Phoenix Hy Score Query

[steve medlock]

Could anyone please tell me what the silencer thread is please. My pistol is missing the silencer and I would like to make a replica.

I've just spent ages trying to measure it and still not a clue. I would have expected UNC if they used the US tooling but it doesn't seem to match up. So much harder to measure an internal thread than an external one!

Steve.

[WebleyWombler]

Could anyone please tell me what the silencer thread is please. My pistol is missing the silencer and I would like to make a replica.

I've just spent ages trying to measure it and still not a clue. I would have expected UNC if they used the US tooling but it doesn't seem to match up. So much harder to measure an internal thread than an external one!

Steve.

No experience with the Hy-Score but never seen a UNC thread on the muzzle of anything. Usually UNF for airguns and rimfires or UNEF for the bigger powder burners. Can't see it being a Metric fine

[Ragle Jnr]

I'll dig out mine and check with a thread gauge, will take some time to find both! David

Oh, well external dia of thread is ½ inch, but neither my metric or un thread gauges match! It's less than 20 tpi, and coarser than 1.75, angle similar to metric. I reckon 16 tpi, if any one can do Whitworth or BSF that might help. David

[Farsight]

I'll dig out mine and check with a thread gauge, will take some time to find both! David

Oh, well external dia of thread is ½ inch, but neither my metric or un thread gauges match! It's less than 20 tpi, and coarser than 1.75, angle similar to metric. I reckon 16 tpi, if any one can do Whitworth or BSF that might help. David

Do you mean 1.25 ?

[Ragle Jnr]

No, in metric threads the numbers are the distance apart of the top of the threads, so they are closer, finer as the numbers decrease. The coarsest thread in my gauge is 1.75mm, and it's finer than my silencer.
Perhaps an engineer with a set of thread tables can find what it is, given the age of these I suspect whitworth or British standard fine, unless it's a weird American size, given their origin. David

Just googled whitworth threads, 1/2 WW has 16tpi, so try and borrow a bolt or plug tap to check, may still be a different pitch!

[WebleyWombler]

No, in metric threads the numbers are the distance apart of the top of the threads, so they are closer, finer as the numbers decrease. The coarsest thread in my gauge is 1.75mm, and it's finer than my silencer.
Perhaps an engineer with a set of thread tables can find what it is, given the age of these I suspect whitworth or British standard fine, unless it's a weird American size, given their origin. David

Just googled whitworth threads, 1/2 WW has 16tpi, so try and borrow a bolt or plug tap to check, may still be a different pitch!

From what you have written, I'd be looking at 1/4" NPT

[steve medlock]

Thanks for the interest so far chaps. I should have said that I went through the taps that I have at the outset.

Its larger than 1/2 BSW and thread is finer. Also larger than 1/4 BSP.

I've managed to self tap a bit of delrin rod in and out and the pitch is bang on 1.5mm (17tpi).

bearing in mind these were made circa 1990 (?) is it M14 x 1.5 ?

Steve.

[johnbaz]

I just measured mine at 14.15mm and has 16 tpi, 14.2mm is equal to 9/16" and a 9/16UNF has 16 tpi so I reckon it's a 9/16UNF





EDIT, I divided 25.4 by the 16 (Pitch) which came out at 1.5875, This is the (Metric) pitch given when I looked back at this site..

Thread site

Another edit!!, I only have metric thread guage but have several imperial thread files, I used a thread file to id the pitch at 16tpi



John

[steve medlock]

A quick update on this great mystery!

I forked out £9 on some sample bolts and the results are in...

9/16 UNF - spot on for diameter, but the thread isn't close. I turn before it binds.

M14 x 1.5 - slightly looser fit than above but will go in about 6mm before it binds (hole is about 20mm deep).

So' I'm fairly sure, as David suggested, that its 9/16 BSF.

I've not managed to find a bolt in that size as yet unfortunately. I was just going to cut one but I think my thread tools are all 60 degrees.

Steve.

[Ragle Jnr]

If you have a local classic car or motorcycle restoration enthusiast near you, they may have some of these bolts or even tap and die sets you could try. Google BSF thread and you may find the thread angle, then grind a single point cutting tool, I recall doing this 50 years ago! David
PS BSF thread angle is 55degrees, same as WW.

[Mobiasstrip]

Hi, thread perfectly fits my Whitworth 55° 16G 3/8 thread gauge.
Thread outer diameter is 14mm.
http://imgur.com/gallery/ydK1qJk
Not sure if this helps as, to be honest, I'm not 100% sure how to interprete the gauge as it's a long time since I used one 🙄

[Modski66]

Bit of a thread resurrection...

I will hopefully receive a Phoenix Hy-Score pistol in the next couple of weeks, it does not have the silencer included, but am looking to make a suitable adapter on my lathe with 1/2 UNF at one end, and 9/16 BSF at the other.

Reading the above thread, I have located a suitable die, but before I commit to buying it, did the conclusion of the wise members prove that it was indeed the correct thread specification?

[harvey_s]

On the back of this resurrected thread, if anyone has as a Pheonix loading end cap going spare I'd be very interested...