Powder (not Varget) for a 308 that will keep a 175 gr Nosler CC supersonic at 10

[lee1000]

Can someone recommend a powder that will keep a 175 gr Nosler Custom Comp supersonic at 1000 yards without pressure signs and destroying the brass? My abilities limit me to 600 right now but I would like to stick with the same powder once I’m ready. I have the Nosler CC’s because they are cheap.

Anyone else tired of even seeing the word Varget?

Will they even stay supersonic using that bullet without running into pressure signs? I’ve read that German Salazar is able to do it but he’s using a 175 Berger LRBT (I think) and is easily over the 1.2 Mach. He’s getting 2830 with H4895. See here http://riflemansjournal.blogspot.com/2010/10/cartridges-308-palma-preparation-and.html

The components I have on hand and would like to use are as follows
Lapua 308 Large Primmer
CCI BR-2 Primers
Nosler Customer Comp 175gr (BC of 0.505)
My throat is pretty short. With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.810 per manuals). I loaded up rounds to 2.810.

My setup is as follows:
Savage FTR with 308 Stock barrel
NF 12-42x56
EGW 20 MOA Rail
EGW Rings

I’m fairly new to reloading but grasp the requirements for shooting at 1000. I know the bullet must be 1.2 Mach (magic number) at the target.

The velocities I need to be at with the conditions are as follows:
Altitude 738
Humidity ballpark 80%
Atmospheric pressure 29.69 hg

Temp MV Mach
100 2760 1.201
90 2775 1.202
80 2785 1.200
70 2800 1.201
60 2810 1.200
50 2820 1.200
40 2835 1.201
30 2845 1.201


I did try AR Comp but ran into pressure signs fairly early and found 10 loose primers after repriming the cases, that gets expensive.

Alliant's max is 41.4 and that chronoed at 2710 fps.

I started seeing pressure signs (very light ejector markings, 1 out 3) at 42 gr and 2740.

With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.800 per manuals). I loaded up rounds to 2.810.

I didn't see pressure signs at 43.6 / 2834 but i believe that was a fluke.

These velocities were shot at 60 degrees.

 

[gaboon]

Try IMR 4064 and 4895. Both powders will do it no problem and my loads are less than max.

 

[Dos XX]

Factory barrel? Chamber dimensions come in to play here as well. How far out can you seat the bullet? Can you get the boat tail out past the neck shoulder junction?

 

[Ont0001]

Consider AR Comp by Alliant.VERY temp stable and approx same burn rate as H4895 in my tests so far.
That cartridge bullet weight combo has a number of powder options....

 

[Dos XX]

He may have trouble if he is running a short throated chamber that is restricting him on powder capacity. I couldn't get that velocity in that rifle with the factory barrel using Varget and 185 gr Bergers because of it. The bullet he is using might be dimensionally different enough from the 185 to allow it. Just something to be aware of.

 

[stool]

rl15

 

[lee1000]

Factory barrel? Chamber dimensions come in to play here as well. How far out can you seat the bullet? Can you get the boat tail out past the neck shoulder junction?

Yes, factory barrel.

With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.800 per manuals). I loaded up rounds to 2.810.

Not sure, I know my throat is short though.

 

[lee1000]

Consider AR Comp by Alliant.VERY temp stable and approx same burn rate as H4895 in my tests so far.
That cartridge bullet weight combo has a number of powder options....

I did try AR Comp but ran into pressure signs fairly early and found 10 loose primers after repriming the cases, that gets expensive.

Alliant's max is 41.4 and that chronoed at 2710 fps.

I started seeing pressure signs (very light ejector markings, 1 out 3) at 42 gr and 2740.


With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.800 per manuals). I loaded up rounds to 2.810.

I didn't see pressure signs at 43.6 / 2834 but i believe that was a fluke.

These velocities were shot at 60 degrees.

 

[lee1000]

He may have trouble if he is running a short throated chamber that is restricting him on powder capacity. I couldn't get that velocity in that rifle with the factory barrel using Varget and 185 gr Bergers because of it. The bullet he is using might be dimensionally different enough from the 185 to allow it. Just something to be aware of.

I'm starting to think it's the short throat. I read about a guy getting pretty good velocity with a long throat.
http://forum.accurateshooter.com/index.php?topic=3774576.0

175 gr Berger
OAL 3.000"
45 gr AR Comp
2756 FPS
24.5" Barrel

At this point I really don't want to lengthen it.

 

[lee1000]

thanks for all of the help, I appreciate it very much

 

[lee1000]

Try IMR 4064 and 4895. Both powders will do it no problem and my loads are less than max.

How temperature stable are these?

Do you have any data that shows the effects of temperature?

What do you think of H4895?

