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New to JSB 25.39 monster redesigned, what to expect

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R

rodevans

Member
Jan 17, 2021
43
5
CA, United States
I'm interested in knowing what characteristics I should expect when I start shooting the JSB monster redesign in my FX Impact 2 with 700 barrel. I shoot silhouette matches that go up to 100 yd distance and have been having good results with FX 22 gr slugs. Will the 25.39 monster redesign retail stable at the 100 yard distance? What accuracy results can be expected when comparing to the JSB 18.1 grain pellet.

Thanks in advance for your expertise
 
My Daystate Pulsar HP .22 shoots them consistently around 20mm(0.787") or less every day at 100m(109 yds), velocity 935 -940fps, on bench with bipod and rear bag. Still to try them in my Maverick Sniper .22 at 100m, but at 50m looks promising.

Some say the are not good for 100m due to tumbling\instability, I have never seen that......
 
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Yes, Those like to travel 950 FPS ...they are a unique pellet in that regard. 18.1gr is only supposed to be shot out to 75 yards max. I heard they will go 100 yards but you need to shoot them slower. ...but 18.1gr is not for shooting at 100 yards. 25.39gr is.
Click to expand...

THE 18 GR WILL SHOOT AT 100 YARDS 
 
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The 18.1 grain would knock down the silhouette targets at 40 and 50 yds but is iffy at 75 and would only occasionally knock down at 100. The FX 22 gr slugs work at all those distances. I will be testing the 25.39 monster redesign at all distances and if they don't tumble they should work as good as the slugs at the longer distances. I will likely have to bump my power up a bit to achieve 950 FPS with the monster redesign.
 
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I agree fully about the 25 gr likes higher speeds ,In my prophet , taipan ,impact , R5m and maverick all likes 900 to 950fps for the 25 gainers . I have no problem shooting out to 125 yards with them and I take squirrels on a regular basis these ranges , with the 18 gr JSB I also shoot them out to 100 yds and under 1 moa on a day with wind not blowing , with the lighter pellets wind likes to move them around more then slugs or heavier pellets ,

On a different note , MY Steyer pro x shoots under .75 inches at 100 yards with the HN 18 gr pellet in 5.52

I took more squirrels here with 18 gr out at 100 yds then any other ammo out there I do like the 25 gr but the 18 gr are more then adequate for hunting at those ranges as long as wind isnt howling like 20mph

LOU
 
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Couple comments of them needing to go fast and a couple comments of them tumbling at long range. 

I've shot them from 850-900 out to 135 yards. No tumbling at these slower speeds and accuracy that average EBR card scores from 210-230 at 100 yards. BCs measured in the 0.05 area.

From speaking with other shooters, I think the RDMs really excel when they're pushed 940+, but they shoot very well from 850-900 too. 
 
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Hi Greg

Maverick sniper 700mm barrel, .22 cal, adjustable slug power probe.

Here are some of my Maverick tunes with RDM's with 11g Hammer weight and Superior liner:

1st Reg 2nd Reg PW IHS(Turns CCW) MV

145 115 5 2 940

145 115 7 3&3\4 995 - 1000

Here are some of my Maverick tunes with RDM's with 13g Hammer weight and Superior Heavy liner:

165 128 4 0 890 - 900

165 128 5 0 935 - 940

165 128 6 0 985 - 995

165 128 7 0 1015 - 1020 

I have a digital 2nd reg gauge hence I am fairly confident on the bar values:)

Larry.
 
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I have a shortage of .22 for some time and just recently one of the "locals" online got them in stock (3500 Km away).

So all of these are 25 grain what I was actually looking for in .22 and I don't understand what is a major difference or which can get me to 100 meters with greater accuracy:

#1 - JSB Redesigned Monster Pellets - https://dlairgun.com/collections/jsb-pellets/products/jsb-redesigned-monster-pellets-22

#2 - JSB Exact Jumbo Monster Pellets - https://dlairgun.com/collections/jsb-pellets/products/diabolo-exact-jumbo-monster

#3 - JSB Straton Jumbo Monster Pellets - https://dlairgun.com/collections/jsb-pellets/products/diabolo-straton-jumbo-monster

??? which to order? I ussually order 10 tins in a single shipping and I don't really like to mix the pellets but keep it simple one size one model....
 
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Larryt,

Well, the tune didn't quite work out. My Maverick with the 700mm barrel, 580 cc bottle to 250 bar, barrel on slug port, the FX slug prob, 10.53 g hammer, IHS set 2 turns CCW (for a total length of 3mm). regs at 145/115 and PW 5 shooting the JSB RDM 25.4 gr did not even register on my FX Radar Chrono. When I bumped the power wheel to 7 I was getting in the low 700's. So I turned the IHS out (in steps) to 6.5mm and bumped the 2nd reg to 125 bar. That got me in the high 800's (with an occasional 910 or so). But the ES was 50 and the SD something like 18 - so obviously not a happy rifle. Last night I moved the regs to 155/130 and today with IHS at 7 it still shot in the high 870's. The ES and SD were down a little, but not what I am used to seeing with other pellets and my 500 mm barrel. I don't think I am blowing air out behind the pellet as I am getting around 150 shots (including retune dry fires) for 250 to 150 bar drop in the 580 tank.

Maybe my valve needs to be hit harder? I have the 13.22g hammer and could try that. I also ordered the higher power hammer spring from Huma. Any other ideas?

Cheers,

Greg
 
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Something is not right there. I have the same setup and currently running 120 on the 2nd reg and IHS is somewhere around halfway and I get 950 on PW5. Couple of questions here....first have you upgraded the gauges or stock? I know many have had those be off by 10 bar or more. Second, can you check the oring in the transfer port to make sure it is there and in good shape? Even maybe take a couple shots with a piece of tissue sitting over the probe to see if aa bunch of air hammers it.
 
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Greg

Definitely something wrong there. I agree with bunkeru2k, check the O-rings. I originally had the OEM Wika\FX gauge and found similar to what buneru2k said, mine was 7 bar off. How I determined that was, I set it to a known mark on the analogue gauge of 120 bar. Empty rifle of air and replace with Huma digital gauge, fill with air without changing reg setting and see digital reading, mine said 113 bar, hence the 7 bar difference that the reg actually was at, assuming that the Huma digital is way more accurate, which most seem to believe it is.

Maybe try bump the reg by 6 -10 bar on gauge, then try again. It is quite significant what a difference these few bars can make, as long as you match the appropriate hammer weight and pre-load on hammer.

I definitely am finding that the 13g hammer gives me better consistency at 125 bar plus levels, whereas the 11g hammer weight is better off below 122 bar

Larry.
 
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