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Posted: 8/25/2008 6:53:52 PM EDT
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I am looking at buying an ACOG and an wondering about the issue of bullet drop. I want to use 55 grain and 62 grain rounds and am wondering about the issues of ranging reticle. The TA01NSN for example is one I am looking at. It is calibrated for .223, but what does that mean? Is it for .223 that is 55 grain, or 62 grain rounds or something different? Do I need to zero it to the round that it is being used with on a 100 meter range? Will there be an issue of using a bullet drop compensator with a 16" barrel instead of a mil-standard 14.5 or 20" barrel? Maybe I am just a bit confused... Thanks. |
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A BDC is going to give you a rough idea of your impact for the round you are shooting. The TA01NSN is setup for a 14.5” to 16” barrel using a 62gr. You would be able to use it on a 20” and it will work out to about 400yds. If you are only shooting out to 400yds you really can use any of the ACOGS for the BDC pattern seams to work for any barrel length 14.5 to 24” and 55gr to 75gr. Side note I’m not a fan of the TA01NSN. Mike @ CSGW www.csgunworks.com [email protected] Here’s some testimonials about CS GunWorks FEEDBACK about CSGUNWORKS on AR15.com FEEDBACK about CSGUNWORKS on Snipersparadise FEEDBACK about CSGUNWORKS on the HIDE |
It is the best BDC I have used.. I shoot 55gr and 62gr also.. The BDC is for 62gr but it works fine with 55 also.. you really will not notice a difference untill you get out to 500 yards with the 55gr.. I have a TA31F it has the Chevron and I find its best for speed and accuracy.. When using the Chevron from 100-300 yards shooting 55 and 62 seems about the same.. it will be off by 1 or 2" high or low at the most.. I keep mine zerod for 62gr and it shoots the 55gr fine untill like I said about 500 yards.. after that you are going to want to use 62gr anyway.. |
BDC are set to a specific height over bore, BC, and velocity. Bullet weight and barrel length are not factors. Of course different barrel lengths effect velocity (or in some cases they dont) and different weighs can have different BC (or the same) but thats is just an easy way for them to describe what to use with the BDC. If you change the optic height like taking one set up for carry handle and use it on flat top or the opposite you screw up the BDC. If you use a bullet with a different BC it will get worse as range increases. If you change velocity it also screws it up proportional to the change in velocity. Use an ACOG for 14.5" barrel and 62 grain flat top and use 55 grain ammo and a 20" barrel and you will be way off... mount it up on the carry handle and you will be so far off the BDC is useless on BAC equipped ACOGs as most of those start at 400. You can simply plug all the data into a ballistic calculator and know exactly how much you will be off at any given range for your set up before you decide on a purchase. Also you could just remember what range YOUR rifle hits at those marks and adjsut accordingly. |
| or just stick with keeping the ACOG on one upper with a 14.5 or 16" barrel and you will have no probs with going from 55gr to 62gr untill about 400 or 500 yards.. I didnt know he said he was going to be changing uppers.. but anyway the TA31F is made for 14.5" barrels but works a little better with 16" barrels after 500 yards.. |
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Ok, I should add: I have an LMT Defender with 16" barrel that I am going to be shooting 55 grain rounds 90% of the itme with the other 10% being 62 grain rounds. What AGOG (without red-dot) would be best for ranges out to 500 meters using this set-up/bullet weight choice? |
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