Loading for .308 Win

[Wolfshead]

I have 150 grain Nosler Accubonds, nosler cases, CCI #200 primers, and IMR 4064.
This is for a Tikka T3x lite compact .308, with a 20” barrel, 1-10 twist.
Developing for a hunting load for whitetail deer, as accurate as I can get it for distances out to around 300 yds and in.

Nosler data states 44 gn min and 48 gn max.
It also states that 44 gn was most accurate load tested for 4064.

I load develop using the OCW method and it has worked well for me and my 30-06.
I take 10% off top load of 48 and start from there. Which is 43.2 grains.

Most of the other data I’ve looked at (Barnes, Hornady, Lyman’s, Hodgdons) are similar in amounts.
Hornady is somewhat different, 38.4 min and 44.9 max.
Average of the five is 42.28 min and 47.12 max.
PLEASE NOTE - I’m not interested in other powders! I know that there are others and probably better out there. This is what I have. Can’t get Varget!

I guess what I’m asking is - how low can I go to start with the load development? If the most accurate load is around 44 it seems that it will be difficult to find the “node” or sweet spot for the most accurate load if I start at 44 grains. While I realize the differences in barrel used for Nosler and my rifle but….
Is it risky going with the Hornady min load?
I’m considering, maybe, starting at the average minimum of 42.28.

interested in what others think.
Thank you in advance!

 

[JFrank]

I run a Tikka 308, most every powder and bullet end up tuning about the same.
I start at 43.6 and work up in .2 gr increments

Current load -165 btsp -44.2 gr. Imr 4064

 

[.45Coltguy]

With my .308[Rem 700/22" barrel] it was 46.0-47.0gr IMR4064/150gr Hornady Interlock FB. Accuracy was very good. MV 2800 fps over the screens. Hope this helps.

 

[Charlie98]

You are using a Nosler bullet, I would use Nosler's load data for IMR4064. It's also interesting to note, Nosler's data is with a 1:10 twist barrel... so you are in luck. The starting load of 44grn IMR4064, developing 2740fps (from a 24" barrel) would seem a reasonable load to start with.

I have gone as low as 42grn IMR4064, with a 155grn Hornady SST bullet in my 24" Savage with reasonable results, but if you drop your charge weight too much, it will show up as poor velocity and ballistics in that 20" barrel. This same load, fired from my 16" M1a, only turns in 2400fps, for example.

 

[Thomasss]

The next question you should be asking is what seating depth will you set the bullet at.
Norsler bullets can play tricks on you if you stay with exact SAAMI specs. I've found checking for run out and extending the bullet farther out will substantially improve your groups, especially in Tikka rifles.

 

[lightman]

You can't go too far wrong using the data in any of the books that you have. Using the book that matches your bullet is not a bad idea. Or you can use the average between the books that you have. There is really not a wrong answer. I find myself using the Sierra book more than any other.

 

[Mogas]

When the book says "most accurate load" that would be for the rifle they did the testing with. IMR 4064 is a fine powder for a 308 but you must find your gun most accurate load. They are all a little different

 

[Bfh_auto]

Use the nosler data. Hornady and nosler have different jacket metal. So they build pressure differently.
44.0 was my accuracy load for a 168 in a 22 inch barrel. So I'm sure you will be somewhat higher.
OCW isn't my preferred method. But it works well. Do the same as you have in the past. You have a good bullet and a great powder.

 

[Wolfshead]

Use the nosler data. Hornady and nosler have different jacket metal. So they build pressure differently.
44.0 was my accuracy load for a 168 in a 22 inch barrel. So I'm sure you will be somewhat higher.
OCW isn't my preferred method. But it works well. Do the same as you have in the past. You have a good bullet and a great powder.

thank you for your reply
I never thought about the jacket metal being different.
I would love to know your method of load development if you wouldn’t mind posting.
I use OCW as I don’t have a chronograph or access to one.

Thank you all who have replied it is greatly appreciated!

