300 Blackout, AR platform, LBT wide meplat bullet feeding question

[TooFarGone]

I am new to the 300 AAC Blackout. I cast a lot of WW .38 Special and 45 ACP lead bullets in the past. My AR platform upper has a stainless 8.5 inch 1:8 twist barrel with a YHM Phantom suppressor. I want to get an LBT WFN or LFN (about 180 grain) bullet mold sized for this weapon. My main interest is in subsonic loads, but may do some supersonic loads too. Will these bullet profiles feed out of the AR-15 magazine and into the 300 BLK chamber?

LBT cataloge link:
http://www.lbtmoulds.com/moulds.shtml

Thanks!

[Smoke4320]

anything with over about .180 nose you may have feeding issues
I use a NOE 311-247 HP with a .200 nose and have a few failures to feed

[Jupiter7]

I've actually gotten the NOE311-165rd to fire a full mag, but a bullet that short and fat will be too short in the magazine, it will move forward under recoil and the nose will ride the front wall of mag, this will turn into a base up 3 point jam and require a mag drop and operation of the charging handle, and mangle the offending round. I'd highly advise looking at something else.

[popper]

My meplat is 0.18 with 3R ogive, it works but COAL needs to be just right. Your basically pushing a 309 cylinder into a 375 hole, alignment has to be just right.

[Moonie]

I have an Accurate Molds 245gr mold that is a virtual copy of the NOE with a wide meplat, I've not had any issues with feeding, however at 180gr you will probably have cycling issues if you are trying to run them at subsonic speeds.

I've used the Lee 170gr that has a large flat meplat and the meplat didn't seem to be an issue however because the nose is so short I did have issues with the rounds nose diving in the mags causing feeding issues.

For subsonic I would certainly recommend 200gr or heavier.

[TooFarGone]

Thank you all for your responses. I have spent a few minutes staring at the magazine of the AR-15 and it's relationship with the M-4 cuts in the barrel extension. It is apparent to me now that a really wide meplat bullet will have problems clearing the magazine itself even before engaging the barrel extension. The comments about too-short OAL and too-light weight bullets for reliable cycling while subsonic are appreciated. It looks like I just missed the group buy for the NOE 311-230-FN (BLK OUT). So, a few other questions...
-will the NOE 311-230-FN (BLK OUT) become a stock item?
-If I were to use a gas check, is it unreasonable to use a very soft lead alloy (say pure lead plus 1-1/2% tin) to enhance mushrooming at sub-sonic velocities with a flat nose bullet similar to the above NOE? What about pushing it to say 1800 FPS?
-Has anyone noticed gas cutting at the base of plain based lead bullets that could be attributed to the gas port?
-Has anyone played with hollow point molds that might work with the AR platform 300 BLK?
-Has anyone removed the ridge between the M-4 feed cuts on the barrel extension to allow 30 cal cast bullets to chamber more easily?

Thanks!
TimH

[Smoke4320]

As posted above I am using the NOE 311-247 hp mold
Tryed pure lead/2% tin did not shoot well at all
Same bullet at 49/49/2 alloy shoots great at 1000fps up to 1425 fps powdercoated sized to 311 out of a 10.2" Noveski and YHM suppressor
Shot one doe this year at approx 70 yds. Hi right shoulder exit mid left shoulder. Dtr
Blood squirt about 2ft

[popper]

Toofar mags are sometimes a problem, mag well cuts can be changed. Many M4 cut extentions are too small. Removing one of the lugs, don't know. DPMS gen II has a smaller one. Biggest problem is getting the nose through the lugs and into the chamber without jamming. I'm pushing a PB close to 1800.

[TooFarGone]

Smoke4320
I missed the HP part in you first post. What powder/amounts are you using for the subsonic and supersonic loading? Did you shoot the doe with the supersonic load? Did you recover the bullet and if so how well did it expand? I think the bullet has a 0.200 meplat with the HP version, any feeding problems in your AR?
Thanks!

