JSB Exact King Heavy standard vs. MKII

[sen]

Has anyone measured with a caliper the skirt diameter of the standard Exact King Heavies and the MKIIs? Some say that the MKIIs have a smaller skirt diameter and fit better in some mags... Thanks in advance.

MOD EDIT moved to Pellets & Projectile section

 

[sonny]

i think its the length that makes them different, the MK2s are shorter and the king 25s are even shorter. 

 

[Pelletpinger]

The MK11’s definitely have a smaller skirt, I have to put the MK1’s through a sizer before they will load into my Impact breach without straining the cocking arm. 

 

[sonny]

I too have an impact. It wouldn't take either one of the heavy's 1 or 2s into the magazine without damaging the skirts until i had Ernest modify the magazine, now it loads and shoots them perfectly. Thanks Ernest.

 

[sen]

Thanks for your reply, Sonny. Yes, I know that the MKIIs are shorter. So far I thought that was the only feature that's different in comparison with the standard Heavies. I know JSB started making the MKIIs because the first version did not fit some mags.

 

[sen]

Pelletpinger, do you mean that you use the MK2s without any problem in your FX Impact as opposed to the MK1s? I am asking because the MK1s do take some effort to fit in my Edgun Matador R3M mags... I intend to buy some MK2s in bulk and I don't want them to turn out to be the same skirt size, as I already have enough MK1s...
Also, have you noticed the performance and accuracy of the MK2s to be lesser than those of the MK1s?

 

[Pelletpinger]

"sen"Pelletpinger, do you mean that you use the MK2s without any problem in your FX Impact as opposed to the MK1s? I am asking because the MK1s do take some effort to fit in my Edgun Matador R3M mags... I intend to buy some MK2s in bulk and I don't want them to turn out to be the same skirt size, as I already have enough MK1s...
Also, have you noticed the performance and accuracy of the MK2s to be lesser than those of the MK1s?

Yes the Mk2’s drop straight into the mag no problems and load just fine straight out of the tin. 
Performance wise they both performed equally as well. 

 

[sen]

Thanks for all your replies, guys. I appreciate your assistance and I will try the MK2s :yes: I will share some info on how they fit into the Matador mag as soon as they get here.

 

[grackleblast]

The MK II will fit in your RM3 mag very well.This is the only pellet I shoot out of my Edgun RM3. They load smoothly, and then for extra measure I give the magazine a good smack on the table to seat them better. Hope this helps.

 

[sonny]

sounds good sen ill be looking for your review on them good luck brah!

 

[Glem.Chally]

Both fit very well in my Royale, I have both the MKI and MKII currently the Barracuda's won't fit in the 10 shot "mini magazine" but both heavies cycle nicely and fit nicely into the breech. MKI is slightly taller with a deeper skirt as far as I know.

 

[sen]

Grackleblast, thanks for the info. Pellets will be here this Saturday morning and I will try them asap.

 

[jps2486]

The Mk 1s skirts are thinner, therefore should obturate more easily during the shot cycle. My gun likes them better than the Mk2s.

 

[Haganaga]

Now wouldn’t the mk 1’s being longer have a better BC? I have a single shot R3 so no mag and can shoot almost any size. 

 

[sen]

Hi everyone. I just received the MK2s. I don't have a caliper with me, but there is no doubt whatsoever that the skirt diameter of the MK2 is smaller than the one of MK1. I am loading the MK2s in my mags with the ease I load JSB Exact Kings 25.4 gr.
Pelletpinger and Grackleblast - you were absolutely right guys, thanks again :yes:

Haganaga, I have my chronograph with me. Later today I will measure velocities at 0 and 30 meters with both MK1 and MK2 and I will calculate and post here the BC of both pellets as achieved with the barrel of my Matador R3M Short. It may not be exactly the same BC that your Matador will give you, if yours is Standard or Long, due to the barrel length and/or power setting. But I think the difference would be insignificant, something along the lines of 0.001 or 0.002.

As a point of reference, my Kalibrgun Cricket .25 gives me a BC of 0.048 with the MK1.

 

[sen]

MK2 has a BC of 0.046 with my Matador Short. MK1 gave me almost the same - 0.047. An insignificant difference, in my opinion - may be due to the calculation, the digits after the decimal point and the ballistic calculator rounding up. The MK2 shoots at a slightly higher velocity - 9-10 fps. It surprised me, as like jps2486 said, I expected the thinner MK1 skirts to obturate better. It appears the Matador likes the MK2 more than the MK1.

 

[SMH77]

"Haganaga"Now wouldn’t the mk 1’s being longer have a better BC? I have a single shot R3 so no mag and can shoot almost any size.

Yes, the Mk I's have a slightly better BC than the Mk II's. I've tested both extensively, and have posted the results in the Pellets forum.

I just finished testing both again at 95F and have tested them at various temps from 15F up to 95F to see how the BC's change. Group wise, both shoot very tight in my RAW with polygon barrel, but the Mk II's seem to throw out an occasional flyer that the Mk I's don't, so I consider the Mk I's more consistent in my setup. Others (I think particularly in FX guns?) seem to prefer the Mk II's better.

I'm working on compiling a temperature vs. BC comparison to share shortly. Look in the 'Pellets' forum for that information. As a side note: this thread really should be moved to that forum since it's about pellets...

Sean

 

[Haganaga]

Thx for that. Now before I ask the question, I have searched and have found no results. How do you find the .25 Edgun heavies compare to the Mk 2's?

 

[Lazer1958]

Yes, the Mk I's have a slightly better BC than the Mk II's. I've tested both extensively, and have posted the results in the Pellets forum.

I just finished testing both again at 95F and have tested them at various temps from 15F up to 95F to see how the BC's change. Group wise, both shoot very tight in my RAW with polygon barrel, but the Mk II's seem to throw out an occasional flyer that the Mk I's don't, so I consider the Mk I's more consistent in my setup. Others (I think particularly in FX guns?) seem to prefer the Mk II's better.

I'm working on compiling a temperature vs. BC comparison to share shortly. Look in the 'Pellets' forum for that information. As a side note: this thread really should be moved to that forum since it's about pellets...

Sean

Hi Sean, I'm new to AirGun Nation Forum and I can't find the Pellet forum. I was wanting to look at your test results comparing the Mk1's to the MkII's. I feel really awkward asking you this but I'm new and I'm old, lol. Just got into PCP's and I need some help please. TIA

Lazer1958, Tommy