Mk1 vs mk2 JSB 25 HEAVY

[Frank2533]

I have 6 tins of mk1 and out of that six 3 tins measure 8.5 mm in length 2 tins measure 8.75 mm in length and one tin measure 9mm in length
My impact will not shoot the 9mm heavies without wobble
But the 8.5 to 8.7 will shoot perfectly straight and accurate.

Now the mk2 measure 8.3 to 8.4 in length and they shoot the same as the shorter mk1s

 

[hsnmz]

How about the weight difference? Sort them by weight and see the groups tightening up

 

[Frank2533]

I don't have a scale need to get one any recommendations

 

[wll]

I have just shot MK1 out of the tin at around 975+fps out of my Condor ..... so far they are shooting great.

wll2506

 

[Frank2533]

That's freakin fast