Winchester's new .350 Legend for the AR-15

[Asdf]

I want one for my AR!

 

[cbhausen]

Does anyone have a link to cartridge and chamber drawings? I checked SAAMI and came up dry.

 

[Bigtanker]

Does anyone have a link to cartridge and chamber drawings? I checked SAAMI and came up dry.

I haven't been able to find anything yet other that case length. It's in the article in my OP.

 

[Spear Dane]

Does anyone have a link to cartridge and chamber drawings? I checked SAAMI and came up dry.

It's a proprietary round. SAAMI can't just decide what the specs are going to be when the intellectual property belongs to Winchester. See: Difference between 6.5 Grendel and 50 Beowulf.

 

[Kart29]

I couldn't listen to the audio in the video but I still don't see anything about this round being for use in an AR15. I don't see anything about someone making an upper for this cartridge yet - just a bolt gun.

I suppose someone could chamber an upper for it, but with it being a straight-walled cartridge I suppose it headspaces on the case mouth. Are there any other cartridges fired in AR10/15 that headspace on the case mouth? Maybe the .450 Bushmaster?

I'm interested to see if there will eventually be new .358'' rifle bullets that are going to be available because of this new cartridge. Sounds like there will be.

 

[bstewrat3]

According to some of the T/C guys who have spoke with Winchester, it uses the larger case head diameter of the 357 Max and by lengthening the chamber .1" can be chambered in 357 Max single shots. I don't personally have a use for it because I already use a shortened 35 Remington that I load in a shortened 30-40 Krag case, but I am looking forward to the possibility of better bullets for this velocity range coming available though.

 

[Bigtanker]

I couldn't listen to the audio in the video but I still don't see anything about this round being for use in an AR15. I don't see anything about someone making an upper for this cartridge yet - just a bolt gun.

I suppose someone could chamber an upper for it, but with it being a straight-walled cartridge I suppose it headspaces on the case mouth. Are there any other cartridges fired in AR10/15 that headspace on the case mouth? Maybe the .450 Bushmaster?

I'm interested to see if there will eventually be new .358'' rifle bullets that are going to be available because of this new cartridge. Sounds like there will be.

Yeah, I don't remember where I read that at. When I first heard about it, there was a lot of chatter about it in a few other forums. AR15.com was one the forums that was popping up in my search. So I repeated what I read on the there.

Now actually thinking about it, Winchester doesn't make AR's but they do sell bolt actions. So it makes sense.

But I dont think it will be too long before it's available in some sort of AR.

 

[Disposable Heart]

Yeah, I don't remember where I read that at. When I first heard about it, there was a lot of chatter about it in a few other forums. AR15.com was one the forums that was popping up in my search. So I repeated what I read on the there.

Now actually thinking about it, Winchester doesn't make AR's but they do sell bolt actions. So it makes sense.

But I dont think it will be too long before it's available in some sort of AR.

Tons of these companies anymore just have other firms build the rifles for them, rather than making their own parts, etc... Winchester would be behind the 8-ball as Remington and a VAST myriad of other firms make ARs and dedicated hunting ARs didn't sell very well (Mossbergs and Remingtons come to mind) because of price to build a similar if not superior weapon as opposed to buying from one of the big manufacturers. BUT, they could just subcontract the assemblies, receivers and small parts, just focus on machining the barrels and other proprietary parts for this caliber, they would still do well.

On a side note: Winchester should make something like their upper end bolt guns (beautiful wood, polished steel) and make an AR that has streamlined receivers, made of steel, polished and blued, crafted wood handguards and furniture. If they can keep selling somewhat obsolete BAR rifles for high price tags, they would not keep that AR on the shelf.

 

[Hohn]

I think we'll continue to see variants of AR-compatible medium bores because everyone wants to squeeze the most ballistic performance out of that 2.26 OAL and chamber space as they can. Straight walls appeal to me as a reloader for sure. A basic Lee carbide setup and I'll be happy as a clam.

The problem I see is that most of the higher powered straightwall cases are rimmed for revolvers and lever guns and just won't feed from a mag.

What's out there that's essentially a straightwall .223 case at 2.26" OAL that's plug-and-play in an AR? 300BO is close but has a shoulder. Maybe something 357 sized?

 

[Hohn]

The problem with 300BO is that they decided to use rifle bullets but give up some very scarce case capacity to do so. If you are going to a larger diameter bullet in the same case, you should not LOSE energy or barely break even. Compare the .243, 7-08, .308, and .338 Fed to see what I'm getting at. At you go up in bore size in the same case, you have more surface area on which the pressure can act and the case should be more ballistically efficient (internal ballistics.

That's why a 95gr SST loaded in .243Win by Black hills has only 1850 lb-ft while the 180gr accubond in .338 Fed has nearly 3200 lb-ft at the muzzle-- from the same basic .308 case!!

The cartridges have similar OAL, the same bolt face, and feed from the same mags in many rifles. Yet one is nearly twice as powerful as the other.



So, why is it that 300BO doesn't have more muzzle energy than the .223 it's based on? They gave up too much powder capacity to fit the long rifle bullets into the case. If you had designed the case around a shorter handgun bullet, you'd have a lot more powder volume and more performance.


300 BO has a specific niche it's good for (operators operating quietly) and for the rest of us, there are better choices available.

 

[Disposable Heart]

The problem with 300BO is that they decided to use rifle bullets but give up some very scarce case capacity to do so. If you are going to a larger diameter bullet in the same case, you should not LOSE energy or barely break even. Compare the .243, 7-08, .308, and .338 Fed to see what I'm getting at. At you go up in bore size in the same case, you have more surface area on which the pressure can act and the case should be more ballistically efficient (internal ballistics.

That's why a 95gr SST loaded in .243Win by Black hills has only 1850 lb-ft while the 180gr accubond in .338 Fed has nearly 3200 lb-ft at the muzzle-- from the same basic .308 case!!

The cartridges have similar OAL, the same bolt face, and feed from the same mags in many rifles. Yet one is nearly twice as powerful as the other.



So, why is it that 300BO doesn't have more muzzle energy than the .223 it's based on? They gave up too much powder capacity to fit the long rifle bullets into the case. If you had designed the case around a shorter handgun bullet, you'd have a lot more powder volume and more performance.


300 BO has a specific niche it's good for (operators operating quietly) and for the rest of us, there are better choices available.

.300 Blk was designed specifically for subsonic work that happens to be a decent supersonic performer, similar to 7.62 Soviet. Low case capacity is great for subsonic cartridges as your charges are going to be lighter and you don't want powder to become case position sensitive, which often happens when folks try to make .308 Winchester subsonic ammo. I love .300 as I have hunted pigs with it in TX and use it for HD. It's flexibility is passed over by folks that really can't appreciate what it offers: It can take game, it can be quiet and quiet accurately, it can be supersonic and have the penetration/throw weight/velocity similar to a reliable combat performing 7.62 Soviet.

.300 CERTAINLY beats out .223 in subsonic roles: Subsonic .223 can't cycle reliably and would require massive modifications to the weapon to do so. 300 Subs? Just switch magazines. .300 retains a MUCH higher velocity percentage going to short barrels compared to .223 (7" .223s have sapped nearly 1/3 of its velocity compared to maybe 10% with .300 BO). Lower muzzle blast compared to 5.56, better velocity in SBRs/Pistols, it's a winner!

If it wasn't for .300s cost, I think it would be readily adopted by more Americans compared to .223, especially with the proliferation of short barreled ARs for HD.

Your other cartridges certainly have the range and velocity on .300 BO, but if I am shooting a pig in the brush at 50 yards, I would prefer the .300 over .243 for meat destruction. 200 yards on deer in Utah? Gibs me dat sweet .243. I can't efficiently defend myself with a bolt action .243 (or try to cope with the horrific cost of making a .243 AR10 lol). Apples to oranges hunting environment. I would never use .300 WinMag against a deer, that's idiotic... unless that deer was near the edge of a 200gr Accubond's expansion threshold of 600-700 yards.

