Optimum weight for 1000y, .308

[Bart B]

Re: Optimum weight for 100y, .308

I think Bart B might agree with me that most of the best 1000 yd loads are not magazine fed. I would load something in the 200 to 210 class out to the lands. It may infringe on case capacity, but these bullets are shaped so well for over 1k. Choose from 210 sierra mk, berger 200 gr hybrid or 210 vld, or the hornady 208 gr amax.

I agree and your reasoning's good.

But those heavy bullets need at least 24 inches (26 is better) of barrel to shoot them out fast enough to benefit from their higher BC's and keep peak pressures at safe and accuracy-producing levels. Yes, one could load to higher pressures and shoot them out of a 22 inch barrel fast enough, but the pressure curves won't be as repeatable so muzzle velocity spread will get larger and barrel whip won't be as consistant so bullets won't leave at the same angle and speed uniformly enough to arrive down range on target close together.

185 grain bullets are the heaviest I would want to use in 22 inch barrels. And with medium speed powders loaded to the limit of safety. A 1000-yard team match record was set at this year's Nationals in the USA with AR10's shooting 7.62 NATO ammo with Berger 185's from 20 inch barrels. The US Army's Marksmanship Training Unit's not letting out the load used, but I'd bet a bucket of sheckels it was well over peak pressure specs; they've been doing that for decades for their service rifles used in competition as have the other US military teams.

Note that the heavier a bullet is for a given cartridge, the more recoil it has while the bullet's going down the barrel. That's why a lot of folks in the USA have stopped using Sierra 190's in their long range .308 Win. rifles and switched to 155's but from longer barrels to get they out at 3000 fps compared to 2550 with the 190's. One can shoot more accurate with less barrel time recoil; the bore axis moves less after the firing pin smacks the primer.

 

[Farmer Rob]

Re: Optimum weight for 100y, .308

That's a sensible answer, so back to the 185's, starting at 39gn 4064 or adi2208(equivalent) working upto to about 42gn.

Next stupid question, will these heavy loads settle at 100 or 200y or do i need to work up my load development loads at 300 plus? I'd like to develop the loads at short range as it takes out more error options, but if there not going to settle before that ill need to go out further. I can do 350 from my current range whilst im still building my 1000 yarder.

 

[Bart B]

Re: Optimum weight for 100y, .308

Next stupid question, will these heavy loads settle at 100 or 200y or do i need to work up my load development loads at 300 plus?

Yes on settling bullets. No on long range development. And your question's a sign of intelligence; 'tain't stupid at all. Smart people ask good questions about stuff they want to learn about. You just did that.

Sierra Bullets tested all their bullets in a 100 yard indoor range for decades. They tested their 30 caliber 190 and 200 grain match bullets with max loads. The best ones would shoot in the ones; groups under .2 inch/moa, one 10-shot group after another. I've seen sets of them; very impressive. Most good bullets from the correct twist for velocities used stabilize very well before 70 to 80 yards. When in their California site, they tried 200 yard testing, but the groups were only a tiny bit over twice the size of those at 100 yards with the same lot of bulets. So they quit 200 and just used 100. Their best bullets shooting in the ones at 100 won matches and set records at 1000 yards.

If you have a chronograph, then short range tests will be good enough. Keep standard deviation below 7 to 8 fps. A 50 fps spread (17 fps std. dev.) muzzle velocity causes a .1 inch spread vertical at 100 yards; at 1000, it's 20 inches. Most of the time this won't be visable as slower bullets leave later in the muzzle axis up swing so their more downward curved trajectory is compensated for; sometime's it's not so you gotta shoot at that long range target to find out.

 

[Farmer Rob]

Hi all,
thanks for all your help, I couldnt get any berger in my town and dealer cant even order it, id need to mail order it and that gets hard here in Aus!!!

So I bought some sierra 180gn hpbt match, has a bc of .496, not quite the .56 of the berger, but best i can do for now.

And my rifle has liked the sierra'a in the past too.

So I have loaded from 39 to 42gn of ADI's 2206h in .5 increments with federal match primers, 2206h is a little faster than imr4094 but again my riflr liked it better than 2208(4094)

I hope ill get the chance to shoot these sunday and ill post results.

 

[Bart B]

So I bought some sierra 180gn hpbt match, has a bc of .496, not quite the .56 of the berger, but best i can do for now.

A word of caution if you're going to shoot at targets 800 yards or further away with Sierra's 180 hpbt match bullet. . . .

Sierra changed the boattail on thier 30 caliber 180-gr. match bullets in the early 1980's. Instead of the long boattail used on their 190's and heavier match bullets, they used the short one that's the same as their 168's so only one size and shape of die was needed for both types. The 180 was no longer popular in long range matches when fired from the .308 Win. case; it went subsonic and changed directions a bit when that happened around 800 yards just like the 168's did and still do.

