Pellet speed question

Forums Pellets, Projectiles, Slugs, & Ammo Pellet speed question

  • Views : 1274
  • Link

    Bob_O
    Participant
    Member

    Regarding JSB 25.4gr pellets, is 925 fps too fast for a stable pellet?

    I would like to try and find a HS setting on my Wildcat 25 that will let me shoot the 34gr pellets right now at 848fps and then with a simple HS adjustment I might be able to shoot the 25gr pellets without having to dive into the regulator.

    TIA!

    Link

    Hajimoto
    Participant
    Member

    Hey Bob,

     It has been my experience that the Diablo wasp waisted pellets have a stable typical rate of travel from 850 to 920 but as with any rule, there is the exception as I have had certain pellet fly at 955 and remain stable. 

     

    Link

    Bob_O
    Participant
    Member

    Thank you Haji.  I will try to do some testing today.   

    It would be great if I could find a setting where I don't have to touch anything and just swap back and forth between the two pellets.

    Right now I have the Huma set at 150 bar and the 34gr pellets are going 848fps average.  If the 25gr pellets travel 100fps faster, that puts me a tad too fast I think.  That's why I was thinking if I back off the HS adjustment 1/4 to 1/2 turn for the 25gr pellets, that might be all it needs to be at the upper end of stable.

    Link

    Alejandroo
    Participant
    Member

    Hi Bob,

    Maybe I can step in and give you my thoughts on the matter also, in my experience with the JSB 25gr, shot from my Edgun R5M long, I have better results at longer ranges when they are around 880 FPS, you can check my pics with groups at 50 and 100 mts here: https://www.airgunnation.com/topic/edgun-r5m-my-well-intended-mistake/page/2/#post-324727

    Edit: I have my Huma set at 105 BAR (using the white sticker guide) and I get 945 FPS with HST adjustment tops, so I've shot them at 880 and 920 AVG only by adjusting HST.

    Link

    Bob_O
    Participant
    Member

    Thanks Alejandroo.

    I guess the only way to know is to try it.  

    I would back the regulator down from 150 to 145bar if I wasn't nearly maxed out on my HS already and have max fps on the 34gr pellets at 848fps.   I don't want to lose the accuracy I'm currently getting with the 34gr.  If I drop the reg to 145bar, I will lose 25fps on the 34gr pellets and that puts me just below the low end for stability with that weight.

    My thought was if the 25gr increases 100fps that would put me around 950fps.  If I then back the HS adjustment out 1/2 turn, that should give me a drop of roughly 25 fps.  Though it may not be an ideal setting for the regulator at 150bar.   If I can get out to the range today I'll see how things go.

    It may or may not make a difference, but I'm running the SmoothTwist X barrel liner.

    Link

    Alejandroo
    Participant
    Member

    Ok, keep us posted on how all went, good luck Bob !

    Link

    Centercut
    Participant
    Member

    Hi @bob_o, I think you have the STX barrel on your WC if I’m not mistaken? From what I’ve seen and read, that barrel “acts” more like the LW Poly barrel, in that it allows higher speeds with the same pellets compared to LW or ST barrels, yet still retains accuracy – and results in a significantly higher BC. I would think with that barrel you can easily go to 950 FPS, even higher, and still maintain long distance accuracy. Ernest has said that he is testing a new STX .22 slug barrel, and testing has shown accuracy at 95 yards with speeds in excess of 1000 fps (1020 to 1030 fps) with the .22 JSB 18.1 grain pellets. This is totally contrary to everything we currently know about those pellets losing accuracy at over 915 to 920 fps in standard LW or in ST barrels. So check it out, and let us all know? ;)

    Link

    Bob_O
    Participant
    Member

    That sounds promising!   I will try the 25gr JSB pellets today without touching the reg or HS and see how that goes!   Thank you Centercut.  🙂

    Link

    alpine84
    Participant
    Member

    I shoot the kings in my kalibrgun cricket at 950-955 and thats the best speed for that barrel. I have tryed to lower to 900 fps but that opend up the groups att 105 yards t 2 inches. At 950 i get 1-1.5inch groups. 

    Link

    Bob_O
    Participant
    Member

    Holy cripe, check out this Chrono chart!

     

    And this target…..25 yds in the lower right…..I was mostly sheltered from the wind.

    50 yards lower left, I was 25 yards out into the open wind…15 mph.

    100 yds in the middle, 75 yards out I to the open area with worse winds.

    I'm going to plug this into Strelok and head to the local farm for some shots.

     

     

    Link

    JimNM
    Participant
    Member

    Get you some!  You do good work, amigo.

    Link

    Bob_O
    Participant
    Member

    Not bad for a bipod off the trunk of my car. 

    ?

    Link

    Bob_O
    Participant
    Member

    I'm going to wait for this guy this evening.  He came out yesterday as I was leaving the farm but went back down before I could get the gun ready.

    Link

    Phildog59
    Participant
    Member

    Good shooting Bob I like the work you put into your guns and the information you share keep up the good work and thank you

    Link

    Bob_O
    Participant
    Member

    Thanks Phil.  

    I got a few shots in this evening.  The trajectory is a lot flatter with this lighter pellet going 100fps faster than the 34gr pellets.

     

    Haji, Alejandroo and Centercut,

    Accuracy doesn't seem to have suffered…..maybe due to the ST-X barrel?   I have yet to get some long shots to check for pellet wobble, but she's good so far!  And trajectory with the lighter pellet is a lot flatter.   My 35 yard zero with the 34gr pellets turned into a 50 yard zero with the lighter pellets…..I even had to make a 2-click down adjustment on the elevation turret!  POI was a little to the right so I made a 2-click adjustment there.

    So far so good.   Thank you guys!

    Link

    Bob_O
    Participant
    Member

    Thanks to all for your input and knowledge!

    Link

    Alejandroo
    Participant
    Member

    Great Bob !!!, thank you for sharing the new results, as you said it might be due to the ST-X but in any case, the new setting is doing good for your purposes, tell us the results or if you see any pellet wobble in the future, happy hunting.

    Link

    stoti
    Participant
    Member

    My Crown shoots the 25.39 pellets at 940fps and is ragged, one hole accurate. Everyone told me that was too fast, absolute maximum should be around 920fps. The 33.95 pellets also shoot lights out and I don't adjust anything at all. They shoot at 835fps. The gun is now sighted in at 35yds with the 25.39's, I have dope cards for each and have just been switching pellets back and forth at will without adjusting anything. I haven't shot past 80yds yet, but out to 80yds I couldn't be any happier, the groups haven't opened up more than usual. I can't see anything changing out to 100yds unless it's my fault. My gun is set on .25-30, high and the reg. is set at 140bar. I haven't messed with the hammer spring and don't think I'm going to because I don't want to screw anything up. Stoti

    Link

    Bob_O
    Participant
    Member

    If I knew in the beginning what I know now, and if the synthetic Crown existed, I'd have gotten that or an Impact to start out with. 

    I actually considered an Impact when I bought the Streamline 22, but I didn't think I'd get into tuning and such.  It sure would be nice to have all these adjustments at your fingertips……I'm sure I'd have made good use of those features.

    Link

    Bob_O
    Participant
    Member

    Got some scope cam of some 100yd shots at the range today.  I'll need to pop it on the computer to check for wobble.

    There might not be any, as one group managed a hair over 1" and  a second 4-shot group was about one-half inch.  I have about 16 other shots that are about 2" vertical and 8" horizontal due to winds.

    I'll get on the computer in a bit.

Viewing 20 posts - 1 through 20 (of 25 total)

You must be logged in to reply to this topic.