Is faster always better in the wind? New slug info page3

Forums Pellets, Projectiles, Slugs, & Ammo Is faster always better in the wind? New slug info page3

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    Centercut
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    Its something I've been wondering about for quite a while now, especially in todays PCP, with shooting faster and harder being all the rage. I've seen Impacts shooting 44.75 grain JSB Exacts at over 1000 FPS, Daystate Safaris shooting 34 grain MK2 Heavies at over 1050 FPS. Even the RMAC winner shot his Ernest Rowe tuned .30 Impact at very close to 1000 FPS, I think the number I heard was 990.  

    So, I've been tinkering around with this. Common sense would tell you that the faster the pellet flies, the less time in the wind, and therefore the less its flight path is affected. But, is this really true, or is it a myth? Obviously shooters that have spend hundreds of hours and thousands of dollars getting their guns to shoot faster will tell you without a moment's hesitation that faster is better… but is it?

    There are two things that made me start questioning this, and thinking that perhaps it is a myth, an old wives' tale. 

    First, I was shooting Sunday, and had my .25 Vulcan Tactic shooting the Kings at 888 FPS. And next to it, I had my .25 Cricket, which normally shoots the Heavies at 905 FPS. I was shooting targets at 85 yards, in a fairly strong left to right breeze, probably 6 to 8 mph, and steady.  I had shot a couple of magazines with the Vulcan, and the pellet was moving between 1.5 and 1.75 mils.  I thought, lets try the Cricket, with the Kings, at about 1000 FPS. The pellets are flying much faster, so it should be less affected by the wind. Right? Well, not…  With the much faster pellet speed, I was getting pretty much the same drift, maybe even slightly more (1/8 mil more on average).  To say I was surprised would be an understatement…

    Second, I decided to do some "what if" with Strelok Pro. So I looked at my standard setup for the Vulcan, and did the 5 mph wind at 100 yards from 90 degrees.  It showed a 1.3 mil drift (.25 JSB King 25.4 gr, BC .042). Then I changed my pellet speed to 1000 FPS, and Strelok showed a drift of 1.4 mil.  Huh? Every other variable the same, and it drifts more with higher speed…? Is Strelok broke, or perhaps the physics of a diabolo pellet in flight backed up what I experienced at the range…  Perhaps it has to do with the BC going down dramatically as you enter the transonic region, and the BC starting high and remaining high at the lower (850 to 900 FPS) ranges. Not sure about that?

    So, there's my two cents on the matter. I can understand the additional power for a slightly flatter (remember, no pellets really shoot "flat") trajectory and more energy downrange for hunting. But for target shooting, is jacking up your power to shoot in the wind really necessary?  ;)

    Mod edit: moved to Pellets, Projectiles, Slugs, and Ammo forum

    • This topic was modified 3 weeks ago by Centercut.
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    Hoople
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    Hi all, new here. I read this article the other day. Hope you find it helpful: https://hardairmagazine.com/ham-columns/the-external-ballistics-of-diabolo-pellets/

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    Centercut
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    @hoople, thanks much, great article. It basically proves what I've written about above… It shows scientifically that there is no benefit  to raising your pellet speed much over 900 FPS for target shooting at 100 yards.  Whodathunk?  

    {From the Hard Air Magazine article referenced above:

    When you shoot in a crosswind, the pellet drifts sideways, causing your POI to be downwind of your POA. The largest factor governing the magnitude of this drift is the BC.

    There are many misconceptions about wind drift, the biggest being that “time to target” is the key [velocity]. That is NOT the case. The wind drift is proportional to the DIFFERENCE in the actual time of flight, compared to what it would be in a vacuum. This is called the “lag time”.

    This is a difficult thing to wrap your brain around, and even harder to explain without involved mathematics, so I will leave to you Google it if you don’t believe me. However, it is a fact that we have to deal with when considering the external ballistics of diabolo pellets.

    Since the lag time is the key, then how fast the pellet slows down (mostly governed by the BC) is the key.}

    So now the big question. Except for shooting slugs (whose BC is much higher than pellets), why are all these shooters working so hard and spending so much money to get their 100 yard target rifles (diabolo pellets) shooting at 950, 975, 1000 fps and beyond? Other than using more air, and making the gun harder to shoot, what's the point???

    • This reply was modified 1 month ago by Centercut.
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    18.13
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    CC

    I have done the same years ago with Chairgun. At 100yrds somewhere around 880 gives you the least wind drift,different pellets a little different speed. But once you get farther out like 250yrds the higher speed does help but not much.

