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Ultrastu

Bc testing

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So i went out yesterday for a couple of hours with both my chronos and a .177 bsa ultra sub 12 ,and thought id test a few of my fave pellets for bc.

I set up in a big barn at exactly 20 yds wind free  and set about shooting 5 pellets of each - taking the muzzle and target velocites .i worked through most my guns charge in its sweet spot .

After i got the values i then worked out each individual pellet shot s bc with chairguns help .then took an average of the 5 to get my final bc value for that pellet type from that gun at that power over that distance . (Other variations  on the above may alter these results -  also it may not) 

Bcs As follows 

Jsb exact 8.44 grn  4.53   0.024 

Jsb heavies  10.3 grn   0.0255

Bisley magum  10.4 grn  0.0235 

Air arms match 8 grn  4.50  0.011 

Qys  streamlined  8.44 grn  0.020 

H+n extreems  9.5 grn   0.019 

  So as expected flat heads low bc .

Extreems with a x hollow point have a pretty high bc for the design .

Jsb heavies not as high as many people think they are .this goes  for bis mags too .exacts are higher than i expected .and the qys were lower than i would have thought.

Though not supprised .

I know this is hardly definitive but its start .much more is obviously needed to be more relevant to more people .

But for that gun it would appear  that jsb exacts would be the best choice for velocity and  energy retention .other than that ultra doesnt like either the jsbs for accuracy and the muzzle energy for the 8.44 s was really low .

The best all rounder is actually the extreems  they are accurate powerful at muzzle ,consistent  and hold plenty of energy down range and use that energy well when it hits .

As it turns out i knew this already as that gun has been shooting these almost exclusively for 3 years now .

Still nice to have it confirmed by science .

More to follow 

Stu 

Edited by Ultrastu

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I have a magpie and a couple of tree rats who question your figures on JSB Heavies, they think your a tad low in your estimation............................................

Nah. Just joking, an interesting little experiment. Thanks for sharing.

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Cheers nev .

My mate thinks the same as he likes jsb heavies and i prefer the 8.44 grns instead .

So chair gun gives a value of

0.021 for exact 8.44

0.031 for jsb heavies

Which to my mind seams too high and low .my testing would show that they are a lot closer .need to test them next at fac and different barrels  

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I will .

Thats the problem i have with publicised bc values. They never state the range or muzzle velocity .

I intend (when time allows ) to test at different ranges 20 ,40 ,60 yds 

And different energies .5  , 11 , 16  fpe for .177 

11 , 23 , 30 fpe for .22 

And 50 fpe for .25 cal 

I think that should cover it .through as many barrels as i can .but to be fair most of the ones we own are bsa .or fx .

 

Though i do have a hw and a crosman also 

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Crossman pistol at 50 yards🤣🤣

I'm surprised that the QYS and exacts are different. 

Did you record the velocities?

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A few have found the JSB Express to have the best BC. 

It's at longer ranges the better BC will show lots more.

As you say the speeds at muzzle may make a difference. Be nice to see the results from your fac tests.

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42 minutes ago, Mice! said:

Crossman pistol at 50 yards🤣🤣

I'm surprised that the QYS and exacts are different. 

Did you record the velocities?

Yeah .im thinking maybe the crosman pistol will only go to 20 yds  😄

 

Figgy i do have jsb express but never found a gun that likes them .

I always find 8.44 or 7.34  grns work better in most my guns  

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1 hour ago, figgy said:

A few have found the JSB Express to have the best BC. 

It's at longer ranges the better BC will show lots more.

As you say the speeds at muzzle may make a difference. Be nice to see the results from your fac tests.

Cor yes please Stu. .25 FAC next up?

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3 hours ago, Mice! said:

Crossman pistol at 50 yards🤣🤣

I'm surprised that the QYS and exacts are different. 

Did you record the velocities?

Yes i recorded the velocites .both of them thats what you need to work out the bc 😒.

Out of that gun the qys made more muzzle energy than the jsb .but that so far doesnt seam to be a factor in bc calculations  .

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All very interesting stuff, I can tell more and more you were the kid to sit next to at school :good:

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All guns can be different on BC 

I have found the best two pellets in most 177 pcp and spring to be AA express 7.9 gr and JSB / daystate heavies 10.3 gr

AA express running @ 806 FPS BC .021

jsb/ daystate heavies running @ 715 FPS BC .21 

the BC was average over 14 shots from HW100KT.177 at 50 yards .

The only pellet I use now AA express 7.9 and I find these to be better than JSB express 

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Ok next round of results in .

