.308 load development question

[GuroChris]

I've been working on some load development for my Remington 700 .308 win.
I did the 10 shot powder charge test. here is a photo.

I found a couple flat spots in the velocity chart so I loaded up 5 each. At the low end I got a decent group but lousy ES and SD numbers.

At the higher end I got a terrible group size but pretty decent ES and SD numbers.

The load data info is in the photos. I'm not necessarily looking for the Highest velocity I can get. I'm more concerned with group size/precision since I don't shoot past 400 yds all that much.

I'm stuck with mag length or shorter for seating depth. Is seating depth testing really going to help me make a silk purse out of that sow's ear? And what increments are standard practice for testing seating depth? The bullets are 168gr Sierra MatchKings.

 

[sierracharlie338]

I suggest you toss the chrono aside and focus on groups then. I found a ridiculously accurate load by shooting groups with my 223 bolt gun. It's very slow for what it should be but shoots under half MOA at 500.

 

[Doom2]

I'm surprised 43.2 is not better. You might drop back to 43 and see if it tightens up. In FC brass that shoud be around one of FGMM loads. You might try working with searing depth on the 43.2 load.

 

[longrangehunterII]

The fact is a accuracy node, whether it's ES/SD sucks is not the tell all to what a load is doing.... Go with the smallest groups size. If you're concerned, shoot the better group out further, it will tell you the story.

 

[Dmagna]

I never liked to 10 shot thing, it has never worked for me. I am old fashioned I guess, I usually just load 3 bullets for each powder charge I want to shoot. I only really care about the SD and ES and then when I find the best group I adjust the seating depth of that particular load till it shoots. If it don't shoot I change the bullet or another component. I usually load in .3 increments till I hit my max powder charge. This method has never failed me

 

[GuroChris]

I'm surprised 43.2 is not better. You might drop back to 43 and see if it tightens up. In FC brass that shoud be around one of FGMM loads. You might try working with searing depth on the 43.2 load.

What seating depth increments do you suggest? Is 5 thou or 10 thou appropriate or are small increments like that too close together to tell what's going on?

 

[Dmagna]

Start at your max length, then load 3-5 rounds seating each group .010 deeper. I like to go with about 5 groups giving my .050 difference in seating depth. Or you can do the Berger method, but I have never had a rifle where I havnt found the seating sweet spot within .050 of the longest

 

[rustyshackleford]

Can you not try another powder or primer? With ball powder I've seen magnum primers turn your bad group into your good group and keep the low ES/SD

 

[sierracharlie338]

Start at your max length, then load 3-5 rounds seating each group .010 deeper. I like to go with about 5 groups giving my .050 difference in seating depth. Or you can do the Berger method, but I have never had a rifle where I havnt found the seating sweet spot within .050 of the longest

I agree with your recommendation but as a side note I have a rifle that was at .120 off the lands before it tightened up. Only reason I found that was due to the Berger method and the fact I was shooting VLDs.

 

[30BR]

Go 43 grains Varget at max mag length, and you're done.

 

[emp1953]

I've been working on some load development for my Remington 700 .308 win.
I did the 10 shot powder charge test. here is a photo.
View attachment 218236

I found a couple flat spots in the velocity chart so I loaded up 5 each. At the low end I got a decent group but lousy ES and SD numbers.
View attachment 218237
At the higher end I got a terrible group size but pretty decent ES and SD numbers.
View attachment 218239

The load data info is in the photos. I'm not necessarily looking for the Highest velocity I can get. I'm more concerned with group size/precision since I don't shoot past 400 yds all that much.

I'm stuck with mag length or shorter for seating depth. Is seating depth testing really going to help me make a silk purse out of that sow's ear? And what increments are standard practice for testing seating depth? The bullets are 168gr Sierra MatchKings.

Leave the chrony out of the mix for now. I'd fool around with seating depth on one of the loads that gives you the best group. I have 9 centerfire rifles 7 different calibers. All but one likes the seating depth at .020 off the lands. The one that doesn't care is a Sig 970SHR which seems to shoot the same bug hole no matter where I seated the bullet. Also, those 8 rifles all like to be dirty. and the Sig doesn't care if its bore is shiny clean or grimy grungy. I've settled on Nosler ABLR's, they've been performing well for me.

 

[Ace Quackhunter]

I've been working on some load development for my Remington 700 .308 win.
I did the 10 shot powder charge test. here is a photo.
View attachment 218236

I found a couple flat spots in the velocity chart so I loaded up 5 each. At the low end I got a decent group but lousy ES and SD numbers.
View attachment 218237
At the higher end I got a terrible group size but pretty decent ES and SD numbers.
View attachment 218239

The load data info is in the photos. I'm not necessarily looking for the Highest velocity I can get. I'm more concerned with group size/precision since I don't shoot past 400 yds all that much.

I'm stuck with mag length or shorter for seating depth. Is seating depth testing really going to help me make a silk purse out of that sow's ear? And what increments are standard practice for testing seating depth? The bullets are 168gr Sierra MatchKings.

Chris, I understand your frustration with trying to get your Remington to shoot. I had the same issues with my own and while I tossed everything and was ready to sell it and let someone else worry with it. I decided to take mine to local gunsmith and let him take a look. The first thing we found was the muzzle crown not be concentric and the bolt lugs only making contact on one lug. Since I do like the rifle and I have had 308 rifles in the past that would shoot I am going to rebuild it. The barrel will removed and re-crowned, cut off one to two threads at the chamber and re-cut chamber with custom match reamer. Replace recoil lug, square receiver, lap raceway, re-cut bolt lugs and bed the action into the stock. "Why" you ask? Because I can. It's good for my local guy, it's good for the vendors, it's good for me and good for the Ole USA. So sometime in early next year I will be at the range, knowing the 308 should be able to shoot and I will find out, if I will sell it of keep it. I have enclosed a few photos of my efforts in trying to work up a load before the rebuild.
Ace

 

[Coldfinger]

I've been working on some load development for my Remington 700 .308 win.
I did the 10 shot powder charge test. here is a photo.
View attachment 218236

I found a couple flat spots in the velocity chart so I loaded up 5 each. At the low end I got a decent group but lousy ES and SD numbers.
View attachment 218237
At the higher end I got a terrible group size but pretty decent ES and SD numbers.
View attachment 218239

The load data info is in the photos. I'm not necessarily looking for the Highest velocity I can get. I'm more concerned with group size/precision since I don't shoot past 400 yds all that much.

I'm stuck with mag length or shorter for seating depth. Is seating depth testing really going to help me make a silk purse out of that sow's ear? And what increments are standard practice for testing seating depth? The bullets are 168gr Sierra MatchKings.

Don't get stuck on speed or the other complications like SD. The .308 isn't a speed demon to start with. I chase groups till I get what I like. Rarely do I worry about the speed unless I'm planning on heading west and want to look up ballistic data to get me on paper at my self defined max ranges. I love 4064 in my .308 and it's one of my most neglected powders. Depending on barrel temperatures your groups do odd things. I try to shoot 3 shot groups. I happen to have a great shooting hunting rig that I decided to run a full 10 round magazine through as fast as I could just to see what happens. First pic is 3 @100. Last pic is 10@100 those are 1/2" square grids. Either an ok 5 round group and 5 missed the paper or a great 10 round group imho! Sierra 155 grain mk IMR 4064 Winchester brass and CCI BR2 match to light it!

 

[Coldfinger]

I'm surprised 43.2 is not better. You might drop back to 43 and see if it tightens up. In FC brass that shoud be around one of FGMM loads. You might try working with searing depth on the 43.2 load.

I'd also tweek the seating depth on that load of 43.2.