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Posted: 4/2/2016 11:38:07 AM EDT
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loading for a noveske rifle 16" match barrel 5.56/223 1/7 4x 14x scope bushnell
with 77 grain sierra 8208 xbr 23.1 grains cci small primer 2.25 oal with 68 hornday match 8208 xbr 23.9 grains cci small primer 2.235 oal 77gn are right on center of target 68 gn are 3 inches low and right 2 ** {problems seam to be this load} Any suggestions on how to get both loads to center of target with out adjusting scope Is there some wrong with my load numbers ? Or am i going to have to adjust for every different load? i could see a couple of clicks per load but 3 low 2 right is bad |
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Barrel harmonics.
Getting the POI the same with different bullets, bullet weights, powder and powder charge can be a Real challenge, or it can be a piece of cake depending. Sorry, range time and load development is you only option and that may not get you what you desire. http://www.varmintal.com/amode.htm |
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Quoted: thank you. Anyone have suggestions on picking up and over 68 grain hornday with 8208 xbr or tac powder i have both We really have no idea how you barrel will shoot, just use loads from reloading manuals and do your own testing. Your barrel is the one who will tell you what it likes, not us. |
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It is a rare day indeed that two different weight bullets will shoot to the same point of impact. This is especially true at longer range. Pick a load that groups best in your rifle and zero for it. Make that your go-to load.
Keep records and you'll be able to quickly and accurately make sight adjustments for different loads. Chasing the same zero for different loads is like finding a Unicorn. |
| How far are you shooting? 100 yards? 300 yards? 600 yards? If you're at 100 I'd say try them at 2 or 300 yards and see how the impact changes. You might find the 68s are better at distance or impact closer to the 77s. I'd also follow the line of testing is the only way you'll find out how to make them match. Maybe it's velocity that changes things and you just need to speed up the 68s to make them impact where the 77s do. Maybe you need to slow them down. Invest 100 68s at various lengths and speeds to see what works for what you want. |
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Where are you getting your data from? In the Hodgdon online for the 69 grain bullet, max is 23.8 of XBR. Lyman and Lee don't have it because the powder is too new.
I know the max in the Hornady manual will be higher, they usually are. Try something in the 2800 fps range for the 68 grain Hornady. 22.3-22.5 grs of XBR should put you in the ballpark. For TAC and the Hornady 68 grain bullet try 23.0-23.2 grs...from the Western Powders Load and Data Guide Edition 5.0. Should get you around 2800 fps. The Sierra 77 MK. The sweet spot with that bullet should be in the 2600 fps range. The Hodgdon online says 21.5 grs-22grs should be about 2600 fps. The TAC load should be 22grs-22.3grs, that should put you in the 2600 fps range. From the Western Powders Load and Data Guide Edition 5.0. Good luck! |
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I might try to speed the 68 grain bullets up a little. I have no idea if that charge weight is close to maximum.
Albeit it small, the 77 grain bullet recoils a little more than the 68 grain bullet and causes it to strike the target a little higher. The two bullets might still not shoot to exactly the same point of aim, even with the same elevation on the target. |
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