Airgun vs firearm comparison at distance?

[Dairyboy]

I know I saw this before somewhere but I can't find it for the life of me! I believe Bob had posted about it before but I can't find it anywhere. Was curious if there was any. Like 100yds with an air rifle is similar to a firearm at ________.

Why I'm curious is my brother in law and his cousin got some Gunwerks rifles in 7mm for long range hunting. They were sighting in at 200yds so I decided I wanted to try shooting my WARP in .30 at 200yds. All I gotta say is I shot 5 shots within 6" or less for sure with a crappy rest and only on 10x so I was thrilled for my first try! If I was more steady I bet it could have been tighter but I was very satisfied. It was awesome shooting and then like 3 secs later hearing the hit.

Id appreciate if you can explain the difficulty equivalent just to tell them. If not then that's ok as well!

[dapoun]

If comparing drop the 6.5 creedmoor drops the same amount at 700 yards that my 257 dropped at 270yards if comparing  flight time for same distances the 257 made it to 265 yards in the same time it took the 6.5 to get out to 700.

[rsterne]

If you are shooting decent round-nose pellets in the mid 900's, and the rifle is sighted about 1/3 of the way to the target, an airgun at 100 yards has a similar trajectory and wind drift (in MOA) to a .308 Winchester (7.62 NATO) at about 600 yards (and sighted at 200).... If you scale the target down by a factor of 6 as well, you will be facing a similar challenge, which is one of the reasons for the dimensions chosen for the N.U.A.H. targets for use at 100 yards....

If you use bullets in the airgun instead of pellets, you can easily cut the wind drift in half compared to a pellet, although the trajectory (over 100 yards) won't be that much different.... Although most shooters would never believe it, using a bullet with a good BC in an airgun with the velocity in the mid 900s actually has similar wind drift to the same bullet in a PB at 3 times the velocity.... This is because of the huge increase in drag in Supersonic flight....

Bob

[TF89]

That is great info.

[Dairyboy]

Thanks for the info! That's exactly what I was looking for. Mine wasn't quite ideal as that as my WARP is tuned at 815fps and was sighted in at 55yds but I needed to crank it one full turn up and then the bottom hash on the reticle was right where it hit.

[OZ Harry]

I wrote the referenced post in 2005 in an attempt to match an airgun to other rifles for some reasonable comparison.
If it will open, disregard punctuation symbols.
In brief the concept indicates that matching the apogees/apex of trajectory curves at a range chosen for one rifle may  give a somewhat fair comparison.
Some examples are given.
It assumes that rifle and ammunition quality, range conditions and shooter status/skills are equated.

https://www.tapatalk.com/groups/yellow/airgun-accuracy-versus-other-rifles-levelling-the--t74185.html#p510558

Kind regards, Harry in OZ.

[rsterne]

G'day, Harry.... Your post linked above summarizes the criteria nicely to match the trajectory, and as you state, for that purpose incorporates the BC into the equation.... However, it does not guarantee similar wind drift.... which IMO is part of the "target solution" problem to simulate firearm performance with an airgun.... Part of the problem, IMO, is that you should be using MOA instead of inches to match the trajectory and wind drift.... In that way, you can scale the target size as well....

Here is an example, using ChairGun…. Using a PB velocity of 4X the airgun velocity, I adjusted the BC, zero point and range to get the trajectories to correspond as closely as possible, using MOA.... staying within BC values that were reasonable for the situation, and keeping the zero close to mid distance to target.... Other comparable solutions are possible, using different velocities and BCs.... In some cases the wind drift is not as good a match as in this case....

Pellet with BC 0.040 @ 800 fps, gun sighted at 50 yards, target at 100 yards, 10 mph crosswind....
Top of trajectory 4.23 MOA at 25 yards
Drop at 100 yards = 15.98 MOA
Drift at 100 yards = 10.49 MOA
Time to target = 0.437 sec.