 

[Kevin Thomas]

Farmer Rob,

Just a few suggestions here, along with a correction or two that may explain some of this. As has been suggested, with your rifle, the Berger 185s are probably going to be the best choice here. They are capable of speeds that will keep them supersonic at 1,000 yards, thanks to their higher BCs. While you can get those same speeds with the 180 SMK, they won't cut it. The older ones would, but these were dropped in favor of the new design in the early 1990s to save on tooling expense. Stupid move at the time, and totally destroyed the usefulness of this bullet. Since then, if you leave them sealed in the box, they make a fine paperweight, but beyond that they're a waste of powder and primers. Forget about them. The 175 SMKs are a bit more useful, and can reach 1,000 from a 22" 308 if you really push them. They'll need an inital velocity of right around 2650 at the muzzle to get them that far out, and it will will be a stretch. The Berger's should save you some frustration here.

As an aside, Sierra does the vast, vast majority of their testing at 200 yards, and has for the past 30+ years. In Califronia, we had a full 200 yard tunnel, and that was the stadard distance for testing virtually all rifle bullets. The Sedalia plant was built over a 300 meter range, but the testing is still done at 200 yards for daily QC stuff. The 300 meter capability only gets used for some special projects, certifications and the like. Once something becomes ingrained, it can be hard to get away from the "we've always done it this way" mentality.

As to your last question regarding bullets settleing, that's not really the issue. Bottom line here is you can't develop a 1,000 yard load at 100 yards, or even at 300 for that matter. You need to develop the load at whatever distance you're going to be shooting, period. I've seen many, many examples of loads that gave horrible extreme spreads and very high standard deviations, and yet were absolute tack driving combinations group after group. At shorter ranges, these variations often make no discernable difference at all on target. Move these same loads out to the longer ranges (and certainly at 1,000) and this becomes a whole different story. Those same loads will string wildly on target, totally unacceptable for this sort of shooting. Unfortunately, merely coming up with a low SD and reducing the Extreme Spread is no guarantee that the load will perfrom at the longer line, either. It's just one of those things that you need to develop at the distance you're shooting, and there's simply no substitute for this.

 

[rscott5028]

I haven't tried the 185 Berger or 175 SMK. So, I can't draw a comparison with either of those. But, I can tell you that the 175 Berger OTM will get you there while feeding from an AICS magazine.

-- richard

 

[Farmer Rob]

I know your all going to tell me I told you so but.

I finally got to test my new 180 smk's but the best group i got was .94moa at 100. That was with 41.5gn adi 2206h., which i have mentioned before is a tad faster than imr 4064

Here's what i did, firstly i seated the rounds as deep as i set my 168, by that i mean i didnt move the locking ring on the seater, my theory was i dont much with a known depth so there is one less thing to think about, but every round was hard ish to close the bolt, not too hard just felt like it was too far out.

Everyone else tells me the 180's probably wont fit in the magazine, but mine went in fine but seem too long??

My set up was exactly the same as every other time i have load developed for the past 15 years, no wind, stable rest platform.

Any thoughts?

 

[Speck]

185 bergers, Hybrid or BTLR. Great bullets, high BC and accurate.

 

[emn83]

I'm going to be trying 155gr hunting Bergers, my hope is to get up to 2900-2950fps, out of my 26in barrel Savage, but I'll have to check what pressure my rifle can handle when I get it back. That combination should keep the bullets supersonic past 1k. I mostly shoot midrange F-class at 600, so I'm trying to make a load that will work for me at both distances

 

[Farmer Rob]

well, after much fussing and trying different loads i have settled on a hornady soft point boat tail @ 165gn, this seems to be the best i can get and shoots at .6 moa at 100y and .9 at 400y. Next best is a 150gn, i just cant get the heavier bullets to shoot well, so ill just have to put up with the lighter projectiles

 

[308winlongrange]

farmer boy i would like u to try one more round before u give in i highly recomend the 208 amax over 40 gr of varget i have even seated them to the same depth of the 175 hpbt from federal gold medal and have had great accuracy from all i have used this round out of a factory barrel to shoot sub .25moa at 100 and shot .5 moa at 1000 and this is with a factory remington 20 inch heavy barrel they seam to love the 1 10 twist and have great wind bucknig abilities with a bc of .648 they also are devistatin on coyotes to 500 which is as far as i have shot at one the pic attatched is of a yote i shot recenly at 1107 with a 308 winchester i have worked up a great load just recently with the 215 bergers and 45 gr of re17 and had them shoot sub moa at 1500 soon to push thwm to 2000 if i can get the elevartion out of my scope both of these rounds suggested have worked great with me in 1 10 twist barrels

 

[OneShot0351]

for 1,000yd 175 SMK... but like any LR shooter once you get 1k you wanna go 1,200, then 1500, then 1M! even a hair past 1k i would have 208 amax no doubt.

 

[Bart B]

I doubt any 208-gr. bullet can be shot fast enough from a 20 inch barrel with safe pressures with a .308 Win. case fast enough to remain supersonic through 1200 yards. That A-Max bullet needs to leave at more than 2450 fps to do so. Guessing what's safe is dangerous, but a popular practice.