W748 (& WC846) hot loads

[ErikW]

In .223 Rem, is W748 (and its surplus clone WC846) suitable for running a 55 gr bullet up to 3100-3200 fps from a 20" AR barrel? I want to run the bulk Hornady 55 FMJ (moly-coated) at least 3100 fps in WCC and LC brass. There should be plenty of space for powder.

The Winchester manual says the max load is good for 3170 but I'm sure that's from a longer test barrel or bolt rifle.

[uscbigdawg]

Erik,

I have plinker loads with Winchester 55gr. FMJ-BT's and there around 2950-3100 fps w/ H335. As I recall, W748 is pretty close to that. Just keep an eye out for all the normal pressure signs. While 748 is great, it's a bit temperature and elevation sensative.

Rich

[George]

Hey Erik,

This is not for use as is and should be worked up to but I have gone out to 28.5gr 748 under a 55gr at 2.230" OAL with a bulk Hornady TMJ. It gave me 3175-3200 with a whole lot of primer flow. I used to load 28.0 of 748 under 55's for 3100-3125 and OK looking primers, but went to 27.5 grs and am happy with 3075ish now for my junk ball loads. All of this is in a 20" 1:9

I hope this helps.

BTW, Moly coating will probably give you slower results than I indicate due to less friction, therefore less pressure, therefore less velocity. All other things being equal, Moly will typically drop velocity until it builds up enough in the barrel to really raise the velocity (and the pressure!). Buildup is the big problem point to Moly coated bullets in rifles.

--

Regards,

[D.Hayden]

Anyone ever chrono like loads from 846 and 748? Are they really the same or "very" close?