Ghost Ghost HP .22 Light Hammer Spring - TUNE TRIALS

[IRBent]

Can the MRD be backed down around 880-900 and give you good accuracy? And is there good accuracy mid 900s with the 18.13gr? If so that may be ideal.

I've not shot groups with the MRDs yet, or since swapping to the light .047" spring. So far I've not been able to get the MRDs above 850fps but I've not tried to ease the reg up further after watching the velocity drop yesterday once I went from 108 to 110bar. As for the 18s, that sub MOA group I posted, .33", was at 964fps. So yeah, my gun tends to group pretty well even above 900fps. Here's that 18gr group shot at 964fps.

 

[AtlasAirguns]

I've not shot groups with the MRDs yet, or since swapping to the light .047" spring. So far I've not been able to get the MRDs above 850fps but I've not tried to ease the reg up further after watching the velocity drop yesterday once I went from 108 to 110bar. As for the 18s, that sub MOA group I posted, .33", was at 964fps. So yeah, my gun tends to group pretty well even above 900fps. Here's that 18gr group shot at 964fps.

View attachment 851

That is a nice group

 

[IRBent]

That is a nice group

That was the 4th group I shot after polishing the barrel with JB's and Flitz.

 

[Solo1]

I was getting springs from ebay from china. Got i think it was a 1.2 mm wire which was the same as the 47 got a 1 mm stainless which was a little too light ( the 1 i refered to above) and searched all over for a 1.1 mm wire but couldn’t find any.

 

[IRBent]

I was getting springs from ebay from china. Got i think it was a 1.2 mm wire which was the same as the 47 got a 1 mm stainless which was a little too light ( the 1 i refered to above) and searched all over for a 1.1 mm wire but couldn’t find any.

The weight rating is where it's all at, moreso than wire diameter. You can get a .047" spring the same size as the BRK Light spring, but with different strengths in pounds per inch.

Note the screenshot where the 3rd from last column on the right lists weights for .047" springs and the dimensions are all usable per measuring the OEM springs.

 

[Solo1]

Well dealing with Chinese they had wire diameter spring diameter and length. Got 1 the same as the 51 spring too. If you find something a little lighter than the 47 get 1 for me too please i know all that i ordered were in groups of 10

 

[Solo1]

Well now i remember why I didn’t order from that site min $40 order. Lol

 

[IRBent]

Well dealing with Chinese they had wire diameter spring diameter and length. Got 1 the same as the 51 spring too. If you find something a little lighter than the 47 get 1 for me too please i know all that i ordered were in groups of 10

Let me try to measure the weight rating on the .047" and .051" springs. When using the .051 spring the shot cycle was pretty airy but had plenty of power. @ 150 bar and PW on MIN, the 18gr JSBs were singing @ 1100fps I believe. That's why right out the gate I adjusted the reg down to @ 113 bar per the OEM gauge but I think the new digital gauge showed 108bar. I was hoping the lighter spring would let a crisp sharp blast of air do its thing, and it is. However under very limited testing, it might not be strong enough to send the MRDs.
I bet if we measured multiple BRK springs of the same size, they may not all fall into the same weight rating, not exactly, but I could be wrong.

 

[Solo1]

Well if you look at the listed weights they pretty much go along with wire diameter they even have a couple 1.1 mm wire i just don’t want to buy $40 worth

 

[Franklink]

There a lots of places online where you can plug in spring specs and get their rating.

I went through all this when I was hunting springs for the Ghost and generally learning the gun. I HAD the weight d for both OEM springs worked out but don't think I ever shared it and it was just on a slip of paper long gone now.

 

[IRBent]

Well if you look at the listed weights they pretty much go along with wire diameter they even have a couple 1.1 mm wire i just don’t want to buy $40 worth

There a lots of places online where you can plug in spring specs and get their rating.

I went through all this when I was hunting springs for the Ghost and generally learning the gun. I HAD the weight d for both OEM springs worked out but don't think I ever shared it and it was just on a slip of paper long gone now.

