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600 yard loads for Service Rifle Competition

I have limited access to 600 yard shooting and thus am working up 80 grain VLD loads for my service rifle at reduced ranges. My best load with both JLK and Berger bullets will hold the X ring at 100 yards.

Question: is a standard deviation of 19 feet per second sufficiently small to get acceptable vertical stringing at 600 yards?
 
I believe you mean an extreme spread of 19fps. A standard deviation of 19 would be entirely unacceptable but the ES at that range isn't too terribly bad. I would suggest however, trying to get an ES somewhere under 10 if you can.
Side note: "X" rings come in all shapes and sizes so "holding the X ring" is a relative statement. Group size is the better measure of accuracy.
 
Lapua40X - Thank you for the reply. I will be more specific.

The X ring on the MR31 target is .750 inches in diameter; the target is scaled to represent the official 600 yard target at 100 yards.
My average velocity for a chronographed 10 shot string was 2525 fps, with the extreme spread of 59 fps (one round at 2561 and one at 2502 created this). The standard deviation from the 2525 fps was 18.43 fps. The loads were metered off of my Dillion RL 550 using N140 powder.

I am firing a Bushmaster DCM Match AR15
I used LC brass that was sorted within a 1 grain difference of each other and Federal 205M primers.

The groups were the best of numerous combinations tried thus far.

I shall attempt to narrow the extreme spread of this load via measuring each load, and tightening the casing variance.

Thanks
 
There's your problem. 600 yd ammo should be hand weighed charges. You already have enough variables to deal with at the long line, no need to add to it. I always ran 24.0-24.3gr of varget behind the 80 SMKs and AMaxs. That combo accounted for a couple of cleans with the service rifle.

Get a good scale, weigh the charges, and favor up wind and you'll be fine.
 
You may get very good accuracy at 100 yards and find that the same load shoots all over the place when you get to 600 yards. You may get what you think is sub par accuracy at 100 yards but when you go to 600 yards it may shoot lights out. You will never know until you actually go to 600 yards. Take what you have and go to 600 yards and see what you get. No use in wasting components chasing a few thousands tighter group at 100 yards that may not help you at 600 yards. 10 shots data do not a kingdom make. ;D From the old school of been there and done that. Good luck.
 
For 600 yard service rifle shooting, 23.5 grains of Varget or Reloader-15 behind an 80 grain bullet will be accurate enough to win Highpower matches in almost any rifle you shoot it in. You might find a sweet spot a little higher or lower than that, but it will be right in that neighborhood. The Berger VLD's tend to be pretty depth-sensitive, and I personally would not bother with them for this type of shooting, though some do. The 80 SMK and 80 A-Max are both proven winners for this, and can be had a bit cheaper than the VLD, and will most likely be easier to tune. This wheel was invented a long time ago, no sense wasting a lot of time trying to make it better. If I had to shoot 600 yards with a service rifle tomorrow with no load data, I'd just dump 23.5 of Varget under a 80 SMK, jump them .020" and go shoot. I'd do just fine, too.

Good luck.
 
I have used the Hornady 75 HPBT seated at mag length over 24-25 of varget. It is extremely accurate and I can hold 2 moa in the prone to 600. The 80s will beat it out in the wind a little bit, but I use one load out to 600.
 
I've used the following loads at 600 with good results. Shooting a 1-7.7 CBI barrel

Sierra 80gr MK
22.7gr AR-COMP
CCI450 primers
LC brass
2.5" OAL

Berger 82gr MT
23.3gr AR-COMP
CCI 450 primer
LC brass
2.5" OAL

Both of these loads chrono at ~ 2680 fps through my rifle (CMP/NRA service rifle). I can't recall the exact STDDEV as I'm at work, but it was in the neighborhood of 17.

As long as you and your given load will hold 2MOA, you'll clean the 600 yard target.
 
You are shooting at a 2MOA 10 ring, and a 1MOA X ring. I wouldn't get too wrapped up in load testing them
 
Thrown charges are perfectly fine for 600 yard service rifle competition.
However, thrown charges with N140 are not. As small kerneled as it is N140 is terrible in a powder chunker. It has a propensity to stick to itself and will cause everything from total bridges to to a grain or so hanging in the measure.
I have proved this when throwing charges light to trickle up. The extreme spread can be as high as .8g on a 24 grain throw. Totally unacceptable for 600 loads. Varget throws much better even though it's kernels are 30% larger.
 
I have thrown AA2230 in my Dillion, weighed every 10th on my chargemaster (not getting into putting them on a .02 scale) and the only variations I've seen were + .1gr, and they were rare. it's a little fast for heavy bullets but it works. I picked it because it does meter well. In my bolt gun jumping who knows how far those mag length 77s shoot inside .5 MOA at 200 yards. I use them for foulers and sighters when I go do load work. (which can be frustrating when they shoot better than the loads I'm working on)

I have loaded a lot of developmental loads for my 223 and 308 bolt gun with 2000MR, i haven't put it in the Dillon yet, but I have to think that is would meter like water, and it works great with heavier bullets.

In Service Rifle, if you drop points it's because you pointed it over there, it's not going to be the loads fault unless you just make really bad reloads.
 
You do not need to hand weigh charges , i load all my ammo, 600yd included with a Dillon 550. Berger 82 seated 15 off the lands and 24.3 of reloader 15. Good enough to leg out and make high master, and I have cleaned. 600 yds with it. I load 24.2 for my juniors, which also shoots lights out.
 
I'll add this as well, the amu shoots black hills 77 gr accross the course, this is factory loaded ammo on lc brass. It's not that hard to load ammo that has a lower sd or es than factory ammo. However The amu shooters consistently lead the pack at perry and any other match that they shoot . Mostly because they shoot every day and know their rifles.
Doing load development for service rifle is not necessary, the established loads are out there for all the common chambers used. All the loads are plenty accurate. I load for our juniors, all the same load in different rifles , in addition, all the shooters in our club are basically shooting the same loads I do. If we ever have a barrel that won't shoot those loads, something is wrong with that barrel and it will be replaced.
If your having trouble with vertical stringing at 600 and your rounds will hold the x ring at 100 yds, your problem is your position and your pushing the post into the black, most likely from aiming to long.
Start shooting smallbore prone to find weaknesses in your position.
 

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