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Burris Ballistic-Plex Retical |
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maxxis31
Optics GrassHopper Joined: June/26/2010 Status: Offline Points: 6 |
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Posted: June/26/2010 at 18:13 |
Ok this is kind of a complex question. I kinda understand how burris's
corr@100yard system works and can get the calculations by dividing the
bullet drop by the shot distance X 100= Corr@100yds but how do I apply
it to my ballistic plex reticle. I have the tech notes from burris and
it has the reticle and has the yds besides each reticle mark and has
corr@100yds I'm wondering if these numbers are for the ballistic plex
reticle its self and if you are to match the numbers you get from your
caliber to there numbers they give and add/subtract the difference. Here are the numbers 200yd -3.1" 1.54Corr@100yds
300yd -13.5" 4.51Corr@100yds 400yd -30.1" 7.52Corr@100yds 500yd -55.3"11.06Corr@100yds They use these numbers with a example for the 308 Win 150grain so I'm not sure if its for the 308win. Here is the link if you have no idea what I'm talking about.http://www.burrisoptics.com/pdf/BALLPLEX.pdf I'm shooting a 22-250 55 grain bullet at 3680FPS. I would really appreciate anyone who can help. |
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bert gummer
Optics GrassHopper Joined: June/11/2010 Location: southcentral va Status: Offline Points: 22 |
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What I think they want you to do is calibrate your load to
the power ring and use that magnifying # when you hold
on target, it's like they averaged all cals and loads to get their
lines then require you to sight in at those ranges then if it's
off use the power ring to calibrate, It's never gonna be perfect.
I get the idea these reticles are for hunting and not for target shooting?,
once you set it your done unless ofcorse you change loads??????
I like mildots better they're always right, but you need a dope sheet,
otherwise I don't really understand the burris reticle.I usually fire 100g at
about 3300fps then zero at 275 for my 25-06 and hold dead on out to 325
it's PBR which is ok for hunting deer anyways and ok for most others unless
your going for a head shot on a chip monk at 290yds?????then dial up 10
clicks for 400, 15 for 450, and 20 for 500 chances are I wont hit anything
passed 300 anyways unless I'm on a rest shooting at paper??????
I think though once dialed the burris ballistic plex will be a good hunting reticle??
I think the math your asking for is way over my head....maybe someone can
shed some light............................
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slow is smooth, smooth is fast. right?
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3_tens
Optics Jedi Master Joined: January/08/2007 Location: Oklahoma Status: Offline Points: 7853 |
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What is the BC of the bullet you are shooting? then you can plug your numbers into A ballistics calculator for best fit. The 22-250 is not the best bullet match for this scope. You will be better off to use a 200 yd Zero with the 22-250. Your numbers match velocity with Winchester Supreme Bal. Silvertip. These are the # I am using. The hash drops are as follows.
Hash Ret Drop Bullet Drop Aim
1****** - 4.5" 300 Yd - 1.9" - 2.6"
2****** -18" 400 Yd -15.4" - 2.6"
3****** -38" 500 yd -32.9" - 5.1"
4****** -66" 600 Yd
Edited by 3_tens - June/27/2010 at 00:32 |
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Folks ain't got a sense of humor no more. They don't laugh they just get sore.
Need to follow the rules. Just hard to determine which set of rules to follow Now the rules have changed again. |
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maxxis31
Optics GrassHopper Joined: June/26/2010 Status: Offline Points: 6 |
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I keep forgetting that the 22-250 is a magnum caliber and i was using the Retical drop numbers for the standard caliber instead of the magnum caliber. But I would like to figure out the math for the first option they give on how to calibrate the scope. I think it will a little more precise. Also the reticle drop numbers you gave are for a one hundred yard zero how do i apply it for a 200yd zero.
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maxxis31
Optics GrassHopper Joined: June/26/2010 Status: Offline Points: 6 |
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what i ment to say i need to use the numbers for the magnum calibers since they are for a 200yd zero
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3_tens
Optics Jedi Master Joined: January/08/2007 Location: Oklahoma Status: Offline Points: 7853 |
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The holdover that is on my chart is for 200 yd zero That is why the first hash is 300 yds.out to 600 yds. The Winchester table for the 55 gr I had only goes out to 500 yds. Since I did not know what bullet you are shooting this table was the closest for me to use. You soot zero out to 200 yards. at 300 yards your bullet will hit 2.6" above the first hash. You aim the hash 2.6" below where you want to hit to hit the hash. At 400 yards the bullet is still traveling 2.6" above the curve that Burris is using. Again you aim 2.6" below. At 500 yards, your bullet is hitting 5.1" above the 500 yard hash. If you are shooting at a PD you aim at the ground where it is standing and you will have a good chest shot. If you set your 200 yard zero 3/4" low the fits will be closer. (If you read the wind correctly) The Burris curve fits the .270 150 gr. almost perfect. .223 55 gr. very well out to 400 yds.. Did you keep the stickers that Burris supplies with the scope? These tell you close loads thar fit the curve that is used in the scope. It is not perfect but Burris does more to help find the rounds that work than most of the other makers.
