop or Fultons at Bisley, but it would have been around 1990. As far as the sights are concerned Parker Hale went out of business years ago, PH is now just a trade name used by John Rothery Wholesale, mostly for gun cleaning equipment and lubes/solvents. About eight or nine years ago I was able to get a replacement reconditioned AJ Parker TZ1 rearsight for my Mauser from them as they were at least then still in business in Birmingham England. If they are still going they may be able to help with PH sights as well. The designs were almost indistinguishable unless you really know what you are looking at.

Alan

BigAl wrote:I mention this because the location of the rearsight on the action of my mauser is fixed, just as it is when using AJ parker/PH sights on a smallbore BSA Martini rifle.

Alan

Alan,

that's not true of the International series, which I think the OP has. The pre-war designed 12s and 12/15s have the rearsight bolted directly onto the receiver, but the PH25 rearsights found on the Internationals mounted via a grooved bracket. The rearsight could be moved back and forth to alter eye relief; admittedly the range wasn't great, but it could be moved.

Yes, the PH25C sight can be moved as stated above. So the real question is... if I find an adaptor, is it worth getting a Gehmann for it or, should I just leave it as it is right now? I have never used a Gehmann Iris before but, they look impressive. I have shot the standard PH25C sights, they seem to work fine for what I am doing.

Just curious to know if this is worth another $200 plus investment....

What sort of eyepiece does it have at present? The standard option was a 6-hole disc, but P-H did make their own iris eyepieces. The 6-hole offered aperture sizes from 0.030in to 0.080in in 0.010in steps. Under normal light conditions 0.040in and 0.050in are about right. A Gehman iris would offer more flexibility, and the option of colour filters, polarisers, and if you want a variable focus 1.5X lens (this last is not permitted under ISSF rules), but as you say is more expensive. Try the standard eyepiece, and if you don't get on with it, then think about upgrading to a Gehmann.

As an aside, I would suggest seeking out a good selection of foresight elements, particularly in larger sizes. The size of the foresight aperture can have a profound effcet on your grouping.

Closer to home. Nikkos in Quebec carries them.

http://www.ebay.com/itm/Gehmann-Rear-Si ... 566a728ee1