Home Forums Reloading Big Game Rifles The Mauser M12 Extreme .308 Handloading Thread

Those Scenars sure show a lot of promise. I'm still not comfortable using that bullet for hunting like others on this forum do.

It's been way too hot here to shoot, but I did recently buy 2 boxes of 165 Grain Nosler BT bullets the other day to try out. My buddy uses those exclusively daily in his .308 and says no other bullet he has shot gives him better killing performance. I trust a guy that kills animals daily for his job

yes, I will be using my rifle this fall in the Upper Peninsula of Michigan

Tag

I took the 155 Scenars up to book max levels yesterday with both Varget and PP 2000-MR in my M-12. I had used 2000-MR before in my 23" barreled 98 Mauser .308, and was familiar with the very impressive speeds it achieves in that cartridge, and it delivered the same in the M-12's 20" barrel. Alliant got in the mid 2900's with the three 155 grain bullets in their published data but I can't find a citation for barrel length. That's consistent with my results in the 23" barreled M98, as well as the 2892' the 20" M-12 delivered.
I stepped up to 46.5/Varget* and 50.5/2000-MR with the 155 Scenar seated .020 off the lands in Lapua brass with Federal 215 Match primers.
Velocities were 2810' and 2892' respectively. Accuracy was similar at 0.88" and 0.92" for three shots each. Pics attached.
My gut says to go with the Varget load as its ES and SD were a fair bit better than the 2000-MR, though 2000-MR had an 80 FPS speed advantage. Also, I am very confident in the temperature stability of Varget but just don't know enough about 2000-MR's stability (though it is the powder in my go-to hunting load for the 35 Whelen AI).
Based on the impressive results on the "Deceased by Scenar" thread, I am comfortable that this will be a satisfactory hunting bullet, so maybe I am finished in my search for "the load" in my M12. It meets all the criteria I set for "the load" when I started this thread. Of course I still need to load up a larger quantity and confirm consistency. I'll follow up next week.

Still hoping to hear what others are achieving with their M-12s. I hope what I'm posting may help you.

Cheers,
Rex

*[EDIT: Nosler's published max for Varget with 150-155 grain bullets is 46.5. Earlier today I went through several other manuals and found four references to Varget max for 155 gr bullets from 47 to 48 grains. AFAIK, Lapua doesn't publish a load for their Scenars using Varget. So while I am confident 46.5 is safe, it might not actually be max. close enough for me though.]

Lapua LR Case, Lapua 155 Scenar, 46.5/Varget, F215M, .020" off the lands (2.90" COAL)

Short version of this week's results: Ten rounds in 1.32", with the first 3 in a half inch and 8 of them in one inch.
Velocity was 2807 FPS with an SD of 6 for these ten shots. Last week's velocities were 2810 FPS with an SD of 3. Combining both weeks together gives velocity of 2808 FPS and an SD of 5 for 13 shots - getting close to statistical significance on the SD.

Long version: Yesterday I went back to the range with ten identical rounds of the 46.5/Varget, 155 Scenar load described above. I'd cleaned my M-12 after last week's session, so I fired three rounds of factory ammo to pre-foul the bore before shooting these ten.
I was off to a great start with the first two rounds going through the same hole, and #3 landing a half inch to the right, all right on desired POI of 2.2" high at 100 yards.
Then #4 went a bit high/left, and #5 went right back into the same hole as #1 and #2, putting four rounds in a half inch, and five in an inch. I fired the second five rounds on a new target and that group opened up a bit, with rounds 1-3 cutting a 1.32" triangle. Happily, 4 and 5 landed inside those three, and drawing a composite group of all ten showed the five rounds of the first 1.00" group were all inside the 1.32" second group.

I think I can live with this for this fall.

Cheers,
Rex

I am in the final sight-in and transitioning from the bench to the bipod and field position practice phase with this rifle, since I'd settled on the Varget load above for this fall. I ordered a custom dial from Burris for that load and it was done in less than a week, and is in the mail now. That said...

I realized that since going to the 155 Scenar from the 165/168 NBT, I hadn't given Ramshot TAC another try, so I did that this week, in addition to the other work. I found no data for TAC with the 155 Scenar, but searching the data and others' posts online I decided to try 45.5, 46.0, and 46.5 grains. This is based on the following max loads with each bullet maker's 155 gr target bullets:
Nosler 46.0 for 2996'
Sierra 46.9 for 2900'
Barnes 46.6 for 2904'
Ramshot published the following for these 155 gr. bullets:
155 Berger 45.6 for 2883'
155 AMAX 45.1 for 2851'
155 Sierra 45.7 for 2874' (I found this interesting. Probably represents a difference between the test barrels they used and Sierra themselves used.)

