.338 random questions

snowplow · Nov 25, 2024

I got a couple of random questions of the .338 cal. I wasn't sure exactly where to put them, but I have them in mind for a bolt action so I put them here.

I'm basically a noob learning about reloading so I have limited understanding but I'm trying to put it all together.

A .308 win can be loaded subsonic and many but not all seem to think it's adequate, so why is it so hard to load a .338 fed subsonic? I'm asking because that doesn't make sense to me with the facts l (think) l know.

1. Same basic case l believe
2. Can get up to 300 gr bullets
3. People complain of having way too much case capacity in .308. Doable but on the edge. My understanding is that's with the large trail boss powder.
4. The larger 2-300 gr .338 bullets should only help in that regard.

What am l missing? It seems like this would be the perfect cartridge for a short range super/sub gun.

Also with the same idea in mind

How good is an 8.6 blk supersonic? Is it anywhere near the 338 Federal? How about the 308 Win? I can't find much info on that. I thought I remember hearing that it was supposed to be good. Super and subsonic but maybe I remember wrong. Just a sub caliber?

Hondo1 · Nov 25, 2024

You can absolutely load .338fed subsonic, what you will run into as far as limitations are C.O.L. while using heavy for caliber bullets in a short action. Trailboss is the answer if you can find it. The whole point of the 8.6 BLK is to fix the length issues.

snowplow · Nov 25, 2024

That's what l mean though. If C.O.L. is maxed, then presumably more bullet is in the chamber vs a .308. So if a .308 works ok, a .338 fed should only work better, no? I've read about people saying there's not enough room for trailboss, but pretty much everything else is smaller powder which would solve that problem right?

45-90 · Dec 5, 2024

The 338 Federal has too slow a twist rate for 300 gr subs. Get a 6.5 twist barrel and it will shoot 300 gr subs.
It has too much case capacity for subs just like the 308.
But TrailBoss powder will do the job in bolt guns of most any caliber, I use it & Red Dot in the 50BMG subs.
With the 1-12 twist you would need to shoot light short bullets to stablize them at sub velocities. Like 180 gr or 200 gr Speer is 1.118" a short bullet will probably work for you, as well as a 175 gr works in a 308 1-12 twist with TrailBoss.
Even the 8.6 Blkout has too much case capacity for subs, but it's a lot better than any 338 Federal. Get the 6.5 twist my 8.6 was terrible in the 3 twist for accuracy and mostly a copper bullet shooter with 1000 fps velocity limits for most...or it blows up inside your muzzle device throwing shrapnel everywhere.
For subs only the 338 Spectre 6.5 twist is very good as well as the new 338 ARC should be...but Hornady is putting it out with an 8 twist...might be too slow for shooting long 338 bullets in the 300 to 350 gr range, as their bullet appears to be a non match profile but a short flat point for short range hunting.
Your best bet with the 12 twist is 200 gr Speer loaded to normal length and TrailBoss powder if you could find some.

SMH · Dec 5, 2024

I haven't reloaded for the 338 Federal but I did work up a load for a friends 8.6Blk (1:3 twist)

15.3 grains of Accurate 1680
280 grain Barnes LRX
OAL 2.760
1055fps MV
USE AT YOUR OWN RISK!

The factory Gorilla 210TSX averaged 2065fps.

I felt that is was too slow in supersonic loads and had excess capacity in subsonic loads.
Yes, it could easily do both, but the trajectory was very depressing for use as a hunting round.

snowplow · Dec 5, 2024

45-90 said:
The 338 Federal has too slow a twist rate for 300 gr subs. Get a 6.5 twist barrel and it will shoot 300 gr subs.
It has too much case capacity for subs just like the 308.
But TrailBoss powder will do the job in bolt guns of most any caliber, I use it & Red Dot in the 50BMG subs.
With the 1-12 twist you would need to shoot light short bullets to stablize them at sub velocities. Like 180 gr or 200 gr Speer is 1.118" a short bullet will probably work for you, as well as a 175 gr works in a 308 1-12 twist with TrailBoss.
Even the 8.6 Blkout has too much case capacity for subs, but it's a lot better than any 338 Federal. Get the 6.5 twist my 8.6 was terrible in the 3 twist for accuracy and mostly a copper bullet shooter with 1000 fps velocity limits for most...or it blows up inside your muzzle device throwing shrapnel everywhere.
For subs only the 338 Spectre 6.5 twist is very good as well as the new 338 ARC should be...but Hornady is putting it out with an 8 twist...might be too slow for shooting long 338 bullets in the 300 to 350 gr range, as their bullet appears to be a non match profile but a short flat point for short range hunting.
Your best bet with the 12 twist is 200 gr Speer loaded to normal length and TrailBoss powder if you could find some.

