Confused: Remingtion subsonic ammo specs

Have a box of Remington .22LR subsonic ammo.

Was reading the ballistic data on the side of the box:
Bullet weight: 38gr
Velocity: 1050fps @ muzzle, 901fps @ 100 yd
Drop: -2.6" @ 100 yd, sighted at 50 yd

I'm confused by the drop data.
If you sight (zero) .22lr at 50yd, and shot a target at 100yd, then you will definately be much lower than -2.6". Something closer to 10" low I think.

Anyone know how to interpret then Drop data ?

SK

Is it 50 yards or 50 feet? With slower bullets at 50 yards you re aiming "up" quite a bit so the drop at 100 yards might not be as much a faster bullet sighted at 50 yards because the elevation of the faster bullet would be lower at 50 yards. I haven't looked at 22LR rimfire ballistics in a while but it may very well be correct.

Think of it as pitching a baseball. A slow underhand pitch goes in a large high arc. A fast ball would be in a lower arc. The 22LR is so slow that at even at 50 yards it must be aimed / sighted in a rather large arc. Since it goes higher than a faster bullet sighted at 50 yards it goes higher from the ground than the faster bullet for the same sight distance.

Is it 50 yards or 50 feet? With slower bullets at 50 yards you re aiming "up" quite a bit so the drop at 100 yards might not be as much a faster bullet sighted at 50 yards because the elevation of the faster bullet would be lower at 50 yards. I haven't looked at 22LR rimfire ballistics in a while but it may very well be correct.


I am not at all understanding this....it is not about "lobing bullets".... but if you are ZEROED at 50yards (bullet is on line of sight!)...for two rounds, one fast and one slow.....

How can the slower bullet have less drop at 100yards? The both fall @ 32ft per second/per second. The law of gravity is always with us. The slower bullet will take more time to travel to the 100yard mark, and drop MORE due to gravity.

Sure you LOB a slow softball to the plate and ZIP a fast ball... But they have WAY different heights at midrange ....the question assumed the same projectille hight at midrange...and that was line of sight ("ZERO"). A .22 Zeroed @ 50yards does not rise above the line of sight beyond 50yards, does it?

I am not at all understanding this....it is not about "lobing bullets".... but if you are ZEROED at 50yards (bullet is on line of sight!)...for two rounds, one fast and one slow.....

How can the slower bullet have less drop at 100yards? The both fall @ 32ft per second/per second. The law of gravity is always with us. The slower bullet will take more time to travel to the 100yard mark, and drop MORE due to gravity.

Sure you LOB a slow softball to the plate and ZIP a fast ball... But they have WAY different heights at midrange ....the question assumed the same projectille hight at midrange...and that was line of sight ("ZERO"). A .22 Zeroed @ 50yards does not rise above the line of sight beyond 50yards, does it?

I haven't looked at 22LR but I have at other calibers at long distance. It's not as simple as the drop past 50 yards. It's not bullet drop but the sighting factor. Sighted at 50 yards, bullseye on target, then aim the same sights at a target 100 yards away. It's the sights that make the difference. Without adjusting them they are still zero'd for 50 yards even when aimed at a target 100 yards away. Because the 22LR may have so much drop at 50 yards the sights are already aimed "up" above the line of ight. Moving the aim but not adjusting the sight causes the bullet to be higher than if the aim was still at the 50 yard target but bullet travels 100 yards.

I haven't looked at 22LR but I have at other calibers at long distance. It's not as simple as the drop past 50 yards. It's not bullet drop but the sighting factor. Sighted at 50 yards, bullseye on target, then aim the same sights at a target 100 yards away. It's the sights that make the difference. Without adjusting them they are still zero'd for 50 yards even when aimed at a target 100 yards away. Because the 22LR may have so much drop at 50 yards the sights are already aimed "up" above the line of ight. Moving the aim but not adjusting the sight causes the bullet to be higher than if the aim was still at the 50 yard target but bullet travels 100 yards.


I understand the geometry involved....and the Hornady site is graphic and great.

I just don't understand your text at all. If you are hitting point of Aim at 5oyards..your sights and bullet impact are IDENTICAL...sights are not "aimed up" any more when you then shoot at 100yards.....you just see the reslult of the bullets droping trajectory as illustrated on the Hornady web site.

