Flat pellet trajectory - really?

So I think I brought this up a while back, but again I’m seeing comments like “I like shooting the lighter pellets for a flatter trajectory”. Let’s take a look at facts, using my .25 Vulcan Tactic gen4. The third column is inches and the fourth is Mil. It shoots the 25.4 grain Kings at 895 FPS, and is zero’d at 50 yards. So it’s drop at 100 yards is 12.3 inches and 26 FPE. Five yards more at 105 yards it’s drop is 14.6 inches. 
1575336641_17491459395de5bac19fd242.68351370_F3F58B6A-EF52-41AA-9746-459BA996D2C8.jpeg


Now let’s look at the same gun shooting Mk2 heavies at approx 800 FPS. It’s drop at 100 yards is 14.8 inches with an FPE of 30 FPE.
1575336657_5719367805de5bad17d5c55.61802020_3151FF4B-08D4-4669-942F-5609E79AFD08.jpeg


So in reality, what you’re gaining by shooting the lighter pellet is the equivalent of shooting 5 yards closer to the target. So yes, it by definition is “flatter”, but in the big scheme of things not by any amount that really matters...? And do you really think in excess of a foot drop from 50 to 100 yards is flat?
 
What goes up must come down. I also shoot compound bows and the last few years it all you here is it shoots flat and its fast and my question is can you hit your mark every single time, the speed and perceived flat doesn’t guarantee a bullseye. Sitting and practicing shooting fundamentals and how to use your sighting system and knowing your chosen projectile slinger. I had a buddy in the Marine Corps. I swear he could take some pile of a rifle home from a gun show clean it up (a little) and shoot like nobody’s business after a few days spent getting to know the pile. He said it was easy to miss but even easier to hit what your aiming at if you did the basics and understood the limitations.
 
I agree and played pretty in depth this past summer with my Field Target pistol at >12fpe

8.4's @ 790 fps or 10.3's at @ 710 fps yielded a hold point at 35 yards of .42 mil hold over with 8.4's and .62 mil hold over with 10.3's

In the wind the 10.3's were superior even tho traveling slower. same thing when I shot WFTF rifle out to 55 yards the 10'3's did not move around as much.

End of the day however .... Is RANGING Accuracy being more critical the shower you shoot. sad but true supporting there's no free lunch !!



Scott S
 
So I think I brought this up a while back, but again I’m seeing comments like “I like shooting the lighter pellets for a flatter trajectory”. Let’s take a look at facts, using my .25 Vulcan Tactic gen4. The third column is inches and the fourth is Mil. It shoots the 25.4 grain Kings at 895 FPS, and is zero’d at 50 yards. So it’s drop at 100 yards is 12.3 inches and 26 FPE. Five yards more at 105 yards it’s drop is 14.6 inches. 
1575336641_17491459395de5bac19fd242.68351370_F3F58B6A-EF52-41AA-9746-459BA996D2C8.jpeg


Now let’s look at the same gun shooting Mk2 heavies at approx 800 FPS. It’s drop at 100 yards is 14.8 inches with an FPE of 30 FPE.
1575336657_5719367805de5bad17d5c55.61802020_3151FF4B-08D4-4669-942F-5609E79AFD08.jpeg


So in reality, what you’re gaining by shooting the lighter pellet is the equivalent of shooting 5 yards closer to the target. So yes, it by definition is “flatter”, but in the big scheme of things not by any amount that really matters...? And do you really think in excess of a foot drop from 50 to 100 yards is flat?

It seems that the primary gain in shooting "lighter for faster" pellets might be in the MPBR department. The absolute variance in drop is maybe not that important (but 2.3 inches in your above example could easily lead to a miss on a small target). Lighter/faster pellet might extend the range between near and far zeroes a very usable amount, especially in lower power guns and assuming one uses the two zero method.
 
Bandag

The absolute variance in drop is maybe not that important (but 2.3 inches in your above example could easily lead to a miss on a small target).

Not sure what you mean by that or why the shooter would miss by 2.3 inches unless he was shooting the heavier pellet and holding over for the lighter one? Which in that case is 100% the shooter’s fault. I do see your point about near and far zeros and the variance being maybe an extra 1/4” at the peak between the two. 
 
