.25 cal JSB King Exacts ... 155 yard target.

[Yrrah]

Last week at the farm I had a brief opportunity, "brief " is the operative word, to put some down at my 155 yard little cast iron frypan.
That wind we had dropped to almost nothing (not quite) for long enough for me to get four shots away then the breeze kicked in hard and there was no point in shooting the fifth shot: This was the only attempt. The BC input for Chairgun was 0.039 for my altitude of 1100+ metres. That is 0.034 at sea level and so I think that 0.040 at the farm or 0.0355 at sea level is about right for my rifle.



That's four shots in 1.3 inches 33 mm at 155 yards. ... I think these four shots, under almost ideal conditions, are still probably enough indication that these pellets can hold their stability far beyond normal air gun range. You may recall the 0.60 inch ctc 100 yard group I posted shot with them some weeks ago.

viewtopic.php?f=20&t=8808

While at the farm I was invited to get rid of a patch of rabbits that were spreading into a friend's farm from a neighboring property's warren. I had three late afternoon sessions and mostly shot from my parked Kombie. The tally retrieved was 34 rabbits to lasered 92 yards shot with the .25 JSB Kings at MV 920 fps ME 48- fpe. Many were from 70 to 88 yards. I lost just two others that were solidly hit but managed to kick into the burrows. .. Les now has more dog feed than he probably needs and that patch of rabbits was pretty well decimated.
Retained KE is 35 fpe at 50 yards and 26 fpe at 100 yards and for what it's worth 18 fpe at 155 yards................

I think this .25 cal BSA Hornet and JSB Kings are going to become a favorite combination ... Kind regards, Harry.

[RayG]

Retained KE is 35 fpe at 50 yards and 26 fpe at 100 yards and for what it's worth 18 fpe at 155 yards....(Quote)............

What a great performance from your "Beeza" and the new pellets,18fpe retained at 155 Yards. Mr Bowkett can certainly tune a .25 airgun and the JSB boys seem to have cracked it again with their .25 KINGS.
Do you think that you will ever go back to a powder driven rifle Harry?
Cheers, Ray.

[Yrrah]

Do you think that you will ever go back to a powder driven rifle Harry?
Cheers, Ray.

Normal sporting .22 rimfires? - I doubt it Ray. I still have a 1949 BRNO Hornet # 3725 which I find hard to part with and a Don Black Mashburn .218 Bee BSA Martini but seldom shoot them. I have mates who will lend me anything bigger that I may have an occasional use for but I think air power will pretty well see me through now. ... Kind regards, Harry.

[curan]

I think air power will pretty well see me through now

With results like that, I'm not surprised!

Mind you, with a view to the future, do you reckon we'll ever see any of those Korean .50cals in Australia? Shin Sung Dragonslayers?

And do you think that with work they could push the air performance envelope even further?

Or do you think better ballistics development (?) from the .25 is the way to go?

Interested in your thoughts (as always).

regards, curan. (oh, ps: stupid me, I forgot to mention......bloody nice shooting! )

[Yrrah]

[quote="curan"][quote]

Mind you, with a view to the future, do you reckon we'll ever see any of those Korean .50cals in Australia? Shin Sung Dragonslayers?
And do you think that with work they could push the air performance envelope even further?
Or do you think better ballistics development (?) from the .25 is the way to go?
regards, curan.

Curan the Korean big bore air rifles all suffer from rapid decline in velocity from shot # 1 and very few shots on a fill.
If I were to seek that power I would be getting Brendan Clarke in New Zealand to make me a .308.

Quote Brendan of Clarke Arms ... "Now if we're talking an even lower state of tune, say 90gr @ 850fps,
then the useful energy figure might rise to 1500 ft-lbs total, or just over 10 shots!" End quote.

Now that is 10 shots at 150 fpe 850+ fps . There would be nothing I would want to hunt that could not be dispatched with a 90 gr .308 soft lead bullet at that power. Brendan's .50 cal rifle has shot 3 shots into less than half an inch at 100 yards with a 330 Gr ( from memory) bullet.

Presently I think insofar as diabolo pellets are concerned the 15.9, 18.1 gr .22 Exacts and 25.4 gr .25 Exact Kings I have are the cutting edge. In best conditions they are all sub inch 100 yards pellets. Lead powder bullets shot from sporting rifles of any calibre have never done better.

