First impressions of the JSB King Heavy (33.9 grain) 25 cal- pellets

[blackdiesel]

This is not a full review but just my first impressions of the pellet. Right away I noticed they seemed over large when I tried to load them in the magazine of my Sumatra. Normally any pellet will fit into these mags with no problem. So I measured the pellets. The heads are .250 but the skirts are .260. I have read of other people got the same measurements so it wasn't a fluke in my case. I decided to see how they shot none the less. I shot them at the highest setting . There was no curve at all. The first 3 shots were over 1000 fps with the highest being 1026 fps. After the first 3 shots speed dropped about 10-15 fps with the sixth shot being at 975 fps. I only shot at 25 yards and they were hitting one hole except the last 2 which dropped slightly. They maybe a viable pellet but I hate forcing them into the magazine. I had to use an allen key to make sure they were fully in the magazine and prevent problems cycling them. Hopefully JSB will correct the skirt size issue. I had planned on using them mostly for long range plinking because I figured I could adjust my power to shoot them around 950 fps and still get a nice curve and at least 18 shots. This what I get with Benjamin Domes and Barracudas now and figure, heavier pellet, better wind management. I'm glad I didn't jump in wholeheartedly and buy a lot of these. I will continue to experiment with different power settings to see if I can make them work for me.

 

[SteveS.]

Yeah I have some on the way, hopefully tomorrow, and I'll let you know my findings. I heard that it was a tight fit too. So I think your on the money with that. We'll see. I will get back to ya. I wonder if JSB puts there tests out there for people to see and read. I'm going to look it up. Best Steve

 

[Yrrah]

Hopefully JSB will change nothing.
I started pestering Pavel to make this pellet over 4 years ago. The .30 and .357 cal craze set it back.
I re-size all my .25 pellets to .2500".
Have just done that with these King Heavies and shot over the Labradar to get ballistic coefficients at four ranges to 20 yd. Each shot recorded at 5, 10, 15 and 20 yd.
The velocity retention and derived ballistic coefficients are stunning.
I have never seen any diabolo pellet that comes remotely close to matching what I'm seeing. 
Yes I did put a control King and some .177 heavy Exacts over the radar to ensure it was still showing their particular values at today's temp, humidity and At pressure.
My BSA barreled FX Elite is loud. Thus here in cityland I shot just a few. Silencers are forbidden in OZ. 
Am glad I held off buying another tube of Kings. These have been sitting with Customs Border Control for a month. My real tests begin this coming week as we go to the farm on Monday.
You guys play around with them. I am really looking forward to putting them through the Pinelea paces ..... Best regards, Harry.

 

[blackdiesel]

"Yrrah"Hopefully JSB will change nothing.
I started pestering Pavel to make this pellet over 4 years ago. The .30 and .357 cal craze set it back.
I re-size all my .25 pellets to .2500". So couldn't care less that the soft thin skirts are what some rifles' magazines may see as large. I don't have a use for .25 cal magazines and prefer my two single shot rifles. 
Have just done that with these King Heavies and shot over the Labradar to get ballistic coefficients at four ranges to 20 yd. Each shot recorded at 5, 10, 15 and 20 yd.
The velocity retention and derived ballistic coefficients are stunning.
I have never seen any diabolo pellet that comes remotely close to matching what I'm seeing. 
Yes I did put a control King and some .177 heavy Exacts over the radar to ensure it was still showing their particular values at today's temp, humidity and At pressure.
My BSA barreled FX Elite is loud. Thus here in cityland I shot just a few. Silencers are forbidden in OZ. 
Am glad I held off buying another tube of Kings. These have been sitting with Customs Border Control for a month. My real tests begin this coming week as we go to the farm on Monday.
You guys play around with them. I am really looking forward to putting them through the Pinelea paces ..... Best regards, Harry.

Maybe you don't care but I'm sure there are more magazine shooters than single tray shooters. After I exhaust the 2 tins I bought I probably will not get anymore unless they are resized. I'm sure they're leaving a ton of lead in my barrel and I hate cleaning my barrels frequently.

 

[scotty]

Blackdiesel, maybe you could get someone to drill a hole in some plate steel that is the diameter of the skirt you need to function in your magazines. I imagine you could round the end of a drift punch of the appropriate size and push the pellets through and get them to the size you need. Not super efficient but should work on the cheap and yield your long range results and not harm your magazines. It would be nice to have them function out of the box but second to that it would be nice to have a flat shooting thumper. Good luck whatever you do. 