Of the few sites I've looked at I've seen springs that measure the same in all dimensions but have varying weight ratings. I'd imagine too, you could measure a handful the same size and find variances even if they were supposed to be the same weight. I stopped by Ace this afternoon and picked up 2 that were supposed to be .047" wire size. I carried my dial calipers and mic'ed several with the 2 I brought home being .049" and .0485", somewhere between the light and heavy OEM springs. Then I came home and proceeded to attempt to check the weight rating on each. I felt pretty good about measuring them and found a listing online that says they should rate at 8.44lbs per inch. I measured 8lbs 2oz on the .049" and 8lb 5oz on the .0485" spring. Then I went to trying to measure the OEM factory spring and my knot or my 20lb braided line gave up the ghost. I tried using Paracord and got a measurement but I've not had a chance to look online and see if springs of that size fall in the range I weighed it. I wasn't too happy with the weighing method on the heavy spring either because it wanted to make the spring cant, possibly causing it to bind and give a false high weight. The "heavy" spring weighed in at a whopping 18lbs 11oz, well over twice what the Ace Hardware springs weighed. I'll continue this attempt at weighing the OEM springs tomorrow and hopefully find data to prove I'm within a few ounces on each.

 

[IRBent]

Latest Update on my Ghost HP .22 cal Tune Trials:

I left off the other day trying out the "light" .047 hammer spring with the MRDs and the PW on MAX. Once I got the reg to 108 bar the gun was averaging @ 850fps. I bumped the reg to 110bar and the velocity fell about 10fps. I assumed I didn't have enough hammer spring to overcome the extra pressure from the reg so I started checking local hardware stores for slightly heavier springs, hoping to find one in between the "light" and "heavy" springs, with the heavy being the stock spring that seemed to be a tad too much. The few springs that I brought home from Ace Hardware ended up being a tad too large in O.D. to fit in the gun, then too when attempting to measure their weight in pounds per inch, the industry standard, I found the Ace springs to be about 2lbs lighter than the "light" BRK spring. Had they not been too big in diameter they might have been what @Solo1 is looking for.

This eve I took my power wheel out and mic'ed everything and found that the spring is only compressed @ .175" at MAX compression on the power wheel. I decided to try a temporary shim and I chose to use a 5mm ID by 2mm thick o-ring. I slid it onto the end of the power wheel and reassembled the gun. I tested a few MRDs with the power wheel on MAX and saw avg velocities between 880-885fps. I'll test it further across the spread of ammo from 14gr to 25gr when we have good weather again and report my findings. My only concern about the o-ring shim is that I don't know how stable of velocities it can reproduce as I expect the o-ring to give/squish at varying degrees depending on temp and of course PW setting. The higher the power wheel, probably the more the o-ring might squish. I wouldn't be too surprised either that eventually the o-ring will deform or begin to tear. I see a fair amount of potential though knowing that the spring is 2 inches long and at it's maximum compression it would be less than an inch long. However the power wheel only moves forward 0.175". The one thing I don't know is how far the hammer moves back when cocking or how much squish it puts on the spring. I will say, that 2mm shim did not cause any binding or tight cocking.

I still need to run the reg up further too so I can see what happens across the power wheel with various weight ammo. I simply did not test very much with higher reg pressures after seeing the MRDs fall at 110bar while using the light .047" spring.

"Stay Tuned" More to Come.

 

[Solo1]

Be careful shimming, i tried that with a thin spacer got the first shot off then the spacer slid off the stem of the power wheel and i had to tear the gun apart to fish it out.

 

[IRBent]

Be careful shimming, i tried that with a thin spacer got the first shot off then the spacer slid off the stem of the power wheel and i had to tear the gun apart to fish it out.

I completely understand that. I mic'ed the bore depth with the spring inside and the length of the power wheel at both MIN and MAX and I believe there was dead space, meaning the spring is free floating until you cock the gun. That's why I went with an o-ring, making sure it was good and snug. As far as it crushing and effecting the amount tension, I was just thinking a sealing washer might work. I'll look at the dimensions of those today.