Bandag

The absolute variance in drop is maybe not that important (but 2.3 inches in your above example could easily lead to a miss on a small target).

Not sure what you mean by that or why the shooter would miss by 2.3 inches unless he was shooting the heavier pellet and holding over for the lighter one? Which in that case is 100% the shooter’s fault. I do see your point about near and far zeros and the variance being maybe an extra 1/4” at the peak between the two.

Yes, that is what I was referring to, maybe not so eloquently. But exact distances aren't always known, maybe even rarely known in field shooting. Nice when they are but it's not always the case so anything to flatten the trajectory within the accepted shooting range seems like it would certainly be helpful, especially as range varies and target size is small or also varies. And are you so sure that 1/4 inch would be the maximum variation. Seems it would depend on the distance between zero distances, velocity, and pellet weight. Again, how accurately can each individual shooter know the range and how small is the target? 
 
So I think I brought this up a while back, but again I’m seeing comments like “I like shooting the lighter pellets for a flatter trajectory”. Let’s take a look at facts, using my .25 Vulcan Tactic gen4. The third column is inches and the fourth is Mil. It shoots the 25.4 grain Kings at 895 FPS, and is zero’d at 50 yards. So it’s drop at 100 yards is 12.3 inches and 26 FPE. Five yards more at 105 yards it’s drop is 14.6 inches. 
1575336641_17491459395de5bac19fd242.68351370_F3F58B6A-EF52-41AA-9746-459BA996D2C8.jpeg


Now let’s look at the same gun shooting Mk2 heavies at approx 800 FPS. It’s drop at 100 yards is 14.8 inches with an FPE of 30 FPE.
1575336657_5719367805de5bad17d5c55.61802020_3151FF4B-08D4-4669-942F-5609E79AFD08.jpeg


So in reality, what you’re gaining by shooting the lighter pellet is the equivalent of shooting 5 yards closer to the target. So yes, it by definition is “flatter”, but in the big scheme of things not by any amount that really matters...? And do you really think in excess of a foot drop from 50 to 100 yards is flat?

What's really surprising is when you run numbers for various calibers and power levels. I played with the ballistics calculators and was surprised to find that anything over about 20fpe has about the same drop at 100-125 yards, provided pellets are being shot. The BC range of 0.03-0.06ish (liberal range) seems be the "flatness" limiting factor. Yes, the big fpes still have more juice that far out, but gravity is a constant and most decent pellets, even at pretty high fpe seem to fall into a rather narrow window of BCs. I think I've used a 50yard zero when doing the comparisons and most 100 yard drops are around 12 inches, at least per the ballistic calculators. 
 
Interesting. I usually zero my guns at approx 50 yards to the MPBR is around 55 yards for a 1/2 inch vital zone radius. So yes, not knowing the exact yardage up to around 60 yards give or take isn’t required. But once you get much past 60 yards you’d better know the range to the closest couple of yards or else you’ll about guarantee yourself a miss. That’s why hunting at longer ranges requires a laser rangefinder. 

With the above example of .25 JSB King at 895 FPS, let’s look at shooting a ground squirrel. You look and estimate 95 yards. You don’t laser it. You shoot and miss since the actual range is 100 yards. Only a 5 yard distance difference you say, but a 2.1 inch drop from 95 to 100 yards. And I don’t think anyone is that good to estimate the differences between 95 and 100 yards just by eyeball.

My point is no one successfully hunts small game (ground squirrels, 1” target kill zone) at much more than say 75 yards without a laser rangefinder... If anyone thinks they do, I’ve got a bridge to sell them in Brooklyn. ;)


 
Interesting discussion!



I made a comment recently about preferring lighter pellets for flatter trajectory and might have prompted (provoked?? LOL!) this thread. Guess that I should know better that to make a statement without including reasons eh?



Anyway, ideas are based on perspective so I thought that I would add mine to the mix…



I hunt squirrels and rabbits where shots are 10 to 40 yards and rarely farther than that. Most shots are off-hand or leaning on a tree - there is no time for ranging or twiddling scope settings or setting up a prone shot with a bi-pod.



