Lets start over: how do you design a GPC?

[cory]

But, here comes the good news. When it comes to building a SAW variant, you can actually start with a 5.56 Minimi M249 rather than the 7.62 mm M240. So with the SAW, you can create a much lighter machine gun, but with much greater firepower.

Coming from someone who carried the SAW (no longer than I had too), starting at the SAW design is the last thing we need to do. To put it in the proper light, when breaching a room you NEVER lead with SAW gunner unless you had a death wish.

Anyways, I don't want to get this thread off topic.

We're assuming the necessary length of a tracer round is a constraint for using the Grendel. That assumption comes from another assumption that if we wanted to use a 130gr FMJ round as the primary round we need a 130gr tracer round, but what if we used approximately a 123gr Tracer round that would be shorter than the 130gr FMJ. Could the BC and charge of the Tracer round not be adjusted to match the trajectory of the 130gr FMJ or at least to the tolerance of the current 556 tracer round to the M855A1?