NSA 34.9gr .25 cal at 1020 fps

[gmoua83]

My setup is fx impact 2, power wheel at #5, 150 psi on reg, valve adjuster 4th line. Sighted in at 45 yds can cover a quarter with 5 shots.

My question is, is that to fast for the 34.9 gr? I haven't shot at 100yd to see how the groups are yet.

Should i stay with 1020 fps or drop it down to 1000 fps or 950 fps?

thanks you

 

[Rickrick]

100 yds will spread out quite a bit. Slower speeds should help tighten your groups

 

[gmoua83]

What speed do u recommend? Mid 900s?

 

[Chapjl]

Slow it down, mine will put 5 in a dime, at 50 yards at 950ish. Groups open up as it goes faster.

 

[wWilliam]

I shoot mine with the same slug you have At 930 and have great results

 

[gmoua83]

Thanks 

What psi do u guys run?

 

[gmoua83]

What psi?

 

[Rickrick]

I'm shooting my condor with AVS .253 44g slugs at 980 fpe with 3000 psi which is giving me 1/2" groups at 50 yds. Most posts I've seen regardless of calliber or gun seem to be shooting 950 to 980 or so. At some point I'll see what 75 and 100 yds will do.

 

[nplez1]

I’ve always wondered about this. Powder burners will push to speeds over 1000fps for the best groups, but they are using much thicker, heavier barrels. Theoretically, the higher speeds with more spin will yield flatter trajectories. That makes me think the spread at higher speeds is a result of harmonics in the barrel and high 800s to mid 900s just hits the harmonic at the right point. Theoretically, you could use a harmonic tuner (or barrel weight) to minimize the effects of harmonics and push harder.

 

[bigHUN]

The speed is the enemy #1.

So there is no argument that all of us trying to get a most accurate shot or a tightest group. And we can go from here to next question what the accuracy means to me or to you or to Joe.

Basically,

the liner/barrel twist rate dictates what speed you can - or you need to - propel the projectile for a best result. There is only a min-max speed range where the projectile can give the best accuracy. With higher speeds it is harder to tune, the margin of error is narrow.

And this is not all of it. The above mentioned "barrel tuner" is only maybe a very last 5% (or 3) that contributes.

 

[qball]

Best speed is around March 0.8 or about 900fps depending on temp, this is no different than powder burner sub sonic ammo. Also the 700mm barrels seems to be happy at 940-950 max, fast is possible but harder to tune. I usually just turned it to 930-940 average and call it a day, have great accuracy with 34.9 @940 average, probably tune it done to 920 in the winter.