BIG Freakin' Cartridge Test 005: PMC XP193 5.56x45mm 55gr FMJ, 14.5 Barrel, and Accuracy
Next up for the Big Freakin’ Cartridge Test is Korean manufacturer PMC’s clone of M193 Ball, called XP193. This ammunition features very uniform-looking external dimensions, attractively finished brass cases and projectile jackets, and a reasonable price. Interestingly, XP193 appears to use a lower drag 55gr bullet, possibly based on the Sierra 55gr, instead of the somewhat draggier Remington-style projectiles used by Federal, IMI, and others for their M193 clones. I like to use XP193 when I need full-power ammunition without spending too much. The test procedure was as follows:
- Condition ammunition to 70 °F +/- 5 degrees for at least 1 hr (in practice ammunition was always conditioned overnight).
- Mount chronograph to barrel or rail.
- Record the temperature in the conditioned container before each string.
- Withdraw one round of ammunition from the cooler.
- Load and immediately fire the round.
- Cool chamber back to ambient conditions for 30 seconds
- Repeat steps 3 through 6 nine more times.
This procedure was followed for 14.5″, 16.1″, and 20″ barrel length velocity tests. To measure velocity, a Magnetospeed V3 chronograph was used attached to the barrels of the 16.1″ and 20″ uppers, and the rail of the 14.5″ upper. In addition, three 10 shot groups were shot for each round through my Criterion 14.5″ chrome-lined 1:8 twist hybrid contour midlength barrel in .223 Wylde, to determine accuracy. These targets were then analyzed using OnTarget analysis software.
The chronograph results for the 14.5″ barrel are as follows (Shot #, followed by muzzle velocity in ft/s):
1. 2,976
2. 2,976
3. 2,986
4. 3,009
5. 2,980
6. 2,996
7. 3,015
8. 2,976
9. 3,007
10. 2,984
Which gave us the following figures:
Min: 2,976 ft/s
Max: 3,015
Avg: 2,990
Standard Deviation: 15
Extreme Spread (highest minus lowest): 39
I was extremely pleased with the consistency of this ammunition from the 14.5″ barreled upper receiver. It’s very encouraging to see an SD below 20 for ammunition that typically retails below $0.40/round! Velocity was also good, at a hair below 3,000 ft/s – which is about right for this barrel length.
On to accuracy:
Looking at the extreme spreads alone, you might think XP193 is disappointing in the accuracy department but the mean radius tells a different story. In reality, with an average mean radius of under 1, the XP193 is quite accurate generally speaking, but prone to occasional fliers. Or, if you prefer to believe, maybe I have a tremor.
Tomorrow, we look at the 20″ and 16″ velocity results for this round, so stay tuned!
Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. He can be reached via email at nathaniel.f@staff.thefirearmblog.com.
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Nathaniel F, who makes the hand guard on your SBR? Looks as strong as the one on my my MR762. And a great article, by the way...
Did I read that correct, 5+ inches? if I ever shot a rifle with accuracy that poor I'd instantly part it out after trying different types of ammo. That's crazy bad!