I Have Issues! .308 Win Problem

[Rharris]

Need the pro's to weigh in as I'm about to pull what little hair I have out! I've been loading .308 Sierra 168gr MK with 43.0gr Varget, CCI 200 and consistently grouping 1/2 MOA or better at 300 yards, however, can't shoot a 1 MOA at 600 yards. Muzzle vel is running about 2595 so I really feel I'm still transsonic at 600. Neck tension is .001 - .0015", ES and SD are at single digits (or very close). I just think that a great 300 yard load should be a good 600 yard load. Thoughts?

Second problem, loading on a Forster Co-Ax with their micro seating due. All cases trimmed to same length. My issue is the variance I'm seeing in seating depth. It is very frustrating to set the Die up to seat to 2.250" and one is fine and the next seats .003 - .005" over or under! To get it right I have to back up .005 - .007" and creep up on the target length. Sometime when I need .003" and rotate dial 3 clicks it's spot on. The next time those same 3 clicks might equal .005" or may only move it .001". It makes no sense to me.

Thank in advance for help with these problems.

 

[snert]

Answer to part two:

Of course your cases are all the same length. But the distance from the base of the bullet to the ogive (or better...the place your seater strikes the bullet) is different on each bullet. Basicaly what I am saying is the place your seater strikes the bullet changes because the exact point each bullet reaches that arbitrary diameter varies.

You can seat all of them the same, (measuring from the base of the case to the land bearing point by doing the follwoing.

Establish ow long you want the base of case to land bearing point to be (that place where the bullet will bear against the lands), typically an arbitrary number either at the lands or some amount off the lands of YOUR rifle.

Use a T7 press. Set your adjustable seat die in one hole. Put an instant indicator in the other.

Set the seater to make a cartridge long. seat a bullet. Switch the T7 to the Instant Indicator, take a reading of "how long". Subtract the length of the cartridge you WANT from the cartridge you just loaded. The difference is the number you dial into the adjustable seat die (down). Dial it in, seat again and you have a cartrige set up to the overall length you want (to land bearing point) regardless of the difference in each bullet.

Regarding the rest of your question, I have no idea.

 

[DRNewcomb]

..... Muzzle vel is running about 2595 so I really feel I'm still sub sonic at 600. .....

Did you mean to say, "supersonic"?

 

[Richard Coody]

i would look for a higher velocity load. my .308 with 168 gr. berger hybrids likes 44 gr varget.

are you measuring base to ogive or base to tip? i use a co-ax and forster benchrest seater and i haven't changed the setting since i found my seating depth. i would say your measuring tecnique is where your problem is. or possibly poor consistency operating the press.

 

[DirtySteve]

Well the only thing I can add is I absolutely hate the 168 SMK for anything. The 175's have a lower BC and are better suited for long range shooting. They stay SS beyond 1000 yds were as the 168's won't make it that far. I know you are shooting 600 but still use a bullet better suited for the task. The Lapua 155's are also a good choice. Try 175 gr SMK and 43.5 grs of Varget. I have not seen a rifle that will not shoot that load well.

 

[Shynloco]

i would look for a higher velocity load. my .308 with 168 gr. berger hybrids likes 44 gr varget.....

I fully agree with Richard. Generally speaking and upon the recommendation of one of the bulletsmiths at Sierra I spoke to a few years ago, the 168 gr HPBT is out of it's league when shooting beyond 500 yds. As Richard wrote, it has been suggested to me as well that I try out the Berger 168 Hybrid if I'm shooting at 600 yds. With a Sierra bullet, you'll need at least a 175 gr to go that distance and group decently.

And as for you Seating issue, I suggest you consider using a Wilson Seater die and forget using the big presses to seat your bullets. You''ll Sdeayer quickly see there is very little variance using the Wilson Seater or comparable die along with an Arbor Press.

Alex

 

[Texas10]

How, and how often are you annealing your brass? Work hardened necks, and springy shoulders will make precision seating guesswork at best.

 

[Papa Charlie]

I tired everything with the 168 SMKs but when I switched to the Berger 185 Juggernaut is when the group at 500 got to 1 moa. That is with a stock Remington Varmint barrel.
The SMKs have way too much variability to them. Weight, ogive and length. Not worth it as far as I am concerned.
Also are you annealing your cases? I annealing every firing to be sure I have consistent neck tension and seating depth. Consistent bullets and neck tension are critical to seating depth.

 

[Rharris]

Did you mean to say, "supersonic"?

Whoops, yes - supersonic.

 

[Rharris]

Ba

i would look for a higher velocity load. my .308 with 168 gr. berger hybrids likes 44 gr varget.

are you measuring base to ogive or base to tip? i use a co-ax and forster benchrest seater and i haven't changed the setting since i found my seating depth. i would say your measuring tecnique is where your problem is. or possibly poor consistency operating the press.

Base to ogive using Hornady length gauge. I really apply great effort in my reloading technique. I believe it now it must be the inconsistency of where the seating stem meets the bullet as the Die itself is pretty simple the way it works.

 

[Nowhere Man]

Part1. 2595 is too slow I push mine at 2850 out of a 30 inch barrel.
Part 2. Snert answered as I would

 

[Rharris]

Well the only thing I can add is I absolutely hate the 168 SMK for anything. The 175's have a lower BC and are better suited for long range shooting. They stay SS beyond 1000 yds were as the 168's won't make it that far. I know you are shooting 600 but still use a bullet better suited for the task. The Lapua 155's are also a good choice. Try 175 gr SMK and 43.5 grs of Varget. I have not seen a rifle that will not shoot that load well.

Thanks DirtySteve, I will try the 175. In fact, I've just bought a box of Nosler 175 RDF thinking a heavier bullet with higher BC would help.

