Modski66
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Helpful member, Share holder & resident Barrel Smith.
Go ahead, make my day - give me a pie!
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Post by Modski66 on Apr 13, 2023 22:09:45 GMT
Starting to get the hang of this pistol now after all the tinkering to improve the fps. It seems to like Meisterkugeln or R10, giving a slightly sharper hole in the target card than the Econ II. Muzzle velocity is around 360fps, which is just a shade up over the Econs. However, they are blown into the weeds by the Kvintnor Delta extra light lead pellets, which pop out at over 425fps! Not sure about the accuracy of them though, opinions welcome based on the two cards pictured for comparison.  |
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Post by HeadHunter on Apr 13, 2023 23:35:08 GMT
The Supertarget certainly lives up to its name with the MK 4.5s ! That's a great grouping for 8m  But the Kvintor Deltas leave you thinking that you were shooting a gat gun, in fact you could have probably shot just as well (if not better) using lead BBs, lol.  |
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Post by flatrajectory on Apr 14, 2023 7:00:24 GMT
Mark,
I am interested to know , what you have done to improve the fps.?
Pete.
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Modski66
Moderator
Helpful member, Share holder & resident Barrel Smith.
Go ahead, make my day - give me a pie!
Posts: 3,774
Likes: 4,661
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Post by Modski66 on Apr 14, 2023 16:05:44 GMT
The main thing was to eliminate the dead space at the end of the piston in order to improve the compression ratio, I used some 0.1mm aluminium foil tape, adding four layers to the front of the piston, I also polished all the machining marks from the breech face around the transfer port. Swapped the breech and piston o-rings for x-rings (or quad-rings), but these didn't have as much effect as I hoped. The other things I did were relieve the breech taper a bit, and radius the outer edge of the barrel breech so that the barrel could be pushed as close to the breech face as possible without it digging in at the end of the compression stroke.
I got all the tips from a guy called Steveoo on the airgun nation forum, I will dig out the link to the thread later for you.
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Modski66
Moderator
Helpful member, Share holder & resident Barrel Smith.
Go ahead, make my day - give me a pie!
Posts: 3,774
Likes: 4,661
|
Post by Modski66 on Apr 14, 2023 16:51:28 GMT
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Post by flatrajectory on Apr 14, 2023 18:58:00 GMT
Thanks Mark.
Pete
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