Improving the 308 Win performance

[nralifer]

I think yes. As good a BC as possible. The gentleman I chatted with here was wanting to try this 130 combo he had on deer and elk. Me myself deer yes, as to elk I have no experience. I've had conversations with folks who talk about 243 Win., 7mm-08, 6mm creedmoor as of lately. One site in particular the conversation we had, he was taking a trip west with his 6cm and videoing. I need to check with him. Another site is Simple minded fellow on YouTube. He shoots higher velocity loads into gel, then reduced loads. As of lately checking if rpm makes a difference. Some bullets have been very suprising. I think some folks just wanna use the rifle they have within its limits, (hopefully) and use different bullets for different tasks. No arguments that a 300 Win mag tops a 308. That's a given. Today everything is expensive and some folks can't afford to go buy the next latest greatest. Putting meat on the table is still what some folks are pressed to do and want to do it with what they have. The 308 Winchester is a popular cartridge, helping folks get a little more out of it isn't a bad thing. Maybe like me. I just wanna push the limits to see what I can get from some cartridges. In the process I might get even more versatility out of my old 308 Winchester that seems to be brought up as of lately as a cartridge of the past. That to me is gonna be awhile longer.

I guess I'm dating myself, but the 308 Win is probably THE most efficient cartridge in terms of ft-lbs of energy imparted to the bullet PER grain of powder used. The number of powders available in the burn rate spectrum that works in that case is large, and in these days of scarcity you are more likely to find something that works. It is not hard to get 3000 ft-lbs of bullet energy from that case which is more than enough to kill most anything within 500 yds given the right bullet with a good BC. You can bet that if we make a 130 gr class .30 cal bullet its BC will be best in class, 'cause BC is our thing. I do a lot of experimental loading and without a doubt I love it when I have to use the 308Win because it does use less powder and it is so easy to make shoot well.

 

[nralifer]

For the 308 Geeks, I hope you get to try a "palma" chamber in a 4 Groove Brux or Krieger 10-12 Twist. 155's-175g TMK shoot TINY bug holes at 200 yards.

If you want to shoot those max pressures, Bush your firing pin and have your firing pin turned to match, and Palma Small primer brass demands a CCI 450, in my experience. The 450's have thick cups.

Certainly agree with your comments on the SRP brass and primer choice. That's why they tolerate higher pressure. Thanks for the info on the barrels. With a 1:10 twist you can use almost any bullet.

 

[bamban]

For the 308 Geeks, I hope you get to try a "palma" chamber in a 4 Groove Brux or Krieger 10-12 Twist. 155's-175g TMK shoot TINY bug holes at 200 yards.

If you want to shoot those max pressures, Bush your firing pin and have your firing pin turned to match, and Palma Small primer brass demands a CCI 450, in my experience. The 450's have thick cups.

Which Palma reamer did you use?

 

[VinceMule]

Palma reamer, from PTG, very short freebore. Most of these bullets Have shot LOVE to be seated just barely touching to .003 off the lands

 

[bamban]

Palma reamer, from PTG, very short freebore. Most of these bullets Have shot LOVE to be seated just barely touching to .003 off the lands

Is it the '95, the 2011, or Bisley? PTG and JGS 95 have the same spec, somehow I don't have the PTG print. I have both PTG's '95 and Bisley reamers. Just curious which one worked the best with the bullets you used, the TMKs. FYI, I shoot the 175 TMKs in my sporterized 1903a3. Related topic - bullets.

 

[Varmint Hunter]

I guess I'm dating myself, but the 308 Win is probably THE most efficient cartridge in terms of ft-lbs of energy imparted to the bullet PER grain of powder used. The number of powders available in the burn rate spectrum that works in that case is large, and in these days of scarcity you are more likely to find something that works. It is not hard to get 3000 ft-lbs of bullet energy from that case which is more than enough to kill most anything within 500 yds given the right bullet with a good BC. You can bet that if we make a 130 gr class .30 cal bullet its BC will be best in class, 'cause BC is our thing. I do a lot of experimental loading and without a doubt I love it when I have to use the 308Win because it does use less powder and it is so easy to make shoot well.

You could have a winner there because an awful lot of shooters are shooting the 130TTSX in their .308/30-06 rifles.

