FX Impact MkII .22 600mm w/Nielsen 31.2

bobgm3 · Sep 13, 2020

Decided to follow Bob O’s direction to get a harmonic tune on my Impact MkII.22 600mm. Followed the instructions laid out in his YouTube: https://www.youtube.com/watch?v=biIg0iiZjFU&t=369s

Started with a velocity tune at 850 ft/sec with Nielsen 31.2gr. Made small adjustments until 1 hole group at 30 yds on the splatter target.

Took it immediately out to 100 yds. Shot 7 groups (zeroing as I went along). Made very small adjustments to the valve. All respectable groups. 4 of 7 under 1 MOA. 1 group at .17″!

I’m happy!

qball · Sep 13, 2020

.17 group at 100 yards???? That is simply ridiculous!!!

I really should spend some time doing that too, my setup is identical to yours: impact MK2, PO and 600mm .22 superior liner. I got mine to shoot 23 grain NSA really well but don’t think it’s 1 hole at 100 yard good. That’s simply amazing!

bobgm3 · Sep 13, 2020

Thanks qball, The .17" is a bit crazy but the thing I'm most happy about is all the groups are pretty good right at 151 bar on the reg. Hammer on Max right at end of the adjustment range and valve just about 3/8 of a turn from max. The .17" group was at 858 ft/sec average. The liner is the Heavy Superior. Give those 31.2 a try!

qball · Sep 13, 2020

Thanks for the info! I really want to shoot the lighter 23 or 25.8 grain slugs, so far they are amazingly accurate and had no issues consistently hitting a bottle of water at 160 yards. However it definitely isn’t .17 inch at 100 yards! Hell I’ll be happy with 1/2 inch group at 100 which I think is very doable. I really need to spend some time harmonic tune my impact.

For comparison shooting 23 grain slugs 840 FPS out of impact mk2 600mm superior liner my regulator is still under 90 bars and hammer spring screw half way.

bobgm3 · Sep 14, 2020

qball, yeah the 31.2 does eat the air up fast at 151 bar. I have a couple boxes of the lighter NSA in various weights. I will give them a try too! -thanks!

Bob_O · Sep 15, 2020

Wow.....thats impressive bob!!

I'm glad you took the time to do this and for posting your results.

bobgm3 · Sep 16, 2020

Thanks Bob_O, I thought I'd bit off more than I could chew when I purchased the MkII. I'd never even adjusted the HST on my Airforce Talon in 10+ years of ownership! I rationalized that with all the info out there I could get a handle on it at some point. Of all the video's on how to tune yours made the most sense to me. Simple and straightforward. I'm very pleased with these results and I am going to explore other weights with this set up using your method. I'm the one who should be thanking you for taking the time to post that video!

One other thing, during the tuning process, instead of hanging the FX Chrony off the end of the barrel I hung it off the front of the extended saber pic rail and just put the bi-pod right behind it. I haven't seen anyone mention this, I know it doesn't matter for a velocity tune but it seems like it is imperative to have the chrony anywhere other than hanging off the barrel during a harmonic tune-

qball · Sep 16, 2020

Very good point point on not hanging the chrono off the barrel. I usually meter the speed and then shoot groups without it.

any luck with trying out 23 of 25.8 grain slugs? I got a 500mm TJ barrel and tempted to try to shoot slugs in it too.

bobgm3 · Sep 16, 2020

Hey qball, I will be giving them and a few others a go this weekend hopefully!

Bob_O · Sep 16, 2020

Good to not attach the chrono to the barrel during the harmonic tuning process.

I will be doing this again when the Javelin slugs arrive. I have been thinking of doing a video of the whole procedure.

bobgm3 · Sep 17, 2020

Bob_O I'm interested in the Javelin slugs too. Hope you decide to do the review-

Kurt110 · Sep 17, 2020

Received a whole range of Javelin slugs today, 23 gr, 26 gr and 30gr, in both .217 and .218. Will be testing them soon. First need to get my brand new FX Impact 600mm tuned. Impressed with the service I got from Patriot. Packaging is innovative. Like it.

I'm keen to support products from real enthusiasts and shooters. Let’s hope my rifle likes them.

bobgm3 · Sep 17, 2020

Hi Kurt, please let us know how they do. Gerhard and Matt seem to love them. I know they have a stake in the game but I bet your results will be interesting!

Search

Search

FX Impact MkII .22 600mm w/Nielsen 31.2

bobgm3

Member

qball

Member

bobgm3

Member

qball

Member

bobgm3

Member

Bob_O

Member

bobgm3

Member

qball

Member

bobgm3

Member

Bob_O

Member

bobgm3

Member

Kurt110

Member

bobgm3

Member