I have a friend that just bought a 338 win mag. I am not familiar with loading for this cartridge. What are your favorite loads and powders? Thanks

I assume you are referring to loads for a .338 Winchester Magnum. There are few more .338 caliber guns out there now days.

I have been shooting the .338 Win Mag for a long while and have found what I think are some outstanding loads for the cartridge.

The lightest bullets I find much use for in the .338 Win Mag are the 200 grainers. I have found that 74 grains of IMR 4831 behind the 200 grain Nosler Ballistic Tip shoots really great in my rifle. The last trip to the range with this load produced a 3 shot group at 100 yards of a mere 0.44 inches. The velocity was 2955
fps. This load utilizes the Fed 215M primer.

My particular rifle just does not shoot the 210 Nosler Partition well. This bullet is favored by lots of 338 shooters, but my gun has never shot very good groups with it.

My rifle much prefers the 225 grain Nosler Partition. My favorite load for this bullet uses 71 grains of H 4350 for a velocity of around 2890 fps and groups of about 3/4 inch.
This load again uses the Fed 215M primer.

I used to just shoot the 250 grain Sierra boat tail all the time. That is a big old bullet with a hell of a shape. I have never recovered one, they have gone through everything I ever shot with one.

With the 250 Sierra I could never really decide which of two loads was best. I had great luck with the CCI 250 primer, 70 grains of IMR 4350, and the Sierra 250. I had identical performance using the CCI 200 or Fed 210 primers under 72 grains of Reloder 19. Groups were 3/4 of an inch if I did my part and velocity was about 2770 fps.

Pay particular attention to my primer recommendations here. DO NOT use the Fed215 primer with the IMR 4350 or RL 19 loads, pressures will climb to unsafe levels.

As a side note, I tried the new Nosler 225grain Accubonds but could not them to shoot well for the most part. I tried them in 5 different rifles of .338 Win Mag or 340 Wby Mag calibers and they all shot poorly. But, when I tried it in a .338 RUM they shot very small groups. You just have to find what your rifle shoots best.

R F

H4350, IMR4831 & RL19 are good powders to start w/ for bullets 200gr-250gr. Check any of the laoding manuals for loads, but these pwoders will usually give best accuracy w/ highest vel.

I went to the range yesterday. The best loads out of about 10 I tried in my model 70 .338 WIN MAG all had AA3100 powder.

The best was 69.0g, 250 Sierra BTSP, Fed 215 primer. 3 shots in less than an inch. Plenty good enough for hunting, if I do MY part!

It WAS 67.0g 3100, NOT 69.0g with the Sierra.
It was 69.0g 3100 with the 225 Hornady.
Sorry 'bout that!!

I agree. Watch the pressure with the 215's. They do seem to show signs of pressure earlier than other primers in my limited experience. Sometimes 2-3g less powder.

I am going to try my same loads next weekend with CCI primers. An "old guy" at the range said they are more consistent in his loads and do not show signs of pressure like the 215's.

This guy is an old-school reloader, been doing it for over 30 years. I will see if his wisdom pays off...

D Hunter:
I never could get consistant accuracy in my .338 Mag. with any of the 4831/4350 powders. After a lot of work, I found the 225 gr. Northfork in front of 70.5 grs. of Rldr-22 gives me the best & most consistant accuracy. I always hunt with a premium bullet so cost of those to me is negligable. I tried the 225 Gr. Partition but still could not get the accuracy I do with the Northforks. Work your most accurate load up using an inexpensive bullet - I used the 225 gr. Hornaday, then follow the instructions for load workup that comes with the Northforks. Finally, I play with seating depth. At the range & from a bench, I wear a Past recoil pad to help mitigate the effects of recoil. HTH some. Bear in Fairbanks

If you want to have a reduced load for a load of practice shooting, 35 grains of Blue Dot powder with a Speer or Hornady Bullet will give you a very accurate load, with about 50 to 60 % reduction in recoil. Velocity will be in about the 2250fps range, equal to the old 30/30, but with pointed bullets a lot flatter trajectory.

