JSB 18.13 pellet at 950 fps for best accuracy?

[KodiakJac]

After reading this Hard Air Magazine article The External Ballistics Of Diabolo Pellets and watching this Ted Holdover YouTube video Pushing the Velocity of .22 Pellets I'm wondering if we should be testing the .22 JSB 18.13 pellet in the 950 to 960 fps range for maximum accuracy at 50 or even 100 yards?

I've been shooting firearms all my life, but other than shooting BB and pellet guns as a kid, I've only been shooting airguns seriously for about 2 years. And when I got started with airguns, I fell into the 880 fps crowd for the .22 18.13 pellet pretty quickly, as that seemed to be the consensus velocity I kept reading about.

So, is 880 fps really the sweet spot for the .22 JSB 18.13 pellet at 50 or even 100 yards?

 

[Sqwirl57]

If its accurate go for it. There are other factors to consider though. Your starting BC is probably going to be a bit lower on the curve at 950fps than it is at 875fps which can result in more wind drift.

 

[bdzjlz]

My experience is to achieve max accuracy probably between 890 and 920

 

[KodiakJac]

If its accurate go for it. There are other factors to consider though. Your starting BC is probably going to be a bit lower on the curve at 950fps than it is at 875fps which can result in more wind drift.

That's what I found interesting about the article. Yes, the wind drift is more at 950 fps, but the article suggests the trade-off is worth it for the flatter trajectory. But if your scope is already sighted in to allow for the increased pellet drop at 800 to 850 fps (pick a speed, say 820 fps), what's the value of a flatter trajectory?

Wouldn't you want the absolute sweet spot for wind drift, which the article cites being at 800 to 850 fps (looks like about 820 fps on the graph)?

 

[Sqwirl57]

That's what I found interesting about the article. Yes, the wind drift is more at 950 fps, but the article suggests the trade-off is worth it for the flatter trajectory. But if your scope is already sighted in to allow for the increased pellet drop at 800 to 850 fps (pick a speed, say 820 fps), what's the value of a flatter trajectory?

Wouldn't you want the absolute sweet spot for wind drift, which the article cites being at 800 to 850 fps (looks like about 820 fps on the graph)?

Oh I should probably read those articles instead of just commenting

Jeopardy music starts playing in the background

So apparently I have read that exact article and was quoting it so not saying anything you didn't already know. Sorry about that haha.

Personally I'd rather have less drift than a slightly flatter trajectory. The trajectory you can know with pretty definitive accuracy. Wind on the other hand is an invisible b**** that can be very difficult to read at times and can take a bit of luck without flags and wind reading equipment. I'd rather reduce that particular variable because I'm not amazing with it. Between speed and direction and that specific directions affect on drift and drag, less is more. Thats my personal take.

 

[Raider03]

Not every .22 cal airgun will have the same twist rate. A lower twist rate barrel could be more accurate (stable) at higher velocities.
There is also barrel length, with a shorter barrel achieving a muzzle velocity of 950fps will require a higher regulator pressure. That will cause a higher pressure when the pellet exits the barrel. Resulting in more muzzle blast, which will degrade accuracy.
And distance, shorter ranges will allow for higher velocities. Less time for the pellet to destabilize. You can have great results at 50yards and terrible performance at 100 yards with the same tune.

 

[EPG]

Attached are some results that show two rifles I have that show extreme accuracy with JSB 18.13g at velocities of 1,013 and 1,028 fps.

Daystate Wolverine R HP .22 and RTI Prophet Performance V1 .22 LR. Both rifles have Lothar Walther barrels with polygonal rifling. The Prophet’s barrel also has a slow 32:1 twist rate.

I am surprised myself. I am shooting 30 Yard Challenge cards at 40 yards. These results show scores of 189 to 197. I’ve shot 200 scores with both rifles at 30 Yards. (Edit - one of the attached is a 200 @ 30 yards shooting 1,028fps)

To put these cards in perspective, the X is 2/100” and the 10 ring is .125” in diameter.

So, as far as the 880fps rule, it seems to be a good accuracy guideline, but there are some barrels that will shoot the 18.13s accurately at over 1,000 fps. Freakin Wolverine shooting 197 at 40 yards blew my mind.

-Ed

 

[airgungil]

From what little research I've done, 950 is definitely the top end for JSB 18's right?

 

[Raider03]

Attached are some results that show two rifles I have that show extreme accuracy with JSB 18.13g at velocities of 1,013 and 1,028 fps.

Daystate Wolverine R HP .22 and RTI Prophet Performance V1 .22 LR. Both rifles have Lothar Walther barrels with polygonal rifling. The Prophet’s barrel also has a slow 32:1 twist rate.

I am surprised myself. I am shooting 30 Yard Challenge cards at 40 yards. These results show scores of 189 to 197. I’ve shot 200 scores with both rifles at 30 Yards. (Edit - one of the attached is a 200 @ 30 yards shooting 1,028fps)

To put these cards in perspective, the X is 2/100” and the 10 ring is .125” in diameter.

So, as far as the 880fps rule, it seems to be a good accuracy guideline, but there are some barrels that will shoot the 18.13s accurately at over 1,000 fps. Freakin Wolverine shooting 197 at 40 yards blew my mind.