 

[VinceMule]

Mine is the FullBore 211, 5 barrels shoot the 155-175gTMK incredible. 169g Sierra with this reamer is absolutely perfect with the shank/bt just above the shoulder neck junction.

 

[nralifer]

You could have a winner there because an awful lot of shooters are shooting the 130TTSX in their .308/30-06 rifles.

 

[VinceMule]

Win 748 = 3150-3200 fps at the accuracy node with the 130g TTSX, jumping .050 from the lands, easy!

There is a load with varget also, not quite as fast with the accuracy node in my rifle.

The Nosler 125g Ballistic tips have performed great at 3100-3200, so has the Sierra 125g Pro hunter. I don't know if we will ever see the 125g Accubonds anymore.

 

[nralifer]

Mine is the FullBore 211, 5 barrels shoot the 155-175gTMK incredible. 169g Sierra with this reamer is absolutely perfect with the shank/bt just above the shoulder neck junction.

So what speeds, powder charges, jumps, brass and primers are needed?

 

[VinceMule]

I shoot Lapua large rifle primer brass and different primers with different powders.

8208 is fantastic, 42g with the 175g TMK shoots a bug hole. 43.3g with the 169g MK and tipped match king. These two bullets like to be within .003 of the lands. I can not remember the primers off the top of my head.

155g Palma, and the 168g Sierra Match kings are so easy to tune in this chamber. R#15 and Varget with the 155 Palma are both incredibly Accurate seated just barely off the lands.

The 169g Sierra MK is a much better long range bullet vs the 168g MK that was designed for 600 yards.

Controlling your neck tension is key in getting those tiny groups with many firings on the Lapua brass. I use 21st Century expanders that you can order in .0005 increments.

 

[Mike D Texas]

If you are thinking Blackout you'll need to stay in the 110 grain range to keep velocity up and not crowd powder space.

 

[nralifer]

If you are thinking Blackout you'll need to stay in the 110 grain range to keep velocity up and not crowd powder space.

We have a 125 gr in the works

 

[Wachsmann]

I finally got out Tuesday shooting but ended up getting stuck in the south desert. Luckily some friends came and got me out. So if I can add these correctly to the post with load data and velocity.. These were all annealed, shoulder bumped, trimmed, and loaded with LVR and CCIBR2s. Bullet was a 195ELDM all were seated to 2.830 but I think on my earlier post I was getting compression on the last 4 bullets and they started seating longer out to 2.835. Also when I checked the shoulder on these cases the first 6 or 7 had not even expanded all the way. The range was from 1.93 to 1.94 inches. 1.94 is what I get with the .420 Hornady gauge when measured for regular expansion of factor rounds. CF223 would always push the shoulder out to the 1.94 measurement. I did not get the pictures in order to match the charge weights but it was basically slowest to fastest. Charges are as followed
46.0= 2698fps, 46.3=2707, 46.6=2711, 47.0=2713, 47.3=2717, 47.6=2717, 48=2737, 48.4=2777, 48.8=2810 49.1=2823.
I finally had really faint ejector swipes starting at 48.4. 49.1 game me a little and it was not really even noticeable bolt lift. SO FOR ME...and my rifle I'm going back to the 47 to 47.6 area. This seem to be a good flat spot again. I also had a flat spot at or around 2650. Data was in an earlier post. I have not got pics of the cases but I did remove the primer from the highest load and it had some flatting of what I have noticed as flatting. It also had the ejector swipe and this is the one I had a little to none noticeable bolt life difference. The primer pocket on this highest charge is still not loose and this is a 5th firing on these cases. So for me LVR is turning out to be a win over CF223. I just hope it hold its consistency in hotter temps. Its not a temp stable powder but for a 195grn bullet moving along at 2700FPS out of a 308 case. That pretty sweet. Now to put this in a little more perspective and I know the match bullets are supposed to punch paper but...at 1000yrds, this is coming off the applied ballistic app calculated data, 1000yrds, 1505fps/981ft/lbs...910yrds 1600fps/1108ft/lbs.....enough for me for mule deer.....1801fps/1405ft/lbs of energy. Enough for an elk. Actually for some 1200ft/lbs of energy/1664fps at 850yrds. My next move is to find what charge weight I want to load these at. 47.3grns I'm thinking. Right in the middle of the flat spot. I would of liked to see how these done actually on paper but since I had my scope already zeroed I was rock shooting out to 300yrds with these.