Reloading a .308 208gr

glockgrouptherapy

glockgrouptherapy

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So if any of you saw my thread in general firearms about my first time goin out to 850 yards you know I was using 168gr SMK's and I couldn't hit that 1250yd gong.
well I grabbed some heavier bullets today and I just realized that I don't have any load data in any of my books for the 208gr Hornady Amax for using Vhirtouvi N-135.
Now I have been looking at the powder lists ranked by burn rate in the front of the Hornady reloading manual, and im looking at what is closest to that powder on the chart and figure I would run a couple grains lower to play it safe. for example: Hornady book says that for the 208gr Amax IMR4064 start load of 36.2 grains. on the Burn chart 4064 is #85 and N-135 is #83. So if the theory is right I should be able to run a grain or 2 lower and be safe, no?

Anyone recommend a better way or know of a good load to start with?

much appreciated,

Steve
 
Something is wrong with the burn rate chart. VV N-135 is a pretty quick powder, there's no way it would be immediately next door to 4064.

The reason that you found no load data for N-135 behind a 208 grain bullet in a .308 Win case, is that N135 is such a fast powder that it is not a good or useful combination.

What rifle powders do you have on hand that are slower than N-135? Do you have any Varget, H4895, Win-748, 4350, N140, N150?

If you plan to shoot this at long range (and 850 or 1250 yards would certainly count!), it would be worthwhile to:

- work your load up to max. Not because you need/want the velocity per se, but oftentimes loads get more accurate and more uniform as you get hotter.

- chrono your ammo. Try to pick/select/develop a load that has muzzle velocities as uniform as possible (SDs under 15fps if possible). Plus, know your muzzle velocity will help you prepare a meaningful and useful ballistics table, so you'll be able to get on target at long range a lot quicker than just (semi-)blindly poking around.
 
Powders kinda scarce around here. Most of my other loads had data for n135 so I picked up a couple cans to tie me over until things got better. I think the local store has n-140 and 150 in stock.
 
Just rolled 50 last night for a ladder test.

From my research most use a slow powder like Varget or RL17 (which is what I used).

Can't comment on your Vit. powder. There may have been a comment or two about it on the Sniperhide forum thread about 208gr in 308.
 
I feel compelled to mention that be safe with whatever you use.

As you mentioned, a slow powder must be used. Not sure what you are using, but even low powder chargest of a fast powder could make a very high pressure spike. That 208gr slug isn't going to accelerate nearly as fast as a 155gr. Basically just saying a lower charge might still be unsafe.

Varget is very hard to come by these days, but Reloader 17 is an odd powder. Not used by many (but that's changing). It's also not on most shop's order list so that makes it even more difficult to find. Varget and RL15 tend to be the most common choices for .308. (I have not heard anybody using RL15 for 208's though)
 
"...couldn't hit that 1250yd gong..." That's not caused by the bullet. A 20in barrel might be your issue. Too much velocity loss. That's why proper target rifles have longer barrels.
 
I just started running 208's out of a 20 inch barrel sitting on top of 46.3 grains of RL17, its compressed. (to say the least) I haven't chronied it yet as I'm still doing a bit of testing. As far as I can tell from my actual drop, I am around the 2500 fps mark.
I don't think your 20" barrel is the determining factor in hitting or missing at 1250.
Some one correct me if I'm wrong, but isn't the 168 SMK notoriously terrible once it gets out around 1000Y compared to other 168 grain bullets?
 
sunray said:
"...couldn't hit that 1250yd gong..." That's not caused by the bullet. A 20in barrel might be your issue. Too much velocity loss. That's why proper target rifles have longer barrels.
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Along with your comments about muzzle brakes, you are dead wrong.

20" barrel will have absolutely no issues hitting 1250y +.

Muzzle brakes are annoying at ranges, but not everybody shoots at a range, and yes, they are VERY useful on .308's to see your hits/misses.

I'm not certain the details behind using faster powder in shorter barrels, but if it were me, I wouldn't try it. Not worth the risk. The pressure is still there to get the bullet moving. A fast powder will "flash" causing those pressure spikes to be higher no matter the barrel length.

168 SMK's were designed for shorter ranges, but that's because they lose stability once dropped out of velocity. Lots of people use them out to 1000 where they are still moving fast enough. Are they the perfect bullet? Maybe not. Do they still work? Probably.

Long range favours projects like 175 SMK's, 178 AMAX, 208 AMAX, 155 Scenars, etc.

My info may not be 100%, but better than saying all brakes are bad, brakes on 308's are not needed, and 20" barrels can't shoot past 500 yards.

Last weekend I targeted at 15" gong at 1000yards in 2 shots. I then rang it 3/4 times in a row. Sure that's more than 1MOA, but it was easily done with a 20" barrel. 26 MOA, 5200 ft, 24 degrees, 102 kpa, average humidity and admittedly very low wind.
 
I know through interweb diggin that the smk without proper propellant it'll hit sub sonic just before the 1000m mark and begin to tumble. I figured that the non hits were either due to that or I had proper speed but not enough elevation adj on the scope. I had some berger VLDs in 190 and at 850 they were doing just fone sitting on top of 35 gr of N-135. There's no load I found for this bullet with this powder but it did produce 3 shot groups that printed on top of each other to the point where it was almost debateable to say it was one hole @100yds. I set those @2.227in from the ogive which is about .020 off the lands if I remember. The reason goin to the 208gr pill is the schooling of a heavier mass holding speed over a longer period thus achieveing a suitable load for that 1250yd shot.
 
Shibby! said:
My info may not be 100%, but better than saying all brakes are bad, brakes on 308's are not needed, and 20" barrels can't shoot past 500 yards.
.
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There is a vid on youtube that shows 2 guys running 20in remingtons out to 1000+ yards so i know it can be done its a matter of finding a powder in this market to do it lol
 
glockgrouptherapy said:
There is a vid on youtube that shows 2 guys running 20in remingtons out to 1000+ yards so i know it can be done its a matter of finding a powder in this market to do it lol
Click to expand...

All common, and proper powders will do it with absolutely no issues.

20" barrel has NO PROBLEMs shooting 1,250yards.

Bullet selection is more important than barrel length in this discussion. I don't know anything about the VLD's, but I bet that 190 would do 1,250y without issue.

What a 208gr will do is give more energy at that distance. Make for a louder ring of the dong, or take down power if shooting at an animal (which I don't advise at that distance)
 
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