Same again .177 at 20 yds 

This time shot out of a bsa lightening xl .

Aa match  bc  0.011 same as pcp 

H+n extreems 0.019 same as pcp 

Qys 8.5 domed    0.018

Qys 8.5 streamlined 0.021 slight increase on pcp 

Jsb exact 4.53   0.0255  increase on pcp

Couldnt get jsb heavies to shoot straight or bismags . Gave up on them 

Falcon acc plus 0.0166 

So ive long said a short barreled springer can give a higher bc than a pcp due to the ballooning of the skirt created by the higher air pressures created .

It would appear  that with the jsb and qys  this seems true  .

Not so much with the match and extreems .

Have to say im disappointed with the falcons bc .as they shoot very well out of this gun and others .

Must try the 7.9 grn  express next time .

 

 

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1 hour ago, Ultrastu said:

Have to say im disappointed with the falcons bc .as they shoot very well out of this gun and others .

That's about the same results cloverleaf got mate, but if your barrel likes them does the BC really matter?

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No .not really .im a big fan of falcons in both .177 and .22 .i find they fly flat and kill well .the speed combined with a fragile makeup makes them very effective at dumping all  their energy on impact .Great for rats ,rabbits and pigeons .

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Knowing the BC and inputting that data into your ballistic app will give very accurate outputs.

 

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I have 20 tins of H&n barracuda match with a specific batch number that suits my XTX ultra se. Wouldnt mind trying some of the falcons to see what there like.

Also may try something different other than the H&N ftt 5.53mm in the SFS Imp .22 

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Did a few .22 pellets today at 20 yds with a bsa  pcp 

Crosman prems 14.3 grns  0.0217

Falcon acc plus13.4 grns 0.0244

Rangemasters 15 grns 0.0262

Bisley lrg   14 grns  0.0197

H+n ftt    14.7  grns 0.0243 

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A few more pellets tested today again at 20 yds bsa pcp in .177 

Daystate rangemaster 8.5 grn 0.0262

Defiant 7.5 grn 0.0245 

Airarms express 7.9 grn 0.0175

Barracuda ft 9.5 grn 0.0235

Qys streamlined 9.4 grn 0.0228

So the 2 pellets which are almost identical the ft and qys are very similar bc and are a bit higher than id have thought.

The rangemasters are discontinued but are basically h+n snipers are as  high as id expected .they have proven to hold energy very well in the past .

And the defiant for a7.5 grn pellet is astounding .

As for the express what can i say -DISAPPOINTMENT -  maybe they just dont suit my barrel but then ive never really found a gun that loves them .

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Whats interesting - to me at least .

Is if you compare these pellets to the .22 ones above the bcs are broadly similar meaning at this range at least that the .22s (often thought of holding more energy down range and hitting harder for hunting etc) dont have any advantage over the faster flying .177s .

Though to be fair i havent tested jsb jumbos at 16 grn or the heavies at 18 . Yet .

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The air arms Express in the test that Cloverleaf did came out better than anything else, his results really surprised me,  might be they really suit the gun/barrel he used but made me think about using a light weight pellet. 

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5 minutes ago, Mice! said:

The air arms Express in the test that Cloverleaf did came out better than anything else, his results really surprised me,  might be they really suit the gun/barrel he used but made me think about using a light weight pellet. 

hello, Mike is the foremost expert i know on air rifles, oh that is the ones he writes up on, a lot go in the trash bin.

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15 minutes ago, Mice! said:

The air arms Express in the test that Cloverleaf did came out better than anything else, his results really surprised me,  might be they really suit the gun/barrel he used but made me think about using a light weight pellet. 

Of all the pellets i tested today the aa express were the most consistent over both chronos .surgesting that the pellets are well made and actually fit my barrel well .why the bc was as low as it was i dont know  

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11 hours ago, Ultrastu said:

Of all the pellets i tested today the aa express were the most consistent over both chronos .surgesting that the pellets are well made and actually fit my barrel well .why the bc was as low as it was i dont know  

Is it possible that you worked something out wrong?

Since he did that article a few lads on the Agf have started using the light weight pellets,  fast flat and hold their energy 

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No didnt work the express number out any different to the other pellets  .

There was no mistake that only applied to the express  .

 

Ive long been a fan of fast flying light pellets .ive always felt that they kill airgun quarry better than a slower heavier pellet .but seeing how well the jsb exact perform (bcl) its no wonder they are the worlds most popular pellet .

Results speak for them selves .

 

Tell you what mice .i will test the express again through a few different guns see if the results are similar .

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