JSB are going to make a heavier 30+ gr pellet. For rifles that will shoot 50 to 80 fpe that may be the ultimate diabolo. Bullets are another chapter. There are numerous on the market for air rifles. But so far accuracy is no better than run of the mill .22 rimfire ammunition. The BC potential is there but they have to be matched to barrel twist rate and the air rifle barrel makers have not entered that scene for obvious reasons ............ JSB have gone back to the drawing board on their .22 Monster JSB which is tending towards bullet ballistics. I did shoot down to half inch 50 yard groups with the originals but long range precision wasn't as good as I hoped for. The next iteration may be the bee's knees perhaps.

Can you get a big refrigeration plant going out Moomba way to cool down the west wind for us? ................ Kind regards, Harry.

[curan]

If I were to seek that power I would be getting Brendan Clarke in New Zealand to make me a .308.

Quote Brendan of Clarke Arms ... "Now if we're talking an even lower state of tune, say 90gr @ 850fps,
then the useful energy figure might rise to 1500 ft-lbs total, or just over 10 shots!" End quote.

Now that is 10 shots at 150 fpe 850+ fps . There would be nothing I would want to hunt that could not be dispatched with a 90 gr .308 soft lead bullet at that power. Brendan's .50 cal rifle has shot 3 shots into less than half an inch at 100 yards with a 330 Gr ( from memory) bullet.

Hi Harry,

Can you tell me where I could read a bit more about Brendan? I hadn't heard of him, and found nothing in a quick search of the net.

Oh, and I'm sorry, but I reckon all you'll see is more heat from the Cooper Basin at the moment. Mind you, I'll leave the esky lid off for 5 minutes tomorrow night and see if it helps!

regards, curan

[Yrrah]

Hi Harry,

Can you tell me where I could read a bit more about Brendan? I hadn't heard of him, and found nothing in a quick search of the net.
regards, curan

Curan here is a second hand reference to Brendan's work; and I spelled Clark incorrectly adding "e".

If you wish to make contact with him I shall seek his permission to pass on his email address.

Kind regards, Harry.

[curan]

Ah, that's fine Harry.

Using Clark (no "e") I found a little bit in a NZ air rifle site.

I just didn't know if there was some published info you were "in the know" about.
Because it is all interesting stuff.

Never mind, I'll just have to keep reading your posts for my entertainment and education!

regards, curan

[trapper]

Potter Firearms now has these in stock. $25 per tin of 350.

[Predator]

thats some tight grouping! I'm guessing the trajectory would be quite a large arc with these heavy pellets... how much bullet drop would there be at at 155 yards?

[Yrrah]

thats some tight grouping! I'm guessing the trajectory would be quite a large arc with these heavy pellets... how much bullet drop would there be at at 155 yards?

I zero the scope (Bushnell 6500 2.5-16 Elite 30mm tube side focus) for the target. So there is no hold over. For 155 yards the apex of the trajectory is then 19.2 inches above the sight line and that occurs at 84 yards. So the pellet is rising and falling to and from 19.2 inches as I presently have it tuned back to an MV of 890 fps.

However if you mean the actual drop from the bore line if the barrel was horizontal it would be a tad over 6 feet. A .22 rimfire bullet LV drops about 5 feet in 200 yards for comparison.
This last little while I have been busy shooting 200 yards and collecting ballistic coefficient BC data at 50, 100 and 200 yards. There are some real surprises. I doubt anyone else has ever shot over a Chrony at 200 yards before with an air rifle. or maybe a rimfire or perhaps even a c/f outside a bullet factory. I have now, and the data is most interesting. I will post some soon. Suffice is to say that out of my rifle at ME 45 fpe, these pellets shoot significantly flatter than my .22 Excalibre and other BSA Hornet shoot JSB .22s with the same muzzle velocity.... And they slaughter bunnies! .....

Edit. I should have written again that the scope has an 80 MOA elevation range and it is also shimmed in the rear mount. This allows me to presently click to zero to well past 200 yards with these pellets from 890 fps MV. MOst scopes only elevate to 40 or sometimes 60 MOA.
Kind regards, Harry.

[curan]

This last little while I have been busy shooting 200 yards and collecting ballistic coefficient BC data at 50, 100 and 200 yards. There are some real surprises. I doubt anyone else has ever shot over a Chrony at 200 yards before with an air rifle. or maybe a rimfire or perhaps even a c/f outside a bullet factory. I have now, and the data is most interesting. I will post some soon.

And there I was thinking you had been quiet for a while Harry!

and now I know why

Just when I think you are doing amazing things at 100 and 150, you just push that bar a little bit further.

Good on you, and I'll look forward to your posts.

regards, curan.