Longest flattest trajectory

[Ballisticboy]

Just to screw with you guys. Im pretty sure if you drop a pellet from the end of the barrel exactly as one leaves the barrel they will both hit the ground at the same time. That's if the ground and barrel is perfectly level. That's regardless of BC.

This is true if you are on the moon, but not on the earth. If the gun is perfectly level, as the pellet fired from the gun turns down towards the ground to follow the trajectory some of the drag force from the air acts vertically, reducing the effect of gravity. The dropped pellet has little to no drag because of its very low speed. The time difference is very small and difficult to measure.

 

[RScott]

I like what you’re saying but I’m much denser than air. Because this is not about POI or POA; rather this is about beginning of trajectory apex to end of trajectory apex. Here's the thing... high school physics was wasted on me because i was wasted on MaryLou's budding body. However, i believe you are speaking about "angle of incidence". These 3 pictures highlight what i am getting at:
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Great pictures. Assuming the same 10.3 grain pellets and similar muzzle FPS, the needed holdovers for the 10-12 yard distances show that your Steyer's scope is higher above the bore compared to the Red Wolf (Steyer needs a 1.5 inch holdover, RW needs 1.2 inch holdover), and the RW's scope is slightly higher over the bore than the Revere and Marauder that need a 1 inch holdover at 10 yards. (Reason is very little gravity induced drop in those first 10 yards, so the lower POI of the Steyer has to be due to higher scope height).

A higher scope height over the bore will slow the rate of change in POI vs POA at longer distances, and likely explains why your Steyer appears flatter at longer distances. I put my Sightron at over 3.5 inches above bore (and zero at 35-40 yards) because then the holdovers between 45 and 55 yards don't vary much.

Also the Steyer shows a gorgeously smooth line of POIs as distance increases at short distances compared to the other guns. This suggests that it has the best scope or rifle/barrel or shooter actions (i.e., perhaps it is the gun you shoot most confidently)

 

[cavedweller]

Great pictures. Assuming the same 10.3 grain pellets and similar muzzle FPS, the needed holdovers for the 10-12 yard distances show that your Steyer's scope is higher above the bore compared to the Red Wolf (Steyer needs a 1.5 inch holdover, RW needs 1.2 inch holdover), and the RW's scope is slightly higher over the bore than the Revere and Marauder that need a 1 inch holdover at 10 yards. (Reason is very little gravity induced drop in those first 10 yards, so the lower POI of the Steyer has to be due to higher scope height).

A higher scope height over the bore will slow the rate of change in POI vs POA at longer distances, and likely explains why your Steyer appears flatter at longer distances. I put my Sightron at over 3.5 inches above bore (and zero at 35-40 yards) because then the holdovers between 45 and 55 yards don't vary much.

Also the Steyer shows a gorgeously smooth line of POIs as distance increases at short distances compared to the other guns. This suggests that it has the best scope or rifle/barrel or shooter actions (i.e., perhaps it is the gun you shoot most confidently)

Actually the pellets are rising for the first 20 yards after they leave the barrel.

 

[cavedweller]

Great pictures. Assuming the same 10.3 grain pellets and similar muzzle FPS, the needed holdovers for the 10-12 yard distances show that your Steyer's scope is higher above the bore compared to the Red Wolf (Steyer needs a 1.5 inch holdover, RW needs 1.2 inch holdover), and the RW's scope is slightly higher over the bore than the Revere and Marauder that need a 1 inch holdover at 10 yards. (Reason is very little gravity induced drop in those first 10 yards, so the lower POI of the Steyer has to be due to higher scope height).

A higher scope height over the bore will slow the rate of change in POI vs POA at longer distances, and likely explains why your Steyer appears flatter at longer distances. I put my Sightron at over 3.5 inches above bore (and zero at 35-40 yards) because then the holdovers between 45 and 55 yards don't vary much.

Also the Steyer shows a gorgeously smooth line of POIs as distance increases at short distances compared to the other guns. This suggests that it has the best scope or rifle/barrel or shooter actions (i.e., perhaps it is the gun you shoot most confidently)

@RScott since you offered some cool input i posted dope for 4 different guns - look at the Revere!