Bullet with BC 0.230 @ 3200 fps, sighted at 323 yards, target at 680 yards, 10 mph crosswind....
Top of trajectory 4.19 MOA at 100 yards
Drop at 680 yards = 15.94 MOA
Drift at 680 yards = 10.98 MOA
Time to target = 1.082 sec.

Target size for similar difficulty of shot = 6.8 times larger for the PB than for the airgun, at 6.8 times the distance.... ie the same relative target size in MOA.... If you are shooting at a moving target, of course, the time of flight being over twice as long for the PB may cause a miss, so in that respect matching the ToF and trajectory would be a better comparison between an airgun and PB.... However, the wind drift, in a constant wind, would not match up nearly as well (but if the wind were variable, the ToF could be more important).... nor could you scale the target to the distance using the same MOA target.... For example, if the target were 250/75 = 3.3 times as far away, and the trajectory, drop, wind drift and time of flight were the same ACTUAL numbers (in inches and seconds), what size target would make for a fair comparison?....

Just my idea of how to best compare.... I particularly like the concept of using targets of the same MOA in both cases.... which to me scales the "degree of difficulty" quite well.... and is the reason for my "rule of thumb" of 1/6th the distance to target for an airgun (with pellets), shooting at 1/6th scale targets.... A pop can at 100 yards is about the size of a human torso at 600 yards, for example.... 2.5" x 5" scales up to 15" x 30".... Anyone want to see how good a sniper they are?.... 

Bob

[OZ Harry]

Happy recent birthday Bob    . But according to relativity theory - you are getting older faster.
When I was 21 yrs you were less than half my age; now you are 86% as old 
Anyway  the years seem to be growing shorter.

Thank you for " having at it " Bob. And thank you for the time you spent to clearly state your present position on the topic of air v's pb relativity, taking into account target size and shooter involvement.  I appreciate all the points you make including moa criteria particularly when an actual target and shooter be involved.  I recall that at least one of the respondents to my old post/attempt made reference to moa inclusion to which I (silently) agreed.

Take care and enjoy life Bob.  Very best regards, Harry.

[Dairyboy]

I appreciate both of your responses to this question. I think it's fun just to get an idea on how it compares to PBs. You both are very knowledgeable and respected in the airgun community and thanks for taking the time to answer!

[AncientSword]

I think this is an interesting topic. I currently try to follow the state of long range shooting in the PB world. 

There is a movement going on where a lot of them are starting to train with .22 lr. They say that the .22 mimics the .308 fairly well in the 100 to 200 yard range.

I like the comparison to airguns and it's fun to do as well.

[JungleShooter]

Yes, Curt, I just read* about Rimfire ELR = Rimfire Extreme Long Range shooting.
The article writer is a long range shooter and researcher. He compares the flight time of a .22 rimfire bullet at 600 yards with that of the extreme long range 375 magnums out to 2000+ yards.


I imagine the comparison PB rimfire to PB magnum does not directly continue to a pellet-shooting AG – because pellets have much more drag (abysmal BC!) than bullets. It’s not just the flight time of the pellet that is different than the PB bullets, but it’s the projectile’s wind susceptibility – how much it allows the wind to blow it off course.


How would we define airgun extreme long range shooting??   


*The article is at:
http://precisionrifleblog.com/2018/08/05/extreme-long-range-tips-optics-mounts/
NOTE: The part about the Rimfire ELR comes right after the part on the March Genesis scope.

[TPL]

I'd say the difference is about 3-4 times between AG and PB. What do we consider as extreme long range with PB?

For me 300 meters with AG is annual tradition and the most I have ever shot was 509 meters (556 yds), couple 12 oz cans out from that distance. For sure everything past 1000 yds is extreme long range for an AG. Pitty we don't have an oppurtunity for that here where I live.

I'd say 300 meters is long range and something beyond 500 is extreme long range but that is so relative. If you get use to it you need more. Still there is some back limit there, somewhere well over 1000. Yards or meters, does it matter any more?