 

[Kart29]

I don't understand them making ammo with a 145 gr. FMJ for a bolt action deer hunting rifle. Producing this ammo suggests to me that there must be more to it than just this bolt rifle.

 

[dung]

I would love to get into 300 BO, but that price per round doesn't appeal to me at all. however, it would be cheaper for me to buy a new upper than to buy a scorpion. The suppressor I have in jail will only handle 300 bo subs.

 

[bstewrat3]

I don't understand them making ammo with a 145 gr. FMJ for a bolt action deer hunting rifle. Producing this ammo suggests to me that there must be more to it than just this bolt rifle.

Why waste good hunting ammo if you just want to go out and plink with your new rifle?

 

[rooster]

They market it for deer hunting and I know many of you are comparing it to a 300 BLK but I don’t see much performance gain vs even my Mossberg 12 with Hornady SST slugs to warrant adding another caliber and gun.

 

[Broom_jm]

The 350 Legend offers a unique set of characteristics in a single cartridge, and has only one drawback that I'm aware of.

1) It's designed for an AR. Uppers are already available, not from Winchester, but from other manufacturers.

2) It runs at a higher pressure than the 357 Maximum and is .100" longer, so it offers a noteworthy increase in performance.

3) It is a rimless cartridge and based on the most common rifle round being sold today.

4) Since it approximates 35 Remington performance, there are already a lot of bullets suitable for use in it.

Now, the one drawback is that it's a rimless, beltless, straight-walled rifle cartridge, so it has to headspace on the mouth. Anyone who has loaded 30 Carbine, 450BM or other rounds of this specific configuration understand just how critical case length becomes. It is very dangerous to have a high-pressure round that is a tiny bit too long, or entirely too short, when it headspaces on the mouth...so for handloaders, there is a lot of measuring and trimming needed to make sure these are safe and reliable.

 

[daddyusmaximus]

.300 retains a MUCH higher velocity percentage going to short barrels compared to .223 (7" .223s have sapped nearly 1/3 of its velocity compared to maybe 10% with .300 BO). Lower muzzle blast compared to 5.56, better velocity in SBRs/Pistols, it's a winner!

If it wasn't for .300s cost, I think it would be readily adopted by more Americans compared to .223, especially with the proliferation of short barreled ARs for HD.

This is the reason I built a .300 Blackout SBR (and a pistol lower for it) as a HD gun. It's a purpose built tool for close in defensive use in tight quarters. I wanted the small package, and the .300 gave me the ability to keep more energy with the short barrel. Prices on .300 ammo have got better, but have never (and will probably never will) come down to the range of 5.56 prices. Of course it will never be used at >150/200 yds, so it remains a specialty tool, rather than a general purpose go-to gun.

I would have preferred, then, that they used a 16" barrel on their new round. Or if it is unsuited to a 16" barrel, then not compare it to the .300 BO.

I also would like to see how this new round fairs in a shorter barrel. It is being touted as a multi use round, and if it performs well out of a 16" gun (the most popular AR) it would sell better with that crowd. It would look better in my eyes anyway.


CMMG looks to be the first to put out an AR in the new caliber.

[video=youtube;Q5VMr3Yh8hk]https://www.youtube.com/watch?v=Q5VMr3Yh8hk[/video]

 

[Hohn]

.300 Blk was designed specifically for subsonic work that happens to be a decent supersonic performer, similar to 7.62 Soviet. Low case capacity is great for subsonic cartridges as your charges are going to be lighter and you don't want powder to become case position sensitive, which often happens when folks try to make .308 Winchester subsonic ammo. I love .300 as I have hunted pigs with it in TX and use it for HD. It's flexibility is passed over by folks that really can't appreciate what it offers: It can take game, it can be quiet and quiet accurately, it can be supersonic and have the penetration/throw weight/velocity similar to a reliable combat performing 7.62 Soviet.

