Pellet BCs

[Franklink]

A while back JSB shared this with us (I think it was originally on their facebook page). 

BCs from most of what JSB offers, stated to have been collected from their company test facility (with the slight annoyance of reporting in their Euro-centric gms and meters/second).

With the caveat that BCs are very condition specific (and even barrel specific) this little chart has generated a lot of discussion amongst myself and airgunning friends. Discussion mainly revolving around how to get the pellet precisely where we want it down range, expressly WAY down range (relative to pellets). Between long range pdog pesting, Xtreme Field Target, EBR, and just the intrigue that comes with long range airgunning ACCURATELY, we were quite interested in seeing this comparison between so many different pellets. 

I made a red dash to the right of all the standout BCs, as reported by JSB. With the volume in which I like to shoot, and the cost prohibitive nature of the larger small bore stuff (.25 and up), I've personally been most interested in the .22 and .20 offerings.

For .22 the highest BCs reported by JSB were:

• the 25.4gr Monster RDs @ 0.053 (the standout for me)
• the 34gr Jumbo Beasts @ 0.05 (I've not heard of anybody getting these to shoot very well, and I don't have a gun with the oomph necessary)
• the Original 25.4 Monsters @ 0.047 (again, they simply don't shoot very well)
• the 18.13grainers @ 0.042 (I've never got them to measure this high when doing the fps collected at 2 distances method-usually 0.035 or less)

For .20 the 15.89 Heavies being listed at 0.047 struck me as oddly high, as it is not too far behind the best .22 (Monster RD's). Many of the top big competition (EBR/RMAC/Xtreme FT/ETC) competitors run the .22 Monster RDs, and the .20 Heavies BC is only slightly less?!?! You've got my interest JSB. 

Fast forward a year (house sale, house purchase, house remodel, etc) and I finally had some time to collect some BCs of the Heavy .20s this evening. Temps in the high 60s, humidity at 60% (AZ monsoon season), and elevation of 5600ft. 

I first tried them with a muzzle velocity averaging 866 for about 26.5fpe (all 5 shot averages). They were still going 727fps at 54 yards so that gives them a BC of 0.039, which is....lackluster, and more in line with what I expected. 

Next I tried them at a muzzle velocity averaging 908 for about 29fpe. They were still going 793fpe at 54 yards so a BC of 0.0495. Hey now! "That's the stuff!" I thought to myself, more in line with what JSB collected, and explains why these were hanging with the MRDs at paper in wind at 100ish yards a few weeks ago. 

It looked like it was gonna rain on me at this point so I put everything away and had some family come over around then. After they left and the storm blew itself out I decided that I better verify that wasn't a fluke. Got everything out again and repeated the experiment. Got an average muzzle velocity of 912.7 and ended up with the far distance at 56 yards this time, and an average 56 yard speed of 784fps, working out to a BC of 0.0458, still promisingly high. 

So, I averaged out the two for a BC of 0.04765 (0.048-just about what JSB reports) and plugged that into Strelok and plugged the clicks into the scope, and stretched it out a bit. 

These were at 90 yards, 5 shots per paddle, no sighters, just Strelok data and 15 shots in a row. Shooting from a folding plastic table, with my knee riser acting kind of like a monopod (not very stable) and no rear rest (non trigger hand under the rear of gun). 

I'm pretty excited for the .20 Heavies to be my budget long ranger now. I enjoy stretching out the .22 Monster RDs, but they're not quite as cheap as the .20 Heavies (and tough to get lately). 

Takeaways.....

I've always read about people reporting better accuracy/bc/etc from pellets at an optimal speed from a specific barrel/gun, but had yet to see it so drastically as this evening. Nor had I ever had the desire to sit down and do comparisons. The 0.039 BC at around 26fpe is pretty ho-hum, but the 0.047 BC at around 29fpe is something to get excited about. So, if really hunting a high BC, shooting at various speeds to determine what fps gives the best comprise of BC, FPE, accuracy, and efficiency is well worth the time and effort. 

There's still a little magic in the ole worn out, yesteryear's Silver Streak fodder, "on-the-way-out" .20 caliber. I'm glad I bought a bunch of the Heavies!

(yeah that's rising flood water in the back of the photo with the paddles, had and still having (at 130am) some drama around here this evening with concerns of it flooding out the newly renovated house, and actually flooding out some of my neighbors)

As a semi-related aside, I also collected some BCs from the 13.73gr .20s at my field target legal muzzle velocity average of 795 and 54 yard average of 670 for a BC of 0.039, pretty dang high for a field target legal configuration (although shouldnt come as a surprise since JSB reports 0.04 in their table). 

Also generally interesting to look at the speeds JSB reported for each pellet in their BC testing. Makes a guy wonder how they arrived at those speeds. In my particular case, I was shooting the Heavies 25-30fps faster than they did. 

Another one to note, LOTS of 270-290m/s listed on there.

Fun stuff. 

