IMR-4198 in 16inch midlength AR

[nix4me]

Has anyone found a good load that cycles an AR reliably with 55gr FMJ projectiles? I found some 4198 but i'm reading that some people have trouble with cycling with start loads. My books tell me:

18.8 - 20.4 IMR website and Lee manual
17.4 - 20.0 Hornaday manual
19.0 - 21.7 Lyman manual

 

[UziLand]

I used 4198 with a 55gr JHP at 20.5gr. I had no cycling issues in my bushmaster. Didn't see any neck stress, etc on the cases.

 

[243winxb]

20.5 gr with IMR ( old Dupont) Max at 21.5 (manual) Have went as low as 19gr in a Colt.

 

[nix4me]

I think i'm going to try 10 of each; 19.5, 20, 20.5, 21 and see what happens.

I picked up 2 lbs of the IMR 4198 just because it's all i have seen on the shelf that could even be considered for an AR.

Still looking for a 8lb jug of better powder. But it's like fairy dust here in central FL. Looking for Varget, BLC(2), H335.