.300 CERTAINLY beats out .223 in subsonic roles: Subsonic .223 can't cycle reliably and would require massive modifications to the weapon to do so. 300 Subs? Just switch magazines. .300 retains a MUCH higher velocity percentage going to short barrels compared to .223 (7" .223s have sapped nearly 1/3 of its velocity compared to maybe 10% with .300 BO). Lower muzzle blast compared to 5.56, better velocity in SBRs/Pistols, it's a winner!

If it wasn't for .300s cost, I think it would be readily adopted by more Americans compared to .223, especially with the proliferation of short barreled ARs for HD.

Your other cartridges certainly have the range and velocity on .300 BO, but if I am shooting a pig in the brush at 50 yards, I would prefer the .300 over .243 for meat destruction. 200 yards on deer in Utah? Gibs me dat sweet .243. I can't efficiently defend myself with a bolt action .243 (or try to cope with the horrific cost of making a .243 AR10 lol). Apples to oranges hunting environment. I would never use .300 WinMag against a deer, that's idiotic... unless that deer was near the edge of a 200gr Accubond's expansion threshold of 600-700 yards.

Valid points. But, if I may make an analogy, there are times you need an axe, and times you need a knife. 300BO is the huge knife that is neither a good axe nor a good knife. If you have to carry only one tool, then the massive knife makes sense. But it still sucks as an axe and likely as a knife too.


If you want to carry a 10" SBR, then 300BO is about as good as it gets. For everything else, there are better options, imo.

..oh, and meat destruction is a bullet argument, not a caliber argument.

 

[Hohn]

The 350 Legend offers a unique set of characteristics in a single cartridge, and has only one drawback that I'm aware of.

1) It's designed for an AR. Uppers are already available, not from Winchester, but from other manufacturers.

2) It runs at a higher pressure than the 357 Maximum and is .100" longer, so it offers a noteworthy increase in performance.

3) It is a rimless cartridge and based on the most common rifle round being sold today.

4) Since it approximates 35 Remington performance, there are already a lot of bullets suitable for use in it.

Now, the one drawback is that it's a rimless, beltless, straight-walled rifle cartridge, so it has to headspace on the mouth. Anyone who has loaded 30 Carbine, 450BM or other rounds of this specific configuration understand just how critical case length becomes. It is very dangerous to have a high-pressure round that is a tiny bit too long, or entirely too short, when it headspaces on the mouth...so for handloaders, there is a lot of measuring and trimming needed to make sure these are safe and reliable.

Agreed on all points, but cases that are trimmed shouldn't grow very much. And reloading straightwall is so much easier and more convenient than bottleneck in terms of case prep overall.

Reliability with headspacing on the mouth is always something to consider, but it seems to be figured out in every common autopistol caliber.

 

[Broom_jm]

Agreed on all points, but cases that are trimmed shouldn't grow very much. And reloading straightwall is so much easier and more convenient than bottleneck in terms of case prep overall.

Reliability with headspacing on the mouth is always something to consider, but it seems to be figured out in every common autopistol caliber.

My experiences are different, but I grew up out west and never loaded a cartridge for autoloading pistols until about 10 years ago. All of my reloading experience, prior to then, was bottle-necked rifle cartridges, so I have always thought of them as the easiest to work with. (No belling of case mouths or crimping required for ammo shot from bolt-actions and single-shot pistols.)

The extractor provides enough resistance on smaller (lighter) autoloading pistols for (softer) primers to ignite, even if the case is short. Also, most straight-walled cases don't need a lot of trimming, but they're not running at 50,000psi. I can't say for sure if the 350 Legend will require trimming every few firings, but I know the 30 Carbine tends to. I guess it will depend on whether or not it's a truly straight-walled case or if it has a slight taper, like the 30 Carbine.

Perhaps someone with a lot of experience loading 450BM or 50 Beowulf can step forward and describe their experience with case length and reliability in semi-auto rifles?