338-300 Norma Improved 35 degree

[tom]

Actually 338-300 Norma improved would be technically correct. So I had Alex rebuild his personal 300 Norma improved into a 338 version for me. I plan a bit more testing with maybe some actual hunting bullets down the road. But I was able to put off winter hibernation long enough to get everyone some data. I was looking for edge performance in a repeater and believe we have that in only a 26 inch barrel.


Fire form load was 250 Sierra match kings, in the lands about 15 thousandths. Winchester wxr powder (I believe it's basically identical to rl 22.....possibly the "sweepins" lol)

Fire form load, zeroing at 100 yards.



Tall target, scope calibration with fire form load





871 yard 3 shot fire form load, 2920 fps.


871 yard 3 shot group with v570. 300 Berger at 2870 fps.




A look down my "range"



The die fits great and is very nice by Hornady(for Alex), and does sizing for both his 300 and 338 Norma improved cases, it's just a matter of switching the bushings. The rifle is 14 lbs 14 ounces and shooting 300s I wouldn't do it one ounce lighter!
This rifle finally gave me a chance to mount my kahles 525 HD, and wow is all I can say. 25 power and have seen my 338 holes 4 of 5 trips at 871 yards! I really need to pester them for HD glass in the 1050!

Tom

 

[tom]

I actually shot RL 33 the day before in terrible wind and liked what I saw better with it. My first "pet load" with this one will be 300 Berger, 45 off touch, 99.0 grains of RL 33. 98.5 and 99.3 held 2.2 vertical for 6 shots (3 of each overlapping). Velocity was 2859 to 2871 for all of those 6 shots, both charges. 215 primer on the RL 33 load was best for me. It started coming in at 100 grains with cci 250s but the powder was compressed to much for my liking. I just need to verify on a better day how much horizontal the load has, and maybe tweak the seating to get the most out of it.




100.0 RL 33 below, with a very slow pour and drop tube.


I haven't measured anything as of yet that would indicate any pressure. I've yet to expand a rim even a tenth. So far have taken +100% fill of v570 to 95 grains, velocity of 2925. And RL 33 to 100 grains, velocity 2900. This is as stated earlier only a 26 inch barrel. Hopefully @Alex Wheeler can chime in here with build components. I buy to many NEW bench guns, so I have to resort to these old used hunting guns .




Lapua 300 Norma cases necked up with a Sinclair .336 carbide turning mandrel. No turn chamber, and as of yet have only used a 364 bushing..366 loaded with my lot of 300 grain Berger's.

Tom

 

[Drop Port]

Nice BAT! Are you running Lapua brass?

 

[Alex Wheeler]

Thanks for the data. Right now I have more of these 338 Norma imps to build than the 300s. Its an impressive case and offers a lot for a repeater. Still like the 300 in the lighter rifles just for the recoil. Thats a tuned up Bat HR in a McMillan A3 with a Krieger barrel, jewell trigger, and T3 brake.

 

[tom]

Nice BAT! Are you running Lapua brass?

Thanks,, edited above. Yes lapua 300 norma.

Tom

 

[tom]

@rhovee has one as well. I believe so far he is liking the v570 best with his 24" barrel for around 2810 velocity. I believe he said he likes cci 250s with that powder, which I haven't tried as of yet. Alex is doing one for my boss in a 28", and we should have data for that at some point this winter.

Tom

 

[Drop Port]

Thanks,, edited above. Yes lapua 300 norma.

Tom

I've been through three 338 Norma barrels and they were all awesome. I always felt there wasn't much to improve on but was wrong. No experience with Lapua brass but with Norma Brass the improved version shines with a full case of R-33 at 2900-2925

 

[tom]

I've been through three 338 Norma barrels and they were all awesome. I always felt there wan't much to improve on but was wrong. No experience with Lapua brass but with Norma Brass the improved version shines with a full case of R-33 at 2900-2925

28 inch barrels I'm assuming?

Tom

 

[rhovee]

I have the same set up as Tom from Alex. I have a hard time finding great distance in western WA. But I have been liking cci 250’s with N570. My rifle is:
24” Broughton
EH1 stock
Bat HR.
2700 and 2810 are the nodes I have found. The lower one is the standard 338 Norma speeds. It can be achieved with H1000, Retumbo. Upper one needs a slower powder like N570 and RL33. I have some N565 I will test this weekend. Very similar burn rate to H1000. I am shooting the 300 grain Berger EH. This was my seating depth testing at 100 a few weeks ago.

 

[Drop Port]

28 inch barrels I'm assuming?

Tom

Yes, most are 28 but 26 aren't giving up much at all

 

[tom]

Even at only 2870, these 300s are turning up the frozen tundra behind the 871 target boards.

 

[mikeeg02]

Even at only 2870, these 300s are turning up the frozen tundra behind the 871 target boards.

View attachment 1149965

That's a pretty cool picture!

 

[TikkaSporter]

...Lapua 300 Norma cases necked up with a Sinclair .336 carbide turning mandrel. No turn chamber, and as of yet have only used a 364 bushing..366 loaded with my lot of 300 grain Berger's.