Thanks for the reply. My idea (which is just a faint idea still) is to use my short 18" 308 deer rifle to experiment with my suppressor. That I got thinking if I rebarreled it to a 338 Federal maybe it would do both supersonic and subsonic better. If I'm understanding how this works correctly, I can also choose a tight twist. For context supersonic I'm always under 200 yd. Realistically mostly under 100. There are some areas where I can hunt legally small plots, but it would require be quiet at the owner's request. So I was thinking it might also provide a good hard-hitting subsonic round where a Max shot is like 60 yd. That's the idea that I'm exploring anyway.

45-90 · Dec 5, 2024

snowplow said:
I got a couple of random questions of the .338 cal. I wasn't sure exactly where to put them, but I have them in mind for a bolt action so I put them here.

I'm basically a noob learning about reloading so I have limited understanding but I'm trying to put it all together.

A .308 win can be loaded subsonic and many but not all seem to think it's adequate, so why is it so hard to load a .338 fed subsonic? I'm asking because that doesn't make sense to me with the facts l (think) l know.

1. Same basic case l believe
2. Can get up to 300 gr bullets
3. People complain of having way too much case capacity in .308. Doable but on the edge. My understanding is that's with the large trail boss powder.
4. The larger 2-300 gr .338 bullets should only help in that regard.

What am l missing? It seems like this would be the perfect cartridge for a short range super/sub gun.

Also with the same idea in mind

How good is an 8.6 blk supersonic? Is it anywhere near the 338 Federal? How about the 308 Win? I can't find much info on that. I thought I remember hearing that it was supposed to be good. Super and subsonic but maybe I remember wrong. Just a sub caliber?

First ..What are you missing you?
You have so much to learn, in grade school, appling for a college degree job. Plus you don't pay attention.
Not to be demeaning, but I already gave you the only answer that will apply to a 338 Federal 12 twist subsonic.
But you insist on a 300 gr bullet that definitely will not work...most run a 9 twist or 9.5 twist to stablize them and that's in giant magnum cartridges ....NOT SUBSONIC.
Example a 10 twist barrel with a 250 Atip at 2985 fps will not stabilize the bullet at 100 yds in a 300 RUM with 101 grs of powder...a 12 twist 308 has no chance.
I run 8 and 9 twists in 308 Win supers for 200 SMK to 230 Atip.
One can run 350 gr 338 bullets in the 8.6 or 338 Spectre...6.5 twist or 3 twist barrel.
It's the barrel twist ....factory 338 Federal is made for up to 225 gr bullets in supersonic mode...period.
So for you 200 gr Speer because the bullet short for you 12 twist barrel, and TrailBoss because it's bulky & works with most any cartridge for subs.
I discarded the 3 twist AR and went to a bolt gun in 8.6 with a custom 6.5 twist, works great on supers lead bullets or copper, and is accurste with subs.
But the tiny cased 338 Sprctre and almost identical 338 ARC should be a good sun gun except the ARC has an 8 twist the Spectre a 6.5 twist which works for all bullets lead or copper as fast as you can shoot them without blow up in these smaller cases.
This is what I run ....
8.6 Blackout ...200 gr Speer to 2600 fps.
225 gr Speer 2400 fps, 250 Speer GS 2200 fps, 300 gr SMK 1970 fps....for supers.
The Speer bullets are short in OAL so they allow more powder capacity.
I also utilize hybrid cases and run to 65,000 psi loads in QL...they have a bit mire capacity.
You can not duplicate these velocities in a 3 twist, it Max's out around 2.5 to 3 grs less powder, as I ownd both 3 and 6.5 twists.
And those lead cup & core bullets can Not be shot past 1200 fps in a 3 twist barrel, full copper only for supers... even the 350 copper expanding Maker can Not be shot over 1050 fps according to Maker...I shoot them to 1670 fps in the 6.5 twist with accuracy.
Can't see the charge weight but here is the 8.6 Blk with 160 gr Barnes at 2800 fps and the 200 gr Speer at 2600 fps.
Do not even try in a 3 twist barrel the bullets will explode as soon as they leave the confines of the barrel.
One can improve things for the 8.6 Blk, but it's still not as good as the 338 Spectre or possibly the new 338 ARC with subs..

45-90 · Dec 5, 2024

snowplow said:
Thanks for the reply. My idea (which is just a faint idea still) is to use my short 18" 308 deer rifle to experiment with my suppressor. That I got thinking if I rebarreled it to a 338 Federal maybe it would do both supersonic and subsonic better. If I'm understanding how this works correctly, I can also choose a tight twist. For context supersonic I'm always under 200 yd. Realistically mostly under 100. There are some areas where I can hunt legally small plots, but it would require be quiet at the owner's request. So I was thinking it might also provide a good hard-hitting subsonic round where a Max shot is like 60 yd. That's the idea that I'm exploring anyway.