Where am I coming from? I feel that once the rifle is properly configured and tuned that allowance for wind and trajectory are the main considerations for putting a pellet in the vital area. I can only practice allowing for the wind but I can minimize trajectory concerns by setting up my Point Blank Range to suit the kill zone - which brings me to the discussion at hand…



Since my .22 and .25 hunting PCPs have plenty of power for my quarry within my typical 10-40 yard range I prefer to trade some of that power for a higher velocity, for the flattest trajectory to get the best Point Blank Range I can.



The kill zone for what I hunt is about 1 inch in diameter; to allow for a bit of tolerance, in ChairGun, I set up +/- .38 inch kill zone for a 3/4 inch circle and use the program to compute the zero for the optimum Point Blank Range. I’ll use that zero as a starting point from which I check the results with real world data.



After trying different pellet weights and tuning to suit I ended up with this for my hunting rifles…

.25 PCP; 25.4 gr pellet; MPBR 23.6 yards (17.6 > 41.2); NZ 21; MR 29; FZ 38

.22 PCP; 15.9 gr pellet; MPBR 24.2 yards (16.0 > 40.2); NZ 20; MR 28; FZ 37



So, with both rifles set up similarly, I need a bit of compensation at very close range and can hold dead-on out to 40 yards. I tend to hold a bit low at 30ish yards and wibbles and wobbles aside can usually get my pellet to hit within 3/8 to 1/2 inch of my POA on a stationary target using a tree for support.



I agree totally with the OP. At longer ranges a bit of velocity doesn’t mean much and a heavier pellet is the way to go.



I’m spending a lot of time hanging out on the forum because now that the technology is available, long range shooting is very interesting. I’ve made the investment in what I hope is suitable equipment (including a laser range finder) and, come warm weather, look forward to learning to shoot at ranges way past what I ever thought possible. You guys are having way too much fun for me not to join the party.



Cheers!

Hank
 
Agree with the above as well as Centercut's initial point (as I understood it) that relative drop at longer ranges isn't that important since compensation will be made anyway. My experience is much greater with long range firearms than air guns at longer ranges and I've always found that even though I can relatively reliably compensate for trajectory through various methods (I do use a rangefinder), the windage compensation is exponentially more difficult as range increases and is usually the cause for a miss. Being able to ignore the trajectory through shooting between maximized MPBR ranges allows one to focus more on the wind.
 
@bandg

Yeah, the wind is the thing to watch. A steady wind from one direction is not too bad but that is rarely the case. I have "windicator" flags every 5 yards on my range and regularly see them rapidly showing serious changes in force and direction over the 55 yards - it can be very hard to predict pellet flight over that relatively short distance. Hopefully, "long range" will mean shooting across open areas with less turbulence.
 
@bandg

Yeah, the wind is the thing to watch. A steady wind from one direction is not too bad but that is rarely the case. I have "windicator" flags every 5 yards on my range and regularly see them rapidly showing serious changes in force and direction over the 55 yards - it can be very hard to predict pellet flight over that relatively short distance. Hopefully, "long range" will mean shooting across open areas with less turbulence.

Seems that it usually just gets harder. You can feel wind near you and even use a meter to measure it. Once you add distance there is no way to quantify the velocity (ways to estimate visually are often discussed) and it's not uncommon to see debris moving two more directions out to a long distance target. I live in the south and it may well be easier further west with more open terrain as you note but it hasn't been my experience. In east Arkansas farm country you often find very large open areas but wind will often swirl along tree lines and change directions unexpectedly.
 
@vana2 yes you got me there. Your post did “provoke” me... ;) I normally set my kill radius to 1/2” and 50 yards zero and on most of my guns get a MPBR between about 17 to 55 yards or so. That’s aiming dead on an hitting plus or minus 1/2 inch. No need to estimate or laser range until further than that. 
@bandg totally agree that windage is the major factor in hitting what you’re aiming at. Correct yardage and scope dope are pretty easy once your gun is dialed in. As long as you remember that the wind closest to you has the largest affect on your shot you can most of the time figure out swirling winds. Not all the time of course....