The .308 mantra...

DaveID

Student of Life...
Jan 5, 2018
3
2
3
Virginia
#1
My goal is to develop a very accurate target load, not a hunting load. I know, .308 is far from the ideal target bullet, but this is my first bolt gun, and this caliber is what I chose and what was suggested to me. I understand that every rifle and component is different, and will yield relatively different outcomes, and your loads are just suggestions. Regardless of what powders and bullets I have on hand, I am interested in the kind of loads that have worked for you, with similar length barrels and the same or similar twist rate.

My rifle: 26" barrel, 1/10 twist

Bullets: (on hand), but open to suggestions.
168gr. HPBT, Sierra
175gr. HPBT, Sierra
168gr. HPBT Hybrid, Berger

Powders: (on hand), but open to suggestions. Not all powders below were purchased to reload the .308.
IMR: 4898, 4320, 4166
H: 4895, Varget, Benchmark, 4198
Alliant: RE-15
Vihta Vuori: N540

Cases: (on hand)
Federal: from Gold Medal ammo I bought/shot.
Lapua: I fire formed them already.

Primers: (on hand), suggestions welcome.
CCI: larger rifle, BR-2

I just got a Pro Chrono to develop an accurate load. I have been using Lyman's 50th handbook, but can you suggest links to data with relative ideal velocities for the bullets I listed, or bullets you suggest? I see ranges in velocities in Lyman's 50th reloading handbook, and if you prefer something other than that, I would be interested in the source. Every powder, bullet and reloading book comes up with different numbers for the same powder loads, etc., and interested in data others refer to.

Thanks!
 

Skookum

Entropy Personified
May 6, 2017
1,134
1,094
113
Your mom's
#3
There are many good combinations with the components you have listed. Every rifle being different, as you noted, your sweet spot will likely be just a bit different. That being said, there is a narrow range that has worked in innumerable rifles with certain combinations.

With Varget and the 175g Sierra, the sweet spot for the high speed accuracy node most often shows up between 43.5g and 44.2g. Overall length of 2.8" - 2.810". Federal and Lapua cases have similar case capacities so the load won't vary much between them. This is an extremely forgiving combination.

With the above components and overall lengths, IMR 4320 is very likely to be in the same range, as Varget and IMR 4320 have almost identical burn rates.

The 168g Sierra often shoots it's best in the same powder charge range as the 175's though it will be slow compared to what you could get from max charges. For some reason the 168 Sierra's don't respond well to being pushed hard.

4198, and Benchmark are too fast to be optimal with the bullet weights listed.

With 4895, your best loads with the bullets listed are most likely to be between 42g and 43.5g.

None of this is meant to be taken as absolute, but this represents the range that I have seen work well in a multitude of rifles. All of these combos are well within SAAMI spec.
 
Likes: DaveID

1J04

Morale Officer
Aug 7, 2011
10,196
7,458
113
PACIFIC NW
#5
How did the FGMM shoot? Did you try both 168 and 175 SMK's? I don't think you can go wrong sleuthing it and tweaking it to your gun.


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Likes: DaveID
May 8, 2013
207
55
28
Portland
#6
How did the FGMM shoot? Did you try both 168 and 175 SMK's? I don't think you can go wrong sleuthing it and tweaking it to your gun.


<iframe width="560" height="315" src="
" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
How did the FGMM shoot? Did you try both 168 and 175 SMK's? I don't think you can go wrong sleuthing it and tweaking it to your gun.


<iframe width="560" height="315" src="
" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
I tried that a couple weeks ago. To me it seems FGMM has come up with a different propellant. Pulled bullets from 168s and 175s, weighed change, 40.0 for 175s, 40.1 for 168s.

FGMM 168 = AV 2626. SD 6.4
I didn't load to match this. Just testing.

FGMM 175 = AV 2569. SD 9.7
My load 40. 4064,
175 SMK = AV 2452. SD 15.6
So now I'm just loading up with another powder (rl 15) to get up to speed between 2560-2600.
So I think in the last 4 or 5 years something changed? By the way , as everyone knows) FGMM has got it together.
 

demolitionman

Sergeant of the Hide
Feb 26, 2013
1,114
352
83
Ohio
#8
If your going to shoot past 900yards, the 168's start doing some weird transonic stuff that makes for all of head scratching.... At least at my DA.
 
Likes: DaveID

DaveID

Student of Life...
Jan 5, 2018
3
2
3
Virginia
#9
Dave, did you spend any time looking through this thread? Here:
https://forum.snipershide.com/threads/308-winchester.135/unread

19 pages of .308 loads used by people here with speeds and other good information.
Thank you: "lash", "Skookum", "KZP", "1J04", "GONE BAD", "Greg Langelius" and "demolitionman", for all of your info, input, and links. Work has been busy and I have been hard pressed to make time to get back with you all, or for much shoot'n to tell the truth.
After reviewing info some of you guys added, it has been a help in developing a good load. I did not use my (cheap ass) chronograph with this round of shooting, so my opinion is more or less strctly "opinion", in regards to velocity, etc., but I had very good accuracy from my RE-15, using 45.5 gr. loads, using the Sierra's HPBT 168 gr. bullets, with Lapua brass, CCI B-2 primers, and plenty of sweat equity on my brass (as per needed)....
 
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