 

[dminn1]

While there are certainly better bullets for 600 yds and beyond, the Sierra 168 is very capable of better than m.o.a. accuracy at 600 yards and slightly beyond. As many on here will tell you a good load at 100 or 300 yards does not always hold up at long range. Load development at the range you wish to shoot, if possible, is the best way to get the accuracy level you desire at extended ranges. Search this site for some of Alex Wheeler's post on long range load development and positive compensation for some insight on this subject.

Also don't ignore the effects of wind conditions at 600 yards. Very subtle changes in wind can cause big movement on the target in both horizontal and vertical directions. A higher b.c. bullet will help you somewhat here, but you still have to stay on top of wind changes to shoot sub m.o.a. at extended ranges.

 

[Rharris]

I tired everything with the 168 SMKs but when I switched to the Berger 185 Juggernaut is when the group at 500 got to 1 moa. That is with a stock Remington Varmint barrel.
The SMKs have way too much variability to them. Weight, ogive and length. Not worth it as far as I am concerned.
Also are you annealing your cases? I annealing every firing to be sure I have consistent neck tension and seating depth. Consistent bullets and neck tension are critical to seating depth.

Good points, I've just started the annealing process and can already tell a difference in consistent feel when seating bullets. Thanks for your help.

 

[Rharris]

Answer to part two:

Of course your cases are all the same length. But the distance from the base of the bullet to the ogive (or better...the place your seater strikes the bullet) is different on each bullet. Basicaly what I am saying is the place your seater strikes the bullet changes because the exact point each bullet reaches that arbitrary diameter varies.

You can seat all of them the same, (measuring from the base of the case to the land bearing point by doing the follwoing.

Establish ow long you want the base of case to land bearing point to be (that place where the bullet will bear against the lands), typically an arbitrary number either at the lands or some amount off the lands of YOUR rifle.

Use a T7 press. Set your adjustable seat die in one hole. Put an instant indicator in the other.

Set the seater to make a cartridge long. seat a bullet. Switch the T7 to the Instant Indicator, take a reading of "how long". Subtract the length of the cartridge you WANT from the cartridge you just loaded. The difference is the number you dial into the adjustable seat die (down). Dial it in, seat again and you have a cartrige set up to the overall length you want (to land bearing point) regardless of the difference in each bullet.

Regarding the rest of your question, I have no idea.

Snert, thanks for the detailed answer and yes I agree that will solve the issue. From your reply and the others I think I can fix the problem. I'm also thinking a change in bullet is warranted too. Appreciate your help.

 

[Rsadams]

Yup they are correct.. you need to step up to a fast 175 gr matchkings... I hardly ever shoot over 400 so the 168s are fine..

 

[johnfred1965]

While there are certainly better bullets for 600 yds and beyond, the Sierra 168 is very capable of better than m.o.a. accuracy at 600 yards and slightly beyond. As many on here will tell you a good load at 100 or 300 yards does not always hold up at long range. Load development at the range you wish to shoot, if possible, is the best way to get the accuracy level you desire at extended ranges. Search this site for some of Alex Wheeler's post on long range load development and positive compensation for some insight on this subject.

Also don't ignore the effects of wind conditions at 600 yards. Very subtle changes in wind can cause big movement on the target in both horizontal and vertical directions. A higher b.c. bullet will help you somewhat here, but you still have to stay on top of wind changes to shoot sub m.o.a. at extended ranges.

Everything D said. At sea level with your velocity, you don't reach transonic untill just over 700 yards. as you go up in altitude it only goes farther out. I consider the 168 to be a good, cheap bullet for shooting under 800. Like was mentioned, good short range loads don't always hold up, and unless your wind reading is excellent, your groups are going to get bigger. I could be a sniper if I only had to shoot 300 yards, but my wind reading sucks so bad, I"m lucky to keep inside the 6 ring at 1000!

 

[C.E.Smith043]

I had an ole timer once tell me.... "load develope at the distance you plan on shooting".... i would increase your neck tension to .002" and go out to 600 yards and develope there.

 

[DRNewcomb]

I had an ole timer once tell me.... "load develope at the distance you plan on shooting".... i would increase your neck tension to .002" and go out to 600 yards and develope there.

Good theory but hard to put into practice. I'm lucky because I only have to drive 50 miles to get to a 600 yard range. Many shooters have to drive much, much farther. If I shoot 600. I need a partner in the pits, radios, etc. We both have to be approved by the club to shoot 600 without supervision. Then there's the issue of sorting out all the factors that affect accuracy at 600: wind, mirage, lighting, etc. It's much easier for me to do load development at 100-200 yards where I can work alone, see the impacts. The shorter range is much more sheltered so my chronograph doesn't blow around as much. Etc.

 

[Papa Charlie]

Good theory but hard to put into practice. I'm lucky because I only have to drive 50 miles to get to a 600 yard range. Many shooters have to drive much, much farther. If I shoot 600. I need a partner in the pits, radios, etc. We both have to be approved by the club to shoot 600 without supervision. Then there's the issue of sorting out all the factors that affect accuracy at 600: wind, mirage, lighting, etc. It's much easier for me to do load development at 100-200 yards where I can work alone, see the impacts. The shorter range is much more sheltered so my chronograph doesn't blow around as much. Etc.

Couldn't agree more. It would be great to do load development out to the range you want to shoot, IF, you could eliminate the environmental impacts on accuracy along with the shooters impact as well. However, I have not figured out how to accomplish this.
For me, it seems more practicable to do load development between 200 & 300 yards, depending on the range. My range is fairly well protected from wind by trees. Also, there is generally little to no wind in the early hours of the day. So I can assume that my groupings are more a result of the load and not outside influences.
Once you have the load, practice at greater distance, to me, seems to be more logical.
I may be wrong in this, but that's my logic.