300 Blackout - curious. [Archive] - Glock Talk

PDA

View Full Version : 300 Blackout - curious.


Uncle Don
06-03-2014, 20:23
Been thinking about the 300 Blackout - anyone loaded it? Granted, I have some research to do, but any input on steps beyond standard loading, I'd appreciate it.

PCJim
06-03-2014, 21:29
Don, I picked up a 10.5" upper in 300BLK a couple of months ago for use with a suppressor. I have prepped roughly 200 brass of varying LC headstamps, but have yet to begin reloading them. Waiting on the SBR stamp as I can't see getting any accurate load developed using a pistol lower.

H110, AA1680 and Lil Gun are supposedly the preferred powders. I'm stocked with 4# A1680 that I will be working with. It apparently will produce enough gas pressure with subsonic rounds to reliably operate the AR.

The most interesting aspect I've come across of reloading this cartridge relates to determining the COL when loading to run on the AR platform. Measure the intended bullet to determine where the bullet diameter is .25" and mark it with a Sharpie. You will want to seat the bullet such that this mark rides on the guide bump inside the AR magazine - this keeps the cartridge properly aligned in the magazine for pick up by the bolt.

Uncle Don
06-03-2014, 21:39
Thank you - that is excellent information, most of which I was unaware. Sounds like it's an investment in additional knowledge and some basic equipment to create the brass, but it seems it may be worth it.

rg1
06-03-2014, 21:45
Easy to load and fun to shoot 30 caliber bullets from 110-220 grains. You only need a way to cut the necks off of .223 brass and a lot use the cheap Harbor Freight mini-chop saw. Best brass and most recommended is to use Lake City LC brass. Some brands have too thick walls and the necks of converted brass may be over diameter. Loaded neck diameters should be .334 or less. I load 110 V-Max, 125 gr. Nosler Ballistic Tips, and pulled or new 147 grain M80 FMJ loads. I use Hodgdon data and H110 for loading 110-150 grain bullets. Lil-Gun is another popular powder. There are others that work better for heavier bullets and for sub-sonic loads. Steps to convert brass are simply to cut off the necks of .223 brass. The brass will grow about .005-.008" when sized so don't cut too long or there will be more trimming to do. Use the chamfer tool to remove saw burrs. Lube and run the cut cases into the 300 BLK. die, trim to length and load. I do highly recommend a headspace gauge and Hornady's Headspace gauge set with the B350 insert works great. Factory rounds sized minimally can have as much as 7-8 thousandths headspace depending on your chamber where you actually only want 3-4. All rounds fit AR15 .223 magazines and the only warning is I have read that a .223 Rem. round will not chamber in the short Blackout chamber BUT it is possible to accidently load a .308 dia. Blackout round into a .223 AR15 and it could chamber and fire. A bad thing as a .308 bullet won't fit a .224" bore. It's a fun round to load and fun to shoot.

willie_pete
06-04-2014, 13:13
300 Blackout fired in 5.56 upper = bad juju. I've colored my BO magazines after I read about three or four guns destroyed. This is one:

WP

Atomic Punk
06-04-2014, 14:22
Some good info here, also seems a good place for a question I have been wondering.

With subsonic rounds, and a suppressor, how does the 300 blk differ from a heavy and slower pistol round? I want to build an sbr setup and reload for it, but it almost seems like it would be cheaper to put a suppressor on a G21, and get similar results.

PCJim
06-04-2014, 15:47
.... With subsonic rounds, and a suppressor, how does the 300 blk differ from a heavy and slower pistol round? I want to build an sbr setup and reload for it, but it almost seems like it would be cheaper to put a suppressor on a G21, and get similar results.
AP, I've heard that same argument numerous times. For hunting purposes at close quarters, you could well do that with a pistol and appropriate SD bullets that will expand at pistol velocities, and maybe have better success.

The 300BLK gives its owner the option of using a rifle, shoulder rested, which "should" result in more accurate shots at further ranges. The biggest problem with its use in hunting is that there currently are no bullets available in 30 cal that will reliably expand at the subsonic velocities. Hunters I speak with regularly tell me that hogs that have been downed with the 300BLK look like someone took a .30" ice pick and drove it thru the hog. (these hunters only take head shots - these are 75-125lb meat hogs they are after).

