That 240ish fps difference (roughly 10%), combined with the difference in bullet shapes, makes a huge amount of difference. I'm not surprised. Now, a fairer comparison would be using the same round-nose bullet. Then you'd be comparing apples to apples with the only difference being the velocity and perhaps the twist rate.
That's telling! Never was a fan of the .30 Carbine, Performance was always questionable even with modern bullet designs, and while it can be lethal, it's also a well known question mark! What's crazy is that the modern .300 Black Out is as capable as it is ( At full zoot loadings) with the advantage of being an awesome choice for really quiet sub loads with REALY good ballistics!! Been really considering a major quandary that's come up lately, that of a "Sub - Gun" I.E. something between a pistol and a rifle carbine with an intermediate cartridge, Like the M-1 Carbine, or such things as the HK-MP-5 and its various flavors, or the FN-P90 with it's tiney but hyper effective cartridge! Here's the issue, a sub gun may pack more punch at super short ranges, but lacks the range and accuracy to be effective beyond maybe 200 yards! Here's where the .300 B.O. coms in, with a hyper sonic load, 300+ yards reach is within it's capabilities, and it's short range punch is beyond question, so,............ Guess it's time to settle this once and for all, and start a new build!
I wonder how the 6.5 Grendel performs here, especially with the known ballistics of that bullet diameter! I know they suppress well, and I know folks that deer hunt with them, so power isn't an issue! Still, lined up against the Mighty M-1 Carbine, that could be a pretty fun challenge!
keep it up and il have to make some more. 10k a batch. i think i have some gifs of my tooling. hole hog drill runs my dillon 1050, annealing machine from scratch, jig for band saw cut to length, drill press 3 way trimmer. treadmill 8gl brass tumbler. who put all this 3dprinting crap in the way,shit,, im gonna need another connex.
bullet weight M1 - 110 gr 300BO - 110 to 125 gr for supersonic loads. Bullet shape - 300BO wins before the race. I've looked the M1 as a .357 level of power, so for a PDW, should work fine esp with HP rounds. Ymmv
I love the .30 Carbine. For what it is. It's lightweight, has minimal recoil, is cheap to feed, is a hoot to shoot. If I had to grab just one long gun from the safe, it would probably be the one, as I have multiple mags, and it's lighter to carry than just about everything else I have. Edited to add: And it's got a decent rate of fire. Oh, one more thing. I have a lot of ammo for it.
I believe that BTPost once told us that @alaskachick took a black bear with 30 carbine when it was molesting her apple tree. Least that's what I remember. But I'm old so i could be misremembering the story
this is some of the 300 blk loads i made left to right 36gr varmit grenade .223 proj in a .30 sabot 38gr .223 in .30 sabot 77gr .223 in .30 sabot 125gr soft point .30 125gr frangible .30 125gr cast .30 125gr jacketed poly tip .30 230gr cast .30 subsonic 230gr copper plated .30 subsonic i got all of them to cycle in a ar 300 blk. the short ones id load in 10rd mags and not shake or tap the mag to keep them cycling. i dont remember group sizes but i think 2" at 50yd for the sabots and 2" at 100 for the rest. hitting a pop can with the varmit grenades was hilarious. kissmybrass is the biz name of the blackout brass biz i started in 2008. iv done a few.
If you don't need a folder that can fire folded an AR build like my Crack Weasel could be your answer, especially with a Radian receiver set if you want true ambi. If you need a folder that can fire folded the SIG Rattler is the best value in a quality sub If folding doesn't matter then base it on an AR. I went with a 6" barrel so I could stuff it in a bag with silencer attached. You could go with a slightly longer barrel, but 300 BO is not sensitive to barrel length - to me that's the magic. You gain nothing after about 9". That Faxon 6" barrel puts an amazing 300,000 RPM spin that unloads energy like crazy when it hits. Heck, set it up like your twin tiny terrors, just don't get confused as to which is which.