The 8.6 Blackout in 6.5 Twist will fit your needs, especially for supers.
The 338 Spectre is available in AR 15 it's light handy a 16" or 10.5" barrel readily available along with cheap dies and brass.
It has Maker bullets available for it the 165 gr super expansion bullet at 2100 fps down to 900 fps should get you 200 yds max.
But they also have 300 gr expanding subs on the shelf I have some, good for most of your work and one guy claimed to have killed his deer at 200 yds with this tiny cartridge.
The new 338 ARC is very similar with 30.5 gr H20 compared to 29 4 gr H20 for the Spectre, but Hornady brass is $104 per hundred and Spectre brass oils $46 per hundred, with SR primers.
Just got the ARC brass today, they are very similar.
So its your choice, but for best accuracy, low powder consumption, good case fill, good velocity spreads, with subs, these tiny cases make the most sense, the 338 Spectre is already available, the 338 ARC is on the way. These are AR 15 platform, much lighter than AR 10 for the 8.6 blackout and do the same job with 300 gr subs, and are so much more accurate than my 8.6 AR 10 with its rough Faxon 3 twist.

snowplow · Dec 5, 2024

I appreciate the info. I know l don't know much about this stuff, that's why l am asking stupid questions. Hopefully they get less stupid soon but l am not stupid. And l assure you l am paying attention. Just for clarification l mentioned that l am thinking l could get my Ruger American 308 rebarreled. Maybe it doesn't work this way (l have more to research) but l was thinking l could possibly have it rebarreled with a 6.5 twist just like you said. I was thinking of rebarreling anyway. You said trailboss in bolt guns works with just about everything. So it sounded possible. Not sure how lm not paying attention. Maybe the spectre and arc are the answer. Everything I've been hearing about them though has been in regards to AR platforms. And it seemed from all the Hornady stuff that I have been hearing that there is kind of an emphasis on stretching out the subsonic to longer distances. Neither of which lm looking for. Therefore l was curious if the 338 fed in a bolt gun could give me similar sub performance at very short range (and l don't need life or death reliability like the 300 blk guys) along with way more super performance 0-200. Seems logical to me. Again, I'm not saying you can do it, but I'm just looking into it until I find out you can't. Even with what you said above, it seems like I might be able to do it. Still not exactly sure. When I find out I can't do it. I'll move on to a different idea. Just trying to have fun and learn something here

45-90 · Dec 6, 2024

Sometimes I have to get your attention, so I can actually help you out with Your needs.
Grumpy old man don't like to type long notes, but it's hard to get the point across in just a few sentences, that you can not get there from where your at, but changes can make it possible.

MOS-TEK will rebarrel your 308 Win Ruger American to 8.6 Blackout with a 6.5 twist barrel, the 5 R SS 6.5 twist 16" to 18" or any length ya want....they charge by the inch.
They have 3, 5, & 6.5 twists for the 8.6 Blackout, I'd get the 6.5, maybe the 5 but never the 3 twist as it's too limiting for supers.
Go to their site, they have many options available...send in your action for solid barrel to action fit, or go barrel nut, and do it yourself with a go gauge, or have your local gunsmith do it for you.
Check your options and final costs and see if it's right for you and your pocketbook.
I build my own rifles and buy chamber reamers so I have the 8.6 Blackout finish chamber reamer.
Here are 2 subsonic barrel blanks one 6.5 twist for the 8.6 Blackout and one 10 twist for tbe .510 Whisper.
The 8.6 chambered.
I also use hybrid cases with SS case heads for my 8.6 supers.
But you won't be doing any of that instead get Alpha Munitions 8.6 Blackoit cases they have good brass, on sale now.
I have tons of load data for careful reloaders to consider.
Have fun with your new project.

snowplow · Dec 6, 2024

Thanks for the info. That is really cool you are using the hybrid brass. I'll look into all of that. Thanks again.

snowplow · Dec 6, 2024

So here's a question then. The appeal of a .338 fed was mainly supersonic to me. It's pretty much ideal for how l hunt. So any way to also get it adequate to go sub was going to be worth it. Given that, how do the 8.6 blk and 338 Arc compare supersonic? I haven't been able to find a whole lot of info on supersonic 8.6. I'm assuming since it has a larger case than the 338 Arc, it would be a better supersonic round? Is it that simple?

Also since you don't prescribe fully to the 8.6- 1:3 twist coolaid and want to mellow it out with a 1:6.5" twist, your experience does that extra twist give it an x Factor of greater damage?