I just like the idea of carrying two uppers and one lower out to the range and being able to shoot whichever I want. I haven't a place to hunt hogs yet (unless I want to just go shoot one in one of those multi acre pens, which I do not consider hunting). The 300BLK for me is for the most part a curiosity thing and being able to shoot it suppressed just adds icing to the cake.

Atomic Punk
06-04-2014, 16:37
AP, I've heard that same argument numerous times. For hunting purposes at close quarters, you could well do that with a pistol and appropriate SD bullets that will expand at pistol velocities, and maybe have better success.

The 300BLK gives its owner the option of using a rifle, shoulder rested, which "should" result in more accurate shots at further ranges. The biggest problem with its use in hunting is that there currently are no bullets available in 30 cal that will reliably expand at the subsonic velocities. Hunters I speak with regularly tell me that hogs that have been downed with the 300BLK look like someone took a .30" ice pick and drove it thru the hog. (these hunters only take head shots - these are 75-125lb meat hogs they are after).

I just like the idea of carrying two uppers and one lower out to the range and being able to shoot whichever I want. I haven't a place to hunt hogs yet (unless I want to just go shoot one in one of those multi acre pens, which I do not consider hunting). The 300BLK for me is for the most part a curiosity thing and being able to shoot it suppressed just adds icing to the cake.


thank you. thats all pretty much what i thought, i thought i may have been missing something. still want one.

batman4706
06-05-2014, 07:55
I use a band saw and a wooden block I drilled to the right depth to cut cases, I can do 10 at a time this way.

I have used the above listed powders with success and also 5744, 4227, Lil Gun & H4198. The 5744 loads are very quiet with a suppressor using Nosler 190's.

With the 125 TNT (cheap for fun shooting) I've had good luck with 4227 & Lil Gun.

I've even used Unique in it and got good accuracy, but doesn't work action.

Scott30
06-05-2014, 10:07
Uncle Don.. Reloading for 300 Blk is the same as any other after you cut/reform the case. If you plan on running subsonic get a pistol length gas system. It will run both subs and supers. Many have problems with carbine gas and subs and end up drilling gas ports, etc. You cannot overgas a 300.

For your reading enjoyment. http://www.300blktalk.com/forum/

I built my 300 and love it. Mainly shooting 125g bullets as I use it for hunting whitetails. PM me if you have questions.

Andrew Tacquard
06-06-2014, 15:00
Loaded some in my pro1000 and also in my LM. Good results. I've done 125s super, and 220s sub. I ended up loading the 220s to long, the bullet is in the lands/groves. I've since looked up how to determine max OAL for rifles (was the 1st rifle I loaded for). Also, outlaw state bullets makes a reliable 225 grain for subsonic in the AR. I haven't tried any myself, but I am on the waiting list. I converted both of my ARs to 300 BLK, so I don't have to worry about a 300 in a 5.56. Someday when I get to move home I plan on using both for pigs and whitetail. I did buy a couple thousand converted LC from a guy on the 300blk forum. Several folks sale it there, I didn't want to go through the trouble of converting.

Uncle Don
06-06-2014, 16:00
Getting some good info here so I think I'm going to pull the trigger so to speak, and buy an upper. Since I know nothing about gas systems, I'll have to buy a complete one, but regardless, it should work.

Andrew: I can only tell you my elementary manner of determining OAL in a particular gun, your way may be better.

I place the bullet alone in to touch the lands and grooves and hold it there - then put in a dowel that is a fairly close fit for the bbl, and put in the front of the bbl until it stops which is the front of the bullet. Make a fine mark at the end of the bbl and then knock the bullet out and do it again with the bolt forward. Make another mark - the distance between the two is the max OAL. I subtract about .010 and so far, it's never let me down but still allows clambering without a problem.

Andrew Tacquard
06-06-2014, 19:55
I found my method online, I was a Nosler article. Use a fired shell, make a small dent in the neck for tension. Make a bullet with a sharpie, put the bullet into the neck at more than max OAL, chamber, send the bolt home, extract. The bullet will have a mark at the point it pushed into max OAL (it was seated in the grove/lands), line the mark up with the case neck, measure max OAL, subtract .01 to .03. I think I measured something like 2.26 which was what I was loading to, so I needed to subtract a little. The still work well enough for plinking.

cohutt
06-07-2014, 06:47
If you are looking for something that you can endlessly tinker with, this is the round for you.