 

[shambozzie]

@Franklink, your finding on the jsb heavys 15.9 is on the money. The heavies start doing crazy stuff @ 925 fron my Az .20 rapid mk ll. I shoot them @ 900 fps and they are lazors. Caught them on two chronys @ .047. They will reach out and touch at that speed . Here is a 12 shot (one mag ) @ 85 yds that a dime will cover. When all is said and done they are a 30 fpe pellet that is accurate as hell. Love them.

 

[Centercut]

Nice write up Cole. I did the same a while back with the .25 King Heavy (Mk1) and got 0.060 to 0.062 at 875 FPS. It’s a shame that JSB decided to only make the Mk2s and has dropped production of the King Heavy Mk1. Those are the highest BC of any production pellet made that I know of…. ;(

Although it’s not always about BC. Sometimes consistency in the wind, especially at 100 yard EBR type shooting is more important. I watched a very good shooter attempt to shoot .177 Beasts at 35 FPE at a recent tournament and the results were abysmal…. 

 

[dizzums]

i think bc has alot more bearing on bullets than pellets .. pellets actually rely 'more' anyway on their shape to stabilize and actually 'fly' regardless of bc... so its more about finding a pellet thats going to stabilize and fly well at the speed 'range' your kicking them out in your particular barrel and setup then bc ..way i understand it anyway .. if it drags more but stabilizes well, drop we can deal with better than a squirrly pellet ...

 

[Kgphotos]

Great testing results. Great timing as well. I was doing some very similar testing on Thursday. I went up to camp at 7500 foot elevation. I was curious about BC change at high altitude. I took my Crown, chronograph and JSB 18.13 pellets. My method was to shoot ten shots and get an average velocity at the muzzle (880 fps), then at 29 yards( 819 fps) and then again at 49 yards (779fps). Then used ChairGun to determine BC. I then shot targets at 50,60,70 and 80 yards to graph the pellet drop at each distance to verify the BC with real world results. The BC that ChairGun gave me was .0571. That was an average of the BC at 29 yards and the BC at 49 yards. I then made a drop chart in ChairGun and compared it to my actual shooting results. It was very very close all the way out to 80 yards.

 

[Franklink]

Nice write up Cole. I did the same a while back with the .25 King Heavy (Mk1) and got 0.060 to 0.062 at 875 FPS. It’s a shame that JSB decided to only make the Mk2s and has dropped production of the King Heavy Mk1. Those are the highest BC of any production pellet made that I know of…. ;(

Although it’s not always about BC. Sometimes consistency in the wind, especially at 100 yard EBR type shooting is more important. I watched a very good shooter attempt to shoot .177 Beasts at 35 FPE at a recent tournament and the results were abysmal….

I've been following all the comments on this over the past couple months or so. Doesn't make a lot of sense on JSB's part, unless that particular day ran out and they didnt want to invest in another one, although, all the interest this has garnered seems to suggest that there's a market for the Mk1's, especially amongst the competition shooters who were having such good results prior to their apparent discontinuation. 

Would be really interesting to see/hear if anybody receives the Mk1s any time in the future. 

 

[Franklink]

Great testing results. Great timing as well. I was doing some very similar testing on Thursday. I went up to camp at 7500 foot elevation. I was curious about BC change at high altitude. I took my Crown, chronograph and JSB 18.13 pellets. My method was to shoot ten shots and get an average velocity at the muzzle (880 fps), then at 29 yards( 819 fps) and then again at 49 yards (779fps). Then used ChairGun to determine BC. I then shot targets at 50,60,70 and 80 yards to graph the pellet drop at each distance to verify the BC with real world results. The BC that ChairGun gave me was .0571. That was an average of the BC at 29 yards and the BC at 49 yards. I then made a drop chart in ChairGun and compared it to my actual shooting results. It was very very close all the way out to 80 yards.

Glad the post created a data point which you could compare the two speeds at known distance method of collecting BC to. Although that seems pretty high for 18.1s, perhaps the elevation. 

I've compared this method to using speeds captured from a friend's labradar (seems like it was the 25.4gr Monster RDs from my Vet Long) and they were surprisingly similar. I'd have to give the nod to the Labradar in the confounding factors area though. The problem with the chrono at two distances is that you can't collect the speed of the same shot. So, if fps collected on a near shot leaves a bit higher up in the ES spread (say 918) than the speed collected on a far shot (say left muzzle at 908) than it'll skew the data. And if two chronographs are used for the same shot then you've got variation from one chrono to the next, which skews the data. 

This method is worth the time, and gives an idea of BC, but I really think a Labradar provides more conclusive evidence. 

 

[Kgphotos]

I agree that the Labradar would be a better way to go if I had access to one. The method I use is the same that I have been using for a long time. Even back to my firearms days. I think that shooting a lot of shots at each distance is the best method for minimizing the errors that might come with each shot. I was happy to hear you say that you have compared this method to the Labradar and found them to produce similar results. Using my method has given me fairly accurate BC readings that had produced drop charts that were very close to real world testing. Thanks for starting up an interesting thread.

