5.56 @ 750 yards

[littlejerry]

Looks like 3GN will be hosting some long range matches in my area next year. One of the ranges is limited to 500, but another not too far away will go out to the full 750 yards.

Targets at that range will be "big", like 18x28 plates, 16" circle, etc.

Due to range limitations I've never pushed past 600 with my 5.56(or any rifle for that matter...). The calculators show that my current 16" + Mk262 combo will go transsonic around 675-700 yards. Velocity at 750 will be ~ 1150-1175 fps depending on weather.

My question is: what should I expect to happen? I've seen 55gr rounds go completely erratic at 600. Will the same thing happen with 77 SMKs? I don't need pinpoint accuracy, but I do need to be able to hit a silhouette.

I don't particularly want to invest in a new barrel or caliber for this game. The current combo works great out to 600 yards and I'm happy with that. There is some possibility that the newer Black Hills 5.56 TMK loads will push a bit farther out before going transsonic, but they are awfully spendy at ~$1.10 per round and I don't reload.

[Clusterfrack]

I’ve had great results out to 900 with 77 Berger OTM. My load is transonic stable.

[ST911]

BHA's Mk262 and the 5.56 77 TMK are GTG at 750 and far beyond. The 5.56 69 TMK is pretty impressive. You could also try the 68 OTM (new or reman) for a less expensive option. 750 isn't far for any of those rounds. I don't have any trouble keeping BHA 55 FMJ and JSP on half-Es or so to 600 with my 1/8 twist.

[JM Campbell]

I load 77gr tmk at 2504fps out of a 18” barrel AR15 and have solid hits on 12” gong at 750. The IMI razorcore 77gr or Blackhills 77gr will get you there once you find your dope.


Sent from my iPhone using Tapatalk

[SecondsCount]

My experience with the 77 Nosler Custom Competition has been very good out to 1030 yards. A good friend was hitting milk jugs at that distance with his 18" AR. Also try the 77 TMK.

[Mike C]

I load 77gr tmk at 2504fps out of a 18” barrel AR15 and have solid hits on 12” gong at 750. The IMI razorcore 77gr or Blackhills 77gr will get you there once you find your dope.


Sent from my iPhone using Tapatalk

If you have to shoot factory the IMI stuff is pretty fantastic, you could do a lot worse. JM Campbell, how are you liking the TMK's any really difference? I got away from using 5.56 shortly after they really started to become available but am still really curious about them.

[JM Campbell]

If you have to shoot factory the IMI stuff is pretty fantastic, you could do a lot worse. JM Campbell, how are you liking the TMK's any really difference? I got away from using 5.56 shortly after they really started to become available but am still really curious about them.

I have found you can push them to those distances with less powder since then the smk, they are longer. You save a tiny bit of powder but I would have no problem with the smk. Accuracy wise I think it’s mute unless your shooting in some good wind. I have followed MarkM on M4 and pretty much mimic his old 77gr load with H332 because it meters very well on my Dillon 550b. I do want to play with some Bergers in the future and the 80gr Sierra if it ever comes to market.


Sent from my iPhone using Tapatalk

[SecondsCount]

I have found you can push them to those distances with less powder since then the smk, they are longer. You save a tiny bit of powder but I would have no problem with the smk. Accuracy wise I think it’s mute unless your shooting in some good wind. I have followed MarkM on M4 and pretty much mimic his old 77gr load with H332 because it meters very well on my Dillon 550b. I do want to play with some Bergers in the future and the 80gr Sierra if it ever comes to market.


Sent from my iPhone using Tapatalk

What kind of accuracy are you getting from the markm (I think you mean H322, not H332) load?

[JM Campbell]

What kind of accuracy are you getting from the markm (I think you mean H322, not H332) load?

Yes H322 (fat fingered the iPhone).
Right about 3/4 moa at 100yd.

I’m running a Faxon big gunner 18” rifle gas barrel.

My buddies is a Faxon 416r stainless match heavy barrel that is fluted. Also 18” with rifle gas.
His is 3/4 moa with 75-100 rds down the barrel.


