How to find most accurate 308 load 168gr SMK vs A-Max, Varget vs IMR-4895

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adrenaline681

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I want to find the most accurate load for my 308. I purchased 100 Hornady Amax 168gr and 100 SMK 168gr. I have 2 powders Varget and IMR 4985.

The gun range I go to is like 1.5 hour drive from my home so I would like to test as much as possible when I'm there.

I was thinking I could load 50 bullets of each brand using Varget and 50 of each using IMR 4985. Doing 5 increments of powder every 0.5gr. 2 groups of 5 shots per increment.
I thought that shooting 2 groups of 5 will give me a better average since a "lucky small group" can deceive you into choosing a load that might not be very consistent when you shoot more groups.

I would be loading using Winchester once fired brass in my bolt action, neck sized only and CCI primers. OAL 2.800".

So something like this:

SMK (100 bullets)
-Varget:​
  • 43.5gr (2 groups of 5 shots = 10 shots)
  • 44.0gr (2 groups of 5 shots = 10 shots)
  • 44.5gr (2 groups of 5 shots = 10 shots)
  • 45.0gr (2 groups of 5 shots = 10 shots)
  • 45.5gr (2 groups of 5 shots = 10 shots)
-IMR 4895:​
  • 43.0gr (2 groups of 5 shots = 10 shots)
  • 43.5gr (2 groups of 5 shots = 10 shots)
  • 44.0gr (2 groups of 5 shots = 10 shots)
  • 44.5gr (2 groups of 5 shots = 10 shots)
  • 45.0gr (2 groups of 5 shots = 10 shots)

A-Max (100 bullets)
-Varget:​
  • 43.5gr (2 groups of 5 shots = 10 shots)
  • 44.0gr (2 groups of 5 shots = 10 shots)
  • 44.5gr (2 groups of 5 shots = 10 shots)
  • 45.0gr (2 groups of 5 shots = 10 shots)
  • 45.5gr (2 groups of 5 shots = 10 shots)
-IMR 4895:​
  • 43.0gr (2 groups of 5 shots = 10 shots)
  • 43.5gr (2 groups of 5 shots = 10 shots)
  • 44.0gr (2 groups of 5 shots = 10 shots)
  • 44.5gr (2 groups of 5 shots = 10 shots)
  • 45.0gr (2 groups of 5 shots = 10 shots)


After shooting all this I could probably get a good idea of what my rifle likes the most.

I know most people use only Varget but I read some people had really good results with IMR 4895 and I have several pounds of it so i thought I could test it also.

Do you guys think this would be a good way of testing? Or should I just ignore the IMR 4895 and do more grain intervals with Varget?

Let me know what you think!
Many thanks!
 
What you are proposing is an initial survey to find out which bullet and powder holds the most promise. This is a good idea. Some rifles will show a strong preference for one bullet/powder combination. For a survey I only load 5 of each - not 10.

But the values you suggest don't make much sense to me.

What rifle do you have? Is it broken in? Difficult to do load development in a virgin barrel.

What kind of accuracy have you had so far with it?

OAL The bullets are different profiles. Why is the OAL the same? Are you limited to a magazine length?
For a survey I would load each bullet at 20 thou off the rifling.

The OAL for your rifle is determined by your mag length and the chamber throat in YOUR rifle. Each rifle is different. And the throat erodes as you shoot it, so each year you might find you have to seat your bullets longer.

Load a round with the stem backed out a few extra turns, so that the OAL is around 2.900. Does this chamber ok? Probably not.
Now turn the seater a quarter rev deeper, and seat the bullet a bit deeper. Does chamber or get rifling marks?

Load another round and seat the bullet another quarter rev deeper and try that. Keep doing this until a round chambers without rifling marks. Each quarter rev seats the bullet about 12 thou deeper.

Then load one more round, seated another quarter rev deeper and measure it. That is the max OAL for that exact bullet.

Make a note of that OAL in your log book. It is about 20 thou off the rifling. Now take all the "long" rounds you have made and seat them to the new setting.

Repeat this process with the other bullet. A typical OAL for these to bullets is about 2.825 for the Sierra and 2.850" for the AMAx.