My throat is pretty short. With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.810 per manuals). I loaded up rounds to 2.810.

 

[lee1000]

Do you have comparator to measure to ogive of bullet? In my FTR the 185 LRBT sits right smack at the neck/shoulder junction touching the lands. My OAL is 2.202"(base to ogive). This puts the base of the bullet pretty far down into the case which takes away room for powder.

Power Pro 2000 may be something to look at possibly. Should give you more velocity with equal or less powder

I have one of the hex comparators. I'm pretty sure it's way down there.

 

[gaboon]

IMR 4895 is al litttle temp senistive but not bad. IMR 4064 is more stable I've found. You throat seems a little short. I think you reading mag length measurments. I base to ogive with the 175gr is 2.860 and I got couple thou to go.

 

[lee1000]

IMR 4895 is al litttle temp senistive but not bad. IMR 4064 is more stable I've found. You throat seems a little short. I think you reading mag length measurments. I base to ogive with the 175gr is 2.860 and I got couple thou to go.

I got the minimum 2.800 from the Lee reloading manual, I always thought you didn't want to go shorter than this due to overpressure.

 

[Laurie]

Yes, I can recommend a powder - it's called .300 Winchester Magnum! There is no way and no powder available that will keep this bullet supersonic from the .308 Win at 1,000 with the possible exception of shooting on a range in hot weather that is a few thousand feet above sea level to get thin air and the consequent reduced drag.

The 168gn CC is a very similar design to that of the 168gn Sierra MK whose original purpose in life was to win 300 metre UIT matches. This pair and some similar designs from Speer and Hornady make superb short-range match bullets in .308 Win, but suffer from low BC values and overly steep boat-tail angles for long-range. They will shoot accurately at 800 yards, but a good long-range design will see much reduced wind drift assuming both types are launched at the same velocity. The boat-tail angle is crucial. The optimum angle for a LR bullet is 7-8 degrees, and should never be in double figures. The Nosler CC has a 13-deg angle, same as the 168 Sierra - in fact, they are almost identical shapes throughout except that the Nosler has a shorter mid-bullet bearing surface. The nose and tail sections could be straight copies of the Sierra model. The sharply angled tail section risks causing surface airflow to break away from the bullet walls resulting in turbulence, this most likely to happen in transonic flight from 1.2 MACH down to just below the speed of sound. That increases drag substantially, also induces instability, which is why people who try to use these bullets in the 308 at 1K are often told by the butts markers afterwards that their bullets went through the target sideways.

Bryan Litz gives the 168gn Nosler an average G7 BC value of 0.218 (again identical to that of the 168gn Sierra MK) which is LOW for LR match shooting. You should be able to achieve 2,800 fps + with this bullet from the 30-inch barrel on the Savage F/TR, let's say 2,850 fps MV. Using Mr Litz's / Berger Bullet's PM Ballistics Solver 2.0 program set to the G7 mode (essential for LR as G1 BCs and tables / programs are unreliable / very optimistic beyond 600 yards), the bullet is expected to drop to a subsonic 1104 fps at 1,000 yards. Whether it'll actually achieve even that is debatable because of the transonic turbulence issue, the bullet speed dropping into that zone ~ the 800 yard point.

The .308 Win is still in its comfort zone at 800 yards with a reasonable set up, starts to struggle at 900 and is really up against a ballistic wall at 1,000 yards, especially when trying to conistently hit a target whose top score ring is only the size of a dinner plate. So that means everything has to be (a) specified to be up to the job and (b) really well assembled to work reasonably well at this distance at all, and then you've still got to compete with the next guy on the firingl line who might be launching very expensive and very efficient 200 / 215 / 230gn Berger Hybrids at impressive velocities.

Your starting point should be a 'good' 155 at ~ 3,000 fps and able to group into 0.2-0.4 MOA. The newer Sierra 155 Palma MK (p/n 2156), Lapua Scenar, and Berger 155.5gn BT Fullbore / 155gn Hybrid meet the bill. The 175gn Sierra MK will stay supersonic from your rifle at this distance but is a relatively low BC design for its weight. The new 178gn Hornady HPBT Match (not the A-Max) might do well, but the majority of efficient and suitable 168-185gn bullets that will suit the Savage 12 F/TR's chamber throat are made by Berger. The original 155gn SMK (p/n 2155) at 3,000 fps MV is a known LR performer and very stable in the transonic speeds if lower BC than the other trio suggested. We get them a lot cheaper than the others in the UK, so it's a viable budget option if that applies to you.

The sad truth is that there are no shortcuts to good 308 performance at this distance and there are no out and out budget options available. If the 168gn Nosler works well for you to 600 yards, stick with it but look at developing a 'LR load' for 800 to 1,000 yards - good luck.

