12.5" Suppressed Precision Long Range gun.

[markm]

I'm gonna have to set up a couple and see how far I can ring them from(luckily I can hang my 2/3 IPSC steel on it). Got a 12.5 BCM SBR, I'll slap my 3-9x40 on there and give it a whirl.

If you have a load that'll buck transonic interference, go for it. I have to imagine that our load just falls apart after 700 yards.

[snackgunner]

1100 yard valley that you guys can take over every weekend...

Im so damn jealous. Beautiful setup you guys have out there.

[markm]

1100 yard valley that you guys can take over every weekend...

Im so damn jealous. Beautiful setup you guys have out there.

A 200 yard improvised range is just over the hill.. That's where people stop to shoot.... so no one bugs us in the Valley.

[mtdawg169]

If you have a load that'll buck transonic interference, go for it. I have to imagine that our load just falls apart after 700 yards.

I know nothing of reloading or long range ballistics, so please pardon my ignorance... what actually happens when the projectile goes subsonic? Is this a stability issue or just an extreme drop off in velocity that makes longer range hits impossible? By the way, this is a great topic! Thanks for sharing your experiences.

[markm]

From wikipedia.... http://en.wikipedia.org/wiki/External_ballistics

When the velocity of a rifle bullet fired at supersonic muzzle velocity approaches the speed of sound it enters the transonic region (about Mach 1.2–0.8). In the transonic region, the centre of pressure (CP) of most bullets shifts forward as the bullet decelerates. That CP shift affects the (dynamic) stability of the bullet. If the bullet is not well stabilized, it can not remain pointing forward through the transonic region (the bullets starts to exhibit an unwanted precession or coning motion that, if not damped out, can eventually end in uncontrollable tumbling along the length axis). However, even if the bullet has sufficient stability (static and dynamic) to be able to fly through the transonic region and stays pointing forward, it is still affected. The erratic and sudden CP shift and (temporary) decrease of dynamic stability can cause significant dispersion (and hence significant accuracy decay), even if the bullet's flight becomes well behaved again when it enters the subsonic region. This makes accurately predicting the ballistic behaviour of bullets in the transonic region very difficult. Further the ambient air density has a significant effect on dynamic stability during transonic transition. Though the ambient air density is a variable environmental factor, adverse transonic transition effects can be negated better by bullets traveling through less dense air, than when traveling through denser air. Because of this marksmen normally restrict themselves to engaging targets within the supersonic range of the bullet used.[12]

[Iraqgunz]

Wish I still had the Noveske so I could show what a 16" barrel, good optic and ammo will do at longer ranges.

[markm]

I ran ballistic charts on the 18" barrel... and even that laser beam will barely stay super to 800. And that's within like 5 fps or so... so depending on the conditions on a given day... no guarantee.

I hate to push the load up any more. It's so accurate, I don't dare screw it up.

[Iraqgunz]

When I did the course at GPS we had 18" guns with Leupold scopes and we shot out past 800. On day 3, I made a first shot hit on a steel target at approx. 864 yds.

We were using Black Hills 77gr. Match ammo.

I ran ballistic charts on the 18" barrel... and even that laser beam will barely stay super to 800. And that's within like 5 fps or so... so depending on the conditions on a given day... no guarantee.

I hate to push the load up any more. It's so accurate, I don't dare screw it up.

[markm]

You read my mind.... I was just wondering what a 77gr would do. I've never been able to get those bullets to do anything thrilling in the accuracy department. But I bet a hot load would stay super longer than the 69 grain.

[charmcitycop]

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