300 blackout vs. 350 legend subsonic

[sequins]

Hello friends,

Other than the dirth of 35 caliber suppressors what does one think of a suppressed 350 legend versus a 300 blackout for subsonic 100 yard max loads?

Looking at bullet weights and BCs it seems 350 is flat out superior offering greater energy at the same velocity with a substantial increase in diameter. I've long considered a 300 BO suppressed package but now I'm wondering if the 350 isn't the better option?

A 200gn bullet traveling at 1,000 FPS out of the muzzle does 444ft/lb KE, while a 265 at 1,000 FPS does 594ft/lb. Assuming bullet construction is equal the 265gn 350 legend performance seems superior on its face.

Anything I'm missing?

 

[jmorris]

Anything I'm missing?

The larger boar, heavier bullet AR uppers. A 405gn @ 1000 fps is 899 ft/lb. A 500 gn @ 1000 is 1110 ft lbs.

For the same reasons You have already established.

...flat out superior offering greater energy at the same velocity with a substantial increase in diameter.

You don’t have to stop at 100 but the trajectory makes it so you need to accurately know the distance to target very far after that.

 

[25-20 WCF]

Oddly, SSK never developed a .358” Whisper cartridge, probably because the available bullets in .338” and .375” had considerably better high-BC selections for the original role of the cartridges. No reason the Legend wouldn’t work, but do you really believe that ft-lbs of energy determines killing power?

Will the subsonic .358” bullets be stable in the 1:16” twist of the Legend?

Will the heavy bullets expand at such a low velocity? I have used 220-grain 0.308” bullets at under 1100 fps on deer with success, the long bullets tumble producing very effective wounds. Not sure what would happen with shorter 0.358” bullets at the same velocity.


.

 

[sequins]

The larger boar, heavier bullet AR uppers. A 405gn @ 1000 fps is 899 ft/lb. A 500 gn @ 1000 is 1110 ft lbs.

For the same reasons You have already established.



You don’t have to stop at 100 but the trajectory makes it so you need to accurately know the distance to target very far after that.

One advantage of 300 blackout is the fact that one can carry multiple loads in different mags, if you need to engage a target past 100 you pop the subsonic mag and drop in some supersonic 125gn loads and now you're deadly out to 300 in seconds. 350 legend offers the same advantage- if you want to shoot farther you pop mags and you're good to go. 458 socom is dramatically superior at 100 but less versatile in that regard.

350 and 300 appear equally versatile with a consistent edge due to bullet weights giving the 350 a performance lead, not to mention more forgiving brass and easier loading.

Now, as to bullet construction of 350, that's a fair point but if the cartridge becomes popular I'm pretty sure we'll see the bullets follow. The existing subsonic loads look good. Obviously simple bullet weight is not the only factor (or even the deciding factor) on wounding potential but that's why I said we should assume equally capable bullets- is there an inherent reason we must assume 350 legend BC is necessarily worse than 300? I'm interested more in the potential at this point, and it's fair to say 350 legend hasn't yet reached its potential.

 

[jmorris]

458 socom is dramatically superior at 100 but less versatile in that regard.

This is true. I was going off the OP.

100 yard max loads?

and “subsonic” in the title.

Slightly less quick to do but two pins to swap the 458 upper for a 6.5 and I beat my 300 blk on both ends.

I have a 357 maximum rifle, so I’m not against the concept, I just don’t have situations where I would be swapping out mags and dialing in different zeros, “on the fly”. In all honesty I generally just grab a different rifle but it’s not unheard of for me to swap out ready to go uppers.

Is there an inherent reason we must assume 350 legend BC is necessarily worse than 300?

At 100 yards the BC won’t be a deal breaker on pretty much anything but you don’t need to assume one is better than another, just look them up. Most every major bullet manufacturer gives that data and looking at Winchester’s specs for both says, yes, the BC for the 350 is worse than the 300, actually everything they have listed on the page.

https://winchester.com/Products/Ammunition/Rifle/Deer-Season-XP

 

[mcb]

Personally I think the 350/358 Legend could be a very flexible rifle, suppressed and un-suppressed, especially for someone living in a straight-wall only hunting state and did not need much over 200 yards range. If I didn't already have a 30 cal suppressor and two 300 BO guns I would be seriously temped (maybe more so by 357 AR-Max). That said if I buy another suppressor it will be for my 450 Bushmaster.

300 BO subsonic has a temporarily advantage in that there are some very good, proven, expanding sub-sonic bullets for 300 BO. 350/358 Legend does not have the same development time and thus the same variety of proven bullets available. No doubt there are a few suitable bullet for sub-sonic 350 Legend use and if the cartridge takes off there will be more cartridge specific bullets developed but for the time being 300 BO has a sub-sonic projectile advantage.


Maker REX 220gr, launch with about 500 ft-lbs of energy give or take a bit depending on which of my 300 BO I use. It expands very reliably and very well. Does a number on the tactical assault possums.