Powder Charge. Where did these come from? The 4895 charges look like the powder charges for a 150 gr bullet.

I suggest you drop the 4895 range by 2 grains and the Varget by 1 gr and be prepared to bring ammo home if you hit pressure signs.

Why the Sierra 168? The Sierra 175 is the same bullet with a better boattail, so it will shoot better beyond 300 yards.

What is the objective for the rifle and ammo? What do you hope to use it for?

What distance are you going to test at? What scope on the rifle? Does it have an adjustable objective?
 
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Ganderite said:
What you are proposing is an initial survey to find out which bullet and powder holds the most promise. This is a good idea. Some rifles will show a strong preference for one bullet/powder combination. For a survey I only load 5 of each - not 10.

But the values you suggest don't make much sense to me.

What rifle do you have? Is it broken in? Difficult to do load development in a virgin barrel.

What kind of accuracy have you had so far with it?

OAL The bullets are different profiles. Why is the OAL the same? Are you limited to a magazine length?
For a survey I would load each bullet at 20 thou off the rifling.

The OAL for your rifle is determined by your mag length and the chamber throat in YOUR rifle. Each rifle is different. And the throat erodes as you shoot it, so each year you might find you have to seat your bullets longer.

Load a round with the stem backed out a few extra turns, so that the OAL is around 2.900. Does this chamber ok? Probably not.
Now turn the seater a quarter rev deeper, and seat the bullet a bit deeper. Does chamber or get rifling marks?

Load another round and seat the bullet another quarter rev deeper and try that. Keep doing this until a round chambers without rifling marks. Each quarter rev seats the bullet about 12 thou deeper.

Then load one more round, seated another quarter rev deeper and measure it. That is the max OAL for that exact bullet.

Make a note of that OAL in your log book. It is about 20 thou off the rifling. Now take all the "long" rounds you have made and seat them to the new setting.

Repeat this process with the other bullet. A typical OAL for these to bullets is about 2.825 for the Sierra and 2.850" for the AMAx.

Powder Charge. Where did these come from? The 4895 charges look like the powder charges for a 150 gr bullet.

I suggest you drop the 4895 range by 2 grains and the Varget by 1 gr and be prepared to bring ammo home if you hit pressure signs.

Why the Sierra 168? The Sierra 175 is the same bullet with a better boattail, so it will shoot better beyond 300 yards.

What is the objective for the rifle and ammo? What do you hope to use it for?

What distance are you going to test at? What scope on the rifle? Does it have an adjustable objective?
Click to expand...

I have a Tikka T3x CTR 20 inch barrel. Viper PST Gen2 5-25x FFP. All my groups are shot at 100m. I've shot 300+ rounds through it. With Hornady 150gr FMJBT I was able to get around 1-1.2 MOA with 44gr of IMR 4895 and 2.800" OAL. I also tried shooting Federal Gold Medal SMK 168gr and I got around 0.6 and 0.7 MOA at 100m and 300 yards.

Yersterday I tried to find the lands by putting a bullet with little neck tension and closing the bolt. finally messuring the OAL afters but i was getting inconsistent results...I also tried using a marker and painting the bullet and trying to look for marks, but I couldnt find riffling many marks on my bullets. Maybe I was not long enough. I got a bit desperate and decided to go with 2.800" which lots of people say that seems to shoot those bullets very well. Probably I will have to spend a bit more time trying to find the lands. Will the bullets get ruined by jaming them into the rifling and then removing them? I stopped because i didnt want to waste too many bullets doing this.

I choose Sierra 168gr because for now I will not be shooting past 300yards, there are no ranges here longer than this.


For the IMR4895 charge I followed Hodgons website, I wanted to sample on the upper range to get more velocity, but staying around 0.5gr away from max charge.


Capture.jpg
 
Those max loads would be much too hot in most of my 308 rifles. Be prepared to stop shooting and bring some ammo home.

No you wont hurt the bullets by seating long and getting a rifling mark. Start at 2.9 and see if it marks. Amax might not.

A good start OAL is about 20 thou off the rifling. It will be a different OAL for each bullet.
 