Why didn't I think of that? ... Even if the Unicorn Lapua brand 338 Lapua brass ever does show up, the cost difference between the first box of 300 Norma verses 338 Norma alone would Justify the mandrel purchase. Did you have-to/choose-to turn the necks after expanding?

I've been into my 338 Norma AI since last year. Started off re-using the same 25 Norma-Brand cases over-and-over again. After 5 or 6 firings the cases wouldn't hold the same powder charge without difficult extraction. After backing the charge down the necks/shoulders would get very sooty. Originally they shot well with 99.5 gr RL33 and 300 gr Berger EH's.

I just started with a new batch of Petersen Brass. After fire-forming, I'm seeing good results around 98.5 gr - 99.5 gr RL33 with the Berger 300 EH. In both cases the Federal 215M primers seemed to do better than the CCI 250's for me. I haven't attempted to tune for seating depth yet and am using a 0.015" jump. This jump has worked well for this bullet in other barrels I've had (338 Lapua Mag).

I fire-formed with 87.0 gr of H1000 and cheap 285gr Hornady ELD-M blemished bullets. They shot excellent and chronographed at just under 2700 fps.

 

[tom]

Why didn't I think of that? ... Even if the Unicorn Lapua brand 338 Lapua brass ever does show up, the cost difference between the first box of 300 Norma verses 338 Norma alone would Justify the mandrel purchase. Did you have-to/choose-to turn the necks after expanding?

I've been into my 338 Norma AI since last year. Started off re-using the same 25 Norma-Brand cases over-and-over again. After 5 or 6 firings the cases wouldn't hold the same powder charge without difficult extraction. After backing the charge down the necks/shoulders would get very sooty. Originally they shot well with 99.5 gr RL33 and 300 gr Berger EH's.

I just started with a new batch of Petersen Brass. After fire-forming, I'm seeing good results around 98.5 gr - 99.5 gr RL33 with the Berger 300 EH. In both cases the Federal 215M primers seemed to do better than the CCI 250's for me. I haven't attempted to tune for seating depth yet and am using a 0.015" jump. This jump has worked well for this bullet in other barrels I've had (338 Lapua Mag).

I fire-formed with 87.0 gr of H1000 and cheap 285gr Hornady ELD-M blemished bullets. They shot excellent and chronographed at just under 2700 fps.

I chose not to turn, however Alex's reamer isn't grossly over so a guy could. When I tested seating (coarse) it showed promise 15 in, 10 off, 40 off and 50 off. I've been shooting them 15-18 in on my lapua improved, but that's basically a once per year target rifle lol. I will work on my jump node with 98.8 this Saturday.


Tom

 

[rhovee]

Your going to wish you chose N570 and cci's.

 

[TikkaSporter]

...Lapua 300 Norma cases necked up with a Sinclair .336 carbide turning mandrel. No turn chamber, and as of yet have only used a 364 bushing..366 loaded with my lot of 300 grain Berger's.

Tom

What was your neck wall thickness on the necked up Lapua 300 Norma cases? How consistent was the thickness of the necks on this brass?

FWIW I measured all 50 pieces from my box of Petersen brass. All were between 0.015" - 0.016", pretty much no more than 0.001" in neck thickness variation.

 

[tom]

What was your neck wall thickness on the necked up Lapua 300 Norma cases? How consistent was the thickness of the necks on this brass?

FWIW I measured all 50 pieces from my box of Petersen brass. All were between 0.015" - 0.016", pretty much no more than 0.001" in neck thickness variation.

I measured about 20 after the second firing....my plan was to sort them. But after doing 20, the smallest number was .0137 and my largest was .0143. I set my stop to measure about where my OTM pressure ring would sit, and took 4 readings at quater points in each case. I decided after 20 it wasn't worth worrying about.

I should edit here to add that this was out of the first run of brass they made. I acquired it from out of country very early on. I heard some slightly different numbers from some folks with brass out of later lots. But I haven't seen anything but my first run of brass.



Tom

 

[rhovee]

The second run of brass does measure different.

 

[tom]

Update on load data for everyone.

Since I still haven't gotten myself some N570, I decided to work with retumbo and 285 eld-Ms. My barrel maxed out about 91 grains, and my load wound up to be centered around 89.0, with a jump of .020". I only tried federal 215s with this combo.

It produced a decent group testing seating today at 871 yards, at a velocity average of 2870.




Another sister rifle my buddy had Alex build started load development today as well. I had him pursue the N570/300 otm combination since it was his powder I borrowed to get initial results. He loaded with cci 250s. His barrel is a 28" and came in with great groups(I don't have picture) at 92.0(lowest tried) at a velocity of 2800 even. It came back in up at 94.0, 94.5, and 95.0. All of them were sub 3" vertical at 871 yards, and the average velocity is 2920. These were all at 10 jump today.


Between the 2 I have been around, plus Ryan's.... I would say N570/+-94.5/cci 250s/300 otm seems to be an EASY BUTTON.

Tom

 

[tom]

But they still won't hang with a 6mm for score!




Lol