5.56 vs. 300 BO - SBR Trajectory?

[MikeCLeonard]

Lately, the more I look into the 300 BO cartridge, the more interested I become in running it in my LMT MRP vs the 5.56 I'm using now. Despite the research I've done, I'm still curious if anyone could comment on the differences I might see in trajectory between the two calibers out to about 300 yards given the following options:

11.5" Barrel shooting 62gr 5.56 (TSX, Gold-Dot/Fusion)
vs.
10.5" barrel shooting 110gr 300 Blackout?

I've looked at various charts on velocity per length of barrel for each caliber...but can't seem to determine if there is any notable difference in trajectory curve between these two configurations at this range. I'm thinking around 2700fps muzzle velocity for the 5.56, and maybe around 2200-2300fps for the Blackout...and that makes me think the 5.56 would have a much flatter trajectory...but in reality...I just don't know if it's a noticeable difference?

I'd be grateful for any input!

-Mike

[Corse]

Run it through JM Ballistics to get an idea.

[ALCOAR]

Since your a MRP brother from another mother....I ran your numbers through a calculator. Should give you an idea of the trajectory differences b/t the two.

MRP CQB 11.5" .223 62gr. TSX



MRP CQB 10.5" .300blk 110gr. TSX

[MikeCLeonard]

Ahhh, now I realize that I'm being lazy and asking for a spoon feeding! I didn't intend to be like that, but Alex...thank's so much for plugging that data in for me buddy!!!

In all honesty, I'm a complete novice at any kind of distance shooting, but trying to learn. I actually used a few ballistics calculators such as you've done here, but since I'm still pretty clueless...I was guessing at a few of the data-points...which made me feel like the results would probably not be very accurate.

In any case, to my inexperienced eyes...I see a delta of 7" drop between the calibers at 300 yards, which confirms that I'll be shooting flatter with the 5.56...but I'm not sure if that's really a significant difference to worry about. I think I'll copy your numbers here and play around with the zero to see how that affects things!

300 yards and in is where 99% of my practical shooting/hunting will take place...So I'm basically trying to convince myself that I can cover this range effectively with a SBR...and not have to plunk down $5,500 on an MWS to cover ground that I'll rarely get to use (at least for the time-being).

Again...Thank you!

[Failure2Stop]

Doesn't matter what your shooting with real cartridges, if it's under 11.5, its a 200 meter max application envelope.

.300 has some really good stuff going on, but to me that is mostly in the "suppressed with subsonic", with the option to go loud for long. Just me there.

Sent from my VS980 4G using Tapatalk

[MikeCLeonard]

Doesn't matter what your shooting with real cartridges, if it's under 11.5, its a 200 meter max application envelope.

.300 has some really good stuff going on, but to me that is mostly in the "suppressed with subsonic", with the option to go loud for long. Just me there.

Sent from my VS980 4G using Tapatalk

So, in the realm of hunting for example...I should probably keep to shots 200 yards and in, regardless of which of these calibers is being used? After reading up on the performance of the Barnes TSX bullets...I guess I was just getting the impression that I could effectively push it out a little further...But again, I don't have the personal experience to make that call.

I'll admit, being able to functionally run subs and supers out of the same gun without modification is one of the things drawing me towards the 300 BO.

[Symmetry]

If you are serious about taking game, then you want to take that game with one shot, and have the animal drop as close to the position that you observed it initially. You can much better accomplish this with a caliber that shoots fast, and shoots flat while maintaining ideal terminal effects. SBR is not good at this. There is a reason why long time hunters tend to go more powerful with their calibers of choice.

[fixit69]

This was the exact reason for my 300 blk project. A 100 max135 yard weapon for deer sized and smaller game. I am almost always using heavy subs and an AAC 7.62. Quiet, hardly any recoil, and it seems to work effectively. My Female friend and my kids can shoot it and not complain. Fun plinking for me too...

[MikeCLeonard]

If you are serious about taking game, then you want to take that game with one shot, and have the animal drop as close to the position that you observed it initially. You can much better accomplish this with a caliber that shoots fast, and shoots flat while maintaining ideal terminal effects. SBR is not good at this. There is a reason why long time hunters tend to go more powerful with their calibers of choice.

My hunting experience to this past season has been with 270, 30-06, 308, and 30-30 rifles. The results I've seen have shown me that they are more than adequate enough to take white-tail in my area. I also believe that 5.56 and 300BO are capable of cleanly taking game within a certain envelope, as long as I can put the shot where I want it. Right now I'm just trying to get a good understanding of what that envelope is...and how these calibers behave within it. The 300 Blackout has a number of characteristics that I like, but I wanted to know more about it's trajectory compared to my 5.56...because it's something that may affect my ability to put the round in the right spot at various ranges.

[rjacobs]

I am sure Robert Silvers will be around at some point, but I believe he says with something like the 110g black tips the round will open up out to around 440 yards(if I am remember my yardage correctly) based off the muzzle velocity and speed loss down to the minimum required for expansion. Personally I wouldnt shoot the 300BLK that far at all. 200 yard MAX would be my range with something good like the 110g black tips. Maybe once some more companies get on with the 300BLK and start designing specific profile projectiles that will open down to much slower speeds you could move that out a little bit.

Subsonic is another world all together as far as hunting and there are only a couple subsonic expanders out right now and they are expensive, but from I have seen(at least from Lehigh) they work extremely well and look devastating.