Is a 10" SBR Effective at 50 yds Using 75gr. Ammo

[masterdrago]

Given that in my Sig P516 suppressed, the least failing ammo turns out to be Hornady 75gr TAP SBR, I'm wanting to know at what range it will become ineffective. Given the 10" barrel and the starting muzzle velocity from a 14.5" barrel test on these forums indicates 2460fps, what could I expect at 50yds from my 10" Sig? I've seen tests indicating from 22 - 30 fps/ft change in lowering barrel length each inch. I've not found ballistic charts for this round from a 10" barrel so am thinking a drop of 250fps down to 2200fps. What could I expect at 50yds? Is there still enough velocity for this round to be effective for home defense?

[gaijin]

Not enough of additional velocity drop at 50 to be concerned.

[Failure2Stop]

Adequate for home defense.

[turnburglar]

Lot's of dudes have used 10.3" barrels with M855 and had good success. I dont have any charts or data that I know the internet wants, but there is the GWOT; where a very common load out was mk18 +green tip. Heavy BTHP are considered very effective man stoppers.

[mack7.62]

I'd guess it is probably good out to 150-175 or so.

https://www.hornadyle.com/rifle-ammu...-gr-tap-sbr#!/

TAP® SBR™ is designed specifically for 10.5"-11.5" SBR’s by using proprietary propellant technology and a bullet designed with technology from industry leading Critical Duty® FlexLock® bullets. TAP® SBR™ provides exceptional ammunition performance in SBR’s suppressed or unsuppressed, with virtually no flash or residue, dramatically reduced sound signature, will not foul or overheat suppressors, uniform velocity and accuracy, and provides controllable rate of fire in automatic platforms. Designed to meet the requirements of the FBI protocol, TAP® SBR™ is the optimum choice for 10.5"-11.5" barreled 5.56 rifles.

LMT CQB 1:7" (10.5") Muzzle 100 Yards 200 Yards

Velocity (FPS) 2201 1865 1566

[masterdrago]

Thanks Mack. That was the info I was looking for. So over 1800fps at 50yds. I strongly suspect I'll not be spraying any ammo farther than that. BTW, I've seen no muzzle flash in the dark with the 6" Sig can on. So good to keep concealed Velocities must be pretty consistent since all the empties make a small pile at 4-4:30. No other ammo I've shot through this shorty is tighter. It is a tad expensive at about $0.89/pop.

[markm]

Given that in my Sig P516 suppressed, the least failing ammo turns out to be Hornady 75gr TAP SBR

Least failing?? What's that mean. Any AR should run almost all ammo reliably.

[masterdrago]

Least failing?? What's that mean. Any AR should run almost all ammo reliably.

I totally agree. It's a long story that has not been finished/ See https://www.m4carbine.net/showthread...s-Inconsistent if you have time. Sig wants it back but I need to put it back in factory condition - brace, original trigger, etc, etc. It has been form 1 with an engraved Trust on lower, so not sure how Sig will take to that. When I get time, I plan on paying a real armorer to fix the issue. Anyway, it runs good with the Hornady ammo and suppressor. It's just that practice ammo, which I have a lot of, is cheaper. The American Eagle ammo for the most part has ejection routes all over the clock from 1:00 to 5:00. I personally think that the velocity variation in the low cost ammo plays hell with the dwell time -

[tellum]

you'd need a varmint bullet to expect expansion in flesh at 1600 fps. Best figure on 1800 fps. I favor the Nosler 60 gr Partiion, 2400 fps, with AA 2520 powder, it's almost impossible to get that bullet now, tho, in virus-time. It still expands in coyotes at 200m.

[masterdrago]

Least failing?? What's that mean. Any AR should run almost all ammo reliably.

Sorry, it's been a while as other things take up my day. Everything I've read claims that an SBR when suppressed is highly picky about what ammo runs well. My son just finished a 6" 300BO with a big can. The only thing it will run well is AE 220gr. He just picked up a set of light weight buffer https://www.midwayusa.com/product/1020899941 to help try to run other ammo. His gas port is fixed size as he only wants to run sub-sonic ammo but some of the high $$ stuff would not lock back.

I may just buy only the low power .223 for practice. So far, it does not jam.