Printable View
So here's a question for you target shooters / real gunsmiths.
I have a lot of Parker Hale sight aperture inserts.
Their thread is 7/32-36 TPI
There doesn't seem to be a readily available in NZ ( or elsewhere ) tap in this size and pitch.
7/32-32 TPI is a thing and available, but no use to me
So who has a tap for the Parker Hale apertures ?
Brand, code, details etc please
That is an odd size. Might be a good case for making your own tap.
Bit like the enfield threads. Just made their own up.
Some crazy little numbers on those ones
Yes this is what I was thinking. A watchmaker's lathe and a fine hand!Quote:
Originally Posted by Makros
You know how to pick the odd projects, I'd have to agree with the others and you may be best making your own as this'll probably happen again and you'll only have to go through the learning curve later anyway.
Machine threads down to 4.90+mm, re thread to 5.0x0.8. they should be around 5.6 originally but in fact I've seen a few slight size variations that made fitting eye pieces from one sight to another a bit of a puzzle. If you could get a 5.5x0.7mm tap you would be in too.
The metric specs for 7/32x36 would be 5.6x0.706. I Think? Any help?
YehQuote:
Originally Posted by 00buck
Maybe approach the problem from another direction
My lathe imperial threads run out at 32TPI
Best bet would be Mike CollingsQuote:
Originally Posted by akaroa1
Sure it's not 7/32x40 or #12-40?
Not sure that I've ever seen that thread listed as a 36tpi, my little cheat list refers to it as a 40tpi?
Just checked. I have a range of apertures - AGP, PH 6 Hole, old PH single hole, very old PH 6 Hole (the flat type), Central sight aperture, plus some unmarked ones, and they are all 40TPI.Quote:
Originally Posted by No.3
Have the corresponding PH sight (and Central Sight) from my old 303 range rifle somewhere but the PH 6 Hole came out of it at any rate so no need for me to turn the house upside down to find it.
Mmmmm that might be the answer ! 36TPI is a good fit on the thread gauge. But 40TPI is also a pretty neat fit. Typical of ultra fine threadsQuote:
Originally Posted by No.3
So I will look into the #12-40TPI taps
Might be worth contacting Tracey Tools in the UK they have lots of unusual stuff
7/32-40 ME taps may be the jobby. Available in a couple of places in NZ but pricey at ~ 38 bucks.
Just going bush for a few days and will get on line over Christmas and see what's available locallyQuote:
Originally Posted by zimmer
Cheers
Well I did track down a full set of 3 taps for this job on loan.
Attachment 240396
They were only a short drive away and the gift of some fresh venison.
I know where they are for next time I need them.
Nicely converted the tiny edged rimfire sight staff to take the Parker Hale eye cups.
Played around to find an aperture size that gives a good sight picture with the globe front sight
Attachment 240399
Now I can continue with the load development and have a better chance of grouping with this 140+ year old rifle which has a very good bore
