Home Forums Reloading Big Game Rifles 308 Win velocity/pressure 12 powder test

I recently purchased a new rifle in 308 Win. and decided to install a strain gage to check a few new powders. This rifle has a 22" barrel. One thing led to another and I ended up testing 12 different powders. I used new Winchester brass, 150 gr. Nosler BT and Fed 210 primers. I shot 7 different factory loads to get an idea of acceptable pressure readings. I decided on a upper pressure limit of about 59,000 psi, although I did exceed that once. I'm using an Oehler 43 to measure pressure and velocity. Temperatures were between 60 and 70 degrees. These are the results from this one rifle and I have no idea how these components will work in yours. I also did a primer test of four different primers and also a bullet test of 4 different 150 gr. bullets.

This was not an accuracy test (that comes later).

Overall impression, I was very impressed with the new Alliant 2000 MR. I did a little follow up testing on it and it was remarkably consistent through a 5 round set. I was also amazed at the consistency of the different primers as well as the consistency between the various 150 gr bullets

150 Grain
Winchester XP3 2818 fps, 53,700 psi
Hornady Sup Perf GMX 2849 fps, 57,600
Fed. Prem Vital Shok NPT 2890 fps, 57,100
Rem Core Lokt PSP 2747 fps, 52,600
Fed Soft Point 2751 fps 50,000

165 Grain

Fed Prem TBT 2655 fps 54,300
Hornady SST Sup Perf 2761 fps 58,800

Powder Test � New Winchester brass (primer pocket, flashholes done), Fed 210 primers, 150 Nosler BT (seconds) seated .030 off lands. From fastest to slowest.

Alliant 2000 MR 53 gr 2938 fps 58,200
AA 2520 47 gr. 2890 fps 58,800
TAC 46.7 gr. 2882 fps 58,900
IMR 4064 47 gr. 2877 fps 59,100
BLC2 49.7 gr 2870 fps 57,100
IMR 4895 46.5 gr. 2865 fps 58,000
VV 540 48.1 2859 fps 57,400
RL 15 47.5 gr. 2850 fps 57,200
IMR 4320 47 gr. 2849 fps 60,200
IMR 8208 XBR 45.5 gr. 2844 fps, 58,200
Win 748 46.5 2838 fps 58,800
Varget 46.5 2791fps 58,700


Bullet Test - all using 50 gr. 2000 MR, Fed 210 primer, bullet seated .030 off lands

Nosler 150 gr BT 2783 fps, 50,600 psi
Barnes 150 gr. TTSX 2793 fps, 50,900
Nosler 150 gr. Part 2778 fps, 48,900
Nosler 150 gr Accubond 2800fps, 51,100

Primer Test � all using 50 gr. 2000 MR, Fed 210 Primer, 150 gr. Nosler BT, .030 of lands

WLR 2808 fps, 51,500
Rem 9.5 2801 fps, 50,900
CCI 2000 2801 fps, 50,900
Federal 210 2805 fps, 51,500

just for your info. I have shot 26 150gr ballistic tips over my cronograph for an average of 2805fps. 1965 remington 700 22" barrel 47gr varget. It is nice to see your data, thanks

Excellent info Logger!

Very interesting.

You wouldn't by chance have a strain gauged 280AI would you?

Thanks that is interesting info.

I recently chrono'd some 150 ballistic tips over 47.0 gr of TAC in a couple of .308's. I got 2840 fps from a 20" M70 carbine, and 2950 fps from a 24" M700. The load was very accurate in the M700, but not in the M70 carbine.

2000-MR is incredible. Equally impressive in 7-08

How heavily compressed is this load?

You beat me to it.

The powder column comes up to about .270" from the mouth of the case. Therefore, for this loading, in this rifle, not much compression. Certainly didn't hear it (although you usually don't with the small ball powders) nor did I feel it when seating the bullet. Since I have a 3" magazine on this rifle I can have a fairly long OAL. In this case, being .030" off the lands gives an overall length of about 2.920". I did not use my 2 ft drop tube as I have on other loadings to shorten the powder column.

