300BO is Meh in my book.
Loaded slow, its a Pistol caliber cartridge (9mm, 38spl/357mag, or 40s&w power)
Loaded sub-sonic- its a 45 acp
loaded fast pistol - its a 357mag carbine
loaded faster its a 30M1 carbine
even faster its a 30/30
even more- its 7.62x39
Then its done. It doesn't do anything different than what has been done before - except that it can be fired in an AR15.
My only 300BO is an 16" AR, and its fun and all, but I have other 30 cals that do the same things. For the time spent developing loads, it just adds to the confusion of what its supposed to do. Its better to get a 9mm upper for plinking/light duty, and a 7.62x39 upper for a hard hitting short range rifle, and of course a 556 upper for general use.
I think it comes down to your commitment level too. Do you want to develop a subsonic, semi auto heavy boolit load for the same upper that also shoots a 30/30 power load? (My Win 94 does that too) (And my 308 mauser does that too), (oh yeah, my 30-06 03A3 does that too) But then bolt guns can't chew through ammo like an AR can, so you get to reload more with your 300BO AR15. The only Semi rifle that I want to reload for anymore is the M1 carbine. Oh and the M1 Garands, but again I'm not just spewing lead at the range from those.
Tell you what is more fun - 38 special lever actions. Cheap to cast for, cheap to find brass for, easy to load, the brass never wears out, the brass isn't flung into the next county, low powder charge, my ears don't hurt after a session in the field, and I can hit what I want out to 100 yds for 5 cents per round. With 5gr of W231 under 125gr cast boolit my 38 spl is zipping along at 1400 fps, shoots 1.5 inches at 50yds, and is a hoot. Getting that fun out of 300BO from an AR takes much more work in case prep and loading, and then the 125gr boolit is too short and likes to jam in some mags or not feed smoothly.
YMMV, I don't shoot the 300BO much anymore.
So, I have a cartridge that costs about 8 cents to load (assuming prices I bought components at and picking up range 223/556) for 300 bo and it is just super sonic. It cycles and shoots great. You need specific brass or turn the neck - either way. Sad part is you are limited by RPM to maybe 1500 or 1800 fps.
I think the 350 legend is a really great cast round as they tend to twist barrels in the 1:15 or 1:16 range. This means you can drive a boolit much faster. I've got a load that drives a 125 grain boolit (GC 9mm boolit) about 2500 fps. With great accuracy and no issues. The load I tend to go to is a 180 grain boolit at about 2000 fps and it is very accurate.
WWG1WGA
i do the same with my 9mm ar15s. The 16 inch gun shoots a 145 cast with 4 grains of surplus pr200 into 1 1/8 at a 100 yards. YUP a 100. My 4.5 ar pistol in 9 does 2 inch at 50. Good enough for the girls i run with. Brass is even cheaper then 38s these days and lasts a long time. 9mm ars have about replaced my 22lr shooting. Almost as cheap and the place i score mine at is WELL STOCKED Add to that a guy can put together a 9mm ar a heck of alot cheaper then your going to buy a marlin 94 or winchester for. Another plus is they use ar parts which i have drawers full of about anything that could possibly break and if it came down to it i could strip parts off of one to keep another going.
I have had nothing but problems getting the 300blk to chamber in the ar with cast also had issues with the 30 hrt (a rimless 30 herrett made from 6.8 spc cases)
I finally gave up on 30 cal cast in the AR
I even got a throat Reamer to try fix the issue
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
Obviously I am not h]going to try it, but still seems unusual to me
It makes long skinny boolits that way.
I had a 300bk in a bolt gun, the heaviest mold I could get locally was a 220 gr, it shot really well. I have since sold the rifle and am concentrating on my 7.62 x 39.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |