Author Topic: JSB EXACT HEAVY .20 DIABOLO PELLET , first impressions & trial (Read 17181 times))

Cloud 9 · « **Reply #80 on:** April 22, 2019, 02:29:57 PM »

Here are my chrony numbers on my 1963 Steroided Silver Streak.

JSB Diablo Exact 13.73gr - 8 pumps = 657 fps Avg, 5 fps ES, 3.54 SD, 13.14 ft/lbs
10 pumps = 700 fps Avg, 5 fps ES, 3.54 SD, 14.92 ft/lbs
14 pumps = 760 fps Avg, 3 fps ES, 2.12 SD, 17.59 ft/lbs

JSB Diablo Heavy 15.89gr - 8 pumps = 601 fps Avg, 11 fps ES, 5.51 SD, 12.86 ft/lbs
10 pumps = 646 fps Avg, 12 fps ES, 8.49 SD, 14.73 ft/lbs
14 pumps = 719 fps Avg, 12 fps ES, 8.49 SD, 18.25 ft/lbs

It seems that my rifle is down a little from 19Sheridan57's Silver Streak @ 8 pumps, but I can go to 14 pumps where it really packs a whollop (over 18 ft/lbs!) I have noticed with these new JSB Diablo Heavy 15.89gr pellets that my Extreme Spread and SD is increased over the JSB Diablo Exacts. Perhaps that is a tighter fit and difference in the skirts. I noticed the same behavior in my Sheridan Supergrade using the JSB Diablo Heavy 15.89gr pellets. That rifle is on par with 19Sheridan57's Supergrade. Unexplained. I didn't have time to do any accuracy testing yet.

Habanero69er · « **Reply #81 on:** April 22, 2019, 07:01:27 PM »

Got my tin of Heavies today. I have tomorrow off & the weather is supposed to be clear & sunny with a light winds. Perfect for accuracy & chrony testing. Stay tuned.

19Sheridan57 · « **Reply #82 on:** April 23, 2019, 06:34:47 AM »

Here are my chrony numbers on my 1963 Steroided Silver Streak.

JSB Diablo Exact 13.73gr - 8 pumps = 657 fps Avg, 5 fps ES, 3.54 SD, 13.14 ft/lbs
10 pumps = 700 fps Avg, 5 fps ES, 3.54 SD, 14.92 ft/lbs
14 pumps = 760 fps Avg, 3 fps ES, 2.12 SD, 17.59 ft/lbs

JSB Diablo Heavy 15.89gr - 8 pumps = 601 fps Avg, 11 fps ES, 5.51 SD, 12.86 ft/lbs
10 pumps = 646 fps Avg, 12 fps ES, 8.49 SD, 14.73 ft/lbs
14 pumps = 719 fps Avg, 12 fps ES, 8.49 SD, 18.25 ft/lbs

I thought your numbers for 8 pumps would have been higher than mine, too !! Maybe it needs a couple drops of oil ? BUT, at 14 pumps & over 18 ft. lbs., it is powerful !

Cloud 9 · « **Reply #83 on:** April 23, 2019, 10:19:17 AM »

It is a actually well lubed with new seals so I’m not sure.

Habanero69er · « **Reply #84 on:** April 23, 2019, 05:34:07 PM »

Here are my chrony numbers for my two Sheridans. A stock '79 Silver Streak & '85 Steroided Blue Streak. I formatted my numbers like 19Sheridan57's for simplicity sake.

Temp: 76°. Winds: NNE @ 2mph. Chrony distance from muzzle: 6ft. Five pellets per set.

'79 Silver Streak

JSB Diablo Exact 13.73g - 8 pumps = 653.9 fps Avg, 18.51 ES, 7.21 SD, 13.04 FPE
10 pumps = 707.4 fps Avg, 38.72 ES, 16.79 SD, 15.25 FPE
14 pumps = 772.0 fps Avg, 42.11 ES, 17.29 SD, 18.17 FPE

JSB Diablo Heavy 15.89g - 8 pumps = 626.0 fps Avg, 22.37 ES, 9.11 SD, 13.82 FPE
10 pumps = 679.0 fps Avg, 18.81 ES, 8.18 SD, 16.26 FPE
14 pumps = 740.6 fps Avg, 20.54 ES, 8.18 SD, 19.35 FPE

After the 15.89g set with 14 pumps set, I loaded a pellet. The residual air gave me 629.2 fps = 13.97 FPE! That's quite a bit of residual air.
I also tried a mere 6 pumps, which is the norm. 563.4 fps = 11.2 FPE

'85 Steroided Blue Streak

13.73g - 8 pumps = 693.0 fps Avg, 15.79 ES, 6.55 ES, 14.64 FPE
10 pumps = 749.5 fps Avg, 8.48 ES, 6.55 SD, 16.85 FPE
14 pumps = 810.6 fps Avg, 10.30 ES, 3.87 SD, 20.03 FPE

15.89g - 8 pumps = 637.4 fps Avg, 27.4 ES, 10.09 SD, 14.33 FPE
10 pumps = 659.1 fps Avg, 86.0 ES, 26.21 SD, 15.32 FPE
14 pumps = 792.2 fps Avg, 10.0 ES, 4.58 SD, 22.14 FPE

After the 15.89g set of 14 pumps, there was no residual air.
6 pumps with 15.89g, 611.7 fps = 13.2 FPE
6 pumps with 13.73g, 614.1 fps = 11.5 FPE

After almost 700 pumps, it's cocktail time! 🍸

As you can see the new JSB has a higher waist & longer skirt. Also, but not really visible in pic, the 13.73g has a grayer more graphite like color. Where the new 15.89g Heavy has a shinier, oily finish.

