Wednesday, January 13, 2010

Range Report

I didn't end up on travel after all, but this is the first opportunity this week that I've had to get some blogging done.

Last Saturday morning I set out to test some handloads for the 308, and I had been planning this range trip all week. I have been diligently trying to copy the 175 grain Federal Gold Medal Match rounds, so I had a dozen of those loads as that is the number of FGMM brass casings that I had left after culling the damaged ones. I had made ten loads of 175 grain Sierra Match Kings on top of 45 grains of Varget, which is a popular load amongst 308 shooters, so I thought I'd give that a try. Also I had some 168 grain Hornady Match bullets pushed by 44 grains of Reloader 15 that I was interested in trying out.

So how did I do?

Well, first of all I'd like to give a big fuck you shout out to the retarded weatherman who posted winds of 2-6 mph NNW on How about those 20 - 30 mph gusts, or the 10 mph constant wind on Saturday, huh? Slip your mind? Find a new career you moron. You don't have what it takes.

The temperature that day was 19 degrees when I left the house, and it had been cold and windy all week. I picked Saturday because the Yahoo weather report said the wind was going to be mild. At the 100 yards I was shooting, it had little impact on my shots, but my gear was blowing all over the place. Since Reloader 15 can be temperature sensitive, I kept all of my rounds warm in my truck, and loaded five rounds into a magazine right before I was ready to shoot. I don't want to have rounds be good to go with no pressure signs, only to find out this summer that they are too hot when the temperature increases.

I started off by shooting the Varget loads, and I really didn't have high expectations for them. I was shooting off sandbags, which turned out to be a real problem. Ever since the Harris bi-pod fiasco this summer, I've been taking them off and stacking the Brownell's sandbags in the front, and using a sand sock in the back. What ends up happening is the sling swivel in the front of the rifle acts as a small tooth that digs into the long and skinny sandbags, making them more and more unstable with every shot until they topple over. My first five shot group of the Varget rounds were all over the place, and with the last shot the bags fell over and the muzzle hit the bench. The group measured about an inch and three quarters.

After re-stacking the bags and flattening them down to make them more stable, I again fired the Varget rounds, laying out a three quarter inch five shot group. Every shot felt solid; but what made me smile was that four of the five rounds went into a quarter inch! Unfortunately, I didn't have any more of them to test that day. Even better than that, my velocities averaged at 2,658 fps out of the 20" Krieger barrel, which is 10 fps shy of my 155 grain load, admittedly a pretty mild load to begin with. These 175 grain SMKs are obviously heavier, but they also have a higher BC, making them a better choice for down range power. ES was 16 fps, and the SD was 8! Who could ask for better than that?

Next up was the FGMM clones. There are still some pending questions about this, like why do the 175 grain SMK bullets from the factory rounds measure different than the 175 grain SMK bullets that are sold for reloading? My loads shot right at true MOA, being 1.047" at 100 yards; my two five shot groups were 1.04-something at 97 yards from the muzzle. For speed, I've clocked factory 175 gr FGMM at 2,521 fps on average from my rifle, and that was my target velocity. I came pretty close. There are many shooters who believe that Federal Cartridge Company change their FGMM load recipes to keep people from duplicating them, and that their secret to accuracy lies in the Optimal Barrel Timing theory: the theory that a fired bullet leaving the barrel at a precise moment will take advantage of the muzzle being as close to a rest in the vibration cycle as possible, resulting in more accuracy. This goes hand in hand with the Optimal Charge Weight theory, which as far as I can tell is a sound principle. In any case, my average velocity was 2,505 fps, with ES and SD at 28 and 11 fps respectively. Not bad for a first try. The cases were once fired FGMM; the primer was CCI BR2 (Federal uses some sort of "Gold Medal Match" primer in their factory loads that different from the ones sold to the public); and powder charge was 42.5 grains of Reloader 15.

Now I have a legitimate race between the Varget and FGMM clone loads. I care the most about consistent accuracy, vice speed; but if I can get that sort of consistency and accuracy from Varget, and 130+ fps to boot, why would I bother fiddling around with the Reloader 15? Well, for one, it would be cool to finally solve the puzzle of what exactly is in Federal's flagship match cartridge. It can't be fairy dust making them shoot so well. Also, some shooters - myself included - like to have a load that is not near maximum pressure and all to save on barrel life, as well as to ensure that there won't be a pressure spike if you're shooting in the sweltering heat. So I think since I came so close with my first shot at it, I'm going to bump my powder charge a couple of tenths of a grain to see if that does the trick. I'm not the only guy who's measured the powder charge in FGMM rounds, and others have reported slightly heavier charges.

The last rounds I shot were the 168 grain Hornady loads, which shot just under an inch. I don't have the exact group measurement handy at the moment, but velocity averaged a sedate 2,500 fps. It's a starting point if I want to pursue 168 grain loads. I mostly loaded them because I had a box of them sitting around, and I thought what the hell. I'm not a fan of 168s for the 308, as I think there is more of an advantage in using 175+ grains, or driving 155 grainers at high velocities; but these Hornady bullets are really nice. They seem longer than others of the same weight, and if I can get them to shoot well, than why not use them.

I have 20 more of the Varget rounds loaded up, and plan on some more shooting this weekend out to 350 yards. I want to give them another go beforehand, to see if they are the ones I should be taking. If not, I may try to OCW them this weekend instead, which is really the 100% solution for the perfect load for this gun. Time will tell. I do have a Shooters Ridge bag type rest now, which will give me the height that I need to shoot the 308 without precariously stacking a ton of sandbags in the front of the gun. I also intend to shoot my AR15 some because I want to use it to slay some coyotes and bobcats the rest of the winter. First I need to load some of my accurate 223 recipes this week so that it will actually shoot where I want it to. I've been loading zombie fodder for that gun for far too long, and those are not what I want to be using.

I'll give another report after this weekend. Stay tuned.
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