Switching from Federal to Winchester brass in .308

[Flakbait]

My rifle is a .308 Rem 700 SPS Tactical 20 inch barrel, 1 in 12 Twist. I developed a decent sub-MOA load with used Federal GMM brass, 168 grain Nosler CC bullets, 45.4 grains Varget, CCI LR primers, COAL 2.81. My Shooting Chrony measured an average MV of 2650 FPS. Factory Federal GMM 168 had a MV of at least 100FPS slower with similar results in accuracy (near 0.5 MOA).

I am accumulating Winchester brass and plan to switch to Winchester for brass longevity once my stockpile of Federal Brass is expended (likely only 4 reloads with Federal).

What adjustments in Varget powder should do to obtain similar accuracy results keeping everything the same except replacing the Federal brass with Winchester. Anyone have a similar experience making this brass switch.

I guess I can use the OCW method to find a nice node starting with 43 grains and working up to 46 grains but I would like a little shortcut if possible.

Alternatively, I can swap from Federal to Lapua but I have a nice stockpile of Hornady and Winchester .308 cases built up. The concensus of the forum is that Winchester is better than Hornady brass.

 

[MitchAlsup]

Re: Switching from Federal to Winchester brass in .308

The standard rules always apply:

Drop down at least 1-2 grains,
Work your way back up,
Watching for pressure signs on the way up.

 

[cox308]

Re: Switching from Federal to Winchester brass in .308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MitchAlsup</div><div class="ubbcode-body">The standard rules always apply:

Drop down at least 1-2 grains,
Work your way back up,
Watching for pressure signs on the way up. </div></div>

+1 but I'd say 2 grains at least

 

[Huckleberry75]

Re: Switching from Federal to Winchester brass in .308

No Free Lunches. You gotta do the work to get it right for your rifle.

 

[roggom]

Re: Switching from Federal to Winchester brass in .308

Same rifle and bbl, I am using winny brass, WLR primers at the same col (2.81) for both 168 amax and Berger VLD. 44.5 gn of Varget puts me at .39 moa and .51 @ 100. avg MV 2614 fps standard deviation 32 (for the amax, havent clocked the bergers yet)

 

[colt933]

Re: Switching from Federal to Winchester brass in .308

I think many people want to over-complicate this. Sure, safety is important. But I suggest that if you drop down 2 grains and come up in .5gr increments until you match the velocity, you will be there!

I don't have a long range at my house, so I can do no accuracy testing here. But if I have a known good load, and for one reason or another I have to change one of the components, I can match the velocity of the known good by just loading 3-4 rounds with the new component - at my house. Once I get there on velocity, I load up a quantity and go to the range for accuracy testing. My experience shows that the new load shoots the same as the old load.

This may not work in all scenarios, but it has worked for me every time.

 

[hamstur]

Re: Switching from Federal to Winchester brass in .308

FWIW my M1A load is 41.5gr IMR4895 in Lake City. I bump this to 42.5 for FC (not FGMM or AE) and 43.5 in Win. AE has about the same capacity as LC, and FGMM about half grain more than standard FC.

If you're safe at 45.4 in FC, I wouldn't go below 44.0 -- this is a very mild summer plinking recipe in Win brass for my TRG (20" 1:11).

A few notes on my 20" bbl guns... I couldn't get keyhole groups without pushing the load really hot. I switched to CCI mag primers and my load settled at 45.0 with very accuracte results. I got a more complete burn as recoil was very noticably less but brass gets beat up more.

Though less temperature sensitive, I've ditched Varget for IMR4895 for 168. That 43.5gr IMR4895, GM210M, 2.800 COL recipe shoots like a dream my TRG and GAP. I still load Varget for 175.