Hy-Score US vs UK

[45flint]

Someone asked when I posted my Hy-Score collection to compare the UK model to the US version. Tough part is you can only compare the models you have and since these are all second hand guns it is impossible to know how many rounds have been fired through them and under what conditions. With my UK version I have only one choice but with the US version I have allot of choices. I chose a 1952 Sportster with multi-barrels that was in good shape to best match the UK version. Also my UK version is a early one so I don’t know if later guns improved?

1. Differences - obvious the UK slab sides give a more modern look, nicely done. Exterior parts the same. Internal piston looks very different. See pics below: the first pic is the US piston.





2. Fit and finish- US gun is better, far better bluing, cocking does seem just a little smoother and more precise in feel? Yes very subjective.

3. Power- tested with 7 grain Hobbys in .177:

A. UK 5 shoot string averaged 388 with a high of 395.
B. US 5 shoot string averaged 431 with a high of 437
C. I do have a US Repeating Sportster that averages well above 500 FPS. This gun is the exception.
Have standard US Hy-Scores in great condition that average 350 FPS but most US guns I think would shoot in the
400s.

I think much of the variation in US Hy-Score power is the variation in the springs. Very noticeable that at least some of the 700’s had weaker springs than later guns. These guns were manufactured for 20 years so much room for variation. Also as a whole there are two areas where air leakage is possible and may vary between guns, the loading iris and the concentric barrel.

As I have said before with these types of pistols difference in power seem pretty immaterial given the ranges and the types of shooting you will do. Your not going to go hunting with one of these, just fun target and plinking.

I have read on this forum many posts that said the UK advertised power of 500 FPS was never really achieved by these guns. Seems to run true with my example. But I do have a US example that shows it is possible. Below this 1952 Repeating Sportster averaged above 500 FPS and I’m sure it’s stock and seems shot little?