 

[Bfh_auto]

Google audette ladder test. I'm not saying it's the best. It just verified my loads as I found them. It's Impractical of your shoot at a busy range though.

 

[thump_rrr]

Just because it is the most accurate in their rifle doesn't mean that it will be in yours.
I have 2 identical rifles that like 2 very different loads.
I like doing my ladder tests at 0.3gr increments.
Especially since you don't have a chronograph I would start at around 43.5gr and work my way up.
I like IMR 4064 just as well as Varget as long as I have an idea what temp range the load was developed in.

 

[jmr40]

I have good news for you. The 308 is one of the easiest rounds to load for. I've not found a bullet, powder combo that didn't shoot good in any 308 rifle. 4064 has a reputation as one of the better 308 powders. IME I've always gotten great accuracy and was able to safely load rounds near top end with good accuracy. I suspect that you're going to get good accuracy with most any powder charge that is listed. It just depends on how fast you want to shoot it.

Its only downside is that it is one of the more temperature sensitive powders. If loaded at around 70 degrees, there will be significant velocity changes if fired in extreme cold or hot conditions. It's also one of those powders that are always available and are priced right. I like to use other powders for hunting loads that will see use in colder temps but use 4064 a lot for target loads that will only be shot at the range. But right now, powder availability is tough. Gotta use what we can find.

More good news. Tikka's also have a reputation for great accuracy. Some rifles may be accurate with only one load or bullet weight. IME Tikkas tend to not be picky and give good results with a wide variety of loads and bullet weights.

 

[Slamfire]

With a 150 grain bullet, just stop at 44.0 grains of IMR 4064.


Ruger M77 MKII 26 " Barrel 1:10 twist


150 Sierra SP BT 44.0 grs IMR 4064 IMI brass CCI200 OAL 2.760"

30 April 2008 T = 80 °F

Ave Vel = 2749
Std Dev = 14
ES = 47
High = 2777
Low = 2730
N = 10



v.good accuracy, no increased effort on bolt lift

 

[IALoder]

I've loaded a fair amount of IMR4064 in .308 for my 20" LR308. Top 3 in accuracy powders for me. Also seems to be pretty temp stable from ~80° and down. My rifle has seemed to like around 44.0 to 44.5gr with a 150gr, IIRC it was around 2750fps. I'd be more than happy with that as a 300 and in deer load. I would probably start around 43.5gr and go up in .3gr increments. You should find a good node pretty quickly!

 

[Random 8]

I've burned a lot of 4064 in this cartridge with 150 grain bullets and find 45 grains to be about the top end of comfort. Recoil and blast get a little sharp past that point.

My wife's rifle runs 44 grains with a Speer 150 SP. It is a deer hammer.

 

[Nature Boy]

A lot of folks have found the magic with IMR4064 but I wasn’t one of them. For me it’s H4895, Varget and RL15, in that order

 

[.45Coltguy]

A lot of folks have found the magic with IMR4064 but I wasn’t one of them. For me it’s H4895, Varget and RL15, in that order

All very good powders for the .308 Win.

 

[Pulldeaux]

On a 1-10 twist 308 like 168gr and keep a little long oal for bolt guns .

 

[Wolfshead]

I went to the range on 8/14 and here’s the low down from that day.
I WAS able to get a couple of pounds of Varget from a person on the forum who lives near me!
VERY fortunate there and a really nice guy, thank you!
After looking at the data from various sources, Barnes, Lyman, Hodgdon, Hornady and Nosler, I decided to use Nosler’s data.
Started at 42.5 grains their min, added 2% to get the next three loads. Then added .3 grains to get one measure over the max load of 46.5
Load weights were
42.5
43.4
44.2 these three are the sighters.
3 rounds each of the following
45.1
45.4
45.7
46.0
46.3
46.6
I struggle reading the results of OCW but I’m going to add what I have and my thoughts.
Im shooting a Tikka T3x lite compact with a 20” barrel.
Shooting 150 grain Nosler Accubonds and Nosler cases.
Hodgdon Varget powder
CCI #200 primers
111 yds because that what my range has set up.
Sun and clouds west wind at 90degrees to target 8-10 mph, 67-71 degrees.