Sure when you shoot at a long range the bullet will climb WAY above the line of sight and the bore will be "angled up"....the sights are not "aimed up", they point straight to the target...the bore line is what you are really moving to shoot at long ranges.

How does that explain the drop of a .22 from 50 to 100yards?

The bbl is below the line of sight, if you align the sight with the bullseye and clamp that sight so it cannot move you could run a perfectly straight line between it and the target. Now, if the bbl were perfectly parallel to that line of sight then the bullets would all hit low as the bullet starts to drop as soon as it leaves the bbl and it is already an inch or so below the line of sight. So to compensate you tilt the bore upward slightly (sights are immobilised remember) and now the bullet climbs in an arcing parabola shaped flight due to the upward angle of the bbl. The Hornady illustration is much exaggerated as to that angle, it is usually only a few degrees. At some point downrange the bullet crosses the line of sight going up and again further downrange as it comes back down again. This creates two spots along the line of sight where the bullet intersects.

At fifty yards the line of sight and the upward arc of the bullet meet, creating the "point of impact meets point of aim" or "sighted in at 50 yds". After the bullet passes that point it is still travelling in an upward arc and now starts to come down again further downrange. At some point before the 100 yds it again crosses the line of sight and continues to drop another 2.6" beyond that before it impacts the target at 100 yds, 2.6" below the line of sight or point of aim. If you moved the target closer to say 75 yds where the dropping bullet again met point of aim it would show no drop at all even though it had traveled another 25 yards downrange. Move it to 60 and it would hit high.

Look at Hornady's ballistics chart for the .308 bullet at 3000 fps MV at the link above, sighted in at 100 yds it hits .2" below point of aim at 50 yds (still going upward) and 3" below at 200 (on the way back down). As your "sighted in" range gets longer (or extremely close!) the upward intersection gets closer so for a gun sighted in at say 200 yds the point of impact in that situation is the second "coming down" intersection of the line of sight and bullet path.

See if this helps. It is with a scoped gun centerline of scope 1.5 inches over
the centerline of the barrel.

http://i448.photobucket.com/albums/qq204/bigwheeler/SnapzProXScreenSnapz001-2.jpg

Ok, I thought for sure everyone would agree this was some type of typo.

With all the discussion, I still can't make sense of this.

With .22lr, if you have a typical barrel to sight distance of 1.5...even 2", I don't think it is possible to have the bullet still rising at 50yd...unless the bullet never crosses the line of sight, which means you don't have any zero.

If you sight / zero .22LR at 50yd, the bullet path must rise above, then fall back below the line of sight (unless the sights are 2 feet above the barrel). If that bullet then continues out to 100yd, the point of impact relative to the line of sight will be roughly 10" low.

The data from bigwhell supports this: it shows a 50yd zero, then your 7.2" low at 100yd. At 25yd the bullet is 0.3 above the line of sight.

It's either a mistake, or a specification that is meaningless to the typical shooter (based on some weird definition of "sighted").

SK

I am not at all understanding this....it is not about "lobing bullets".... but if you are ZEROED at 50yards (bullet is on line of sight!)...for two rounds, one fast and one slow.....

How can the slower bullet have less drop at 100yards? The both fall @ 32ft per second/per second. The law of gravity is always with us. The slower bullet will take more time to travel to the 100yard mark, and drop MORE due to gravity.

Sure you LOB a slow softball to the plate and ZIP a fast ball... But they have WAY different heights at midrange ....the question assumed the same projectille hight at midrange...and that was line of sight ("ZERO"). A .22 Zeroed @ 50yards does not rise above the line of sight beyond 50yards, does it?


The slower bullet has more time to fall, yeah it's just that simple. It takes it longer to get there, and during it's flight because more time elapses, it is continuing to fall during its longer flight time, therefore more flight time= more drop over a specific distance.

Now have a beer and think about that. LOL

My brain is starting to hurt reading this thread....but I like it. :cool_smal

See if this helps. It is with a scoped gun centerline of scope 1.5 inches over
the centerline of the barrel.

http://i448.photobucket.com/albums/qq204/bigwheeler/SnapzProXScreenSnapz001-2.jpg

That chart helped....I understand that the bullet crosses the path of sight TWICE... But at a 50yard zero the first cross is 18.1yards...again (second) at your ZERO of 50yards.

It is all DOWNHILL from there ( really all downhill after max rise of .44" at 36.3yards )