AA 1680 is probably the most used heavy subsonic powder (but rots-o-ruck finding any....)

h110/w296 is the consensus for lighter supersonic projectiles

My latest and ongoing experiment involves subsonic 300 bo -
cast from noe 311-247 mold with 1680 powder through daniel defense 16" 1x8 upper w/ Liberty Infiniti suppressor.

It has taken a while but the combo above is finally tuning to a decent grouping at approximately 1030 fps. last weekend I was hitting a railroad plate consistently at around 130 yards from a sitting position, which is a longer a shot than I'd ever take with this setup (hogs my mountain property). it is ridiculously quiet; i swear I could hear the hiss of the large projectile leaving the area....

http://i107.photobucket.com/albums/m284/cohutt/GUN/DSC_1727.jpg

I've tried both dry and wet powder coating a little and the early results are encouraging despite ugly lipstick colored bullets

http://i107.photobucket.com/albums/m284/cohutt/GUN/20140526_110532.jpg

PCJim
06-07-2014, 08:29
Off thread, but....
For determining rifle COL (on other than this 300BLK cartridge), I take a resized case and cut two slits, 180 degrees apart, lengthwise in the neck with a Dremel cutoff wheel. Insert the bullet of choice just barely enough so that the neck will hold it in place. It will be long.
Carefully, chamber this modified round, close bolt. The bullet will be pushed back into the case as it engages the rifling. Open bolt and very carefully extract the round. Measure the COL. Pull the bullet back out of the neck and repeat this several times, five would be good, each time measuring COL.

When reviewing the results, remember that the shortest COL you measured should be your max COL for this particular bullet.

Atomic Punk
06-07-2014, 12:50
Off thread, but....
For determining rifle COL (on other than this 300BLK cartridge), I take a resized case and cut two slits, 180 degrees apart, lengthwise in the neck with a Dremel cutoff wheel. Insert the bullet of choice just barely enough so that the neck will hold it in place. It will be long.
Carefully, chamber this modified round, close bolt. The bullet will be pushed back into the case as it engages the rifling. Open bolt and very carefully extract the round. Measure the COL. Pull the bullet back out of the neck and repeat this several times, five would be good, each time measuring COL.

When reviewing the results, remember that the shortest COL you measured should be your max COL for this particular bullet.

I have heard of doing something similar. Using special cases with a thinner neck. Same result. I think I like your way better.

cowboy1964
08-26-2014, 17:04
Some good info here, also seems a good place for a question I have been wondering.

With subsonic rounds, and a suppressor, how does the 300 blk differ from a heavy and slower pistol round? I want to build an sbr setup and reload for it, but it almost seems like it would be cheaper to put a suppressor on a G21, and get similar results.

Well if you want a suppressed long gun, it has to be subsonic so it's kind of a moot point. I want one of these:

Daniel Defense Integrally Suppressed .300 Blackout - YouTube

I think a suppressed SBR in 300 Blackout is the ultimate HD gun. Even unsuppressed it probably has less blast and noise than a .223/5.56. I really don't think over-penetration is an issue with proper ammo.

http://www.hornady.com/assets/images/products/ammo/gel/300-whisper-208gr-amax.jpg
(Hornady 208gr)

Andrew Tacquard
08-27-2014, 19:08
Check out the leonidas http://libertycans.net/leonidas/

Gunnut 45/454
08-27-2014, 23:23
I have the 16" CMMG carbine gassed 300 Blk out with 1:8" twist. It has eaten everything I've put in it from 220gr subs down to 125 gr Supers. I mostly reload and shoot cast now a days as factory ammo is just to dam expensive. If you go an get one you better be a reloader /caster. :supergrin:

IGotIt
08-28-2014, 00:20
AP, I've heard that same argument numerous times. For hunting purposes at close quarters, you could well do that with a pistol and appropriate SD bullets that will expand at pistol velocities, and maybe have better success.

The 300BLK gives its owner the option of using a rifle, shoulder rested, which "should" result in more accurate shots at further ranges. The biggest problem with its use in hunting is that there currently are no bullets available in 30 cal that will reliably expand at the subsonic velocities. Hunters I speak with regularly tell me that hogs that have been downed with the 300BLK look like someone took a .30" ice pick and drove it thru the hog. (these hunters only take head shots - these are 75-125lb meat hogs they are after).