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    18.13
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    In a video that Ted did a few years ago he said the .25 heavy MK II had there best BC at 830 fps and that he tuned his guns to that speed. He also won the EBR that year.

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    18.13
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    At 8 min.

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    Raden1942
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    I will do my best to explain what I know on this topic. Each pellet is different and there is a mathematical equation that every high level shooter does to maximize thier efficiency. So a pellet shot from lower fps but with a better bc than one shot at faster fps can be a flatter shooter. I believe these guys are picking the best pellet they can find for thier gun generaly they look for the heaviest pellet thier gun likes and pump up the velocity to as fast as the pellets bc can handle as well as matching barrel twist rates and harmonics. If thier guns can stabalize a pellet and the speed doesn't make the pellet unstable than every fps faster helps. For average shooters I would agree with your idea here but high level shooters often push the limits of thier equipment to gain really small advantages over the competition. Its the same as racing bicycles. In general cadence and fitness will get the win but in high level those guys will spend thousands of dollars to lose an ounce or two. Its not practical for most but can be the difference between silver or gold. Just my 2 cents. 

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    Raden1942
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    Matt dubber on youtube has some great videos on barrel harmonics, twist rates and calculating ballistic coefficient to match your rifle. I guess my point is your not wrong but neither are the guys pushing the limits. 

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    Centercut
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    Raden1942

    Matt dubber on youtube has some great videos on barrel harmonics, twist rates and calculating ballistic coefficient to match your rifle. I guess my point is your not wrong but neither are the guys pushing the limits. 

    I do see your point, but an inch or two in "flatness" at 100 yards for target shooting makes zero difference in performance.  I looked at all the "Pros" shooting their high speed pellets at RMAC, then at the top "Sportsmen" shooting FX Bobcats at "normal" speed,, and the scoring differential was minimal. In fact, the top Sportsman shot better scores than all but the top couple of Pros if I remember correctly. I shot there, and I can tell you without a doubt, and almost everyone there would agree, that WIND reading (and a bit lof luck) was far and above the major factor in scoring…  With no wind, anyone can shoot very good scores at 100 yards.  ;)

    • This reply was modified 1 month ago by Centercut.
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    2fast2furious
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    Ted holdover did some testing and he said he found out pellets do better at slower and not the claim (faster will spend less time in the air, hence it will be less affected by the wind). He shot them over 900fps and he said they are ok accuracy. But he shot them at about 830 fps and he said that's where he get his best accuracy. It all depends on the gun and ammo but faster isn't always better. Sure it will spend less time in the air but will go so fast it will be unstable. Unless you are shoot slugs, you probably don't want to go near 1000fps

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    lbc_PSI
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    The wind drift issue is related to drag.  The more drag a projectile has the quicker it slows and the easier it is for the wind to push.

    Something with a higher BC is less affected by drag.   So slugs generally outperform diabolo pellets. 

    If you have two projectiles with the same form factor, the faster one will drift more..even though its time-of-flight is less.

    According to ChairGun, the drift of a .25 34gr slug with a BC of 0.09 in a 10mph crosswind at 100yds is:

    velocity/drift/hold-off/TOF

    900fps  3.94"  1.1mil  0.356

    925fps  3.98"  1.1mil  0.347

    950fps  4.07"  1.1mil  0.339

    975fps  4.19"  1.2mil  0.331

     

     

     

     

     

     

     

     

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    John_in_Ma
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    I can tell you as a 12fpe shooter that was shooting at 20fpe slower is better. Not only is the wind drift a bit less, but it's also more predictable.

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    DonC
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    In 1998 Allan Zasadney told me for Field Target .177 caliber, best to tune 850 to 875 fps. Most guys I know agree. However Robert Crocker has won several Nationals shooting just under 20 ft/lbs.

    My kits all shoot 875 and I am very pleased with wind effects.

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    Motorhead
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    I shoot FT at the > 20 ft lb hunter pcp class and done so using a .20 caliber gun these past 3 years having very good success at local & the State & National level shooting a JSB pellets at only 795/800 FPS.  All the testing done belief it or not has the BC value at .044 when at that muzzle velocity.   Gun shoots MOA or better all day long having wind move it some, but nothing like a .177 at 100+ fps higher speed.

     

    Just some relativity …

    Scott S

     

     

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    PerkyVal
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    I'm wondering how much spin rate apropos speed get effected by wind. I forgot the name for it but it's basically like english on a billiard ball. 