[GabbyM]

Pooper do you think there is any chance of running my 220 LG through a blackout? Think Lyman 311284 with flat nose. My son in law got a BO out in AZ. Shot it the other day when I was out there. We shot a Hornady 208 grain A-Max into a stack of water filled milk jugs. Sub sonic. Found the copper cup but no lead. Hate to buy another mold just to give bullets away. Have been looking at the NOE improved Lee bullet. 311-230-FN. Don't know why they call in a FN when it is so pointy but hey. They will shoot some javelina with them. http://noebulletmolds.com/NV/product_info.php?cPath=30&products_id=2354

Would prefer a mold from accurate as they make them to fit my Magma machine. But no pointy nose off a lathe.

[Tackleberry41]

I bought one of the NOE .311 247 blackout molds couple weeks ago, straight from their site. I have no idea how well it works in a 300, friend has one but is completely opposed to any sort of cast bullet. I have been using them in a mosin, and soon a 30-30 w the 1-8 barrel when its finished. A single shot so not concerned about how it feeds. Been meaning to see how it will work in a semi, but full powered thru my CETME.

[GabbyM]

Googled a dozen articles and forum post. Plenty of shooters running #311284 in a Blackout. Just they never say if they are magazine feeding them up or just dropping them on a single shot follower. The big flat nose with shorter radius ogive on my custom mold can't do anything but make them harder to feed through an AR. Like I told my son in law. He can load them first round then run a pointy bullet in the mag to follow up. I am one of those who believe a large meplat bullet is going to kill better than a pointy one. We will surely load them in the 308 Win for sub sonic use. BTW I really like the Ruger American Predator. SIL had one in 223. we screwed on his can and gave it a try with regular ammo. Still want ear plugs but it's not much louder than a 22 mag rim fire. The can on that long barrel makes for a seriously out of balance rifle. Took about eight MOA of up on the elevation knob to bring POI in line. Didn't hurt accuracy any though.

[Smoke4320]

I shoot these from both a Noveski 10.2" AR and a Ruger American compact .. both wearing a YHM Phantom 308 suppressor

All are powdercoated Jet Black and sized to 311..

Subs 50/50/2 alloy Lil Gun 7.0 .. a few recovered bullets from sand pile measuring about .500 to .550 anywhere from 180 to 226 recovered weight

Angle impacts tend to bend the nose over .. so if same occurs on a deer I would think you would get a nasty tumble

Supers 50/50/2 alloy Lil Gun 10.6 (IIRC) running 1425 FPS

doe shot with supersonic out of a Ruger American compact with YHM Suppressor at approx. 70 yrs DRT..
Hi right shoulder exit mid left shoulder ..Blood squirt about 2ft.... Bullet long gone back to the earth

[popper]

GabbyM - Amax is thin skinned so I'm not surprised it came apart but that may not be bad for some types of hunting. As to the NOE for an AR, the long boreriding section could give a problem if the throat is tight. At 1.4" long, not much room for powder, don't know if the PB or GC is better. My normal boolit for the BO is 145gr PB with reduced nose dia. for powder coating. I need to try the 170GC (for my AR10) with a slightly blunter nose but the range was washed out this week from the 10" of rain we got. Also have some 150PB loaded in 30/30 to try. What I find is the boolit/case dia.s in the BO are harder to feed than 30/30 or 308W.
It would be interesting to see how it works with the extension lug removed but I don''t have the tools to do it.
Saw a blog by Anderson (shot show?) wanting something between the 30 hunter and blunted 'Crayola of Death' -Dolamite_Superfly design, about 180 gr, for the BO as a deer hunting rifle. Basically same goal as me. I did a velocity/weight/terminal analysis to find best for energy and designed the boolit around that.

[GabbyM]

I believe you are correct on all accounts concerning the 220 grain FP.
I have a nice mold here from MP. A 180 grain hollow point spitzer with a body to fit into 308 Win. Tapered front band. O.L. with check is 1.004". As a super sonic Am wondering if his 1:8" twist pistol barrel could get it going to fast for accuracy. I'm thinking not. Hodgdon data I'm looking at shows 1631fps for a 180gr J bullet from a 16" barrel. With H-110 that he is using. Also have the Lyman 200 grain #311299 and the 160 grain 311672. Then my 30-30 favorite mass production bullet 150gr FN #316 Saeco. RCBS 30-180-FN. M1 carbine bullet and a 140gr FP PB. Something should work lol.
Obvious I'll just need to send him a sampler box.

