New 308 with 1:10 20in barrel loads ideas please

[mg5035]

Hey yall...i have been loading for a 308 with a 24 inch barrel and a 1:12 twist and recently got a new rifle with a 1:10 twist and a 20in barrel...my old load was 45.7 grains of varget with 168gr seirra tipped match kings and a 2.880 oal ( sitting .010 of the lands) on lapua brass....the new rifle has a shorter chamber. It is 2.825 to the lands...My main shooting consist of targets up to 700 yards , turtles and crows up to 400 yards...WHAT CHANGE'S CAN EXPECT IN THE NEW RIFLE...ALSO I DON'T HAVE ANY EXPERIENCE WITH THE SCENARS OR BERGERS AND WAS WONDERING ABOUT TRYING THEM

 

[GhengisAhn175]

Won't be able to run 45.7 I'm going to assume.

Youre going to have to re do load development. Not much else there is to add to the post..

before tryjng scenars or bergers make sure it's something you can afford to shoot with your shooting regimen to save yourself the hassle. They're good bullets but expensive and used to be hard to get a hold of. With more competitive bullets out there might not be an issue

 

[shoot4fun]

I agree it will be best to do some testing to find the 20" "happy place". I have seen all the reports that 168 SMK will not stay stable at longer distances. I saw it first-hand with my own 20" and Federal GMM 168 gr ammo; a twelve inch group with five perfect profiles at 1000 yards. Don't give up on the 168 TMK right away though. I think the TMK is a different design and may be able to handle the trip thru trans-sonic better. At 700 yards you shouldn't have any issues with them.

 

[308Gunner]

Look in the reloading depot, but a good place to start is 43.5 grains of varget and a 175 as for 168s I give up on them awhile ago

 

[Blowby]

Load development is the way you need to go.

My 1:10-20" likes Varget and SMK 175's, F210M seated way off the lands (.050-.070)

Nodes:
Fed or Win brass
42.5 up to 700 yards
44.5

Lapua brass a little hot!!
44.9 still my go to load.

 

[mg5035]

Thank yall....Im excited ...I'm going to start with less powder...last time I started a 44.5 and worked up in .2 gr intervals. ..maybe this time I might start at 42.5 and work up .4 to find that sweet spot...

 

[rweaver00geo]

I'd stick with varget if you have enough, my 20" savage 1:10 twist likes 45 grains of varget topped by any 168 bthp or Amax and that gets me about 2650 over the chrony.

 

[Snuby642]

Tttttaaaaagggggg

 

[ReaperMedic]

On my Bergara with a 20 inch barrel, 41.7g of IMR 4064 with 175 SMKs has got me pretty comparable results to off the shelf 175 FGMM, which is sort of my goal. I like being able to buy GMM when its cheap or load my own when convenient and have pretty similar DOPE.

This load does well out to 800.

 

[Sniper260]

I have a 20 inch in a 10 twist.

175gr SMK and varget...

 

[Snuby642]

We picked up some h eldm 168's, that was available last nite.
Son wanted to replicate gmm's he has been using and try to 1 up them.
We have some cfe223 I want to try with them.

My initial guess from all my sh digging was 175 / varget, was not sure about
The short 920 barrel.

He called an inlaw that shoots prs and got exacly the same advise.

He looked at me and asked how I knew so much about 308?
I don't spend a dime without reading the hide!

Now to try and fix his crapy houge stock and remount his vortex strait. Lol
Thanks to all !

 

[JMGlasgow]

Don't overlook AR Comp powder. I got just under 2800fps out of a 22" barrel with Hornady 168 eld-m and 42.2gr. Work up to that as it was the maximum charge.

 

[Snuby642]

Took off the stock, not floating at front.
Took off the scope, not 1 drop of locktight, finger tight rings and base rail none
of it torqued at all.

2g+ worth of scope swinging in the wind like a dick on a dog. Wtf
Bang bang bang, shit flier, ! Rinse swish repeat.
That "gunsmith" had already been fired when we reported it to management.

I can drink a 12 pack and do better than that.
He Was checking length to lands etc. having trouble.
I went over and told him it was a controlled feed aka mouser type action.
Poped the modified case round in the bolt, wow it worked. Lol

My own bad for feeding him nothing but Remingtons as he grew up.
10 hr shifts wife and 2 sons he is a little ragged some days.

Noticed he has a Sendero profile not 920 but should be ok.
Running his nicely cared for first fired brass now in the tumbler.
Left him with a pile of parts too clean for assembly tomorrow.

 

[perttime]

Would it make any sense to use a different powder, depending on barrel length? Like one powder getting best results at 24 or 26 inches of barrel, and something else at 16, 18 or 20 inches?

 

[OLD308]

From 16”-26” barrels from 1-8 twist to 1-12 twist for pure accuracy Benchmark powder if velocity is a non issue. When velocity is an issue 8208XBR. 175 SMKs in everything due to price and consistency of Preformance and availability. My experience, not intended to be the last word. Good luck, happy to see another 308 in the age of 6.5 and 6mm

 

[ReaperMedic]

Would it make any sense to use a different powder, depending on barrel length? Like one powder getting best results at 24 or 26 inches of barrel, and something else at 16, 18 or 20 inches?

Just a SWAG, but I would imagine different burn rates would lend themselves better to one barrel over another. Something with a quicker burn rate would be more ideal for a short barrel, maybe?