Savage 12 ftr 308, 30in barrel load data help

[Grand poo bah]

Hey all,

I need some help in figuring out what load to use in this weapon. I've done my initial run and have come up with 39.0, 39.5( was a flyer), 40.0 and 40.5 in a good group. From what I've been reading the loads are much higher. I'm using Nosler 175g Custom Competition (same bc as the 175g SMK), Varget powder, CCI primers and LC brass. Can you out there let me know exactly what you are using for this weapon.

Thanks

 

[jbpmidas]

I'be seen a lot of rifles shoot 43.0 Varget over 175 SMK's pretty well. You'll need to do some fine tuning on seating depth and exact charge weight. You need to work up to that charge but I believe it is safe in most rifles.

What are your intentions with the rifle? Play at 200 yards? Compete at 1000? If you're only shooting 200 yards, the loads you've worked up are fine, if they meet your accuracy requirements. They'll probably work fine at 600 as well, if you're into MR F-T/r.

 

[Turbulent Turtle]

Well seeing that Hodgdon's starting load is 42grains Varget with the 175SMK, I say you still have a ways to go.

 

[Grand poo bah]

Thanks for the replies. I shoot at all ranges. I'm using 168 for my under 600 and working up this load for 600-1000. when I was running my initial run my 41.5, 42.0, 42.5 were some what in a line but I had a fairly tight group at 39.0-40.5. What are you loading up for your rig? it would really help to know if I'm way off or should I go back to the range, at 200 yards.

 

[Turbulent Turtle]

You are, of course, developing your load over a chronograph. Otherwise, you are wasting your time and components. To shoot accurately at 1000 yards, I want my bullet to arrive at the target above Mach 1.25 This is the area where compressibility starts to set in on jet planes and I figure it's probably about the same for bullets. Since a bullet does not have fly-by-wire adjustment capability, I try to stay above that velocity all the way to the target.

After computing the G7 BC value for the bullet I use, I spent some time at JBM working out different scenarios of temperature and elevation, ( the worst scenario being near freezing at sea level.) You are lucky in that JBM has the G7 value for your bullet so you do not have to calculate it.

By using Mach 1.25 as my threshold value for 1000 yards, JBM showed me what my minimum muzzle velocity needed to be to obtain Mach 1.25 at 1000 yards. I then proceeded with a ladder test until I reached an accuracy node above the minimum required muzzle velocity. On summer days, my final velocity at the target is actually above Mach 1.4, and on freezing days in south Texas, it's above Mach 1.35. Remember that temperature is the only thing that measurably affects the speed of sound, and that bullets fly faster on hot humid days.

My load is Varget for a 180 gran bullet and it's not at Hodgdon's maximum. I never use the loads from bullet manufacturers, they are way too low.

 

[pdm25150]

Theese are out of a 26" Barrel

My 168 smk load ( this is a tack driver in my rifle)
43.5 grn. Varget
Br2 Primer's
Lapua Brass
.020 from the lands

my 175 smk load (still working on it)
42.5 grn varget
Br2 primer
lapua brass
.020 from the lands

Start under on powder loads and work up. I started at 41 grn. for each and worked up to the above.

 

[Keith Glasscock]

Careful using other's data with LC brass. There is a huge difference in the pressures generated courtesy of the reduced case capacity of LC.

My loads are not too hot at all in Winchester, but LC brass makes ejector marks on the case heads with 2 grains less powder. As a matter of course, I use at least 3 grains less than published "max" to start moving in small increments so I don't get extremely too hot with one increment.

That said, Winchester brass shows a strong node at ~44.7 or so with the SMK based on the experiences of several shooters (barrel lengths from 24-26"). LC would likely show a node at a much lower powder charge (but likely similar velocity). In the Winchester, there is not enough head room to get up to the next node, so that is the highest performance you are likely to get.

As noted above, you want to arrive at 1k with adequate velocity. The SMK is a special case. It remains stable through transonic velocities. It will shoot, but the performance isn't anything to smile at. If you step your game up, and want more performance, you might want to investigate some of Berger's new offerings. The 155 Hybrid has the same BC as the 175 SMK,but it leaves going a lot faster. Likewise, the 168 Hybrid has a BC more in line with the 190 SMK and it can be propelled at quite a clip too.

Good luck, Be safe!

 

[DennisH]

My 168 smk load ( this is a tack driver in my rifle)
43.5 grn. Varget
Br2 Primer's
Lapua Brass
.020 from the lands

My gun likes the above as well, only I shoot them on the lands and use WLR primers! A two time state champ talked me into using the WLR's, and I haven't stopped!

Suprisingly, 175 Berger VLD, .010 in the lands likes the same recipie!

 

[MVW]

Grand - I have the same gun and have been shooting the same bullet with 43 GN of Varget and Lapua brass. Speeds are around 2,720 fps. Different brass responds differently, so be careful.

I just posted a topic on reloads for my gun - trying to get more consistent speed statistics. It contains more data on my reloads.

Mike

 

[Grand poo bah]

bump

 

[XTR]

Careful using other's data with LC brass. There is a huge difference in the pressures generated courtesy of the reduced case capacity of LC.

^^^ THIS!! ^^^

LC has about two full grains less capacity for Varget. If you are shooting F class or competition I'd thing seriously about going to Winchester or Lapua. (I use WW) I keep my LC brass for my hunting rifle reloading, but for long range F class you will have better luck with the higher capacity and better muzzle velocity.

 

[Grand poo bah]

I started to load up 44.0g and will get back to you with the results. I have little time to reload with other time constraints, family, work, etc.. That is why I'm looking for specific load information from you out there that have this weapon.

thanks for your assistance

 

[Turbulent Turtle]

Looking forward to it. My load is a little heavier but still Varget and I use 180gr bullets and have a 32 inch barrel. The chrono indicates just shy of 2900FPS. Don't forget to include chrono readings.

 

[MVW]

44 GN and 2900 seems too hot for 308. Lymans has 175 GN going about 2700 fps tops. Folks have suggested even that is too hot. I'd be careful.

 

[mattt]

2700 is out of a 24 or 26" barrel. With a 30 or 32 you get more fps

 

[Turbulent Turtle]

2700 is out of a 24 or 26" barrel. With a 30 or 32 you get more fps

Exactly.

 

[coreydelong]

Skip the 175 SMK's if you're going to 1000yds. I've had good luck with them out to 800yds, then they seem to get kinda erratic.

155g Scenars have a good BC and the added velocity (2950fps) will get you there no problems.

45.0- 45.5g of Varget around 2.815" should be a decent load in Federal or Lapua brass..... a tad higher for Winchester brass.