GlockBuyer wrote:If you can't own an SBR, then I'd just get an integrally suppressed AR upper that brings the overall length to 16". I've seen them in 300 whisper and would assume they are even better when chambered in 300BLK.
That would be great, but then I couldn't use the suppressor on my .308 bolt action or other guns.
I only ask this since they gang's all here, but at approximately what range does a lightweight supersonic 300 blk projectile start to loose steam out of a 16" barrel? About how far out is it good for punching paper at?
"Lose steam" in terms of accuracy (the question Robert addressed), ft/s or ft-lbs?
The 123gr cartridge listed on the 300BLK website states 2315 ft/s and 1462 ft-lbs from the muzzle of a 16" barrel.
Referencing some simple on-line ballistic calculators I'm led to believe that on a calm, cool, clear day this round will still be supersonic at 600 yards (roughly 1200 ft/s) and still hitting harder than a 124 gr 9mm Luger (roughly 400 ft-lbs) at that same distance ... duh, given the MV of a 124gr pill from most 9mm self defense handguns is generally less than 1200 ft/s. Certainly *more* than enough steam for punching paper although your looking at 50" more drop than the .308Win from the same barrel.
So, the problem depends on how you define lose steam. For me I have arbitrarily defined "lose steam" as 1000 ft-lbs and the steam mark for me is crossed for this 123gr 300BLK combo somewhere around 180 yards, based on data from the same on-line calculators.
My arbitrary line is the sand is based on the energy left in a .480 Ruger around the 50 yard mark from a 7"-8" barrel or simply 1000+ ft-lbs. The Ruger supposedly has 800-900 ft-lbs left in it at 100 yards. I don't know if that's fair or not but at least I'm not trying to compare it to a .454 Casull.
However, I do believe comparing the 300BLK to a 7.62x51mm NATO round from a 16" barrel is simply not a fair comparison. A 150gr .308Win from a 16" barrel with ~2600 ft/s muzzle velocity will be dumping about 1500 ft-lbs on a target at 180 yards and still still delivering 1000+ ft-lbs at nearly 400 yards. Again ... all this data is from my *free* on-line ballistic calculators.
Do I *need* 1000 ft-lbs at target? I'm not sure, it's just the yardstick I'm using for the moment.
MisterWilson wrote:I only ask this since they gang's all here, but at approximately what range does a lightweight supersonic 300 blk projectile start to loose steam out of a 16" barrel? About how far out is it good for punching paper at?
If deer hunting and expect tp recover game 150 yards to 200 yards depemding on your skill level. ( based soley on balistic tables, I have not hunted with BLK out yet). Think of it interms of a 30-30.
Punching hole in stuff as far as yoiur able to, or until you run out of elevation in your optic.
Shooting 2 legged vermin, as far as yoiu can hit them. I have standards for harvisting game but not for selfdefense . If I am defending my self ,I just care about takeing them out the fight, a 30 cal hole is better fight stopper than a 223 dia hole. If they crawl off and die slowly or recover I don't care as long as they stay out of the fight and 30 cal holes do that better.
400 ft-lbs is still like a good hit with a combat handgun at contact distance. 600 is like a 357 Magnum. People hunt with 357 all the time so I would not set my line as high as 1000.
Its probably more accurate to make the energy comparison to something like a .40 S&W at point blank. Also though, at distance it's definitely harder to make good first round hits, especially so with unknown distances with the slower round. I was recently at a shoot that only had a maximum range of 450 yards. There were gongs and silhouettes at random ranges that we timed shooting in sequence in different stations. It was harder than what it looked like, guys had lots of misses past 250 yards or so. I ran it with a couple rifles, not with a Blackout this time, but one was a good shooting AR in 7.62 X 39 with good ammo. It was much harder with this than a 16" 5.56 AR. There was no time for real range estimation, just guestimation, the faster round was more forgiving.
Tom
silencertalk wrote:400 ft-lbs is still like a good hit with a combat handgun at contact distance. 600 is like a 357 Magnum. People hunt with 357 all the time so I would not set my line as high as 1000.
Cannot agree more on the 400 ft-lbs. da bugman summed it up quite well for me although I don't limit my vermin to 2 legs.
da bugman wrote:... Shooting 2 legged vermin, as far as yoiu can hit them. I have standards for harvisting game but not for selfdefense . ...
I also have no doubt I've set my line a little high, well beyond my skill for sure.
I'm sure the 1000 ft-lbs at 250 yards seems a little arbitrary but it drags along with it a few implied ballistics without having to specify bullet weight, BC or muzzle velocity and keeps the point blank range out past 150 yards for various projectiles between 123-170 grains. I'm not that good a shot so I need all the help I can get
Playing around with the demo version of quickload and trying to tweak the case measurements from the demo .308 by hand it seems launching a 150gr projectile from a 16" barrel with the 300BLK to attain 1000 ft-lbs is within the limits of the cartridge ... EXCEPT for the fact that I don't know BLK I'm doing in QuickLoad. But if it were possible that would yield a point blank range of ~175 yards @ ~1200 ft-lbs it would seem like a very respectable cartridge for a wide range of game in North Ameria ... out to a moderate distance. Probably no elk unless you're close enough to hit him with a Red Ryder but still a respectable hunting cartridge.
Seeing what the forthcoming 150+gr factory loads can do is a scale tipper for me, the 300BLK is a fascinating gun on paper and has great (high dollar) plinking potential but I'd like to wring real work out of it as well.
Tom12.7 wrote:... Also though, at distance it's definitely harder to make good first round hits, ...
Yes, MPBR ... I should say the PBR number I put in the previous post (before reading yours and Robert's reply) is based on ~1.5" not 3" ... widening the rise to 3" yields a MPBR closer to 230 yards for the 300BLK in 123gr which is not exactly shabby