45-90 · Dec 6, 2024

These are the cases represented 338 Federal, 8.6 Blackout, 338 ARC( or 338 spectre almost identical).
The more case capacity the faster the supersonic velocity will be.
But harder to get good consistent subsonic ballistics as case volume increases, with bullets of the same length.
It's just physics of smokless powders.
The short bullets up to 225 grains are suitable for supers in the standard 338 Federal.
But they will not expand at subsonic velocities, having very little killing power.
Like an arrow without the broadhead attached.
Most of the bullets that expand in the subsonic arena are heavy like the 300 gr and 350 gr (long ones pictured)...and they require a 6.5 twist. Twice as fast as the 12 twist 338 Federal.
These bullets would require a COAL too long to fit in the 338 Federal Mag well over 3" and you're into the ogive with no way to secure the bullet in place...not practical.
So here's where the short cases come in to play allowing the bullets to be seated on full diameter of the shank, with most of the bullet sticking out of the case, and still fit the magazine, plus reduced case capacity helping the small powder charge be more efficient.
It it didn't work that way, there workd be no 300 blackout, just use the 308.
Thats why all the time and money spent on these subsonic rounds in development, cause the small case, the heavy long bullet, and fast twist to stablize it, give the most accurate, and the most energy available to the target at the limits of subsonic speed.
There is no evidence that a faster twist kills any better, even though its presented as a selling point.
The laws of physics again, same powder charge, same energy applied to a 300 gr bullet but one with a 3 twist and one with a 6 twist.
Energy can not be destroyed but changed.
So more energy is changed to friction and heat, for the faster 3 twist rotation resulting in slightly lower muzzle velocity, maybe 20 fps and the 6 twist will have a 20 fps higher muzzle velocity.
Results, basically same energy is deposited to the target.
It matters little if the bullet rotates 2 or 4 times as it penetrates the target...randomness takes over here, as to what blood vessels or arteries are hit, or even if the bullet stays on path or turns 90° and exits, or comes apart and stops penetrating.
The last picture is a 165 gr Maker, short enough maybe, to work in a 338 Federal 12 twist with its side slits and expand inside 100 yds at max muzzle velocity of 1100 fps...but it's pretty hard to get consistent velocities with all that air space, and no TrailBoss powder available.
But it would be the best bet for any sucess, with much less energy then the 300 blackout hitting the target, by quite a bit with its 220 gr bullet.
It's just how it is ...the physics of bullets, powders, and barrel twists.
You have to make a decision ...or get two rifles one for supers and one for subs.
None is perfect for both...it's a compromise. May get the 510 Whisper, 900 gr expanding sub bullets at 1100 fps. Or 350 gr expanding at 2450 fps for 4700 ft/lbs of energy. It will get to 200 yds and even elephant capable with 750 gr solids.
Here is a 350 gr Maker in 8.6 vs a 750 gr 510 Whisper with 750 Atip.
Last pic the 350 gr expansion copper bullet down to 900 fps, but here running at 2450 fps with 4700 ft/ bs... is accurate.
Probably overkill for deer but it's available.

snowplow · Dec 7, 2024

Very good. I really appreciate the explanations.

45-90 · Dec 7, 2024

snowplow said:
Very good. I really appreciate the explanations.

I spent many years and many thousands of dollars working on gun projects and problems, I pass along the information I've learned to others to save them time and money, and hopefully they find something they can use, in the words laid down.

snowplow · Dec 9, 2024

The 8.6 blk and .338 bullets are the same right? I've seen a note on 8.6 saying 8.6 only or something to that effect or maybe I'm backwards .338 Arc only. But that's just to make sure you don't shoot non coppers in 8.6 because of the twist right?

45-90 · Dec 11, 2024

The 8.6 Blk does indeed take. 338" bullets as does the 338 ARC.
There is a big difference in case capacity one is an AR 10 and the ARC is AR 15, so different rifles are employed.
Here is the problem with bullets the 338 Blackout mostly has a 3 twist barrel, limiting it to mostly subs, at subsonic speeds. So their bullets are "twist specific" to the rifles barrel and will not perform correctly if you do not get the correct twist.

DO NOT use their 6.5 twist bullets in a 3 twist barrel they will come apart as soon as the leave the barrel...dangerous and ya won't hit a target at close range.

Even Maker who makes subsonic bullets for hunting limits the max speed of the 8.6, 350 gr sub to 1000 to 1050 fps.
The 338 ARC has an 8 twist, no bullets are released yet for the 8 twist ARC in subsonic for handloading not even Hornday, but loaded ammo will.

I use a 6.5 twist and have Maker specific bullets for it plus it will shoot any 338 diameter bullet available copper or lead core.....totally versatile.
Do no buy a 3 twist, it's dangerous, impractical, and very limiting IMO. So much so I scrapped my 3 twist barrel, and will never recommend them.

snowplow · Dec 12, 2024

Ok great. Thank you!

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