Kenny

 

[Guest]

A while back JSB shared this with us (I think it was originally on their facebook page). 

Elsewhere you made THIS assertion:

(and it's physically impossible to have two pellets the same weight/caliber/etc and have one be as wasp waist and the other a trashcan, if they were the same weight the length would change, which would change the BC). 

I would invite you to carefully peruse the data in this chart YOU linked top of the thread. I think you will find that your assertion is probably not exactly correct... It is quite possible for two pellets to not be identical and have the same BC.

If you look real close you will discover that BC isn't a perfect description of what is going on except at EXACTLY one velocity... but yeah, I get you point. I encourage you to try (next time) to understand my point before you jump all over it.

 

[Franklink]

Huh? 

Are you referring to the Original vs Redesigned Monsters in .22? Cuz the RDMs are not a wasp waisted pellet. 

Here....

18.13s have a very pronounced narrowing of the midsection, (like a wasp)

The Original Monsters are straightwalled and the Redesigns have a less sharp angle from their narrowest point (midsection) to the bottom of the flared skirt. Or, if you prefer, the Redesigns have a larger midsection than the 18.13s. 

The claim I made in the other thread was that they would be a different overall length, and also a different BC.

They are a different length, and they have a different BC. 

I never said that two different pellets must have different BCs. A BC can be shared by two different pellets. 

And yes, I looked closely and found that BC changed with the speed at which I was sending these Heavy .20s, which was pretty much the point of me starting this thread, and stated more than once in my opening and closing posts. And also holds true for all collected BCs (dependent on conditions, like I ALSO stated in the beginning post here). 

You're trying really hard though. 

Edit: So you got locked out of the other post for being antagonistic so you're going to continue here? 

Airgun Nation is not about being "right." It is about sharing factual information and creation of a resource in which we can all learn together. More than one of the concepts you are so fervently arguing for are simply untrue, proven by much more experienced and talented shooters than myself, both in testing and in competition.. Rather than admit that, you are only digging a deeper hole by drawing your line in the sand on the wrong side of facts.

One of the numerous false claims you've made in all this BC discussion is that a smaller profiled pellet with a wasp waist will be more resistant to wind deflection (paraphrasing, but that's the gist of it). Please sir, show up at EBR with an 8.44 gr .177 ready to compete and then come back on AGN and report how that experiment goes. As far as scientific experiements go, the design will be pretty good, all the other shooters using .22 and up (larger profile) pellets with thicker waists will be the control group, you will be in the "group" testing your hypothesis. But you'll be shooting in the same winds, at the same targets, at the same elevations, etc. Would be great to have more than one shooter campaigning the .177, but I think you'll be lonely in that test group.

Let's stop the silliness that this has become. 

 

[Guest]

No sir, I am not.

Just look at the chart. Plenty of pellets have the same weight and the same BC. They also have an velocity associated with them. All day I have been simply trying to explain that it is possible for the experience that @therealld reported in his post can happen.

Go look at the link posted by the OP in the top post in that thread which was just locked. Read what he linked. Tell me how to resolve your experience and @therealld 's experience. I can resolve it, you want to say it isn't possible. Clearly NEITHER OF YOU ARE LIARS so ...

 

[Franklink]

Bob and weave, bob and weave. 

I see no incongruencies between anything I've stated and the comments from LD to which you refer. Sounds like he likes to test the heck out of a potential projectile to see how it shoots (at various distances). That's a good practice-I do the same. 

 

[Guest]

Bob and weave, bob and weave. 

I see no incongruencies between anything I've stated and the comments from LD to which you refer. Sounds like he likes to test the heck out of a potential projectile to see how it shoots (at various distances). That's a good practice-I do the same.

I guess you will have to actually read the original post in that thread. You apparently missed the actual question the OP was asking. He submitted the @therealld s post as support for his question. At some point it wandered of into a discussion about wind drift.

I've just gone back and reread @therealld s post. What he said was that some pellets which perform in his tunnel do not perform in the wind.

He said:




After testing in the tunnel, I typically do alot more testing at 50yards off the bench outdoors, and sadly, sometime eliminate candidates that were great in the tunnel because they were to susceptible in winds. I normally test known good against the new candidates side by side to better consider wind effects.

No I did not come here to pick a fight with you. I came here to show you that other people's experience does not always agree with yours. I came here to show you that the problem is VERY complicated and ODD things which seem to be inexplicable CAN AND DO happen. I tried to explain to you why I believed that.

Apparently I failed.

No problem... good luck with your endeavors. I trust you will not continue to take offense if I continue posting the results of my studies? By all means, please correct me when I am wrong as @Centercut did but PLEASE don't try to tell me about your experiences as if they are universally true when the math says they are not.

Have a great day. I think this horse is dead.