I just like the idea of carrying two uppers and one lower out to the range and being able to shoot whichever I want. I haven't a place to hunt hogs yet (unless I want to just go shoot one in one of those multi acre pens, which I do not consider hunting). The 300BLK for me is for the most part a curiosity thing and being able to shoot it suppressed just adds icing to the cake.

My friend you are a bit mistaken. Lehigh Defense has a 174gr Controlled Fracture subsonic that opens up to just under an inch, and a 194gr Maximum Expansion subsonic that opens up to about 1.2"

Andrew Tacquard
08-28-2014, 11:51
There is also OSB that makes subsonic rounds that expand.

AZson
08-28-2014, 19:33
I built a 16" barreled one and a 10 1/2" pistol.

copo9560
08-28-2014, 19:46
The 300 Blackout stands out for an AR as a great option for a subsonic, suppressed short barreled rifle. If you don't plan on a suppressor, to me it looses a lot of appeal.

For hunting deer or hogs, if you don't go SBR, a 6.5 Grendell or 6.8 SPC are also great options to consider.

Andrew Tacquard
08-29-2014, 09:45
For supersonic rounds a 125 grain will work for whitetail and pigs out to a couple hundred yards. Most hunting I've done or will do will be well within that range. As long as there is 556 or 223 brass will be available and as long as 762 or 308/3006/etc is around there will be bullets. There perf might not be as good as some of the other options, but it is easy and reloading materials will always be around.

jmorris
08-29-2014, 13:27
I looked at the 300 whisper (more or less the same thing, 221/300, 300 blk) before I went with the 458 socom.

Once you set a speed limit (speed of sound) the only way you can gain energy is with mass. A 458 socom can deliver more energy to a target at 300 yards than the 300blk can at the muzzle.

Andrew Tacquard
08-29-2014, 14:10
How much drop is that at 300 yards, more like a mortar.

jmorris
08-29-2014, 21:50
Subsonic rounds all have similar trajectories. A Barnes 220g .308 SS would be -141.3", a 405g .458 at the same speed would be -143" or about the same as a .22lr.

The point was the fact that the 300 blackout at "close" distances does not bring much to the table that a 45 acp couldn't. A 220g .308 only edges out a 230g .451 by 29 ft/lb at 300 yds. Not to mention, you still have almost a half inch hole even if the 45 bullet doesnt expand at all.

When you can double (or more) the mass of the projectile, like you can with the 458, you gain a lot more energy.

Plugging in data using a 405g .458 and 220g .308 at the same SS speed, the 458 retains almost 150ft/lbs more energy at 300 yds than the .308 has to begin with and only drops 1.7" more than the .308 would at the same 300 yd distance.

freakshow10mm
08-31-2014, 07:41
Supersonic 300 BLK bullets are optimally 110-130gr. The middleweights are just because they are cheap and available (ie 147/150gr FMJ). They don't expand as well as the lighter bullets and they are chosen based on availability rather than ballistic performance. The 180gr+ bullets are optimal for subsonic 300 BLK.

The subsonic appeal of the 300 BLK is that it will cycle an AR15. That's about it. It will take a heavy bullet with higher BC so velocity loss will be minimal versus same weight pistol bullet. Subsonic bullets are not recommended for hunting, except in the case of cast bullets. Expansion is not the wounding mechanism for cast bullets as it is with jacketed bullets. Some of the expandable jacketed subsonic bullets work well but are cost prohibitive. The case can be made for the sake of the ultra low volume of shots required during hunting, however.

A 175gr SMK subsonic will be just as quiet as the 220gr SMK, use similar powder and be lower cost.

H110/W296, LilGun, and IMR4227 are good supersonic powders. 1680 is the optimal powder for subsonic as it has the correct gas volume to cycle the AR system.

I prefer IMR4227 for supersonic and I use it in my commercial 300 BLK ammo with the 110gr to 135gr loads.

Andrew Tacquard
08-31-2014, 14:11
Subsonic rounds all have similar trajectories. A Barnes 220g .308 SS would be -141.3", a 405g .458 at the same speed would be -143" or about the same as a .22lr.

The point was the fact that the 300 blackout at "close" distances does not bring much to the table that a 45 acp couldn't. A 220g .308 only edges out a 230g .451 by 29 ft/lb at 300 yds. Not to mention, you still have almost a half inch hole even if the 45 bullet doesnt expand at all.