 

[AtlasAirguns]

I completely understand that. I mic'ed the bore depth with the spring inside and the length of the power wheel at both MIN and MAX and I believe there was dead space, meaning the spring is free floating until you cock the gun. That's why I went with an o-ring, making sure it was good and snug. As far as it crushing and effecting the amount tension, I was just thinking a sealing washer might work. I'll look at the dimensions of those today.

Interesting. So MRDs at 880s. Will be interesting what your low setting with 18.13grs will shoot. As for the CPs, I think that will be too much of a grain difference but excited to find out.

 

[IRBent]

Interesting. So MRDs at 880s. Will be interesting what your low setting with 18.13grs will shoot. As for the CPs, I think that will be too much of a grain difference but excited to find out.

Here's the results on the latest testing with a 5mm ID x 2mm thick o-ring slid onto the power wheel tensioning the spring a tad extra. I will say, ever since swapping to the lower weight .047" hammer spring, my velocities and SD vary more shot to shot. Although the SD seems to get tighter the further up the power wheel I go. I think the 23gr slugs had an SD of 2fps. So maybe more Reg pressure and higher power wheel settings might be better if consistency is the goal.

Light .047" Hammer Spring with a 5mm ID x 2mm thick O-ring on the power wheel shaft shimming the spring.

Ammo Grains	Reg Bar	Power Wheel	Velocity FPS
14.3	108	MIN	950
Hades	108	MIN	914
18.13	106	3	874
17.5 Slug	106	6	901
20.2 Slug	106	15	907
23 Slug	106	MAX	858
25.4 MRDs	108	MAX	862

 

[Solo1]

Here's the results on the latest testing with a 5mm ID x 2mm thick o-ring slid onto the power wheel tensioning the spring a tad extra. I will say, ever since swapping to the lower weight .047" hammer spring, my velocities and SD vary more shot to shot. Although the SD seems to get tighter the further up the power wheel I go. I think the 23gr slugs had an SD of 2fps. So maybe more Reg pressure and higher power wheel settings might be better if consistency is the goal.

Light .047" Hammer Spring with a 5mm ID x 2mm thick O-ring on the power wheel shaft shimming the spring.

Ammo Grains	Reg Bar	Power Wheel	Velocity FPS
14.3	108	MIN	950
Hades	108	MIN	914
18.13	106	3	874
17.5 Slug	106	6	901
20.2 Slug	106	15	907
23 Slug	106	MAX	858
25.4 MRDs	108	MAX	862

Looks like your getting close to what your looking for

 

[IRBent]

Looks like your getting close to what your looking for

I had way better SDs before swapping the springs and while there's a tune there that might work for all ammo I've been testing, the low weight stuff is too fast and the heavier weight slugs a bit slow. I did more velocity testing today, removed the o-ring spacer, and eased the reg up @ 120. I guess I need to shoot some groups and see what really matters in all this testing.

 

[Solo1]

I had way better SDs before swapping the springs and while there's a tune there that might work for all ammo I've been testing, the low weight stuff is too fast and the heavier weight slugs a bit slow. I did more velocity testing today, removed the o-ring spacer, and eased the reg up @ 120. I guess I need to shoot some groups and see what really matters in all this testing.

Well how are you making out with this?

 

[IRBent]

Well how are you making out with this?

Last weekend I attempted to pick up where I left off and ran into an issue, my FX Pocket Chrony didn't want to work. I tried most of the weekend and eventually went back to the heavy spring and a higher reg pressure. Basically returned to a previous tune that I knew was decent. Monday I dug out my old ProChrono from the 90s and placed the FX Chrony beside it. The FX worker better than it did over the weekend but I still mailed it off Tuesday. The FX was usually @ 10fps faster than the old unit. I may proceed with the .047" Light spring this weekend using the old ProChrono. Although I will say, wherever I left off Monday, I was able to shoot the 18gr and the 25.4gr MRDs on the same time by turning the power wheel up. I felt the cycle to be a bit harsh and probably wasteful, although the SDs returned to 1-3 vs 6-12 using the Light spring. The SD issue might be better if the reg pressure was higher with the light spring, but I can't imagine the light spring being capable of hitting the valve hard enough to send the MRDs @ 900fps while still doing the same for the 18gr JSBs. Time will tell.