 

[blackdiesel]

"scotty"Blackdiesel, maybe you could get someone to drill a hole in some plate steel that is the diameter of the skirt you need to function in your magazines. I imagine you could round the end of a drift punch of the appropriate size and push the pellets through and get them to the size you need. Not super efficient but should work on the cheap and yield your long range results and not harm your magazines. It would be nice to have them function out of the box but second to that it would be nice to have a flat shooting thumper. Good luck whatever you do.

I think the better option is just to use Barracudas, Eun Jins or Benjamin Domes  

 

[DKL]

That is great news

 

[Yrrah]

Maybe you don't care but I'm sure there are more magazine shooters than single tray shooters. After I exhaust the 2 tins I bought I probably will not get anymore unless they are resized. I'm sure they're leaving a ton of lead in my barrel and I hate cleaning my barrels frequently.

BD, are all the repeater magazines on other rifles as tight as your Sumatra's mag? 
I was under the impression that Korean barrels tend to be oversize to match Eunjin and other Korean pellets.
I had no problem resizing these new pellets through my die, manually, with a cut off plastic knitting needle. The skirts are very soft.
Short of resizing them for your Sumatra magazine, it may just not be the pellet for your Sumatra rifle. 
In any case I've removed that sentence BD. It was a little blunt I guess. We'll see what other shooters find in their repeater rifles ... Kind regards, Harry.

 

[blackdiesel]

"Yrrah"

Maybe you don't care but I'm sure there are more magazine shooters than single tray shooters. After I exhaust the 2 tins I bought I probably will not get anymore unless they are resized. I'm sure they're leaving a ton of lead in my barrel and I hate cleaning my barrels frequently.

BD, are all the repeater magazines on other rifles as tight as your Sumatra's mag? 
I was under the impression that Korean barrels tend to be oversize to match Eunjin and other Korean pellets.
I had no problem resizing these new pellets through my die, manually, with a cut off plastic knitting needle. The skirts are very soft.
Short of resizing them for your Sumatra magazine, it may just not be the pellet for your Sumatra rifle. 
In any case I've removed that sentence BD. It was a little blunt I guess. We'll see what other shooters find in their repeater rifles ... Kind regards, Harry.

Hey Man no problem, I didn't take any offense to your words. I was really surprised the pellets were as tight in my magazines. I've shot slugs and the EJ 43 gr pellets which are very large and they fit in the magazines with no problem. The pellets seem to be accurate, but I only tested them at 25 yards. They may not be the pellets for me as I'm worried that they foul up my barrel ( I hate cleaning barrels) and just the trouble of having to almost force them into the magazines. The good thing is that my gun shoot other pellets very well so I have options. I just hoped these would be a bigger, better version of the Kings in my gun. Lately, I've kind of veered away from hunting and shooting live targets (just for the hell of of it), so I can be perfectly happy with the Kings for shooting long distances.

 

[Killzone]

Mr. Diesel – I’m curious of your concern of leading the barrel with the 34 JSB’s pellets over the 25gr. I understood that the pellet skirt conformed to the barrel during the initial shot cycle when the air pressure behind the pellet pushed the pellet skirt against the I.D. of the barrel. This has been shown in other threads where bent or damaged pellets have been shot and it appears the pellets skirt re-formed and the damaged skirt had no impact on trajectory. 

If we look at the .25 diameter pellet with 2000 psi behind the pellet we get a little less than 100 pounds of force initially, pushing the pellet down the barrel. That seems to me to be enough to force to form the skirt to the I.D of the barrel. So, I think any pellet with the same lead alloy would be formed about the same way and leading would be similar independently of the pellet used.

But perhaps your imperial testing has shown different results?

 

[blackdiesel]

They seem accurate, I haven't did extensive testing. My concerns are that they will leave more lead in the barrel and causing me to have to clean it more frequently and just the hassle of forcing them into the magazines. I saw a pellet that Baxter Walton shot through his gun and there is a lot of groove marks on it so I just thought there would be a lot of lead left in the barrel. Comparisons of smooth twist barrels vs conventional barrels show that regular rifled barrels need cleaning more than smooth twist which hardly leave any groove markings. At this time, since I don't plan to do a lot of hunting, the only advantage is more power and it's not enough to balance the other issues I have with the pellet. I'm sure they will work for other people. I plan on shooting up the tins I have but don't plan to do extensive testing because I don't feel it will show anything that radically change my need for them.