When you can double (or more) the mass of the projectile, like you can with the 458, you gain a lot more energy.

Plugging in data using a 405g .458 and 220g .308 at the same SS speed, the 458 retains almost 150ft/lbs more energy at 300 yds than the .308 has to begin with and only drops 1.7" more than the .308 would at the same 300 yd distance.

Yeah I didn't really think about from a physics standpoint, just large object. Same velocity, aero effects are subsonic, 0 AOA, not much difference in drag, so it is just a ballistic trajectory with a little more drag on the bigger bullet.

I realize a 308 projectile is similar to 45 acp performance; I figured that was why it was sufficient at close ranges. Most all hunting I've done shots are within 100 yards; if not less. I also do realize a heavier bullet would have more energy, it is just physics. I also wouldn't take shots that require 141" of elevation, I am not that good. Within 100 yards the subsonic trajectory is about +/- 1.5"; again anything past that would be further than I hunt or would shoot.

Andrew Tacquard
08-31-2014, 14:18
The subsonic appeal of the 300 BLK is that it will cycle an AR15. That's about it. It will take a heavy bullet with higher BC so velocity loss will be minimal versus same weight pistol bullet. Subsonic bullets are not recommended for hunting, except in the case of cast bullets. Expansion is not the wounding mechanism for cast bullets as it is with jacketed bullets. Some of the expandable jacketed subsonic bullets work well but are cost prohibitive. The case can be made for the sake of the ultra low volume of shots required during hunting, however.


I would say the fact that it is only a barrel change to work, I can still put 30 rounds in a 30 round mag an appeal, as long as there is 556 or 223 I'll have an ample supply of brass is an appeal, as long as there is 762 or 308 I'll have an ample supply of bullets is also an appeal.

I'd also say Outlaw State Bullets are not cost prohibitive. They do cost more than a SMK, but not as much as some of the other subsonic bullets.

wct097
08-31-2014, 16:50
Been loading it for a couple years now. Have a 8.2" barrel and a 762-SDN-6 can. Use A1680 and 208gr A-Max bullets for subs and H110 (or IMR 4227) with 125gr SMKs for supersonic. These combos work with and without the can.

I've loaded 180gr, 150gr, and 147gr in addition to 125gr and 208gr, but I've decided to standardize on those two loadings. I had issues getting H110 and 208's subsonic and cycling reliably with and without the can.

I've made the majority of my brass by cutting down .223 cases, but these days I'd recommend going with one of the reputable people that convert brass rather than doing it yourself. It's tedious and a good thing to be able to do if you can't get brass elsewhere, but I'll be buying pre-made brass if I need more.

http://wct097.com/wt/guns/reloading/300_125.jpg
http://wct097.com/wt/guns/reloading/300_147.jpg
http://wct097.com/wt/guns/reloading/300_208.jpg
http://wct097.com/wt/guns/reloading/125grSMK.jpg

freakshow10mm
09-01-2014, 07:25
I would say the fact that it is only a barrel change to work, I can still put 30 rounds in a 30 round mag an appeal, as long as there is 556 or 223 I'll have an ample supply of brass is an appeal, as long as there is 762 or 308 I'll have an ample supply of bullets is also an appeal.
For the overall cartridge, yes I agree. My statement about cycling was specific to the appeal of the subsonic 300 BLK.

I'd also say Outlaw State Bullets are not cost prohibitive. They do cost more than a SMK, but not as much as some of the other subsonic bullets.
OSB are 22 cents per bullet more expensive than SMKs. 65 cents versus 43 cents.

If I were to load for subsonic hunting, I would go with the Missouri Bullet 240gr cast. It offers the best terminal performance for the lowest cost (15 cents a bullet).

Andrew Tacquard
09-01-2014, 12:29
For the overall cartridge, yes I agree. My statement about cycling was specific to the appeal of the subsonic 300 BLK.


OSB are 22 cents per bullet more expensive than SMKs. 65 cents versus 43 cents.

If I were to load for subsonic hunting, I would go with the Missouri Bullet 240gr cast. It offers the best terminal performance for the lowest cost (15 cents a bullet).


Gotcha, it does cycle well; I've had no issues with H110 even around 900 fps.

I will check out MO 308 cast bullets. Cheaper than the OSB, and my suppressor comes apart; not worried about lead.