5.56 NATO load data 69 - 77 grain

[mrcheesemoose]

I’ve been looking around for some load data for 5.56 69 - 77 grain bullets. Specifically for 556 pressures not 223 Remington. I’ve been looking around for load data on this, but it seems that most people provide 223 Remington data, which is a bit cooler then 556 data. It’s also hard to distinguish between the two because a lot of data doesn’t provide the pressures. Anybody have any data specific to 556?

 

[Near miss]

Well the idea is to start low anyways.
Most do not give accuracy nor chrono reports with their load data, so you are not better off anyways with just load data.

 

[mrcheesemoose]

I’m just looking for 556 load data. I’ve loaded to max 223 and had no pressure signs in my rifle. Just wondering if there’s any data out there that does have the max for 556

 

[Near miss]

Few reloading books have 556 data since I have seen it being referenced.

There is a sticky for 556-only over here:

5.56 AR Only Loads

Post your 5.56 AR Loads here Ill Start off 23.6gr 8208XBR 77 SMK 1xLC Brass 205M 2710 20" WOA

www.snipershide.com

Just realize that they are usually where you might end at, not a starting point or a goal you need to get to.

 

[Dogtown]

Here's some predictions from QL and some popular powders for 5.56mm heavies

69SMK w/ TAC

69SMK w/ Varget

77SMK w/ Varget

77SMK w/ TAC

My personal favorite 77gr load is N140

 

[Near miss]

I have done testing out to 26gr of N140 and N540 with Scenar 77s and somewhere around 25gr was ok. But switched to N540 since it is more dense, thus requires much less compression, if at all.

The 10% lot-to-lot burning rate variance buffer is quite much.

My ingredients/gear produced around 2630fps at 24.7gr of N140 in 0C/30F. 24.7gr of N540 was a load I used in the summer too and it barely made any marks, maybe on some cases.

24.7gr of N540 with Hornady 75gr was around 2690 near room temp.

 

[Bacarrat]

I wouldn't shoot 5.56 pressures and expect your brass to last. Last time I shot XM193 or SS109 factory ammo all the ammo had ejector marks and the primers are flat. You want to know why there is a crimp in the primers on the military stuff? That's why. I think factory stuff is loaded to 65-72k? 69-77gr match grade ammo is not loaded to 5.56 pressures you see in the 55 or 62gr ammo. Load for accuracy with the heavies.

 

[reelserious]

26.5 of cfe 223 or 25 grain varget are 5.56 loads. These are max loads for 75 grain bullets

 

[Dogtown]

yeah, I should point out with those QL predictions, my go-to 77SMK N140 load is 24.1gr, which is nowhere near pressure in my gas guns.

 

[Lightning8]

Accurate Powder used to have 556 loads in their book but they have been absorbed by Hogdgon.

I am trying 24.5 grains TAC with 69SMK in 16inch AR

 

[reelserious]

the Hornady #11 book has 5.56 loads from a 20 inch AR 15 barrel. True 60K PSI loads.

 

[Old Corps 8541]

https://ramshot.com/load-data/

 

[Old Corps 8541]

1.You never said what you want to shoot the 556 loads in , AR or bolt ? If it's an AR , what is the Bbl.length?
2. Why are you looking to limit the useful life of your brass ?
3. Do you think driving your bullets at 'warp speed" are going to make them more accurate ?

 

[MTRecon]

Using the 556 load data from Western Powders I worked up to the listed max of 25.8 grs. of Tac, a 75gr RMR BTHP and LC brass. Tested in a 16" barrel.

A potent load but undoubtedly hard on the rifle.

 

[supercorndogs]

My manual has it listed as "service rifle data."

Unless you have pressure testing equipment, you aren't going to know when you reached 5.56 data pressure until you have passed it and start seeing pressure signs. So the data doesn't really matter. If you want to see how far you can go, you're going to have to test it.

 

[mrcheesemoose]

1.You never said what you want to shoot the 556 loads in , AR or bolt ? If it's an AR , what is the Bbl.length?
2. Why are you looking to limit the useful life of your brass ?
3. Do you think driving your bullets at 'warp speed" are going to make them more accurate ?

1) Ar 16 in barrel
2) why? Because I can, got a lot of brass and a lot of steel tips to burn through. I’m not really looking for accuracy (to a degree), and my current loads feel light based on 223 pressures.
3) no. They will always get less accurate with more speed. That’s just how physics works.

 

[nn8734]

1) Ar 16 in barrel
2) why? Because I can, got a lot of brass and a lot of steel tips to burn through. I’m not really looking for accuracy (to a degree), and my current loads feel light based on 223 pressures.
3) no. They will always get less accurate with more speed. That’s just how physics works.

77g SMK, 25g AA2520 (+ or - .3g), LC case, Remington 7-1/2 primer. Same load will work with the 77g TMK.

Load to same dimensions (coal, etc) as BH 77 otm or mk262 mod 1. This load is a clone of mk262 mod 1 and I run it in all three of my carbines as well as my Mk12 mod 1.

 

[LiveFire]

77g SMK, 25g AA2520 (+ or - .3g), LC case, Remington 7-1/2 primer. Same load will work with the 77g TMK.

Load to same dimensions (coal, etc) as BH 77 otm or mk262 mod 1. This load is a clone of mk262 mod 1 and I run it in all three of my carbines as well as my Mk12 mod 1.

I run basically the same load but norma brass and my length is 2.255. AA2520/25.0gr with a 77smk. Very accurate. Does not feel punishing. On the 3rd reload cycle I believe with this brass.

If anybody is Interested Western powder load manuals/pdfs list 5.56 data. The above load is .5gr from max 556 data. I saw no accuracy gain in my 18" wilson combat barrel going higher than 25.0

 

[sinister]