Anyone using vintage(68-69) LC .308 brass

[DIBBS]

It's time to retire some winchester and hornady .308 brass. For those of you using older standard military brass, approximately how much have you had to reduce your loads to get comparable performance. (168 amax/Varget/210's) The LC brass weighs ~20 grains more per case. Will a two grain reduction in powder charge be adequate to start with, or should I drop 10% and commence load development.

 

[turbo54]

Re: Anyone using vintage(68-69) LC .308 brass

Due diligence would be to run a ladder with 1/2gr increments with the new brass.

I just weighed some brass:

Winchester : 157.5
Lapua: 177.5
LC72 Match: 179.7

Hmmmm.... never loaded Winchester brass, but found lapua and the LC72 to take the same charge...

FWIW, a 168 Amax and 46gr Varget (either lapua or LC72) is good to go in my Savage, which handles the LOWEST charges of all my 308s.

 

[ArcticLight]

Re: Anyone using vintage(68-69) LC .308 brass

I'm not running vintage, but considering my WIncheser is at 45.0 gr of Varget, my LC99 brass is at 42.5 and only about 100fps slower...(I think, have to verify).

I'd start low on loading that stuff..

I have some vintage early 70's gov match grade ammo.

 

[aquinas]

Re: Anyone using vintage(68-69) LC .308 brass

I go a grain under minimum. When I have questions like this...I call Sierra. Not impugning the hide. It's a safety issue. I want to hear it from the horse's mouth.

 

[turbo54]

Re: Anyone using vintage(68-69) LC .308 brass

Understandable ... I still suggest a ladder, starting low and working up higher than you think you'll make it. Load them on the lands, so you find you're true max. DONE... In 10 shots!

 

[Borg]

Re: Anyone using vintage(68-69) LC .308 brass

You might also check to see if the flash hole is centered, had that problen many moons ago.
Borg

 

[aquinas]

Re: Anyone using vintage(68-69) LC .308 brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Understandable ... I still suggest a ladder, starting low and working up higher than you think you'll make it. Load them on the lands, so you find you're true max. DONE... In 10 shots! </div></div>

What do you mean by that? You do ladder tests and load them out to the lands for the test?

 

[turbo54]

Re: Anyone using vintage(68-69) LC .308 brass

Seating a bullet such that it is on the lands, or jammed into the lands a couple thousandths will cause maximum pressure for that given charge weight.

Let me give an example, from my own personal experience:

I ran a ladder for the 175SMK in LC72 Match brass for my FN 308. My savage loves 44.25-44.5gr of Varget, so I set up the following ladder:

One cartridge of each, with bullet "jammed" into the lands .001-.002"

42.0 Varget
42.5 Varget
43.0 Varget
43.5 Varget
44.0 Varget
44.5 Varget
45.0 Varget
45.5 Varget
46.0 Varget
46.5 Varget
47.0 Varget


I Began at the lowest charge weight, firing them at 300 yards. I Carefully checked for signs of pressure after each shot, and drew a picture of the target, labeling each bullet hole. For my rifle, I found that the final round, with 47.0 Varget, had a SLIGHTLY sticky bolt lift. This rifle craters primers a bit at any charge weight, but this final charge cratered it more. My rifle doesn't have an ejector, so there was no kick/swipe mark on the case head.

So... Now I know the limit for that bullet, powder and primer in this rilfe. The next step is analyzing the target to identify any nodal groupings, and perhaps a smaller increment ladder test. After that, a bullet seating depth test can be performed.

The main idea of the "on the lands" ideology, is that by altering my seating depth from the lands, my pressure will ONLY go down...so I'm safe to play with the depth.

<span style="font-weight: bold">Had I picked some arbitrary depth when doing the initial ladder, I would have no idea what pressure effects would exist should I decide to load a bullet closer to the lands.</span>

 

[aquinas]

Re: Anyone using vintage(68-69) LC .308 brass

Ok...I see.

So you do it reverse...and probably the correct way than most of us. That's a good idea because then you've eliminated a variable.

Next test I'll try it that way.

 

[turbo54]

Re: Anyone using vintage(68-69) LC .308 brass

Glad I could help, but I can't claim credit...picked up that trick from the loading stickies on the top of this forum.

If you haven't already, I would recommend reading through them, it will only take 30 minutes to an hour, and unless you are a MASTER reloader, you will learn something. I was no spring chicken to loading, but still picked up a few good ideas....like the "on the lands" pressure test ladder.