Ganderite said:
Those max loads would be much too hot in most of my 308 rifles. Be prepared to stop shooting and bring some ammo home.

No you wont hurt the bullets by seating long and getting a rifling mark. Start at 2.9 and see if it marks. Amax might not.

A good start OAL is about 20 thou off the rifling. It will be a different OAL for each bullet.
Click to expand...

Found the rifling marks on my bullets! With OAL of 2.875" I get faint scratch marks on 2.870" I dont get any scratch marks. So I should be safe loading at 2.850" OAL for SMK.
I did the same with the A-Max and I got very similar results maybe 0.005" longer, is hard to tell the last 5 thou with very faint scratch marks.

Is it normal that they are both so similar? I thought that Amax should be 25 thou longer. I guess each barrel is machined differently.

Should be safe to load both at 2.850" then?

Also should I just leave the IMR 4895 for my cheap Hornady 150gr FMJ and do all my tests with Varget, ive read is better quality and less temperature sensitive?

Thanks!
 
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I shoot a lot of .308 and I also think some of those loads are pretty hot. The Hornady manual says max load for 168gr Amax with Varget is 44.0 grains. COL to me is what will chamber and shoot best, every rifle is different. I would stick with Varget, although I have also had good success with IMR 4064. I would try some lighter loads, they are often more accurate. As an example Hornady manual calls for 2500 fps for 168 gr Amax with 41.7 gr of Varget, and it has been accurate for me.
 
I typically will search out the max load and back off 10% to start at. I will increase in incerments of .3 and shoot groups of 5. If you have a lab radar or Magneto speed you can shorten the groups and just find your nodes.
I would also suggest shooting your groups at 200 to 300m and take your best from there (odds are your not missing at 100) once you get your best groupings then play with the seating depth on your favorite pick
Enjoy
 
Lyman has your 168SMK using Varget as max load if 45.7 and Nosler states max load should be 46.0
Only had the 178 Amax so can't help on that one but you should be plenty safe to start loads at 41.5 and go up from there.
I typically find that book max is never been close to max on my rifles so far but that will also depend on your brass and build.
 
If it were me, with those bullets, i would simply load Varget between 42-43gr in 0.3 gr, and then 44-45gr in 0.3 increments.
It seems as tho 99% of 308 win rifles will have a low/high node at each of those powder doses.
Once you find the node, then load 0.2 or 0.1 on either side and see what you get. My 308's seem to shoot best at 2.80-2.81 COAL regardless of distance to lands.
4895 never worked for me in that caliber, but the one rifle i have that doesn't like Varget sure does like 4064.
Oh yes - i will also vouch for 200-300yds for testing
 
I took an unprimed casing, lubed inside the neck, took a virgin bullet, lubed the outside, SLOWLY closed the bolt on the dummy round, SLOWLY ejected it, and measured the OAL. Then I backed off my seating die by 20 thou. for THAT particular bullet. For all my hunting and plinking bullets, I keep the OAL for that bullet/rifle combo in my reloading data. Given that different bullets have differing ogives, you may wish to try that when you tabulate your results.
 
Below are some of Dan Newberry's loads of OCW (Optimal Charge Weight) fame. http://optimalchargeweight.embarqspace.com/

I copied these loads from one of his posting and answering you same basic question.
https://www.tapatalk.com/groups/practicalriflerfr/the-staying-power-of-the-308-winchester-t2185.html?sid=58b16cb25d94d39dc739879306c5db31

The "staying power" of the .308 Winchester
https://www.tapatalk.com/groups/practicalriflerfr/the-staying-power-of-the-308-winchester-t2185.html?sid=58b16cb25d94d39dc739879306c5db31


All Winchester brass. Reduce by .4 grains if using Lake City, or Federal brass. Reduce by .3 grains if using Lapua brass.

155 grain Sierra Matchking (or any comparable 155 grain match bullet)
45.6 grains of IMR 4895
or 46.5 grains of Varget, IMR 4064, or W748
there is a high node with Varget at about 47.8 grains (Nosler's max is 48 grains).