-Ed

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Hi Ed,
None of the 40yard cards you posted score a 197

 

[Ranchibi]

I have found the JSB (branded) 18gr pellets to be accurate with the widest FPS spread than any other pellet I have ever shot. I have my RAW .22 shooting them @ 970fps accurately but have seen folks like EPG shooting them over 1000fps accurately as well as under 700fps. My Daystate Regal shot them accurately @ 870fps. Incredible pellet, my fav in .22 by far. Have taken ground squirrels out to 120yds with them.

 

[EPG]

Hi Ed,
None of the 40yard cards you posted score a 197

Sorry John, its there now - I added it via edit. It was hard to see which ones I was choosing.

-Ed

 

[gendoc]

my crown compact MK2 loves the jsb 18.1 @ 965fps, 75-80yrd shots on pest birds
as long as i do my part and the wind is tolerable from my bog death-grip or the caldwell turrent.

 

[18.13]

I'm all for least amount of wind drift, so below 900 for me

 

[EPG]

Further info for those interested in the topic of stability of 18.13s at speeds in excess of 1,000fps… and impact on wind drift…

Daystate informs the Wolverine HP and Red Wolf HP use the same polygonal LW barrels.
The .22 barrel is 18:1 twist rate, the .25 is 30:1.

RTI informed me that the RTI Prophet V1 .22 and .25 LR (Long Range) barrels are both 32:1 polygonal.

Regarding 900fps showing the least wind drift…

Since my Wolverine R HP seems to be keeping the 18.13s very stable out to 40 yards, I’m guessing that its still at around 900fps as the pellets go past 50 yards - would that be an advantage? My thought is that out past 50 is where you really want to minimize wind drift…?

 

[18.13]

According to Chairgun

Shot at 1000 your pellet will be going 776 at 50yrds and will have drifted 1/4 inch more than one shot at 855

 

[KodiakJac]

According to Chairgun

Shot at 1000 your pellet will be going 776 at 50yrds and will have drifted 1/4 inch more than one shot at 855

Does Chairgun show minimum wind drift for the 18.13 to be 820 fps? That looks like where it is on the graph in the HAM article.

Thanks!

P.S. I just downloaded Chairgun Pro to start researching this myself, but thought I'd ask until I get it up and running.

 

[tommyb]

After reading this Hard Air Magazine article The External Ballistics Of Diabolo Pellets and watching this Ted Holdover YouTube video Pushing the Velocity of .22 Pellets I'm wondering if we should be testing the .22 JSB 18.13 pellet in the 950 to 960 fps range for maximum accuracy at 50 or even 100 yards?

I've been shooting firearms all my life, but other than shooting BB and pellet guns as a kid, I've only been shooting airguns seriously for about 2 years. And when I got started with airguns, I fell into the 880 fps crowd for the .22 18.13 pellet pretty quickly, as that seemed to be the consensus velocity I kept reading about.

So, is 880 fps really the sweet spot for the .22 JSB 18.13 pellet at 50 or even 100 yards?

Ted makes good YouTube videos. Always enjoy watching and learning from him.

I wish the 100Y range wasn’t busy, so we could have seen how the 18.1 would have performed at his 935 FPS velocity. His groups at 50y were good.

I never had any really great groups with the JSB 18.1 pellet at 100 yards outdoors at my local range. I also shot many NUAH ( Nothing under a hundred) paper targets and EBR 8x11” targets at 100y, with poor results.

Too much ( for me) wind drift for the 18g pellet and destabilized somewhere between 50-100 yards. I know others have had better luck, but I can’t recall seeing many paper targets ( I.e., either shooting groups or for score) posted at 100 yards with the 18.1.

 

[KodiakJac]

Not every .22 cal airgun will have the same twist rate. A lower twist rate barrel could be more accurate (stable) at higher velocities.
There is also barrel length, with a shorter barrel achieving a muzzle velocity of 950fps will require a higher regulator pressure. That will cause a higher pressure when the pellet exits the barrel. Resulting in more muzzle blast, which will degrade accuracy.
And distance, shorter ranges will allow for higher velocities. Less time for the pellet to destabilize. You can have great results at 50yards and terrible performance at 100 yards with the same tune.

These are important points. I hadn't considered twist rate when thinking about the article, and a pellet moving at 880 fps with a twist rate of 1 in 17.7" like my Lothar Walther Kratos barrel is going to have different flight characteristics from a pellet moving at 880 fps from my Ghost (which I think has a 1 in 30" twist rate).

And muzzle blast from a short barrel...that's a total wild card! Hadn't considered that at all.

Thanks!

 

[Filnez]

Two groups that I shot yesterday afternoon with my HW100S and the JSB 18 grainers. They launch at just under 1000 fps.

 

[tommyb]

Phil - excellent accuracy at almost 1000 FPS for the 18.1 for the HW100 50J power platform.

I posted some groups on another thread for my HW100 .22 Carbine at 850 FPS at 50Y. Shot eight 5-shot groups with average .61” CTC.

It appears from the responses and information contained in this thread, that at 50 yards and less; there is a fairly large acceptable range of velocity from low 800’s to a bit over 1000 FPS to achieve good accuracy with this pellet.

Not as forgiving at 100 yards though at any velocity IMO, based on my experience and YMMV. I have shot at 100y with my RAW HM1000x .22 HP, HW100, Royale and Revere with the 18.1 and have had no luck for tight groups or shooting for score with paper targets. Wind and pellet destabilization the primary culprits.