As you look at the target please note that the top right circle is #6 and 46.6 grains
I know it is confusing. I should have put it together better and then labeled it different but it is what it is….sorry about that.

I feel that 45.4 the scatter node as it is poi low and before the poi shift which would make it the scatter node? And it is 1.5 grains from 46.0 which I believe is OCW? because it is a relatively tight group in comparison to the other groups and, the next group of 46.3 triangulates the poi of 46.0 which is also an indicator of OCW?
Also have another scatter node at 46.6 which is 1.5% higher than 45.9 or (46.0).
That is how I understand it.

 

[Wolfshead]

I was able to get to the range again yesterday after the last four days of rain.
I set targets out at 111 yds, 204 yds, and 303 yds.
I’m not sure why they’ve used these distances but that is how the targets are set up at the range where I’m a member.
I shot a three shot group which consisted of 45.9, 46.0, and 46.1 grains of Varget in Nosler brass at 111 yards.
The last shot I was not ready for so I would call that a pull and it is the one I actually hit the Red Bullseye.
Then I shot a three shot group of 46.0 at 303 yds.
Then a three shot group of 46.0 at 204 yds.
46.0 grains of Varget in Nosler brass and CCI #200 primers.
At 204 yards, the right hand low shot was my first shot, and I was not ready for that shot either, as I’m getting used to this new rifle and new trigger.
The last three shots were at 111 yds we’re at 111 yds andat the center of the target using 46.0 grains of Varget but with Starline brass to see what effects would be with different brass.
I had meant to do three shots of 46.0 with Nosler brass at 111 yds also but I must have had a mental lapse and did not load those.
My scope is a Vortex Diamondback 1.75-5 x 32.
This is to be my stalking rifle in the big woods where ranges, most likely will not be much over 100 yds.
I’m pretty confident with these results for the up coming season.
I will do more to dial my scope in but I am going with this load as it stands for now.
Thank you all for your help and advice along the way, it is greatly appreciated.
AND, hopefully I’ll be posting some results later this fall!

 

[JFrank]

I must have a different understanding of the OCW method.

 

[Blue68f100]

I must have a different understanding of the OCW method.

I'm with you on that. With OCW your looking at the least vertical spread. I would have picked 45.4 gr to work around. What he did was more of a ladder test.

 

[JFrank]

I would reshoot this one, 43.8-44.0-44.2 -44.4

Added. The reason I say that is two fold and not to be snarky, one is that I know that rifle somewhat but the main reason is the point of the optimum charge window is defined by minimum shifting of group centers and that is not what we see here.
Respectfully
Jim

 

[Wolfshead]

I must have a different understanding of the OCW method.

I'm with you on that. With OCW your looking at the least vertical spread. I would have picked 45.4 gr to work around. What he did was more of a ladder test.

I’m all ears!
Please, explain more!
Seems few people know OCW or are willing to talk much about it.
Definitely not taken as snarky!
I’m not opposed to learning and, as I said, “I struggle with reading OCW”. So if you can help, I’m more than interested in learning more!
Not sure I’m clear on “least vertical spread”?
Jim, could you talk more about the minimal shifting of group centers?
Blue68f100, could you explain more why 45.4 is the group you would pick?
Gentlemen, please, I would like to be better and if you can help to that goal that would be fantastic!

 

[JFrank]

Well now that I’ve opened my big mouth. Your bottom row of groups does somewhat display centers on the same vertical plane, ( note the center line on the target) so that is the concept. Make no mistake about that however your best to ensure repeatability at greater distances and that’s where the load starts moving as noted on the last targets.
I may be all wet but that’s what I see.. I would still go back and review the 44. area