 

[cavedweller]

Great pictures. Assuming the same 10.3 grain pellets and similar muzzle FPS, the needed holdovers for the 10-12 yard distances show that your Steyer's scope is higher above the bore compared to the Red Wolf (Steyer needs a 1.5 inch holdover, RW needs 1.2 inch holdover), and the RW's scope is slightly higher over the bore than the Revere and Marauder that need a 1 inch holdover at 10 yards. (Reason is very little gravity induced drop in those first 10 yards, so the lower POI of the Steyer has to be due to higher scope height).

A higher scope height over the bore will slow the rate of change in POI vs POA at longer distances, and likely explains why your Steyer appears flatter at longer distances. I put my Sightron at over 3.5 inches above bore (and zero at 35-40 yards) because then the holdovers between 45 and 55 yards don't vary much.

Also the Steyer shows a gorgeously smooth line of POIs as distance increases at short distances compared to the other guns. This suggests that it has the best scope or rifle/barrel or shooter actions (i.e., perhaps it is the gun you shoot most confidently)

Irt Steyr - all of the above but now look at the Revere

 

[RScott]

Actually the pellets are rising for the first 20 yards after they leave the barrel.

POI is rising relative to the POA because the scope is above the bore and the bore is angled up relative to the direction of the scope. If you held the target at 0 yards from the muzzle and the scope was 3 inches above the bore, the POI would be just about 3 inches below the POA. As the target is moved farther from the muzzle, the POI "climbs" relative to the POA. At the zero point, the POA and POI line up. So yes, the pellet are rising because the barrel is pointing upwards. Because the pellet exits the barrel at about 3 inches below the scope, they have to be angled upward to eventually intersect the straightline POA line from the scope.

 

[RScott]

@RScott since you offered some cool input i posted dope for 4 different guns - look at the Revere!

Looks like the Revere has some "hold under" at about 43 yards. If that were adjusted to be closer to zero hold over at that point, the 10 yard POI would shift down and probably be closer to the RW's 1.2 holdover at 10 yards, which makes sense if both have scopes 2.25 inches above the bore.

 

[cavedweller]

Yall are talking about two different things. POI v. Range and Drop v. Range. One is relative to the scope, the other is relative to the muzzle. If one is talking about "flatness of trajectory" that is a projectile's flatness relative to the muzzle. Perhaps that's opinion, but it is the widely accepted standard of the term that I know.

Exactly

 

[cavedweller]

POI is rising relative to the POA because the scope is above the bore and the bore is angled up relative to the direction of the scope. If you held the target at 0 yards from the muzzle and the scope was 3 inches above the bore, the POI would be just about 3 inches below the POA. As the target is moved farther from the muzzle, the POI "climbs" relative to the POA. At the zero point, the POA and POI line up. So yes, the pellet are rising because the barrel is pointing upwards. Because the pellet exits the barrel at about 3 inches below the scope, they have to be angled upward to eventually intersect the straightline POA line from the scope.

Said perfectly

 

[cavedweller]

does scope height matter?

 

[JimNM]

The scope height does not matter..... if the alignment is correct. Any kind of cant error is only magnified by the extreme height.

The hold under values are also severely magnified by bore to line of sight silliness.

Does it matter? Nope, if you take the other costs into account. Gravity is a constant. POA vs POI still the flavor of the thread.

 

[cavedweller]

Looks like the Revere has some "hold under" at about 43 yards. If that were adjusted to be closer to zero hold over at that point, the 10 yard POI would shift down and probably be closer to the RW's 1.2 holdover at 10 yards, which makes sense if both have scopes 2.25 inches above the bore.

@RScott - I spent a good bit of time taking your advice and putting it into action! success! I have now lowered every scope on every gun as low as possible and still have a proper eye box/cheekweld. I’ve thusly eliminated any hold unders.

 

[Ranchibi]

Besides your awesome dope charting...I really like your PCP's!