With the big NOE 230 and 245 grain bullets they make just under sonic and that's all that matters. Since the intension is to hold down velocity anyway. That fourth bullet pictured RCBS 30-180-FN has been used sub sonic in a 7.62x39mm Mauser cast BHN #9 to take a deer. Pass through double lung with quarter size exit then two steps and down. unfortunately shot not taken by me. My bullets have a lot more fun than I do. That center 180 grain has a .302" tapered nose or it might work. The Saeco #316 has no bore ride and would chamber nice if it would feed. That 160 grain Lyman #311672 pointy bullet may just be the ticket for a blaster. Bottom photo next to 45 Colt bullet.
I bought a set of NOE's new dies yesterday. Got a nose size bushing in .300" and .270" for long bore riders. Maybe should of bought a .299" too. Along with other things I spent $147 and didn't even get a mold. Swede knows how to run a business.

http://castboolits.gunloads.com/attachment.php?attachmentid=50091&d=1232425178
http://castboolits.gunloads.com/attachment.php?attachmentid=134641&d=1426964408
http://castboolits.gunloads.com/attachment.php?attachmentid=50089&d=1232424448

[popper]

My 145 PB looks like your 140 but no grooves and a reduced nose (297). I had to seat the 150 FBSP hornady ~0.01 deeper to keep it out of the bore, should hit 1900 per sierra data.

[GabbyM]

I did about four hours reading today. Good grief Charley Brown. Looks like the Lyman 200 grain 311299 has been shot a plenty in 300 BO. Most of the hits I got came back here to castboolits. Found shooters running the 160gr Lyman 311672 crimped under the first lube grove on the band. Plus the 115gr M1 carbine bullet 311359. So I’m thinking the 200 grain 311299 for subs and my 180 grain HP for supers. Will send them an assortment of the others to test out.

That first bullet in photo. Plain base 140gr FP. Is a Saeco #360. Same bullet as the #316 minus the gas check shank. I also have the Lyman 130gr #311410 plain base.

[TooFarGone]

Lots of information to digest in the above posts, thanks. I am on the steep part of the learning curve on cast rifle bullets and particularly the 300 BLK fed through an AR carbine magazine. Completely grinding off the locking lug between the two M-4 feed cuts in the barrel extension was not my greatest idea as it removes 12% of the locking lug surface area and would be a set up later for bolt failure. Popper's comments here noted, thanks. My particular M-4 feed cut geometry are two 0.250 cylinders, each cut at a 45 degree angle from bore center line leading to the chamber, with each feed cut located 22.5 degrees either side of a vertical line when viewed from the chamber end. The edges are quite sharp and would benefit from at least a polish and rounding over of the edges that would contact a bullet rising from the magazine.

I have to redefine my "wants" in the bullet. There is pretty good consensus that 220 grains is a better size for action cycling than the lighter weight bullet. The LBT WFN profile will not make it out of the magazine and I don't want to start modifying a bunch of mags. I still want the biggest flat nose I can feed reliably from the magazine. The 0.200 meplat is too large, with several folks reporting that 0.18 works . The NOE 311-247Gr has a meplat of 0.15 and seems to feed reliably for folks. Has anyone had problems with the 0.18 meplat feeding? I have stared at the magazine/cartridge interaction and it looks like a 0.165 meplat will clear the end of the magazine without touching it. Any additional thoughts here?

I want to experiment with bullet alloy +/- GC, +/- soft nose/hard body, and possibly a bit of a hollow point for some of the subsonic soft nose bullets. I may be chasing Nirvana here but what I have in mind is a custom LBT 4 cavity mold with a soft nose hollow, 2 PB hollows and a GC hollow. This would give me two hollows for casting subsonics plus the capability to load develop higher velocity loads and play with soft points/60 degree drilled HP for subsonic hunting. Powder capacity will likely limit the max velocities. Comments are appreciated!

Edited to add: One thought on the flat nose for reliable magazine feeding- Have a 0.150 meplat and then a 60 degree angle truncated cone extending down the bullet until the diameter is 0.200 (about 0.0333 from the nose) then an ogive of choice to the front driving band (no bore ride). Distance from the flat nose to the crimp ring about 0.882 to give a bullet OAL of 2.250. I don't know if this can be done and get a bullet of about 220 Gr, it may end up being heavier. I also do not have a good idea of how much shorter the bullet could be before running into the problem of the cartridges moving forward with recoil.