It is awfully useful when hunting whitetails with range limits of 200 yds also.

Surprisingly in my 338 mags, the point of impact is right on with the regular full power loads at 50 yds, for range practice.

Beyond the reduced load, if I am loading her up, I use every thing from 3031 to 7828 with excellent results for accuracy. It does not seem to be a picky caliber for accuracy potential.

cheers and good shooting
seafire

I like H4350 with 250gr Nosler Partitions. Getting 2700 fps with max loads (which is 69.5 grains in this rifle) and is the only accurate load in my rifle(Ruger old model 77). It has never liked the 210 NP or any of the 225 grain loads, but the 250 gr partition and H4350 shot very well.

BigBullet

The 338 Win Mag and the 30-06 have the same expansion ratio and cover the same range of velocities...hence they use the same powders.

quote:

Originally posted by Sabot:
The 338 Win Mag and the 30-06 have the same expansion ratio and cover the same range of velocities...hence they use the same powders.

Explain please. I understand the range of velocity but what is expansion ration and how is it calculated.

Any other calibers like that? Maybe the 300 win and the 270?

Here's 3 of my best loads for my 338 Winchester Magnum.

225 Nosler AccuBond
Rem. Cases
70.5 gr. IMR 4350 CCI 250 Primers
COL 3.35
Velocity- 2827fps
Accuracy with this load was outstanding.

Another good one...
225 Nosler Partition
Rem Cases
CCI 250 Primers
69.5 gr. H4350
COL 3.34
Average fps 2793
the accuracy with this load was excellent as well.

210 Nosler load...
210 Nosler
Federal Cases
CCI 250 Primer
70.5 gr. IMR 4350
COL 3.31
Fps Average 2916
Great accuracy here too.

For the 210 Nosler load I used Federal cases. They have a little less capacity than the Remingtons, so if you use different cases, you will get different results.

My one and only load for my A-Bolt .338 Mag is 72 gr of IMR4350,Nosler 210 gr Partition, Federal 215 primers. This gives me 3050 fps from a 26" barrel and accuracy that runs between .5-.75 MOA. Work up to this slowly.

Thanks Sabot, just learned something.

Would you mind doing the same calculations for the 270 and 300 win? Where do you find the tables for case capacity and burn rate?

Sabot

Steve lists the burn rate for 4350 at 176. How does this number relate to your 4.1?

I think Steve's 176 is a ranking on an ordinal list from fast to slow...or something like that.

My number is just the ratio factor divided into the velocity. To keep them straight, I often multiply it by 10 and think of it as a car speed...4.1 times 10 is 41 MPH. The slowest powders will be around 25 MPH and the fastest well over 200.

For the 270: 63 grs capacity/ .277X.277 = 808

For the 300 winnie: 83.6 grs capacity/ .308X.308 = 881

If you divide these into a velocity of, say, 3100 fps, you get values of 3.5 to 3.8 which is not that far apart and dead center on 4831.

For case capacity I use the Handloaders guide or just measure it directly with a powder scale and water.

quote:

Originally posted by Sabot:
The slowest powders will be around 25 MPH and the fastest well over 200.

For the 270: 63 grs capacity/ .277X.277 = 808

For the 300 winnie: 83.6 grs capacity/ .308X.308 = 881

If you divide these into a velocity of, say, 3100 fps, you get values of 3.5 to 3.8 which is not that far apart and dead center on 4831.

So how do you correlate 4.1 to be between 4350 and 4831 and 3.5 to 3.8 to be dead center on 4831? Is there a table somewhere or is this your system.

Don't get me wrong. 41 mph for the 30-06 & 338 and 80 mph for the 270 & 300 sounds entirely appropriate. Before, I thought that you used the slowest powder that you had capacity for, since slow powders were supposed to be more accurate. Never would have thought of 4350 for a 338.