JSB 13.73g L & 15.89g R.

19Sheridan57 · « **Reply #85 on:** April 24, 2019, 05:22:00 AM »

Dave,
You were pumping your NON-steroided Streak up to 14 pumps ??
WOW , 790 fps & over 22 ft. lbs. is VERY impressive with the other Sheridan & heavier pellets ! That you for your post !

Yng@hrt · « **Reply #86 on:** April 24, 2019, 06:44:19 AM »

Excellent review Dave & very nice numbers on the '79.

Thanks for taking the time to do that. Thanks to all you guys!

19Sheridan57 · « **Reply #87 on:** April 24, 2019, 07:06:23 AM »

I recently got in an" ugly "Streak that I will be testing. I usually won't buy anything like this, but it was cheap enough, && it works.How good, I don't know. I am unsure if I will restore it or use it as parts. I always chrony every rifle to see if it needs repairs , so I might as well run this one over the chrony & post the test results. I am also picking up a couple of very nice Silver Streaks, & will be checking those out. Results will be posted, later.

Habanero69er · « **Reply #88 on:** April 24, 2019, 07:18:08 AM »

Quote from: 19Sheridan57 on April 24, 2019, 05:22:00 AM

Dave,
You were pumping your NON-steroided Streak up to 14 pumps ??
WOW , 790 fps & over 22 ft. lbs. is VERY impressive with the other Sheridan & heavier pellets ! That you for your post !

I really didn't like pushing the Silver Streak that hard. It had a lot residual air afterward too.

19Sheridan57 · « **Reply #89 on:** April 24, 2019, 07:53:50 AM »

I never go over the recommended 8 pumps.

Habanero69er · « **Reply #90 on:** April 24, 2019, 08:16:44 AM »

Likewise. Usually only 6 pumps as a rule. That was a one & done thing. Too hard on the rifle.

Dairyboy · « **Reply #91 on:** April 24, 2019, 10:34:09 AM »

Very nice guys! Mine are finally going to be delivered today. Spent the night last night putting my .20 Mrod together. Not sure when I'll have time for chrony and accuracy but hoping by tomorrow. We got lots of wind in the forecast starting on Friday so not much time to get my tune done

SteveP-52 · « **Reply #92 on:** April 25, 2019, 01:35:42 PM »

My last post for awhile but Trenier Outdoor now has these in stock, $14.79 a tin:

https://www.trenieroutdoors.com/jsb-exact-heavy-20-cal-pellets-15-89-grains-domed/

Dairyboy · « **Reply #93 on:** April 25, 2019, 01:51:34 PM »

Got my heavies yesterday and they performed amazing at 55yds shooting at 900fps. Very happy with them

19Sheridan57 · « **Reply #94 on:** April 25, 2019, 02:25:19 PM »

Quote from: Dairyboy on April 25, 2019, 01:51:34 PM

Got my heavies yesterday and they performed amazing at 55yds shooting at 900fps. Very happy with them

WOW ! WINNER - WINNER-CHICKEN DINNER !!

15.89. @ 900fps. = 29Ft.Lbs. KERWHOP !!

Correction= 29 Ft. Lbs.

19Sheridan57 · « **Reply #95 on:** April 25, 2019, 02:37:23 PM »

As promised, I took " UGLY " out to test today. I could tell by the first pump that it wasn't all that bad, & I had not even oiled it, yet. Notice the fancy customized bolt . Sorry for the poor pix.

8 pumps

JSB Diabolo Exact 13.73 - 643fps
Benj/Sher 14.3 - 630
JSB Heavy 15.89 - 612

Habanero69er · « **Reply #96 on:** April 25, 2019, 07:56:09 PM »

Where can I get a custom bolt handle like that?

johnnyfoos · « **Reply #97 on:** April 25, 2019, 08:11:24 PM »

I love reading about peoples
chrony numbers
With what ever air gun they are using
BUT-
I hate that people seem to never sate-
At what elevation,
Some are great enough to list Temp, humidity Ect., Ect.
Just for some reason the ELEVATION just seems to be missed

I know it isn't that big a deal,
It is that I live at just under 5,000'
and do some shooting at over 6,000'
once in awhile I even get up to some VERY HIGH
places and wonder about the power difference ?
And I also wonder about what shooting at near sea level would be like,
I did shoot my P-17 last year at about 508' ,
but was trying very hard to not hit what I was trying to scare off-
A SKUNK family
that figured out that my girlfriend was leaving her,
Anchovies out for an easy meal for them.
Lucky for us that I was good/bad enough to miss.
Hitting one would have ruined the great spot we had for camping/fishing.
LOL !

just
say'n

Habanero69er · « **Reply #98 on:** April 25, 2019, 08:16:05 PM »

My numbers were recorded at 11ft above sea level.

Cloud 9 · « **Reply #99 on:** April 26, 2019, 12:37:34 AM »

I’m slightly higher at 630 feet elevation

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JSB EXACT HEAVY .20 DIABOLO PELLET , first impressions & trial

Author Topic: JSB EXACT HEAVY .20 DIABOLO PELLET , first impressions & trial (Read 17181 times))