Looks like my new favorite - JSB Heavy .177

[JMJinNC]

I picked up some more pellets to sample, and managed to get some shooting done in the backyard range trying them out. I got the JSB .177 sampler (Exact, Exact Heavy, Exact RS, and Straton) as well as well as some H&N Baracuda Hunters, Beeman Silver Bears and Silver Arrows.

I liked both Beeman pellets, but when I got to the JSB Exact Heavies in the JSB sampler, I was blown away! I was expecting a significant POI change, since I'm set up for 8.44 grain JSB Exacts.

My carbine shoots the JSB Exacts at 695 fps. I measured the 10.34 grain Heavies at 641 fps average using my Combro, with the same POI (probably due to the higher BC???). Nice fit into the breech and good energy downrange. The JSB Exact RS also shot well, but it's rare that I can put pellets downrange like this, even benchrested.

Here's the target - 1/2" bull, 1/4" grid, shooting a tad over 25 yards, 5 pellet group, with the 6th hole on the lower left is a flyer from another bull. I'm using a modified 9-bull target printed on cardstock.

Not the best shooting, but pretty good for me.

Sorry - just had to share the joy - JMJ

[breakfastchef]

Great result from a world-class pellet. If your carbine loves these pellets, also try H&N Barracuda Match (10.65g). These and the JSB Exacts are my go to rounds for my carbine.

[byhsu]

JMJinNC:

Could you tell me how long is your barrel and at how many pumps was the test at?  also, what power mods did you do the carbine to achieve that performance?

Thank You

[JMJinNC]

Performance, Accuracy, and Ergonomics mods.

Aftermarket Parts:
Mellon flat top piston & valve (ported)
Mellon extended probe bolt
Crosman steel breech
Crosman 24" barrel
Crosman 2289 forearm
Crosman 1399 rear stock
Chavka anodized barrel band & pivot pin
Chrome wide trigger shoe
Leapers 3-9x40, 35 yard parallax mil-dot scope & medium rings


Modifications:
Custom designed & fabricated 17" LDC/shroud, reflex-type
Threaded & crowned barrel (3/8"-16 male)
Added second set screw on steel breech
Lighter trigger spring w/aluminum tube guide
Custom Delrin bushing on rear of Mellon bolt
Custom adjustable Kydex cheek riser
Custom adjustable butt-pad
3rd stabilizing screw in rear stock
Brutuz-type port seal

I generally do 10 pumps for all my shooting. With my setup, I can get up to 12 pumps before the valve starts retaining air, so I'm happy with the valve & hammer springs as-is.

JMJ

[byhsu]

wow, sweet looking rifle 

Thanks

[Crosshairs]

Nice shoting my friend and a sweet looking shooter. I love the JSB pellets one of my favorite. I use a target almost the same as yours great for zeoring in the scope and or practice.
                            Mike

[arkmaker †]

I promised that I would send my Dad more pellets, so I am thinking of a tin or two of these, now that I have seen your results.
Nice looking rig you have there!
Rich

[byhsu]

JMJinNC:

was your barrel cut to 16"?

Thanks

[JMJinNC]

JMJinNC:

was your barrel cut to 16"?

Thanks

No, my barrel is full length. My shroud is a reflex-type which only adds 2" or so to the barrel length.

JMJ

[byhsu]

thanks for the info

i was confused by this Threaded & crowned barrel (3/8"-16 male)

[JMJinNC]

3/8-16 is the thread for attaching the shroud. 3/8" major diameter, 16 threads per inch.

JMJ

[byhsu]

Thanks, learned something new today 

[JMJinNC]

Since my carbine loves them, I ordered some more JSB Heavies as well as a tin of 13.4 grain JSB Monsters. I was shooting the Monsters at 588 fps (about 10 fpe) with less than 1/2 a mil dot elevation at 25m, 8x magnification.

I also tried some 10m shooting (benched & freehand) using RWS Diabolo Basics - 7.0 gr wadcutters, 4 pumps, 3x magnification, 520 fps. Very relaxing. I found I was getting better accuracy with both eyes open, which is a new stategy for me.

I've been using the Heavies for squirrel eradication but may try the Monsters at shorter ranges.

JMJ

[1377x]

how did you like the strattons?
in .22 its my favorite pellet
the monsters in .22 helped me achieve 38fpe with my disco pistol and was one hole pellet size 10 shots at 10m rested
i am wondering if they perform the same in .177
so how do they perform?

[JMJinNC]

The Strattons shot okay in my carbine but it's sensitive to pellet head diameter. I was getting some deformation when loading, resulting in sporadic flyers. I like the shape but I get better consistency with the Exacts, Heavies, and Monsters.

JMJ