18gr JSB Exact Jumbo Heavy vs Exact Heavy

[mtnGhost]

At some point over the last year or so, I realized the 18gr JSB pellet BCs increased for the better. I used to use 0.033-0.035, but now I'm seeing a minimum of 0.042 like Strelok has in their projectile database (as high as 0.046 inside ~50y in certain conditions). I don't ever recall the 18gr having this high of a BC.

Then I realized that there are two separate pellet profiles in Strelok and elsewhere. One being called "Exact Heavy" and the other "Exact Jumbo Heavy". Are these actually two differing pellets?

 

[JungleShooter]

WOW — now this thread has me super interested!

Matthias

 

[hawkeye69]

I don't think the JSB 18.13 comes in anything other than Exact Jumbo Heavy.

 

[douger]

same pellet was always called exact jumbo heavy as far as i know. love the 18 gr pellets whats the 16 gr pellets saying

 

[theLBC]

Pellets - JSB Match Diabolo - pellets, ammunition

zbrane. Jestliže hledáte kvalitní střelivo pro svou vzduchovou zbraň, jste na správné adrese. Ať už střílíte ze vzduchové pušky nebo pistole.

www.schulzdiabolo.cz

Exact Jumbo RS
Exact Jumbo Express
Exact Jumbo
Exact Jumbo Heavy
Exact Jumbo Monster
Exact Jumbo Monster Redesigned
Exact Jumbo Beast

 

[mtnGhost]

Pellets - JSB Match Diabolo - pellets, ammunition

zbrane. Jestliže hledáte kvalitní střelivo pro svou vzduchovou zbraň, jste na správné adrese. Ať už střílíte ze vzduchové pušky nebo pistole.

www.schulzdiabolo.cz

Exact Jumbo RS
Exact Jumbo Express
Exact Jumbo
Exact Jumbo Heavy
Exact Jumbo Monster
Exact Jumbo Monster Redesigned
Exact Jumbo Beast

Yeah, I wasn't sure of myself on what they were called back then, but ai even went back and checked Archive.org for a sanity check to see if the names were the same lol. The only thing that I'm sure of was that the BCs used to be lower

 

[JungleShooter]

The only thing that I'm sure of was that the BCs used to be lower

I'd love to hear what we here at AGN can come up with for a trustworthy BC....

• At various velocities — since Stelok Pro permits to enter up to 5 different BCs with their associated velocities

• Based on the GA drag model (or Miles Morris' improved GA2)

• With atmospheric conditions/ elevation figured in

• With sufficient shots to make the test result reliable:
—For a two-chrono setup, maybe the average of 15 shots
—For a one-chrono setup, about 30 shots, probably

Matthias



PS: Yeah, I did promise somewhere I'd do some BC testing of lesser tested pellets, especially hollow points — since their BC is so critical for to determine their impact velocity — which is critical to assure the hollow point expansion — which is the hole point of a hollow point.....
Yeah, I got sidetracked by work and broken guns....
➔ I'll get on it — I got a second chrono, a second set of lights, a second bipod, and possibly the use of a factory building to eliminate the effects of wind on the measurements....

 

[mtnGhost]

I'd love to hear what we here at AGN can come up with for a trustworthy BC....

• At various velocities — since Stelok Pro permits to enter up to 5 different BCs with their associated velocities

• Based on the GA drag model (or Miles Morris' improved GA2)

• With atmospheric conditions/ elevation figured in

• With sufficient shots to make the test result reliable:
—For a two-chrono setup, maybe the average of 15 shots
—For a one-chrono setup, about 30 shots, probably

Matthias



PS: Yeah, I did promise somewhere I'd do some BC testing of lesser tested pellets, especially hollow points — since their BC is so critical for to determine their impact velocity — which is critical to assure the hollow point expansion — which is the hole point of a hollow point.....
Yeah, I got sidetracked by work and broken guns....
➔ I'll get on it — I got a second chrono, a second set of lights, a second bipod, and possibly the use of a factory building to eliminate the effects of wind on the measurements....

Yeah, I'm talking about with the same barrels, so it's not he factor here. I use my LabRadar with GA as the drag model for pellets, but for short range G1 is not really any different. Wind, barrel twist, air pressure and wind will skew results from one data set to the next (not by much unless you're shooting in a hurricane).

That said, I'd like to prevent a thread hijack to keep my question on topic

 

[JungleShooter]

I'd like to prevent a thread hijack to keep my question on topic

Gino,

I can report the hijacker has been aprehended and shows remorse.

Sorry about that.
Matthias

 

[LCURRENT80]

I don't think the JSB 18.13 comes in anything other than Exact Jumbo Heavy.

https://www.kontrattaky.com/500-pcs...m-1175g-airgun-pellets-air-rifle-p-421346.htm Check Out this Site

 

[hawkeye69]

https://www.kontrattaky.com/500-pcs...m-1175g-airgun-pellets-air-rifle-p-421346.htm Check Out this Site

Have you ever ordered from them? Do you have any info, like are they legit and where they are located?

 

[LCURRENT80]

I have one working Will reply If I have trouble

 

[mtnGhost]

Have you ever ordered from them? Do you have any info, like are they legit and where they are located?

They're in China.

 

[gendoc]

EXACT jumbo heavy DIABOLO 18.13gr is all my 20+ tins are.

 

[Arzrover]

The Exact Heavy are 177. The bc WILL be different. If it's advertised as a 22 Exact Heavy, there are 1 or more errors involved. All 22s are Jumbos as shown above.

On the changing bc, were all the tests at the same velocity? In my testing recently, there was a SIGNIFICANT difference in bc with the 18.1s at 700 vs 900. Different batches, barrels, conditions... maybe even valve configuration, give different bc's for the same pellet.
Bob

 

[HogKiller]

They're in China.

So, who's going to be the guinea pig? And how in the heck are they so low, they aren't making them, IF they are legit.