Now the handloads you made and tested, are those max loads, mid range, what? Btw, very interesting and cool, thanks for sharing.

Ok your next test which loads were more accurate.

Cool test, I use varget in my 308 but I might have to do some expermenting with some new powders.

The info on the primers was interesting as well.

SAUMHunter:

I consider the listed loads to be the max for my rifle. The highest pressure factory load was about 59,000. So when I was working up loads, any time I got to 57,000 - 60,000 I stopped and considered that to be the max load for that powder. Depending on the powder, there is easily 1,000 - 2,000 psi variation on a normal shot to shot basis, even with every thing being held as constant as possible.

Could not agree more.

Thanks for posting your results Ken..

I'll have to pick up some of that 2000 MR...

I've been working with AR Comp recently in several calibers and it is also pretty impressive for accuracy and consistency...

Excellent test. FWIW when I run your results past quickload it thinks all the loads should have been faster and higher pressure. It "thinks" many of the loads would have been about 50-90 faster and pressures might have run 62k to 68k or thereabouts.
Some of this could have been "roomier" brass than quickload used but I am curious....would you consider your gun to have a little extra "freebore". IE what length were those bullets at to be .030" off the lands.
Also....some time for fun...could you shoot a virgin brass and then take the same piece of brass and neck size it and see what the new pressure and speed are....I'm thinking it might go up a bit.

Well done test.
Two questions I would have are, one, how temperature sensitive is 2000MR ? And, two, which shows the least deviation ?
TAC, BTW, is getting my attention as being very interesting. It doesn't work nearly as well in Federal cases. E

Thanks for the info. In my 308 (Ruger M77 Mk II) 46gr of TAC in new R-P hulls, WLR primers, 150gr Hornady SPs gave 2912 fps but at temps at or near 90. Accuracy was inconsistant with that seating depth. Going to shoot with different seating depths and with some RL-15 and Varget loads using same components this weekend.

Kraky:

I noted the same on Quickload and it is one of the reasons that I have enjoyed working with the Oehler 43. I don't have my quickload with me right now (I'm traveling) but a once fired piece of 308 Win brass in my rifle has a water capacity of 57.20 grains measured to the mouth. The OAL length of the cartridge was right around 2.910". The next time I have the pressure/velocity system up and running I'll try the virgin vs. once fired brass test. What version of Quickload is the most current and does that version have some of the newer powders such as 2000 MR and IMR 8208?

E:

I don't know much about the temperature sensitivity of the 2000 MR as I tried to do all my shooting during a time of relatively modest temperature (for those of you in Texas, that means 60-70 degrees). The most consistent by far was the 2000 MR. The result below are for a 5 shot string of 52 grs of 2000 MR (1 grain below my max) fired as quickly as I could do the SAMMI twirl and single load the cartridges, aim and shoot

2877 fps, 54,800 psi
2887 fps, 54,800
2879 fps, 54,000
2889 fps, 54,000
2876 fps, 54,300

Based on my observations over time, the numbers above are really remarkable. Of course, I still don't know how accurate the 2000 MR powder will be, but consistency tends to help accuracy. I have some more pressure testing to accomplish so accuracy test will wait (I use an old stock for pressure testing since the strain gage requires some minor stock modifications. Once I go back to the good stock, the strain gage has to come off).

By the way, I did conduct one other minor test that I forgot to mention early. Shooting the same powder charge, I varied seating depth from .005, to .030 to .060 and saw no difference in velocities or pressures.

+1 about pressure in Quickload. I am running 45.0 grains of TAC in my .308 with 150 TSX's, and was scared to go that high. I do have lots of freebore in my Sako. After cautiously going to 46.0 grains, I found no issues with the load. I settled on 45.0 because it was the most accurate. I think Barnes has 45.5 as max, but I have to look to make sure.

So, any insights why Quicload has the high pressure? I noticed it did the same with TAC in my .350 mag.

Logger, thanks for taking the time to write up your results. Muct appreciated!