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Hi Guys. I need the exact BC of JSB .357 81 grain and BC

May 15 2017 at 8:11 AM
James Dingle  (Login JamesDingle777)

of .257's weighing 87 grains. The RAW I'm considering is regulated at 130FTLBS with these (I've read 77-81 grain JSB's) for about 16 shots. You get 100 for roughly $18.00 and that's PLENTY for Hunting. The .257's cost $25.00 for 100 count. Shipping is not reflected here.
I'm debating on a dedicated RAW in something between .25 to .257 (if they'll make one or a TJ liner will work) to a .30 or .357. The .357 spitting 81 grain Diabolos is capable of 130FTLBS regulated for 16 shots from Factory. That's a normal 480cc bottle. I'd opt for a 500cc carbon fiber 4500psi bottle, custom regulator and valve. As it is from Factory, it CAN do 160FTLBS with 81 grainers non regulated; but I want accuracy over power. I am looking for .22LR comparison in ballistics for groundhogs and coyotes.
Seems like many prefer the Air Force rifles modified for power and long range; but I'd have to go with a RAW over an Air Force. I've even considered a Texan in .308 but I doubt it can do 5 shot under 1" c-t-c like I see some RAW's doing at this power level.
There's also The FX Crown coming out and I'm VERY interested in what calibers and liners will be available. Size and material of bottles (fill pressures) adjustability of factory and custom parts (as we KNOW custom parts will be coming for The Crown.)
Right now, I'm just punching in numbers to Chair Gun and would like exact figures to compare the RAW .357 at 130FTLBS to an unknown platform in .257 which seem to be an average of 87 grains but are cast bullets, not Diabolo pellets. I'd like my own mold to cast bullets with super pure soft lead for complete energy transfer and massive mushrooming if I go this route. I've found that most all JSB's are made of quality soft lead, are super accurate and do mushroom reliably.
With 20MOA droop built in, special mounts with more, a good SWFA mil-quad scope, bi-pod, and either of these 2 main choices between .357 or .257 I foresee NO problem taking out groundhogs or coyotes at 200+ yards.
I can whack and kill Groundhogs at 150 yards with 18.1 JSB's doing 861fps out of my Evanix Rainstorm and only hitting with about a retained 8-10FTLBS, so either of these 2 choices will be a piece of cake. I may even settle for another .25 Raw pushing 25.43 Kings at 920-940fps, guessing 50FTLBS at muzzle, or a .30 weighing 44 some grains. If you have the exact BC of ALL these new pellets, from new heavy .22's to heavy .357 Diabolos, to cast .257's, I'd GREATLY appreciate it.
Also, I'm pretty dead set on this future purchase to be a RAW, Crown, maybe a Talon Tunes fully worked Condor. I am also reading that some are having amazing results with the Evanix REX, Rainstorm II, AF Texan, Hatsan's. I'm looking for ONE high quality PCP and would most likely sell or split my other 6 Air Guns between my 13 year old Boy, my new 3 week old Boy, or my 6 year old Girl who already wants to hunt; but I've told her she has to grow in size and be at least 10 to go with me.
Of the 6 I've kept, they are all amazing. There's probably 10 others I wish I'd kept, but these are great ones for what they are. I'm very interested in The Crown's versatility but I will never be a Beta tester when it comes to Air Guns. I wait for the Guys with the money to play with them and give accurate reports. A RAW is a no brainer. Only thing is the .357 will NEVER be interchangeable, so if I go with it, it's definitely a dedicated caliber. Any other RAW can be configured from probably .177 to .30 or at least a .25. We'll have to see how versatile the Crown is and what they offer from factory.
So again, to clarify. I'm looking for info or a link to the BC of all available or mentioned calibers. Thank you and all opinions are welcome. I don't mind advice, opinions, related but OT subjects.
My true desire here is to have a air powered high quality accurate rifle that can do anything a .22LR can as well or better. If we don't have that now (which it seems to me we do,) then we're sure to see such come about within the next 3-5 years, 10 at most. I believe the true Golden Age is coming in now. More advancements, lower prices on rifles and compressors. It's about to take off and go mainstream popular like in The UK. Just MHO as I see it.
Thank you for reading, considering, answering and or providing requested info.

 
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Prouzy
(Login prouzy)
YF12

Not sure you will get just

May 15 2017, 7:59 PM 

one answer, but thats ok. You have a few different variables, but Ill chime in with some of what I found, know and experienced. I was able to shoot JSB 34gr .22 in high 800s to test BC to 40yd and obtained just over 0.04 if I recall. This was greater than 25 gr .25 which came in just under 0.04 but the 34gr .25 did come out higher and approached 0.042 while 44gr .30 was anput the same. The 81gr was not measured via chrony and was estimated on drop at 75yd, 0.05. Certainly could be more and likely approaching 0.055 or better.

Different barrels, velocities, amd different distances measured will result in some variability in findings but there may be some consensus. Rsterne was doing a thread and collecting from different folks, over on GTA, if I recall. You are in the ball park with muzzle velocity comparisons between .257 and .357 both shooting around 80gr being around 150fpe at around 910-15fps. The difference will be the BC and whether you need that down range. My .257 Condor shooting only 55gr had the same down range energy as my .357 shooting JSB 81gr at 150yd. The JSB is more affected by drift and betond that, the 55gr wins in the fpe. Shooting the gold standard Lyman .257 you are looking at dramatic differences in energy retention and likely a BC exceeding 0.15.

I dont know that much about the RAW, but it takes a lotta air power to push a cast bullet 75-80gr over 900, hence the Airforce conversions. The .357 pellet shooter seems about closest to a .22lr, but cast bullet shooters can certainly surpass. My Extreme .308 could double it, and even my 3000psi PBBA shoots 220+ fpe with its favorite 120gr. Im currently working on a project to shoot cast 37gr .224 with a BC estimated 0.12+. I agree, cool times anead, and Im interested in what the Crown has to offer. Neilsen is working on some great ammo for pellet shooters, but is a solid with higher BC, might be an additional choice for your application. I really like the idea, as pellet shooters and smaller calibers can use air more sparingly per shot and with a quick change out of a hammer spring I cam shoot my .30 for 14+ shots (small reservoir) at around 60fpe to NSA slugs at 100fpe+ and suspected BC 0.07-8 (still testing). I like shooting big ol cast slugs, but shooting .35 pellets is just a hoot!

 
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JD
(Login JamesDingle777)

Thank you kindly, very helpful. N/T

May 16 2017, 9:35 AM 


 
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