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338 Win Mag 1000 yard build questions

By the way I'm from Ohio, moved to tenn. I've designed a few reamers. One is a wildcat cartridge that predates the 22 TCM another is a black powder version of a 444 Marlin. That one turned into a beautiful rolling block. The one that I was playing with just before this for the last few years is a 20 gauge slug gun on a Winchester high wall c sharps 85 action with a heavy pacnor barrel and mva scope
 
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The plan is to use 250 grain bullets. I'll be happy with 2700 fps which should get me to 1400 yd supersonic. Anything more is gravy but I have a feeling I might be able to squeeze a bit extra tho with slow powders and that 28 inch barrel. I've used that philosophy in my 30-06 using rl22 and a 26-in barrel and I can achieve factory 300 win mag ballistics with 190 grain bullets
 
Not sure you'll gain a whole lot more using 300PRC brass vs 300WM brass. With the mag length you speak of having, the 300PRC brass won't be much advantage. If you had longer mag length, maybe.
 
Barrel and receiver are now mated with proper headspace. Dummy cartridges have been adjusted. Small problem with resizing corrected. All is well so far. Hopefully tomorrow I will put on the brake for good.
 
You state your rifle is intended for target work.
I think bag control of your rifle will be a major concern. A heavy weight bullet in a .300wsm is not easy to master and the 250-300 gr bullets in a .338 will exacerabate the problem.
Maybe some target shooters can address this better than I. A hunting rifle is another animal.

If you really want a target shooter perspective........

Nobody shoots the 338 WM as a long range target rifle. While it is an excellent hunting round, there are much better choices for target shooting.

I currently shoot 1000 yd BR. My light gun (17 lbs) is a 6 BRA and my heavy gun (30 lbs) is a 300 WSM shooting 215 grain Berger's. It shoots very well. I shot in three matches this year and wound up with three 10-shot 1000 yd screamer groups (4.33, 3.88, 4.9).

The 300 Norma and 300 Norma IMP seem to do well at 2000 yds, as do the 338 Lapua IMP. We have an ELR shooter in our 1000 yd BR club that is working with the 300 Norma IMP. He has also shot either the Edge or Lapua IMP at 2000 yds.

My "timber" elk rifle is a 33-28 Nosler on a stainless CRF M-70. It weighs 8.75 lbs with the scope. It shot 225 Barnes TTSXs very well at 3170 fps, but my current load is 250 grain Accubonds at 2825 fps. I tried the 250 Berger EOLs and got them close to 3000 fps, but the barrel didn't like them. I also tried the 265 ABLRs, and like everyone else, these bullets shot poorly. They are .0005" underside and we think that is why the 265 ABLRs shoot so badly in most barrels.

I have also had a couple 338 Edges that shot very well, I've had a couple 338 WMs, a 338 RUM, and a couple of 340 Wbys. All of these were custom built rifles. I have also developed loads for a few 338 Lapuas and 338 Lapua Improveds.

With the 338s there is a definite break point. Lighter weight rifles will shoot 250 grain or less bullets well with good accuracy and minimal torque. Bullets above 250 grains start to impart a lot of twist. While having a hunting rifle twist in the bags and occasionally throw a shot horizontally might be fine in a hunting rifle, that is a no go for a target rig. @Alex Wheeler, who has tested this a bunch, says a 338 needs to be in the 12-13+ lb range to really handle the heavier bullets well.

I made my 33-28 because I thought it was about as much recoil as I wanted with a non-braked carry rifle, and 338 RUM brass was hard to find. If I were doing it again I'd just built a 338 RUM and add a brake. I needed a RUM magazine and follower for my 33-28 anyway. I would still keep to bullets 250 grains or less.

For a long range target rifle the 338 Edge is hard to beat for a standard magnum action. You can get long magazine boxes for both Rem 700 and Win 70 actions from Wyatts Outdoors. If you are not stuck on using a factory action, and you shouldn't be nowadays, the 338 Lapua IMP is excellent.

You can get ADG brass for the Edge and Lapua brass for the Lapua. And it is definitely worth picking a cartridge so as to be able to use high quality brass.

If you want a lower power 338 the the 338-300 PRC or 338-300 IMP should be at the top of your list. ADG makes brass for the 300 PRC. Don't even consider the availability of factory ammo for a target rifle.
 
The 33 Nosler is worth a look. With the price of Nosler brass what it is this ammo is not a bad buy.
 