 

[Laurie]

OOPS - just noticed it's the 175gn CC you're asking about. That's a lot better than the 168, but is still a relatively poor choice for 1,000 yards. The ballistic equivalent to a 155 at 3,000 fps for a 175gn bullet is 2,823 fps, so you should be able to just break 2,800 fps.

Litz doesn't list the 175 Nosler match, but it's (again) very similar to a Sierra that appeared earlier. Assuming the boat-tail angle issue is OK, it'll likely have a G7 BC of around 0.243 as per the 175gn SMK. That combination sees it remain supersonic, but not by a lot at 1K under standard ballistic conditions (59-deg F / 29.92 inches mercury atmospheric pressure).

Under these conditions, you need an average MV of 2,725 fps minimum to allow for a reasonable MV spread so that those bullets at the low end of the spread don't drop through the sound barrier.

So, there should be lots of powders that achieve this other than Varget as it's not a particularly demanding target for the 30-inch barrel F/TR rifle. As well as those mentioned, I'd suggest the Accurate / Ramshot numbers from Western Powders. Accurate 2520, Ramshot Big Game will give high MVs with this bullet, TAC too maybe although just a little fast burning. Reloder 15 easily achieves suitable velocities but is rather temperature sensitive. Viht N150 is a good choice and very temperature stable.

Nevertheless at the end of the day, I'd still recommend looking to buy some good 155s and load a combination that provides 3,000 fps or above. You'll be more competitive than using the 175 Nosler and learn more about wind reading. What does it cost you to drive to a 1,000 yard range and shoot on it? With other LR shooting costs often proving substantial, skimping on components may be a poor form of economy.

 

[lee1000]

Your starting point should be a 'good' 155 at ~ 3,000 fps and able to group into 0.2-0.4 MOA. The newer Sierra 155 Palma MK (p/n 2156), Lapua Scenar, and Berger 155.5gn BT Fullbore / 155gn Hybrid meet the bill. The 175gn Sierra MK will stay supersonic from your rifle at this distance but is a relatively low BC design for its weight. The new 178gn Hornady HPBT Match (not the A-Max) might do well, but the majority of efficient and suitable 168-185gn bullets that will suit the Savage 12 F/TR's chamber throat are made by Berger. The original 155gn SMK (p/n 2155) at 3,000 fps MV is a known LR performer and very stable in the transonic speeds if lower BC than the other trio suggested. We get them a lot cheaper than the others in the UK, so it's a viable budget option if that applies to you.

The sad truth is that there are no shortcuts to good 308 performance at this distance and there are no out and out budget options available. If the 168gn Nosler works well for you to 600 yards, stick with it but look at developing a 'LR load' for 800 to 1,000 yards - good luck.

Thanks for comprehensive post, very informative.

Would having the throat lenghtened be worth it, just to lessen the impact of that limitation?

Thanks again Laurie

 

[Clancy]

I didn't read all the replies but surely someone said RELOADER 15

 

[Laurie]

Maybe - depending on the cost. (This is usually done with a hand reamer through the action, so doesn't need the barrel removing and reduces the time you're paying for.)

If you do go down this route, go for a small increase. Unless you plan to shoot the true 'heavies' (210gn and up) at a later stage, a good compromise is one that suits the longer 155s seated relatively shallow in the case-neck when they're just off the lands while such a throat suits the LR BT Bergers and lighter Hybrids very well - 168gn Hybrid, 175gn LR BT and 185gn LR BT Juggernaut.

If you plan to stick to the 175gn Noslers, I'd leave it as it is. Any velocity gain will be small.

 

[lee1000]

Maybe - depending on the cost. (This is usually done with a hand reamer through the action, so doesn't need the barrel removing and reduces the time you're paying for.)

If you do go down this route, go for a small increase. Unless you plan to shoot the true 'heavies' (210gn and up) at a later stage, a good compromise is one that suits the longer 155s seated relatively shallow in the case-neck when they're just off the lands while such a throat suits the LR BT Bergers and lighter Hybrids very well - 168gn Hybrid, 175gn LR BT and 185gn LR BT Juggernaut.

If you plan to stick to the 175gn Noslers, I'd leave it as it is. Any velocity gain will be small.

Thanks, If you could do it all over again and had my rifle, what lower price bullet weight, powder, case combo would you use? At this point I just don't think I would do the higher end bullets justice. You point about costs is a good one, I probably just need to talk myself into using a better bullet.

I originally planned to use the Sierra 155 (2156) and actually bought them but decided to use the 175 because it handled the wind better. Getting practice with that is probably what I need to be working on most of all.

Would the powder option given previously still apply to the 155?