Velocity/Trajectory queation

[mnbearbaiter]

I shoot a TVM 54cal Perc Leman with a 36" brrl. I use .530/.015 and a felt over powder bore button with 95gr ffg T7. Shoots very well but the results I get are contradictory to every ballistic chart I've ran. I'm assuming velocity is around 1850fps? With a 50yd zero I should have about a 6" drop at 100yds. Even at 75yds I should see some drop but my POI is same at 75yds as it is at 50yds? At 100yds its center punched with a dead on hold if I do my part. So either I gained some velocity with the longer barrel I use over the data available or I filed sights to a 100yd zero accidentally? No access to chronograph so I know shooting is best which I've done but thought I'd throw it out there to see what you all think it is?

 

[biliff]

So you're saying it's hitting to the same POI at 50, 75 and 100 yds? Ball only crosses the line of sight twice, not three times.

 

[mnbearbaiter]

No I'm not saying that...it hits 2-3" high at both 50/75yds and my POA stays same at 100yds which is a dead on hold at all ranges out to 100yds. My main quandary is that the velocity may be greater with the 36" barrel I'm using instead of the provided data which is probably using a 28" barrel?

 

[biliff]

Nothing mysterious going on there. I plugged 1700 fps and a 100 yd zero, .5" sight height into my RB calculator and it says POI at 50 yds is 3.3" and 2.8"s at 75.

Your rifle appears to be zeroed for 100 yds.

If you can plug in a more precise sight height and POI's at 25,50 and 75 yds you can work backwards and get a more accurate velocity.

 

[mnbearbaiter]

I know it's going faster than 1700fps. I'd fashion darn near 1900fps if I had to bet.

 

[biliff]

That was just a swag on my part to get a ball park figure. Like I said, plug in more precise numbers for sight height, POI etc with a 100 yd zero and work backwards to get a velocity estimate.

 

[nhmoose]

1 shot does not make for a group. Make 5 at each distance there will be a difference using the same size aiming point for each.

Not doing this the results could be YOU.

 

[mnbearbaiter]

I just basically "rally" shot with a target at each range off bags after I was happy with what I had at 50yds. Shot the 50yd, then 75yd, then 100yd target, then repeat. Did it several times and had a nice print on all 3 targets. I didn't shoot 15 shots but I know I had 3 holes on each target for a total of 9 shots without cleaning between shots.