More adjustments... my dummy rounds had quite a bit of run out since they were formed instead of headstamped brass. Did a chamber cast to double-check everything. Looks like a few of the dimensions are about .0005- .001" over true reamer dimen.... Or so that's what my calipers and micrometer tell me. I don't think it's a big problem, the freebore is right anyways and it's still a tighter chamber than factory. So I'm just going to make the neck walls .001" thicker than originally, and I'm going to trim the cases less my dummy cases measured 2.485" I'm going to use 2.510" instead ... (about .025 longer). I'll still probably lose a few thousandths in length once they are fire formed anyways The muzzle brake is now fully installed.
 
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I'm in the process of putting together a 338 WM for 800-1200 yard target work. I have shot 300 WM at 1000 plenty, and have the desire for more energy downrange. A hammer if you will. There really isn't any other reason than wanting to play with .338 projectiles and not going superdeep down the cost rabbit hole of bigger 338's. What I can't seem to find is how a standard chamber does with 250gr and up bullet options ( smk's, bergers, hornady hpbt's) in regards to seating depth/case capacity. I'd really like some insight with shooters that have played with the heavies in the 338 WM. Barrel lengths vs velocity,
Realistic velocity with 250gr+ projectiles,
Twist rate, etc
Please give me an earful!
I know there are better options for this, I just like beating the hell out of myself as cheaply as possible.
i think you are forcing yourself into a poor choice. a 338edge is a great choice with adg brass available. throated and correct powder it should do well. as a wildcat..how about a 338/300 prc. i have shot 230's out past a mile in a 300 winmag( 3.5/6" coal) as far as chamber length, a throater reamer can be used to get the right COAL.
 
Personally don't have anywhere near me to shoot past 1250. I figure I can stay supersonic to 1400 ish with a 250 gr tho. No need for a bigger cartridge.... Fine by me
 
Finished the final touches this morning. It is officially a working gun. Unfortunately it's too crappy outside for the Chrono to get a reading but I can tell you that 70 grains and 75 grains of h1000 were no problem...cases extracted fine with no pressure signs and very little recoil. Final weight is 18 lbs
 

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Okay, got a sunny morning had to change powders but I did hit 2700 with 7828ssc , then 2800 with imr4350....
Max load with h1000 was 77 grains at 2693 fps(that was using a drop tube and loaded all the way to the base of the neck). no dangerous pressure signs with any load, primer pockets are still good about three firings each on three cases. Resize is stiff but manageable.
 
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I didn’t read the thread yet, and maybe something like this is already mentioned. In my 1,000 yard Fclass shooting, I have found that no .338 match bullet is yet made that permits the .338 LM to shoot “inside” one of the smaller caliber options. The BC for .338 bullets is just not there presently, and that is with the Lapua Magnum case.

I have a number of older, very accurate .338 LM barrels but nothing is more frustrating than making wider, riskier wind calls with ~87 grains of powder and $.90 bullets, just to hope to shoot the same score as .284 can provide, (more easily) let alone a saum.

I think the effect would be even more pronounced with a smaller case. JBM trajectory tables confirm my own match experiences with these, without the cost of proving it three dimensionally. (But matches aren’t everything, thumpers are needed too.)

It’s perplexing and somewhat frustrating that the bullet makers squeeze more BC out of 30’s and even some 7’s, than the .338’s. They aren’t for everyone and I suppose are a low priority. There is currently no match grade .338 that needs the fast twists we have now in 30’s and 7’s meaning that even the heavy .338’s are relatively stubby and short for the caliber, awaiting the next generation of submarines to emerge.

A good example of this is Hornady’s 250 A-Tip 30 cal. It has a higher BC by a lot than the 300 grain .338 Atip Hornady introduced at the same time. .338’s need a catalyst to force them to evolve into the next weight class, with BC’s in the high 9’s, for matches. If splash or impact energy matter, then maybe, but at 1,000 on paper they aren’t pulling their weight as they are presently offered.
 
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Warner tool makes some nice but expensive 338 bullets lathe turned copper. 256 gr Bc almost .900 g1 285 grain with a BC almost 1.00 needs 1:9 twist
......
but in the end it's not just about f class shooting. Sometimes it's just about what CAN be done because you feel like it.:)
Ever seen somebody shoot a 22 lr @ 1000 yards? I frequently do it at 500. That's fun!
 
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I just experimented with 275 gr Speer 2 days ago to see what velocities were possible with that weight in a 338 Win Mag 24" factory hunting rifle.
Surprisingly I was able to get 2675 fps with a mag length hunting bullet...if it was possible to get that speed with the Hornady 285 ELD only ten grs heavier, with throating the barrel if necessary...you would have a pretty good LR round in 338 Win Mag, with easy to obtain, and cheaper brass.
 

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