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    Centercut
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    PerkyVal

    I'm wondering how much spin rate apropos speed get effected by wind. I forgot the name for it but it's basically like english on a billiard ball. 

    I think you're thinking about Spindrift. With pellets at 100 yards, its negligible, less than .1 mil. Although, the spin does affect the pellet elevation a bit depending on the wind direction. For a right hand twist (most guns), it results in a little higher than expected POI when coming from the right, and lower than expected when coming from the left. You can tell Strelok to use this on holdover and hold-off calculations, but in general its minimal for what we shoot. It may affect 25M  or 50Y BR, when 1/32" can make the difference between an X and a 10, or a 10 and a 9…

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    Jayson
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    Wow! What a great topic! Just soaking it up because none of my guns will shoot very fast (over 875). Very interesting feedback so far and I’m having my own little “what the hell” moment? I really did not know or think much about this, I must say, unlike most things explained in detail, it still does not make sense to me? Leave it up to Centercut to strain my brain right after work🤕

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    boscoebrea
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     it is a great topic,my own experiments with faster being better resulted in these findings,faster went farther before losing inertia,butt then dropped off faster than a slower heavier round…..sort-of like RPM vs. Torque thing…also I think the old time mathematician Capericus had that figured out centuries ago….ok I wrote his name wrong,butt you know who I am talking about ,not Galileo

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    Xbowsniper
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    Nation,

    Guys, this is a great discussion……..

    From getting my own dies in .177 to make my own pellets, to testing existing pellet offerings by different companies, I've discovered some pretty amazing things. 

    My dies are a work in progress, head over to the pellet and projectile portion to follow my progress. 

    Being that I am an avid WFTF (12 FT.LB only) Field Target competitor, I'm limited to my projectiles…….or so I thought.

    95% of all shooters in my division, shoot either a 7.87 grain Air Arms or JSB, or 8.44 grain.  The rest (like me), use other similar weights and brands  H&N Field Target Trophy at 8.64 grains.  All of these are shot between 790-820, depending upon the weight to keep them at 12 ft.lb.   This translates to around 6- 6.5 ft.lb of energy at the 55 yard realm.  In a 15 mph 90 degree crosswind, these pellets will drift 10 -12 inches, depending on the weight and brand.

    This fool decided to look into the more extreme weights, and tested a whole slew of out of place projectiles, not even considered for WFTF Field Target use.  I tried JSB Heavies at 10.3 grains, which I've found extremely consistent and accurate, this is what I recently switched to from the Field Target Trophy. 

    I tried JSB Monsters, Redesigned Monsters, Beasts, H&N Rabbit Magnums.  All gave me inconsistent groups at 55 yards.

    Then, I tried insanity.  Yes, I shot some 21 grain Piledrivers @ a blazing 504 FPS.  This velocity gave me 12 ft.lb at the muzzle. At 55 yards, it still retains much of it's energy, at well over 10 ft.lb.   The wind drift in that same 15 mph wind that blew the other pellets 10-12 inches…….only blew these flying bricks 3 inches and change. The only issue with these pellets are the diameters were very inconsistent.  I would stack 5 or 6 of them at 55, and have 1 or 2 flyers.  The flyers had a much looser fit in the breech.   If I sort these the way I do my match pellets, I might have much better performance.   I'd rather have a split with a 10.5 ft.lb flying anvil, than a split with a 8 grain pea at 6 ft.lb or so.

    And the quest continues……

    Tom Holland 

    Field Target Tech 

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    Centercut
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    Jayson

    Wow! What a great topic! Just soaking it up because none of my guns will shoot very fast (over 875). Very interesting feedback so far and I’m having my own little “what the hell” moment? I really did not know or think much about this, I must say, unlike most things explained in detail, it still does not make sense to me? Leave it up to Centercut to strain my brain right after work🤕

    Ahhhh, sorry for the headache brother!  ;) What I find the most interesting is all of us walking around at RMAC, and thinking to ourselves that all those $3,000+ Impacts shooting the 44.8 grain .30 cal JSBs at close to, or over 1000 FPS had some sort of wind advantage over us guys shooting our $1200 Bobcat/Boss at 870 to 880 FPS.  And it turns out that not only was it not an advantage, it may have been a hindrance. Things that make you go hmmm.  Hard to argue with proven science. It kinda makes me smile to know that at least in this instance, money couldn’t buy a wind advantage…

    • This reply was modified 1 month ago by Centercut.
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