How to develop a 1000 yard load for 308?

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xopher

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I just recently started shooting at these distances. My friends and I finally found our 1k spot yesterday and we started shooting the stuff we had on hand at the target. We usually rape the crap out of targets at 600 so we thought we needed more distance haha! After 250ish rounds or so, we only landed 4 hits on our 16 inch plates.

Of course many factors come into play for long range shooting (especially at these distances), but were hoping to first get the proper bullet.

The three of us used a variety of hand loads and factory ammo ranging from 168 Custom Competition Nosler, 168 Amax hand loaded, and myself used 178 Hpbt Hornady. At these distances, we noticed the winds were causing lots of variations for the lighter 168 bullets. For this reason, we have begun looking into heavier and higher BC bullets such at the 178 Hornady hpbt, 185 matrix, and 190 SMK.

What are you long range 308 guys using at the moment? After seeing some consistency last trip, Im pretty sure ill begin to load the crap out of the 178 hpbt and start collecting DOPE for it.

Oh yes and lastly, we have some 190 SMK lying around. I was looking at some reloading data with this round and it seems like most conventional powders are having a hard time pushing it beyond 2500 fps. Because of the slower muzzle velocity, should we be concerned in regards to retaining speed at longer distances (i.e. 1000 yards) to make the best use of its BC?

Any advice will be appreciated!

Thanks in Advance,

Chris
 
What twist and barrel length are you running?

There are lots of ways to get to 1000 yards accurately from 155s all the way to 215s. Personally I like the 200 Hybrids because they seem to help mitigate my wind reading ability, or lack thereof.
 
16 inch pie plate? The NRA bull is 20 inches and I think the DCRA long range bull is 22". The aiming mark( black part of the target is 44")

Not sure what the flavour of the week is for bullets for F/TR but Target Rifle guys, irons and slings use 155 gr bullets.
 
Hm yes I'm loving them heavier bullets.

Im using a 5r (11.25 twist 24 inch, the 2 other guys are using 1 in 10 twist unknown length

What kind of propellant are you using? Ive heard great things about the N550 but i came across a thread on another forum talking about a secondary pressure spike...not sure if i should be concerned about that...
 
xopher said:
Hm yes I'm loving them heavier bullets.

Im using a 5r (11.25 twist 24 inch, the 2 other guys are using 1 in 10 twist unknown length

What kind of propellant are you using? Ive heard great things about the N550 but i came across a thread on another forum talking about a secondary pressure spike...not sure if i should be concerned about that...
Click to expand...

I use N550 in the 06 and the 308. Good powder. I always seem to get the best speed out of it with acuracy and usually low ES.You have to be carful with this powder, Ifind pressure builds quickly. I'm liking the advantages of the Berger 185's these days. I've loaded them for my dad's 700p and my custom 30-06. They do well in the wind.
 
If you are shooting well at 600yds, then wind reading is likely the weak spot now.

Alot happends in that last 400yds.

If your shots are flying around the target at random, then load tuning is needed. If you are simply missing the windage calls, get some wind flags up and prepare for a lot of practise.

Needing to change your aim several feet for wind is not uncommon for a 308.

I have load tuning tips on my website if you want to tweak your load but likely, it has more to do with wind then ammo.

Enjoy...

Jerry
 
I've seen a lot of guys blow primers out over the last couple of years so double base powders scare me, especially if you're sitting out on the range all day at +40C. After experimenting a little with RL17 and N550 I've just settled on Varget.

I run the 200 hybrids at around 2560 fps, which is more than enough to stay supersonic past 1000y. In my rifle that requires 41.8gr of Varget, which is right in the middle of my highest node so if it gets a little hot or cold I should still be in the ball park. While this is a well below my max (43.2) you should start low and work up your loads slowly.

I've read the article on Jerry's site and there's lots of really good info in there, definitely worth checking out.
 
FTRRookie said:
I've seen a lot of guys blow primers out over the last couple of years so double base powders scare me, especially if you're sitting out on the range all day at +40C. After experimenting a little with RL17 and N550 I've just settled on Varget.

I run the 200 hybrids at around 2560 fps, which is more than enough to stay supersonic past 1000y. In my rifle that requires 41.8gr of Varget, which is right in the middle of my highest node so if it gets a little hot or cold I should still be in the ball park. While this is a well below my max (43.2) you should start low and work up your loads slowly.

I've read the article on Jerry's site and there's lots of really good info in there, definitely worth checking out.
Click to expand...

Were these primer blowing loads close to max? Were they developed in cold weather?
 
Thunderstruck You might want to try powders slower than Varget for the heavier bullets. Might I suggest H4350. I am getting 2650 from the 200 Hybrids and was shoting last weekend in 35 degree weather without any issues.

Steve
 
Look at the ballistic coefficients of the bullets. problem with 30 cal is you need to go really long and heavy to get a good bc. doesn't matter if your're shooting 223, 6m, 308 or 338. the bc determines how much wind drift. if you're trying to hit a 20 inch target with a factory hunting rifle good luck. 1000 yards is where many 308 bullets drop off the map as they go subsonic. for my money, either the berger 155.5 or the 185 jug. 1000 yards is no easy ride no matter what you use so just use the time to learn what works for you.
 
I've looked at the Bryan litz bc for both the Hornady 178 hpbt and the smk 190. The problem is getting the right propellant and the charge now
 
no problem. 178 amax, lapua brass, cci-br2, lapua brass, 44 grain of varget, 2.885 oal= 2679 fps with a 11 fps spread with a 5 shot group. Bullet is above transonic at 1000 (1405 fps at 1000).

next load. 185 scenar, lapua brass, cci-br2, 43.5 grains of varget, 2.885 oal=2635 fps with a 3 fps spread with a 5 shot group. Bullet is above transonic at 1000 yards (1403 fps at 1000 yards).

That easy. Thank me later. I use em for HITS at 1000 yards, no problem out of a trg-22. The main thing you got to consider is getting the the bullets around 2650 fps for the 178-185 bullets to stay above transonic. 190 smk is a little stiff in the recoil department to get up to 2650 in my opinion. Might as well be using a 300wm......... better yet, trash the .308 and get a .260 remington. Rebarrel the 5R for a .260 and never worry about the battle for the magic speed and bullet weight. Soon my .308 days will be over.
 
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Thanks for the info!
Good thing i'm using similar components as you. Ill be trying these loads this weekend.

I guess its time for me to get a chrono.

Just out of curiosity, how do you measure or calculate the speed at 1000?
 
Getting a chrono can be very *very* helpful for developing 1000yard ammo.

You can use a ballistics program (I like the online http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi ). You need to enter accurate data, specifically the bullet's G7 b.c., the muzzle velocity, the air temperature, and the elevation above sea level. Among other things, it will calculate your drift, drop and remaining velocity at each distance, to a degree of accuracy quite useful for most purposes.

You don't *need* to use a heavier bullet, though the heavier bullets you list should work reasonably well. You can also use one of the higher performance 155s, e.g. the Sierra #2156, the Berger 155.5 Fullbore or 155 Hybrid.

Shooting a 16" plate at 1000y is challenging - as Maynard pointed out, it is a harder target than the 5-ring or 10-ring of 1000 yard iron sight competition targets. It takes a good rifle, with good ammo, in order to have the capability of reliably hitting that in zero wind conditions. And when there is some variable wind, it is an especially challenging target, even for a national-level competitive shooter - he'll be able to get hits on it for sure, but won't be able to hit it ten out of ten times.
 
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