JSB Beast ballistic coefficient?

Lou:

If you know your muzzle velocity, you can calculate the BC if you set targets at known distances and measure the drop...Plug different BC's in Chairgun or Strelok until you get the drop you shot...

I started a simple thread about this...You may find it interesting:
http://airgunnation.dev/topic/strelok-chairgun-other-programs-and-ballistic-coefficients/

Merry Christmas!

AZ

PS. Just guessing I believe that your BC will be in the .030's range

The length of the beast makes me think the bc is much better than 0.03 (same bc as the much shorter 18.1) the Beast is 0.430" long vs. The 18.1gr which is 0.39"
The waist is much less too. The 18s is about 0.135, the Beast is 0.190.

A more accurate way to determine the BC for shooting any pellet in your airgun, assuming you have a couple of consecutive consistent velocities, is to put your Chrony or velocity measurer at 2 different distances and collect velocity samples. Having the muzzle velocity and another velocity at 10 yards or 20 yards or some other known yardage, you can input BCs into ballistic software and keep computing the results, until you match the velocities at the 2 distances used in your testing. BCs will vary from barrel to barrel, but not significantly. There is a formula to compute the BC which uses 2 velocities, the temperature and altitude, but it is very very long, and complex and will work in spreadsheet software, such as Excel, Lotus, or others, but I don't recommend it unless you are a very mathematically inclined. There are a number of ballistic softwares on the market. I can't recommend one specifically. The highest BCs I recall computing are from the Crosman .25 cal and the H&N Baracuda's. These have higher BCs than the typical rounded domed pellets mostly because they have pointy domes. 

I have a Labradar unit to measure BC. It gives me velocities at specified ranges like 20, 50 and 75 yards and then you can calculate the BC. This is a doppler radar.

Nielsen, Please calculate the Beasts then
They are very accurate in my gun, at least at 30yds (6 shots in a hole 0.1" ctc)

I came up with .0435

That is pretty good, considering the 18.1 are in the 0.0330 range. Afaik

You can use chairgun pro on the desktop (free) to calculate your BC. Go to tools drop down and hover over "calculate bc from" and choose "poi at range' and fill in the information. Pretty easy and gets you pretty close. In order to be accurate you have to to be real steady at your zero and make sure you are shooting consistent in one spot so your air pressure is crucial on every shot unless you are shooting a regulated gun. You also need accurate measurement of the drop or the calculation will be of no value.

Then I would shoot a few further distances to check the BC. So you could zero your gun at 30 yards and then shoot at 50 and 75 yards to measure the drop from 30 yards. You will need a chrono to input the muzzle speed for each shot.

I don’t know the bc of jsb’s Beast. But I can shoot them way faster than any other pellets. 1070fps out of a Warp Cobra. This is because they are basically spin stabilised. Don’t have much of a skirt. I’ve shot a crow in one eye with these at 50yrd.

They’re extremely accurate out of the streched TC barrel at very transonic speeds. You’re not getting much of vacum with these pellets. In my barel they tend to be most accurate and more quiet at 1040fps, haven’t tried them below a 1000 fps... I own many airrifles and all of them are tuned way sloower except the Sinner, that shoot solid lead. 

I’m not an expert but I usually shoot slower than 900fps?! I tune my own guns, these pellets are great for hunting and can shoot moa @100 yrd.

Eyeshot: https://instagram.com/p/BiwNWcmApIQ/

I’m less use apprx a 3 mil holdover at 109yrd 100m shooting at more than 1050fps. With the Morana shooting 18gr JSB they need 4mils of holdover at 920fps (maximum speed for these) With the same scope and rings Sidewinder ffp 4-16 and a 50 yrd zero.

Did anyone get a chance to measure the BC for JSB Beasts? I am trying to decide whether to shoot 22 Beast or 25 King Heavy for Extreme Benchrest.

Sorry I was referring to the 16.2gr .177 Beast. It shoots great. The one in old one .22 need twist and speed that few guns can.

BC for the JSB Beast in .22
There isn’t much info out there. I found a couple of tests done by Airgun Shooting And Related Activities.

2017: 36FPE gun. Distance 47y
BC = 0.046 (GA)
Source: https://www.youtube.com/watch?v=JpsJPgwNrOY

2017: 59FPE gun. Distance 46y
BC = 0.051 (GA)
Source: https://www.youtube.com/watch?v=kKhQ0RdVtnU

I shows like so many other tests that BC does change with velocity.




For a comprehensive list of BC numbers in .22 cal, cf. https://www.airgunnation.com/topic/bc-table-22cal-comprehensive-internet-wide-collection-of-ballistic-coeff-data/

Matthias