I normally shoot 175smk, can I used my same coal and powder charge or should I start with a lighter powder charge or lengthen the oal?
.308 178 amax coal
- Thread starter phillipjr
- Start date
Re: .308 178 amax coal
Because it has a different (secant) ogive profile, the 178 Amax will be more sensitive to seating depth than the SMK 175. You should be able to seat the Amax closer to (if not engaging) the lands.
Because it has a different (secant) ogive profile, the 178 Amax will be more sensitive to seating depth than the SMK 175. You should be able to seat the Amax closer to (if not engaging) the lands.
Re: .308 178 amax coal
Just my observation I load my 175 smks to 2.835 and the 178s to 2.850 so about 15 thou for me.
Just my observation I load my 175 smks to 2.835 and the 178s to 2.850 so about 15 thou for me.
Re: .308 178 amax coal
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: phillipjr</div><div class="ubbcode-body">I normally shoot 175smk, can I used my same coal and powder charge or should I start with a lighter powder charge or lengthen the oal? </div></div>
It depends on how close your load is to the pressure limit of that particular rifle. Seating to the same COAL will increase chamber pressure probably not enough to hurt you but I don't know how close you are to going over pressure already. The 178g A-MAX typically is 20fps slower with higher pressure for a given powder charge of RL-17 and offers no performance advantage over a 175g SMK round. The best of the under 180g .308Win bullets are the 178g Hornady Match. The 178g H Match ballistically are untouchable.
HTH!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: phillipjr</div><div class="ubbcode-body">I normally shoot 175smk, can I used my same coal and powder charge or should I start with a lighter powder charge or lengthen the oal? </div></div>
It depends on how close your load is to the pressure limit of that particular rifle. Seating to the same COAL will increase chamber pressure probably not enough to hurt you but I don't know how close you are to going over pressure already. The 178g A-MAX typically is 20fps slower with higher pressure for a given powder charge of RL-17 and offers no performance advantage over a 175g SMK round. The best of the under 180g .308Win bullets are the 178g Hornady Match. The 178g H Match ballistically are untouchable.
HTH!
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