Short version, 46.5/TAC in my M-12 put three 155 Scenars under a half inch at 2849 FPS.
I used a Fed 215 primer based on Mule Deer's recommendations with the Ramshot powders in general and his TAC results in the .358 Win. OAL was 2.90, .020 off the lands.
The attachment shows the results. All three were sub-MOA, with the max load giving the best accuracy. Also noteworthy is that a composite of all three groups shows all impacts from 46 and 46.5 grains landing inside the three from 45.5 grains - a nice tendency. IOW, the composite is a 9-shot group under 1 MOA. The ES and SD are not as good as the Varget load, however.
Sample size is very small but I will shoot 46.5/TAC some more. I may end up doing some math to see how far off the POI will be at range if I end up using this load (MV of 2849 FPS) versus the POI of the 2808 FPS I had Burris cut the new dial for. Shouldn't be too far off.

Cheers,
Rex

If I ran the data right the difference is 3/4 inch drift (10 MPH crosswind) and 2.5" drop at 600 yards. I don't reckon I'd shoot this load at more than 500 regardless of accuracy, since that's where it drops below 2000 FPS. At 500 the drop difference is only an inch and a half.
Rex

I took 10 rounds each of the 46.5/TAC and 46.5/Varget loads with the 155 Scenars to the range this morning. I shot all the Varget loads at 200 yards off the bipod and they are sub MOA still (0.85 MOA average) so I plan to stick with them for hunting this fall, based on their low ES and Varget's proven temperature stability.
But the TAC load really does show promise. I shot two three-shot groups at 100 yards off the bench rest, with a slight scope adjustment in between, then shot a 4-shot group at 200 yards.
The 100 yard groups are attached, and a sample size now of three 100 yard groups averages 0.55 MOA. These were all off the bench rest.
I shot the 4-shot TAC group at 200 yards off the bipod and it went 1.64" (0.79 MOA). I was able to chrono 7 of the 10 shots with TAC today and they averaged just 1 FPS slower than last week. SD was the same (12), which is worse than the Varget load. That said, it IS looking like this TAC load is a bit more accurate in my rifle than the Varget.

Good hunting folks - I look forward to hearing how your M-12's did for you.

Cheers,
Rex

Took the M-12 to Montana the last two weeks, planning to use it for my Mule Deer B-Tag (I also had an Antelope tag for which I used the 6.5 CM and a Whitetail B-Tag for which I used my old Win M-94 30-30). My .308 load was the 155 Scenar over 46.5/Varget that I have beaten to death in the previous posts.
I had not cleaned the M-12 since the final range session in Tucson, where I sighted it in for 200 yards (the max my range goes to). Upon arriving at the hunt area, I set up a target at 250 yards and dialed the scope to that setting to confirm zero and tracking. I planned to carry the rifle set for 250 yards for the optimum point blank range, then dial if needed for longer than 300 yards. Test shots were prone off the bipod. It was still sub MOA and pretty much right on for POI. There was a very light right crosswind.

I shot my mulie doe late in the morning of the opening day from 118 yards after glassing up the group of a buck and several does up in the head of a canyon from about 1150 yards out and then making a long and circuitous stalk. She was facing almost directly towards me with her lower chest obscured by brush. I center-punched the spine at the base of the neck, and she dropped immediately and never twitched. The exit wound is visible in the picture.

I hope others are having a good season with their M-12s. I look forward to some success pics and more posts of handload results.

Cheers,
Rex

Bumping this thread up.
I'm just now getting my M12 out and realized I don't have a pictinny rail.
Anybody have one they like to sell? In the mean time I ordered some Tally rings.

Rem280,
Did the rail not come with it in the box? Mine (and I think most of the others who bought theirs on that big sale) had it in the box but not attached to the rifle.
I'm not using mine now but since the receiver of the M12 is the same as the M98, and I have a lot of M98 Mausers, I'd like to hang onto it in case I ever need it on another.
I hope you find one.
Cheers,
Rex

It wasn't in the box. Tallys are working OK at the moment

I'm using Talley LWs too. And I have recently learned some good lessons on bedding these bases to the receiver, and the scope to the rings. Going to give it a try on this rig and see if it tightens groups down even more than they are already.