748, 55 gr .223

[rcschummers]

Whats your 748 recipe for 55 gr .223? Im working with a bull barrel 1/9. Thanks gentlemen!

[Davisje011]

26.5gr.

[mark501w]

26gr. Try any of the match bullets. 50gr Vmax real squirrel killer'

[rg1]

Start at 25.9 and work up to 26.4 grains of 748 with 55 grain bullets. In that range you should find the load that your rifle prefers. Mine likes 26.4 grains but I wouldn't go higher than 26.4-26.5.

[GeoffLinder]

I run about 27 grains myself but that is a pretty hot load for some rifles. I have gone up to 27.5 grains in testing but that is NOT recommended unless you are careful and know what to look for as you go. You want to go about 2.230 to 2.235" for OAL. I recommend you start in the 25.8 to 26.0 grain range and work it up a couple tenths at a time in your rifle till you get to around 3100fps or you see primer flattening.

[Germz]

I run about 27 grains myself but that is a pretty hot load for some rifles. I have gone up to 27.5 grains in testing but that is NOT recommended unless you are careful and know what to look for as you go. You want to go about 2.230 to 2.235" for OAL. I recommend you start in the 25.8 to 26.0 grain range and work it up a couple tenths at a time in your rifle till you get to around 3100fps or you see primer flattening.

what exactly are you basing that off of?

[Divernhunter]

My load since 1970 has been a mag primer(or reg if that is what you have), 55gr Hornady SX or reg bullet and 27gr Win748.
I also have used 27.5-28grs without any trouble.
The 27gr would not cycle my mini14 and the 28gr one works fine in the mini 14, Rem Varmit rifle and T/C Encore pistol.

[mark501w]

The only reason I said 26 is because it fills the case to the base of the neck & doesn't spill when I index my machine.

[GeoffLinder]

what exactly are you basing that off of?

Off of my accuracy testing and chrono results in about a half dozen AR's with barrels ranging from 16" to 20" and twists from 1:9 through 1:7.

Chrono results have provided lows of 3050-3075 fps in some rifles and up to just under 3200 fps in other rifles with 27.0gr. Around 3100 fps is a good target velocity for a 55gr in a 20" bbl IME.

I also run around 25.0 grains 748 under a SMK69 and get good results there too. About 5/8 MOA in my JP 20" 1:8 Wylde chamber with 25.2gr and about 3/4 MOA in my Colt 20" 1:7 NATO chambered AR with 25.0gr, both at 2.245" OAL.

Overall, I really like 748 for 50gr through 69gr loads. I use Varget for heavier than 69gr usually, 748 just won't get the velocity needed with a 77gr without excess pressure signs and it's temp sensitivity makes it a little touchy for heavies too.