bulk .223 bullets

[ROGER4314]

Good posts! Keep up the good work!

I shot 600 yard NRA Matches routinely for some years, earned my NRA long range classification, won some cash prizes and earned the Long Range (600 yard) certification at our local gun club. I shot prone military service rifle and match rifle class (both in iron sights) and only a few times, "F" class (scoped). 600 is the longest range I've fired in competition and I used 30 caliber 168 grain SMK exclusively and 69 grain SMK in .223 with a 1:8 twist or 55 grain with 1:9 twist.

Here's s grin for you! I won a cash prize at 600 by shooting a Colt A2 20" 1:9 twist using Winchester White Box Q3131 FMJ .223 right from Wally World! The Colt AR loved that ammo!

"F" class shooters at 600 yards usually shoot perfect 600/600 scores and the winner is determined by "X" count. I shot NRA Master in "F" class and got my ass kicked royally! The "X" ring at 600 yards is the size of a grapefruit. Those guys commonly get 40-50 "X" (out of 60 total rounds) with perfect 600/600 scores!

Regarding tumbling of the projectiles, one factor that you may consider is the position of the bullet as it follows its trajectory. Those long range shooters explained it to me this way. As the bullet begins the downward portion of its trajectory, the tip of the bullet does not point downward. The body of the bullet is traveling downward but the tip is pointing slightly upward.

At very long distances with very curved trajectories, the projectile can leave a hole that appears that the bullet struck "tip up". That may be the source of the "Tumbling" observations. If the bullet actually tumbled, there's little hope of even hitting the target. It would take off for parts unknown like one of those spinning fireworks!

The information came from High Master class shooters but I can't verify or guarantee accuracy personally. I'll share it with you the same way I got it. Considering the skill levels of the guys who taught me, I'll accept it as true.

Flash

 

[1slow01Z71]

My 178 amax load at that range is a perfect splash on steel...

Too bad I dont have any more 168 SMKs, I'd have to try it out on a paper target but I got perfect profile splashes on the steel and some nice round ones so that tells me theyre tumbling. There was a bit of wind and I havent shot a ton at that range so my groups werent that great. It held moa out to that range before everything went to hell. I dont know what the group size was as my steel is only 12" and couldnt keep 5 in a row on the plate. I could with my 178 amax load but its a little hotter than the FGMM stuff and has a better BC so not exactly a fair comparison.

 

[mikeofcontex]

One might read that to believe that the SMK has a flight calculator and gives up its stability on cue at 800 yards. I read it to mean that with conditions close to STP, the trans-sonic effects cause the SMK to destabilize at approx. 800 yards when the muzzle velocity is approximately 2650.

 

[ROGER4314]

Again, that "tip up" bullet attitude may account for that odd impact pattern. If the bullet actually tumbled, the projectile would pinwheel off into the rough. Just a thought...........

Long range shooting isn't learned from a book and you're going about the learning process exactly right! Keep up the good work and please share your observations!

The attached site contains a lot of relevant information and I'll quote some of it that actually contradicts what I've written on bullet attitude. It does shed some light on transsonic shock waves, though. Digest this and see what makes sense.

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 behavior of bullets in the transonic region very difficult."


Flash

 

[Vaquero]

Well, both the x-treme m-193 and the dogtown 55gr hp show very good potential.
Disclaimer though. I robbed a scope and rings off of a fudd gun and literally slapped it on the AR.
I had to hold my head at 90 degrees to even see through it. No cheek weld to speak of.
My sand bags are in a friends possession currently, so a wadded up jacket had to do for my front rest.

Draw your own conclusions. I like 'em both for the money.

Anyone wanna recommend low budget glass and bases? Lol!

 

[Vaquero]

The wood in the previous post is a 15" × 15" box I'd built long ago for another purpose. I put 1/2" dot stickers on it for poa. Filled it with dirt and began firing.
FYI, not a single round exited the box. This pic is what I recovered after dumping the dirt.

 

[1slow01Z71]

Again, that "tip up" bullet attitude may account for that odd impact pattern. If the bullet actually tumbled, the projectile would pinwheel off into the rough. Just a thought...........

Long range shooting isn't learned from a book and you're going about the learning process exactly right! Keep up the good work and please share your observations!

The attached site contains a lot of relevant information and I'll quote some of it that actually contradicts what I've written on bullet attitude. It does shed some light on transsonic shock waves, though. Digest this and see what makes sense.

External ballistics - Wikipedia, the free encyclopedia

"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 behavior of bullets in the transonic region very difficult."


Flash

If it was the "tip up" phenomenon then all of them would leave the same sort of mark on the steel whether it was a profile or square hit though. In my case some were profile and some were nice and square.

Well, both the x-treme m-193 and the dogtown 55gr hp show very good potential.
Disclaimer though. I robbed a scope and rings off of a fudd gun and literally slapped it on the AR.
I had to hold my head at 90 degrees to even see through it. No cheek weld to speak of.
My sand bags are in a friends possession currently, so a wadded up jacket had to do for my front rest.

Draw your own conclusions. I like 'em both for the money.

Anyone wanna recommend low budget glass and bases? Lol!

The PEPRs are nice but since aero precision came out with these
Scope Mounts
I see no reason to go with any other now. Its a really quality piece and priced decently.

Vortex just updated their lower end crossfire line with a nice AR option
Vortex Optics - Crossfire II 1-4x24 V-Plex
Should sell for less than 200 and have their no BS warranty which is nice for a cheaper beater gun.

 

[jrbfishn]

What distance Vaquero?


from a non-recovering coffeeholic

 

[Vaquero]

100 yd.

 

[jrbfishn]

Not too bad


from a non-recovering coffeeholic

 

[Vaquero]

It'll get better. I rushed it due to weather.
Gonna check into a good trigger and get a dedicated scope setup, eventually.