I'm all about compact, which is why I'm really looking at a sub gun, just don't really want to marry into another caliber, the 10MM Auto I'm already vested in, but with as short as I'm wanting, like the MP-5, I'm not loosing anything, but I'm also looking at what I could gain, and both the .300 B.O. and the 6.5 Grendal pack one hell of a punch, though I don't think the Grendel would like such a short barrel! In any case, a side charging, non Buffer recoil system would be my first choice, just don't know who is doing them, and if their any good or even affordable! I need a max range near what my Tiny Tiger C.A.R.16 is capable of, about 400 meters super sonic/full zoot! And super quiet, maybe out to 130 meters at most! In short ( pun intended) I need a GTFO sub sized gun that can ether spray a lot of lead, or can punch hard long enough to make one dude feel like a whole squad! So, a folder/collapsing stock along with a short barrel of no more then 10" should be perfect, even better if you can fire in the folded state like an AR-180!
Maybe take a look at the Brownell BRN 180 in 300BO? It's an unknown quantity but looks promising. Non reciprocating left side charging handle, optimal 9" bbl, and fits on an AR lower. They also have adapters for the AR lower to attach folding stocks. IMO it's worth doing some research.
Spendy, and no options for configuration, would LOVE a bare upper receiver so I could add whatever accessories and such, as well as barrel and not having to spend over a grand, for just an upper!
To me, and there are many here with a hell'va lot more experience than and knowledge than me, but to me, more and more it is appearing that .300 BO will give me what I am after, good intermediate range, small package, suppresses well... I got the hots for the Kuna in 9mm for house/truck gun, good size, cheap to feed but two things cool me down: 1. They have an inherent problem that's been discovered, not only do the magazine feed lips crack (not steel reenforced) but it is possible for a live round to fall and be loose in the chamber area falling into the trigger/fire control group. The first 2 minutes of this video explains it better than me. I'm hearing more and more of this happening, especially if you hold the fire up when you need to clear it. (Note: my guess is the magazine problems will be resolved soon...but Springfield hasn't recognized the loose round problem at all - yet.) Springfield Armory KUNA After 3 Months - a bigger problem than the magazines 2. It's really hard to get one. Plus, it would really be better in a 10MM even though ammo cost a lot more. So, more and more, I am leaning towards .300 Blackout EDIT: However, I am looking at the Stribog SP9 and SP10.
KMB, I have always been a bit leery of that match up of the folding of the barrel into the breech, especially with a hi-powered round like 10MM. However, you've had no problems with it? Did you have to send it in or was it manufactured after 2017? "IMPORTANT SUB-2000 SAFETY RECALL NOTICE This could potentially cause the barrel to rupture when a cartridge is fired and could result in serious personal injury. The safety of our customers is our primary concern, so Kel-Tec has voluntarily initiated this recall because of the possibility of a barrel rupturing."
yep i had a early version and sent it in for the 2.0 upgrade, free. i had keltec install the full mcarbo kit (250$)when i did so more metal, less plastic. like the trigger guard that locks the breach shut is metal now. i mostly shoot a glock load optimized for accuracy 6.6gr 180gr but i also made some hot loads,,,, 7.4gr longshot, but those are for the s2k only. mine is .40 looks like the 10mm is new for the s2k. i like the 45 degree optic mount so it closes with out flipping or twisting anything. its a punchy recoil no doubt but after a few mags it is manageable. mag dumping on steel poppers is a blast. my only complaint now is a weak mag release spring is dropping mags occasionally,,, but i shoot lefty so when i cant the gun 45 left the extended mag release is right under my trigger finger. right hand shooters would not have this problem. i think installing the stock mag release and stiffer spring will solve it. its nice to have same mags for pistol/rifle. i 3dp a stock that carry's 2 spare mags,, i got the settings wrong on the first one and broke it. this one needs some fitting because i beefed up the 3dp settings. i have not fired a s2k in 10mm but have not had a problem with my hot loads. its a blowback non locking breech. i dunno mine runs good. i need to test the 50rd drum, have not tried it yet.
So whats the BO or .30 carbine do better than a 5.56? I mean its a bigger hole, supressed i can see the BO being nice, but my 5.56 is pretry quiet in its own right.
I have never used it so this is just the meanderings of someone considering it. what's the point of considering .300BO if you're NOT looking at subsonic? When suppression isn't the point, wouldn't you choose something else EVERY TIME? Even just in the AR platform if suppression isn't the point, even just .223 is better, isn't it? And if suppression IS the point, then aren't there a lot of better choices? Wouldn't you rather a heavier bullet for more overall energy at the limit of speed of sound? I guess my point is, it's never the best choice, and so what's the purpose of it?
I kinda like 150 grain supersonic soft points…quiet-er with the suppressor, handy with a 9” barrel, with knockdown near a .30-30.
