JSB 33.9 MKII vs JSB 33.9,s fps

[ohio_hunter]

are the 33.9 MKII's faster fps than the regular JSB 33.9's?i searched around a bit but came up with nothing.i now going to drag out the F1 chrony and test to see if the MKII's are faster.i thought I read somewhere they were 20 fps faster but a test will tell...

 

[villaman]

Faster and more accurate in my impact 

 

[stoti]

Yep mine shoots them 15-20fps faster and more accurately too. And...my Superior liner shoots pellets faster than the slug liner by 15fps but the slug liner is more accurate with the King Heavies...In my gun anyway!

Stoti

 

[ohio_hunter]

 i just shot them both over my F1 chrony out of the 25 streamline and they shoot the same fps...i shot ten shots each and there was no difference for me...they are both very accurate out of the rifle.last year I used the 33.9's for hunting but this yeari i using the 33.9 MKII's.

 

[vmaxpro]

I think it depends on the velocity. Regular 34gr I cant shoot over about 890, mk2’s I can push at 1000 and still be accurate. Arent the skirts thicker on the mk2’s? 

 

[ohio_hunter]

I think it depends on the velocity. Regular 34gr I cant shoot over about 890, mk2’s I can push at 1000 and still be accurate. Arent the skirts thicker on the mk2’s?

I was referring to same rifle same air pressure and the MKII having more fps...I think the MKII's are a little smaller skirt,the load easier in mag.

 

[ohio_hunter]

today after shooting more pellets over the chrony there still was not any fps difference to speak of but what I did notice was the 33.9 MKII's shot with less a fps spread...i also think they(MKII's)were slightly more accurate overall,giving me better groups at 42 yards than the JSB 33.9.s.

 

[triggertreat]

The MKIIs have thinner skirts for better expansion in the bore compared to the MK1. The MK1s may just need more power behind them for the same bore sealing.

 

[SniperM]

Is the 33.9 MK II more accurate in the FX Impact than the Kings 25.39. I have not shoot them in my impact yet. Going to install the Huma transfer port and there probe and ordered some of the MKII with the Huma order. Also do they tend to buck the wind better then the lighter Kings,