Been reading more on SBRs and it seems like M193 gets mentioned a lot more in relation to SBRs than M855. Is there a reason? Assuming a 11.5" 1:7 barrel, does one perform better? Have better terminal ballistics?

Speaking of ballistics, is there something online I can plug in my barrel and ammo specs that'll show ballistics?

Velocity is king when it comes to the effectiveness of the 223 round. Therefore, the lighter weight round will always fly faster. In a shorter barrel, this effect is magnified.

quote:

Originally posted by Wreckless:
Velocity is king when it comes to the effectiveness of the 223 round. Therefore, the lighter weight round will always fly faster. In a shorter barrel, this effect is magnified.

All true. The M855 bullet has been implicated in reports of failing to immediately incapacitate enemy fighters when highly stabilized and at low velocities (even from 14.5" barrels) because they fail to upset and tumble.

With the increasing popularity of short barrel guns firing the 223 Remington/5.56mm NATO rounds, that issue has been recognized by at least one ammunition manufacturer. The Speer 55 grain Gold Dot is claimed to expand even at longer ranges from short barrels. If I had no choice but to rely on a short barreled gun for serious purposes, I’d be exploring the use of something other than ammunition originally designed for military purposes and military weapons.

The soft point type loads work better terminally with SBRs, the heavy OTM rounds like 75/77g match loads work better than M193/M855 as well.

I have Federal Fusion which is a 62g bonded SP. Expands to something like 1800fps I believe, in any case well below what it is moving out of my 10.5". It is relatively easy to find and inexpensive for premium ammo, about .50 ea. I practice with less expensive stuff of course.

Para had a post that turned into a great data dump for this question.

As someone mentioned velocity is king, M198 is good for plinking but fir HD I would go with 55gr gold dots or TSX.