168 grain Sierra Matchking (or any comparable 168 grain match bullet)
43.6 grains of IMR 4895 (my all time favorite accuracy load)
or 44.5 grains of Varget or IMR 4064 or W748
there is a high node with Varget at or near 46 grains, Hodgdon's max...
or 39.0 grains of IMR 3031 (slower, but very accurate to 300 yards, a great close range tactical load).

175 Sierra Matchking
43.5 Varget, or 45.0 Varget (high node, be careful).
or 42.4 grains IMR 4895
or 43.4 grains of IMR 4064 (high node)
42.2 grains of IMR 4064 (low node)
or 43.5 grains of RL15

With 178 AMAX (Hornady)
42.0 grains IMR 4895
or 43.1 grains of Varget

At the link below you will find more .308 reloading information, I have a Savage .308 Hog Hunter and found his short barrel testing very informative.
https://rifleshooter.com/?s=.308

9lamYPk.png


NOTE, I would start at the suggested start loads and work up and examine each case as you work up. You will learn more about your rifle and the reloading components used in load development. Look for the load where the primer becomes flush with the base of the case. This is at the point where the chamber pressure is great enough to make the case stretch to meet the bolt face. At this point pay more attention for signs of excess pressure as the load s are increased, each brand of case will have different pressure limits.

Just remember each firearm and the components used will have different limits, and "all" reloading data is only ball park information for reloading "your" rifle.

Example below, this photo is from accurateshooter.com and this long range competitive shooter would increase the load until he got brass flow into the ejector. This told him the elastic limits of the brass and he would then back the load off 1 or 2 grains and call this maximum. After this test he would look for the most accurate loads below maximum.

KtO65uH.jpg


Another method is measuring base expansion just above the extractor groove.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

Below are .308 case capacities and I'm using Lake City 7.62 cases and the effect case capacity can have on your loads.

Qvc8vVV.png
 
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bigedp51 said:
Below are some of Dan Newberry's loads of OCW (Optimal Charge Weight) fame. http://optimalchargeweight.embarqspace.com/

I copied these loads from one of his posting and answering you same basic question.
https://www.tapatalk.com/groups/practicalriflerfr/the-staying-power-of-the-308-winchester-t2185.html?sid=58b16cb25d94d39dc739879306c5db31

The "staying power" of the .308 Winchester
https://www.tapatalk.com/groups/practicalriflerfr/the-staying-power-of-the-308-winchester-t2185.html?sid=58b16cb25d94d39dc739879306c5db31


All Winchester brass. Reduce by .4 grains if using Lake City, or Federal brass. Reduce by .3 grains if using Lapua brass.

155 grain Sierra Matchking (or any comparable 155 grain match bullet)
45.6 grains of IMR 4895
or 46.5 grains of Varget, IMR 4064, or W748
there is a high node with Varget at about 47.8 grains (Nosler's max is 48 grains).

168 grain Sierra Matchking (or any comparable 168 grain match bullet)
43.6 grains of IMR 4895 (my all time favorite accuracy load)
or 44.5 grains of Varget or IMR 4064 or W748
there is a high node with Varget at or near 46 grains, Hodgdon's max...
or 39.0 grains of IMR 3031 (slower, but very accurate to 300 yards, a great close range tactical load).

175 Sierra Matchking
43.5 Varget, or 45.0 Varget (high node, be careful).
or 42.4 grains IMR 4895
or 43.4 grains of IMR 4064 (high node)
42.2 grains of IMR 4064 (low node)
or 43.5 grains of RL15

With 178 AMAX (Hornady)
42.0 grains IMR 4895
or 43.1 grains of Varget
Click to expand...

Thanks for all the info. I was going to put the IMR 4895 on the shelf but after reading "43.6 grains of IMR 4895 (my all time favorite accuracy load)" I guess I will have to do some testing with it.

Will be testing from 43 to 45 gr of Varget and from 42-44 of IMR 4895 in 0.5gr incremenst for both SMK and A-Max bullets. Since I'm loading using Winchester brass, I shouldn't have any pressure problems but I will keep an eye for it.

If I find a very accurate charge for the 168gr SMK, will it be likely to find similar accuracy node with the 168gr A-Max around the same charge? Or do I have to test the full range of charges again for the A-Max?
 
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