Load advice .308 win

[earplay]

Ok, it is summer here at the moment so I figure I should be ok if no pressure signs. I thought Varget was relatively temp tolerant, so I assumed temp increase shouldn't hurt much?

I worked up to 44.7gn with no obvious pressure signs. See target (pulled the lower left shot, not sure about the other one left)

My biggest dilemma now relates to velocity. The first 44.7gn shot was running 2553, then the next 2 shots posted similar velocities. The last 2 got progressively slower... the final shot posting just over 2500fps.

I was a little rushed so wasn't taking long for barrel to cool down between shots. My current understanding was that velocity increased as barrel heated up, but have struggled to find any real info on the net about this. Can anyone explain?

My rudimentary understanding of engineering would indicate a hot barrel has expanded, producing a greater bore diameter and less pressure/velocity??

 

[jamesmc2]

I have had good luck with the A-max and Varget combination. I find that it is quite temp stable and have not had much issue with lot to lot variation. I shoot a Savage with a 1 in 10 twist and it loves the 175-180 grain bullets. My load is 44.5 of Varget with a 178gr A-max. It is consistently capable of shooting 0.3 to 0.5 inch groups. My velocity out of a 24" barrel is 2780fps. Running through the Chrony I get a SD of around 15fps and an extreme spread of 40fps.

One thing to consider is that stock Remington barrels are 1 in 12 twist and tend to favor bullets in the 155-165 grain class. You might check out the 168gr A-max.

The A-max has done well on game for me too. At the slower .308 velocities you get a nice mushroom and often complete pass throughs. A bullet found after a 500yd shot had about 60% weight retention and weighed in just over 100gr.

Here are some pics of a mule deer, inside and out, taken at 400yds with the .308

 

[earplay]

Hey mate,

Thanks for the input. I've been trying to find someone running the same combo. My Rem has a 1 in 10 twist, I wonder if that's a relatively new thing as all the older ones had 1 in 12 as I understand. 24 inch barrel also.

I'm wondering how you get 2780fps at 44.5gns? The reloading data would indicate 2660-90fps max at 45gns. What brass are you running, and at what seating depth?

I am getting ok accuracy at 44.7gn but am wondering if I push it further to squeeze out a few more fps.

Nice animals, thanks for the pics.

 

[backwoods83]

I have been up to 47 grns of varget with winchester brass cci br2 primers and the hornady 178bthp match, 2.904" oal .010" in the lands and it didn't show any pressure at 75*, keep working up slowly and get closer to the lands.

 

[jamesmc2]

Individual velocities vary from gun to gun. I was surprised at the velocity as well as I was expecting something more around 2700. I have confirmed the velocity with shooting ballistics out to 750 yards and 2780 gets me right on at 500, 600, 650 and 750. I also worked up a load in the 168gr Amax which ran faster than I expected so my barrel may be on the fast side. I know of another shooter who gets 2650 with the 178gr Amax and only 43.5 of Varget.

At my current load I am getting flattened primers, but no loose pockets or other signs of pressure so I would not want to go any higher.

I am using Winchester brass and Federal 210M primers. I load using relatively low neck tension with the Lee Collet Die. Using less neck tension did improve my accuracy. I load to a COAL of 2.82" which in my gun is 0.02" off the lands. I use this as a hunting load so I don't want them jammed into the lands. It seems like a lot of people have luck around the 2.8" COAL with the 178gr Amax. I trim my cases to 2.010".

Good luck - James

Here are some recent groups all with the 178 Amax. First two photos from this fall with temps around 80 degrees and last two shot yesterday with temps around 30 degrees. The 0.3" group at 200yds is my personal best ever!

 

[earplay]

Nice shooting! I am wondering whether or not I keep pushing the loads up and see what happens? 45gn is pretty close for me now, being at 44.7gn.

I am running at 2.800 and am keen to stay there unless I need to tweak accuracy. As I understand, pushing the bullet closer to the lands (unless you jam), will reduce pressure and velocity.

I am also running Winchester brass, with Fed 210 primers.

Is the reduced velocity I am seeing any indicator of lower pressure? i.e more room to increase charge?

 

[liltank]

As I understand, pushing the bullet closer to the lands (unless you jam), will reduce pressure and velocity.

There is a sweet spot in pressure between .005-.020". At least that is what I read. I have some loads of 178BTHP w/ 44.0grn Varget that shot .5MOA at 315yds.

 

[diriel]

Have you tried winchester primers? Believe it or not I have had superb luck with them over the years. Don't get me wrong, I do keep a good supply of Fed 210m as well.

Another thing you might try is "smoking" the bullet and seating it out till you just barely see the lands touching the "smoke". This has the side benefit of allowing you to easily see if your lands are all touching at the same time, as they should be.

As far as your barrel not giving you the velocity you was hoping for, some barrels really are just slower than average. Other barrels can actually be a good bit faster than average. Especially with a Factory stick, it is luck of the draw really. I would not worry too much over it really. You might perhaps try a little bit of careful Fire Lapping... if you decide to do that, a little bit goes a LONG Ways...

Gary

 

[earplay]

At this stage I am happy with the accuracy I am getting. I am sure with a proper rest setup it could be improved even more.

If I have to live with the lower velocity I don´t mind too much, but would be nice to push it up. In theory (and according to an article I read), low velocity also correlates to low pressure, so maybe I am safe to keep increasing until velocity starts to look better.

Another factor I have read a little about is batch variation with Varget (although I actually use AR2208). Possibly a slow batch? Although thinking down that track makes me nervous about upping the charge...hmmm

 

[backwoods83]

I'm not going to tell you this so that you will go and do something stupid but, you can not put enough varget in a 308 case under a 178 to harm you or your rifle, blown primers, tight bolt, split cases, etc... so just up the charge 3 or 4 tenths at a time.

 

[earplay]

Ha... well I hope not. It's already starting to get a bit crushed. I think taking over 45gn would be interesting. I think I will load up a few at 45 and see how they go...

 

[jamesmc2]

When working up my load I went as high as 44.9 grains of Varget under the 178 Amax, my primers were flattened a bit but I had no other signs of excessive pressure. That is a compressed load. Just go slowly and inspect your brass.

 

[earplay]

Well I loaded up a number of 45gn loads last night and managed to have quite a frustrating experience. First bullet to be seated remained in the die...

I discovered I had insufficient neck tension to hold the projectiles in place. I was then left with 25 odd cases charged and ready for projectiles, but unable to use them. I had used the Lee neck collet die, and after re-reading the instructions, figured I should be screwing the die down a further 1/4 turn. I think I would have been ok, had not I been running a compressed load that was forcing the projectile into the die.

I ended up removing the mandrel from the Lee die and running the cases through and trying to lightly apply additional tension. This seemed to work ok, and I was able to load them up eventually, although a couple of projectiles still got stuck in the die.

A handy, but frustrating learning experience!

 

[backwoods83]

Earplay, I will give you some good advice that I learned just a couple months after I started reloading, (buy Redding type S neck dies) Lee collet dies just plain SUCK, end of story.