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Folks ain't got a sense of humor no more. They don't laugh they just get sore.
Need to follow the rules. Just hard to determine which set of rules to follow Now the rules have changed again. |
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maxxis31
Optics GrassHopper Joined: June/26/2010 Status: Offline Points: 6 |
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Thanks that clears things up.
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3_tens
Optics Jedi Master Joined: January/08/2007 Location: Oklahoma Status: Offline Points: 7853 |
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I'm glad because it almost got me confused>
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Folks ain't got a sense of humor no more. They don't laugh they just get sore.
Need to follow the rules. Just hard to determine which set of rules to follow Now the rules have changed again. |
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maxxis31
Optics GrassHopper Joined: June/26/2010 Status: Offline Points: 6 |
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These are the numbers I got tell me if my calculations are right
YD my drop burris reticle drop out to 600yds reticle compensation 100 +1" +1.1" 200 +0" +0" 300 -5.6" -4.7' -1" 400 -17.4" -18" +.5" 500 -38" -37.6 +.5" 600 -70.7 -66.4 -4.3" These numbers seem pretty close but are they right. I used the ballistic calculations from federal ammo using a 55 grain power shok soft point at 3650FPS. |
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stork23raz
Optics Journeyman Joined: September/10/2009 Location: Tennessee Status: Offline Points: 676 |
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I emailed Burris they said.
these are at 100 yards at the power the marks are true Crosshair to first hash – 1.54” Crosshair to second has – 4.51” To third – 7.52” To Post – 11.06” |
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And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell.
Matthew 10:28 |
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sscoyote
Optics Journeyman Joined: October/05/2004 Status: Offline Points: 328 |
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Maxxis, you mentioned that u wish to understand the math behind the angular systems of reference with an optic so here it is. The systems of subtension applications for both downrange zeroing and rangefinding (both turrets and multi-stadia reticles) is geometric in nature and fortunately are based on the mil-ranging formula in it's most basic form. Here's a post i put on another forum that describes it--
" It's all based on the most basic form of the mil-ranging formula, because a bullet drop at any distance is the same sort of dimension as a target size when referenced with an optic (turrets or reticle). Any other formula given will be a simplification of this formula--
bullet drop (") x range of reticle subtension or turret value measurement (usually 100 yds.) / reticle or turret subtension (") / "mil-reading" or turret clicks (decimal equivalent) = range (yds.) Looks complicated, super-simple to apply. Hows about 10" low at 400 yds. with 0.25" per hundred yd. turret clicks as OP suggests. 10 x 100 / 0.25 / X = 400 X=10 clicks Now if u have a turret that's graduated in 1.0 inch per hundred yd. numbers then-- 10x100/1.0/X=400 X=2.5 whole # graduations. Repeating interval reticles (rangefinding reticles mostly) are the same way and ballistic reticles require 1 more calculation to get the dope. Rangefinding with reticles is the exact same system just replace bullet drop with tgt. size ("). This time range is the unknown once the "mil-reading" (or even turret click) is determined. Now simplify and/or rearrange as desired." Now a ballistic reticle that doesn't repeat the subtensions evenly requires one more calculation to get the dope from a ballistics program. Suppose u're using the BP reticle as u mentioned before. Now u know from the Burris Tech. Notes that stadia 1 and 2 are 1.5 and 4.5 IPHY (inch per hundred yds.) respectively. You look at your ballistics program profile for your load and you see that at 450 yds. the bullet drops 3.9 IPHY. You know then that there is a total of 3.0 IPHY between the 2 stadia (4.5-1.5), and that 3.9 IPHY is 2.4 more than the 1st stadia (3.9-1.5), so if u divide 2.4 by 3.0=0.8. That means that for 450 yds. u have to aim 1.8 "stadia units" down to make a connection. See how it works?
It's also important to know that the relationship between subtension and magnification is ~inversely proportional. That means that the second stadia of the BP reticle in a 3-9x scope is 4.5 IPHY at 9x, but at 4.5x it's roughly 2x that, or 9.0 IPHY.
Once the shooter completely understands the "modified mil-ranging formula" and the inversely proportional nature of reticle subtension vs. magnification (in 2FP reticles) then he will open a LR shooting door that many will never understand, but is very important to know.
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Steve
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