70gr TSX chrono results - SBR & 16" (10 feet, 100y, 200y)

General Firearms Reloading & Ammunition
1

A friend and I set up the Chrono today to check actual velocities from my two ARs that will be used for hunting deer & hogs.

We tested ASYM .223 70gr TSX and SSA 5.56 70gr TSX

The guns

BCM 11.5" ELW
BCM 16" ELW

All shots suppressed with a Griffin M4SDII 5.56

Here are the 3 shot averages for both guns

First the 11.5"
10 feet - 2467 (ASYM) / 2450 (SSA)
100 yds - 2198 (ASYM) / 2170 (SSA)
200 yds - 1963 (ASYM) / 1945 (SSA)

Next the 16"
10 feet - 2659 (ASYM) / 2620 (SSA)
100 yds - 2380 (ASYM) / 2336 (SSA)
200 yds - 2116 (ASYM) / 2081 (SSA)

We did shoot a few without the suppressor at 10 ft and shots from the 16" were about 25fps slower without the suppressor. With the 11.5 the difference was about 10 fps slower without the suppressor.

I’ve been using the 16" for hunting (Max shot ~175yds). With the TSX expanding down to 1800 fps I’m comfortable using the SBR now. That was really the purpose for today’s testing.

Hope this helps someone out there.

Best
Harold

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2

Very interesting that the .223 load was faster than the 5.56. Thanks for sharing the data. Expansion threshold shouldn’t be a problem at all inside 200 yards.

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3

Interesting indeed.

ASYMs numbers seem to be spot on. They advertise 2800 fps at the muzzle from a 20" 1:7 barrel. Using my average loss of ~40fps per inch of barrel from my little test today, they theoretically should have flown at ~2640 from my 16" 1:7. 2659 was my average. Pretty damn close.

SSAs numbers were a bit off. They advertise 2750 form a 16" 1:10 barrel. I got 2620 from my 16" 1:7. 130 fps difference, or ~5% slower than advertised.

Crucial to me? No. Just interesting.

I have more SSA than ASYM and I’m fine with that. I’ll use them interchangeably without concern.

Best
Harold

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