Sent from my iPhone using Tapatalk

[littlejerry]

Thanks for all the replies. Sounds like the IMI Mk262 should work. Thanks to a forum member I jumped on the midway sale and just got 600 rounds at 50c per round. That should keep me stocked for the first few matches next year.

[ragnar_d]

I've not messed with 77gr stuff since moving south (I stumbled into a thousand rounds of 5.56 Black Hills 77gr/Mk262 before I moved), but the 69gr SMK Federal GMM I had was able to put hits on USPSA sized silhouettes at 500 out to 715-725 and plates of a size I can't remember. This was out of a 18" 1-7.7 Krieger barrel.

The one thing I heard (haven't experienced it myself, this is just hearsay on my part) on a P&S Modcast was there are inconsistencies from lot to lot on the IMI Razor Core stuff. I don't know what the details about that were, but I'd like to find out more, but it seemed like if it was a good lot it was banging. I've got a few hundred rounds myself to experiment should I ever actually get to the range again.

[JM Campbell]

I've not messed with 77gr stuff since moving south (I stumbled into a thousand rounds of 5.56 Black Hills 77gr/Mk262 before I moved), but the 69gr SMK Federal GMM I had was able to put hits on USPSA sized silhouettes at 500 out to 715-725 and plates of a size I can't remember. This was out of a 18" 1-7.7 Krieger barrel.

The one thing I heard (haven't experienced it myself, this is just hearsay on my part) on a P&S Modcast was there are inconsistencies from lot to lot on the IMI Razor Core stuff. I don't know what the details about that were, but I'd like to find out more, but it seemed like if it was a good lot it was banging. I've got a few hundred rounds myself to experiment should I ever actually get to the range again.

I believe that was the 77gr Gold Medal Match, sd varied by average of 43 or 63. The 175gr 308 was in the 6-8 sd range, shooting lights out.

The IMI Razorcore was talked about very accurate and low sd.
https://www.stitcher.com/podcast/matt-landfair/primary-secondary-podcasts/e/51666936

I believe this is the podcast, MarkM from M4 is on there as well discussing his 77gr load.



Sent from my iPhone using Tapatalk

[ragnar_d]

I believe that was the 77gr Gold Medal Match, sd varied by average of 43 or 63. The 175gr 308 was in the 6-8 sd range, shooting lights out.

The IMI Razorcore was talked about very accurate and low sd.
https://www.stitcher.com/podcast/matt-landfair/primary-secondary-podcasts/e/51666936

I believe this is the podcast, MarkM from M4 is on there as well discussing his 77gr load.



Sent from my iPhone using Tapatalk

Thought it was something along those lines. I think it was one of the more recent ones (121) where Adam from KAC mentioned inconsistencies from lot to lot. Anecdotal evidence though, as I'm not sure of the specifics. I've got a few hundred rounds of it, but no place to make use of it right now so I can't contribute much.


Sent from my iPhone using Tapatalk

[JM Campbell]

Thought it was something along those lines. I think it was one of the more recent ones (121) where Adam from KAC mentioned inconsistencies from lot to lot. Anecdotal evidence though, as I'm not sure of the specifics. I've got a few hundred rounds of it, but no place to make use of it right now so I can't contribute much.


Sent from my iPhone using Tapatalk

You may be correct, quick google search for P&S and reloading popped that one up.


Sent from my iPhone using Tapatalk

[ST911]

Bear in mind that there is a specification for Mk262 and only one manufacturer makes it. Regardless of packaging, others load 77 SMKs and may get decent results but they are not Mk262. (See also 193, 855, 318, and others.)

[littlejerry]

Bear in mind that there is a specification for Mk262 and only one manufacturer makes it. Regardless of packaging, others load 77 SMKs and may get decent results but they are not Mk262. (See also 193, 855, 318, and others.)

Understood, it's much easier to refer to Mk262 type ammo than 77 SMK 5.56.

The IMI "Razorcore" has been great for me as a low price alternative to BH Mk262. At 50-65c / round it's cheap compared to just about everything else besides 55/62 FMJ bulk ammo.

[LOBO]

I have had great luck with RL-15 and Hornady's 75 gr BTHP out to 600 yards.