While BDC reticles have been discussed many times, one feature that is not discussed is barrel center bore to scope center. For an optic to have an accurate BDC with a specific ammo, besides being calibrated for ammo velocity and weight, the BDC would only be completely accurate for a specific scope center/barrel bore center distance. A lot of folks purchase optics with BDC's but do they really understand the relationship stated above and the resulting variations? Or, for the ranges they shoot and the variations observed, its not an issue?
Rifle Scopes BDC Reticles
- Thread starter Singlestack_Wonder
- Start date
Re: BDC Reticles
I have a BDC Acog on my SBR... but not interested in one for a scope.
too many variables
I have a BDC Acog on my SBR... but not interested in one for a scope.
too many variables
Re: BDC Reticles
for vortexes bdc it starts at 1.5 moa to , 4.5, 7.5, and stops at 11 moa. each dot is accurate at a different range which is most likely not a straight 300 or 400 yards. for example if it was on my .223 with a 200 yard zero the first dot would be 275, the second 375, the third 450 and the bottom post 550 yards. hope this is what your asking about.
for vortexes bdc it starts at 1.5 moa to , 4.5, 7.5, and stops at 11 moa. each dot is accurate at a different range which is most likely not a straight 300 or 400 yards. for example if it was on my .223 with a 200 yard zero the first dot would be 275, the second 375, the third 450 and the bottom post 550 yards. hope this is what your asking about.
Re: BDC Reticles
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lessthanfour</div><div class="ubbcode-body">for vortexes bdc it starts at 1.5 moa to , 4.5, 7.5, and stops at 11 moa. each dot is accurate at a different range which is most likely not a straight 300 or 400 yards. for example if it was on my .223 with a 200 yard zero the first dot would be 275, the second 375, the third 450 and the bottom post 550 yards. hope this is what your asking about. </div></div>
You missed my point. I completely undestand how BDC's work. I was just commenting that they only work for a specific load AND distance of scope center to barrel center bore, with the 2nd item being something most do not consider.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lessthanfour</div><div class="ubbcode-body">for vortexes bdc it starts at 1.5 moa to , 4.5, 7.5, and stops at 11 moa. each dot is accurate at a different range which is most likely not a straight 300 or 400 yards. for example if it was on my .223 with a 200 yard zero the first dot would be 275, the second 375, the third 450 and the bottom post 550 yards. hope this is what your asking about. </div></div>
You missed my point. I completely undestand how BDC's work. I was just commenting that they only work for a specific load AND distance of scope center to barrel center bore, with the 2nd item being something most do not consider.
Re: BDC Reticles
The bore/scope tube variance is not strategically significant.
The bore/scope tube variance is not strategically significant.
Re: BDC Reticles
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">The bore/scope tube variance is not strategically significant. </div></div>
I disagree. For example, at 100 yards, a rifle with a scope that is mounted at 2" center to center with the barrel bore will have a different firing line angle to the target than a setup with a 3" center of scope to barrel bore. A different attack angle would affect the bullet's drop over long distance.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">The bore/scope tube variance is not strategically significant. </div></div>
I disagree. For example, at 100 yards, a rifle with a scope that is mounted at 2" center to center with the barrel bore will have a different firing line angle to the target than a setup with a 3" center of scope to barrel bore. A different attack angle would affect the bullet's drop over long distance.
Re: BDC Reticles
It seems to me that the "error" would be compensated for the same way u would compensate for any multi-stadia reticle. If u match trajectory to reticle subtension as i do for my BDC reticles it wouldn't make a difference anyway. I calculate and test my zeros. I dont expect any multi-stadia reticle to be perfect. A magnification can be selected though that's close. I haven't tested this myself but my turret-twisting die hard buddy's changing all his Leupold's to Varmint Hunter's for the 6" target coyotes he shoots out to ~650-yds. using reticle.
I prefer BDC reticles for fast-action shooting (coyote hunting)with a more direct system of windage application.
It seems to me that the "error" would be compensated for the same way u would compensate for any multi-stadia reticle. If u match trajectory to reticle subtension as i do for my BDC reticles it wouldn't make a difference anyway. I calculate and test my zeros. I dont expect any multi-stadia reticle to be perfect. A magnification can be selected though that's close. I haven't tested this myself but my turret-twisting die hard buddy's changing all his Leupold's to Varmint Hunter's for the 6" target coyotes he shoots out to ~650-yds. using reticle.
I prefer BDC reticles for fast-action shooting (coyote hunting)with a more direct system of windage application.
