What are Heavy 223/556 bullets

[hounddawg]

77's rock. I saw a shooter a 600 clean match at 800 yards with a crosswind a couple of months ago with his AR in the AR tactical prone class using an off the shelf Palmetto Armory rifle. He loaded them long and was single loading but it was still darn impressive

 

[kilotanker22]

Kilo,

I think you may have things a little backwards there, buddy.
Typically a slower burning powder is used for heavier bullets.
Alliant Varmint, and Ramshot TAC are faster burning than Varget.

I use Varmint with the lighter to me 52gr TMK.
Alliant PP2000MR with the 69-70gr bullets.
These out of a Savage 110 with 1:9twist 24" barrel.

No magazine to worry about, so loaded to 0.020-0.030" off the lands instead of SAAMI spec length.

You are correct. I did get that backwards. I have used all of those powders for all bullet weights at one time or another.

Looking at my notes, I see that I use Varget and PPV for most. BLC-(2) for heavies.

 

[reynolds357]

I agree with others 65gr and higher are heavy for cartridge .

I'd first say don't confuse optimal/best with anything lighter won't work . IMR=4064 will shoot 55 , 60 , 62gr bullets just fine it's just a tad to slow to be "optimal" for those lighter bullets .

Second I'd say long extruded powders like IMR-4064 fill the case fast and the heavier the bullet the longer the bullet . This means the deeper in the case the bullet will sit/seat . That can be an issue if you are using a powder that bridges in the case and leaves air pockets of space in the case . This results in not enough room to seat the bullet as deep as need be for ... lets say mag length for an AR .

Example :

This is how deep a 77gr smk needs to be seated in order to feed from an AR mag . If your powder fills the case to the bottom of the neck , it's going to be pretty hard to seat that long bullet in there .

There are ways to get bulky powder to settle and allow for more room in the case to seat the bullet . Powder funnel with 12" drop tube helps and some guys will use a 36" drop tube . You can tap the sides of the case or vibrate the case to force the powder to settle .

My over all point is many powders that are best for heavy bullets for the 223 will likely need compressed loads , All my 77gr 223 are compressed by at least some .

Due to seat depth, I find the 5.56 x45 to be far from ideal for shooting heavy. IMO the 224 Call and the 22 Nosler are a far better starting place to shoot heavies.

 

[jugornot]

I use 77 gr SMKs for my bolt and AR rifle. I tried Varget but found That 8208 for AR and CFE223 for bolt gun. The AR is a sub 1 MOA gun out to 500 yards. It is a phenomenal rifle. It actually shoots a touch better with 77 gr STMKs, but I worry about them in an AR.