Pellet speed question

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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.
 
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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.
 
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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.
 
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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? ;)
 
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Holy cripe, check out this Chrono chart!

1531782086_14747655295b4d23c6dbdc53.96728587_Screenshot_20180716-185404.png




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.

1531782233_17185550215b4d2459e1b067.50434483_IMG_20180716_184853.jpg





 
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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!
 
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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
 
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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.
 
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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.
 
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