Gunsmithing Bullet choice for new design.

FutureGunDesign94

Private
Minuteman
Jul 25, 2012
2
0
31
Arizona, USA
I want to create a new semi automatic rifle magazine fed with a no longer than 21" barell. This will be a designated marksman semi-automatic rifle . I am stumped at step two. Bullet choice. This rifle needs an affective range of at least 1400 yards, but still needs to be lightweight enough to tote around for days. 5.56 by 45 rounds are accurate, but lack the power I desire. 7.62 by 39mm rounds have the stopping power, but are heavy and lack the accuracy at range I desire. I had thought of using a .308 Winchester. Thoughts
 
Re: Bullet choice for new design.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cruz Design</div><div class="ubbcode-body">I want to create a new <span style="font-weight: bold">semi automatic rifle magazine fed with a no longer than 21" barell.</span> This will be a designated marksman semi-automatic rifle . I am stumped at step two. Bullet choice. <span style="font-weight: bold">This rifle needs an affective range of at least 1400 yards, but still needs to be lightweight enough to tote around for days.</span> 5.56 by 45 rounds are accurate, but lack the power I desire. 7.62 by 39mm rounds have the stopping power, but are heavy and lack the accuracy at range I desire. <span style="font-weight: bold">I had thought of using a .308 Winchester.</span> Thoughts </div></div>

Something built on a .308 platform will not be lightweight at all, add in optics, rings or one piece mount, bipod, etc. and a 21" barrel... it wouldn't be fun to carry for days on end.

You need to focus on something in the AR-15 platform, possibly a 6.5 Grendel which will get you out to 1000 yards accurately.