Some 300BLK Questions

Most 30-30 profile billets have a flat nose for safety in tube fed guns, so they don't work great in AR15 platforms. That said, I have used a few 125gr FNHP and 150gr FNSP bullets in my 300 BLK. If you don't already have these bullet heads, there are much better ones that you should get.
For hunting: 125gr is popular. If you are going to load your own, get some Hornady 125gr SST or 125gr Nosler Ballistic tips. H110 powder works real well with them.
Yes, for plinking, 147gr pulls work well. Different point of impact, and mediocre accuracy but fun none the less.
Another cheap popular and in my opinion more accurate bullet is the 125gr TNT bullets from Speer. Also, I like the Sierra 125gr pro hunters for target shooting. The only 110gr I had much luckl with was the VMAX. The others are really short.
300blktalk is a forum dedicated to the platform. You may want to browse over there and do some searching.

How the cartridges fit in the magazine will be the top issue. There is a rib in an AR-15 magazine the bullet rides on.

So, you may need to do some experimenting on seating depth to see if the 30-30 bullets can work. Off hand, it will be touch and go.

The 125 OTM Sierra bullets designed for the 300 BLK have a very long ogive.

Forum moderator Walkalong shoots 147 pulled bullets in the 300 BLK but I have not tried any yet.

I like 155 Hornady AMAX with Accurate 1680 powder in that weight range.

Hope this helps

Edit: Guess I was slow at the "enter" key

H110 is my primary 300BLK powder & have used it successfully in loads for bullets from 110 grains to 245 grain (cast lead) as supersonic loads.

The 30-30 "leverevolution" bullets feed pretty well (ignore the cannelure when seating). The 30-30 version have a chance to expand properly at 100 yard distances as I have heard they will function as low as 1500 fps.The moderately warm 160 grain FTX loads I did with H110 were in the 1850 fps ballpark with no pressure signs & no issues with feed & function.

Nosler 125 grain BT's are one of the popular choices, especially if you can find blems or overruns at the factory store (thats when I stock up). Sierra 2120's are a pretty good choice for a combination of quality & economy. Both have functioned without problems for me.

I've also been loading with some magnetic M2 ball pulled from CMP Greek 30-06 (they were replaced by 150 grain SP).

The "300BlkTalk" forum has a pretty good collection of posts from folks working up different loads for the 300.

Nick

I shoot H110 using Hornady 110 V-max, have tried Nosler 125 Ballistic tips, and my plinking load is with 147 grain pulled surplus bullets. The 147 grain bullet shoots good in my two BLK's with 16.5 grains of H110. Have tested up to 16.7 grains which give 2000-2010 fps in my 16" barreled AR's. Don't think your 30-30 bullets will feed in a semi-auto AR. Only thing to be careful with is the diameter of the case necks when loaded. Case necks shouldn't be over .334" dia. with a seated bullet. Some brand .223 cases have too thick case walls and the neck comes out to large in diameter. Use standard primers suitable for .223 AR loading. The 125 gr. Nosler Ballistic Tips are supposed to be good hunting bullets for up to deer sized game. The Hornady 110 V-max is pretty accurate and is my so-called target load. Fun to load and shoot!

Don't overlook the pure fun factor of loading up some 220 or 240 grain subsonic rounds. They sound like a muted .22lr. No suppressor required. Big arc but once you figure it out they sail pretty consistently.

For deer I've had good results with Hornady's 125gr SSTs over Lil Gun. I'm still tweaking my load looking for a little more accuracy. The .300blk is good for SC deer out to a little over 200yds

300 BLK is a great reason to start casting bullets. I shoot cast almost exclusively in mine and have had quite satisfactory results.

are you guys shooting cast in AR's? I just finished building my 300blk and was thinking about ordering some cast 245gr from MBC but I thought the blunt nose wouldn't be so kind to feeding.

I bought a box of Misouri 245 grain bullets for the 300 BLK. They chambered just fine. Adjust the seating depth so that the bullet just clears or minimally touches the front rib in the magazine.

I got a Lyman M die to expand the case mouth. The M die made seating easier.

I forget if I got the rifle to cycle enough to reliably pick up the next round or lock the bolt back on the last round but I do not run suppressed. Nothing against the bullets, I just decided to not pursue them any farther.

MBC 245's are a hoot loaded as1300 fps supers. Kinda like chunckin' bricks downrange...
No cycle issues from either carbine or 10.5" pistol.

Nick

If I remember correctly, I think I never loaded the 245 grain bullets hotter than 1000-1100 fps.

They definitely made a thump down range.

For factory rounds, the cost difference between lead and jacketed may be negligible, the cost advantage is there if you reload.

The heavier bullets are usually used for subsonic loads which are good velocities for cast bullets.

Missouri 245 RNFP 30 caliber bullets are $36/250.

Are you experiencing any problems using cast lead bullets in a gas gun? I've always heard that's a no-no, so I've never tried it.

"1) Can I use 30-30 bullets in the 300? The bullet diameter is the same but I believe the bullet itself is different. I like some of the soft points for hunting and would like to use them in my rifle, but if they won't work they won't work.

2) For plinking, I've heard that pulled 147gn bullets are great. Is this true? Anyone have a pet load for them?"

Your initial questions.
1) It becomes a matter of feeding. If you are feeding a 'Handy Rifle', stick any nose shape in. For an AR/M4, concerns are the ogdive of the bullet and how it sits in your magazine/s. Some mags have a hump to position the .223/5.5 for feeding, some don't.
2) I love to shoot the GI pulls. I'm cheap and they are too. I don't expect great accuracy with them. They weren't made for it to begin with. But they are fun anyway.
A 'pet' load! 3 dogs and 2 cats, I don't shoot our pets. Now, old Patty, blind in one eye and deaf as a post... Naw, he's safe.

Seriously:
296/H110 - 16.6 grains - 2.065in COLA - 1945 FPS
Lit'Gun - 15.0 grains - 2.160in COLA - 1870 FPS
630 (won't find any of that) - 13.5 grains - 2.000in COLA - 1764 FPS (my favored load)

Standard warnings, may not be safe in your weapon.... always defer to known and trusted loading data.

All from a 16 inch barrel with carbine gas system/buffer.

I see listings above about lead bullets, my newest quest is to test 'powder coating' bullets. We will see.

I don't do suppressed, no desire or desire to pop all of that cash. For those who want to, go for it.

If you build and you load your own, I think you will enjoy the process. If not, you may wave your hand in the air and blame me.