What velocities are you getting out of Federal XM193 in 18" SPR-like barrel?

[Jicko]

I am interested in knowing what velocities are you getting out of Federal XM193 in a 18" SPR-like barrel?

I am reading a 5-round avg close to 3330fps, I thought that it is only suppose to go at around 3250fps(+/- 40fps) out of a 20" barrel (chrono @ 15ft). So, I want to make sure that my Shooting Chrony Alpha Master is giving me "accurate" readings. Chrono'ing @ 6ft in a warm day, 90deg.

[Prc329]

If I can get to the range this weekend I'll try it and see.

[ar15barrels]

I am interested in knowing what velocities are you getting out of Federal XM193 in a 18" SPR-like barrel?

I am reading a 5-round avg close to 3330fps, I thought that it is only suppose to go at around 3200fps out a 20" barrel. So, I want to make sure that my Shooting Chrony Alpha Master is giving me "accurate" readings. Chrono'ing @ 6ft in a warm day, 90deg.

Standard published velocities are tested at 70 degrees.
You can expect an increase in pressure/velocity with higher temperatures.

High quality stainless barrels are often faster than chromoly barrels due to the difference in rifling designs.

Velocity is a good thing.

[PIRATE14]

I am interested in knowing what velocities are you getting out of Federal XM193 in a 18" SPR-like barrel?

I am reading a 5-round avg close to 3330fps, I thought that it is only suppose to go at around 3250fps(+/- 40fps) out of a 20" barrel (chrono @ 15ft). So, I want to make sure that my Shooting Chrony Alpha Master is giving me "accurate" readings. Chrono'ing @ 6ft in a warm day, 90deg.

Well you're half the distance 6FT instead of 15FT and you're 20plus degrees hotter......sounds pretty close........

[Jicko]

I just want to use the XM193 as a "control experiment" during my Mk262-R&D-clone process.

I was getting some inconsistent velocities after tweaking of my reloading equipment, so I just want to weed out the issue of a "erroreous chronograph".

I used to get 2714fps(3 rounds avg) from 24.5gr of RL15, but after I "fixed" my die issues, I am now getting 2801fps(10 rounds avg) from 24.5gr of RL15.

According to Nosler's website 24.5gr of RL15 yields about 2741fps (most likely from LONG barrels tho).

Back then, my XM193(same lot) gives an avg vel of 3185fps; but now, they are flying @ 3330fps!!!

[Prc329]

I measured 10 feet from the muzzle give our take a few inches from a 1-9 16" barrel (forgot to bring the SPR) and I was getting 3200fps from XM193, 2600+ from American eagle and about 3200 from wolf gold 75g.

[donger]

about 3200 from wolf gold 75g.

Was that a typo? 3200 for a 75 grainer sounds really hot.

[Prc329]

yeah that was I checked my notes and it was 2600. That was an xm193 number I got mixed up.