Whats causing these groups?

[ole farmerbuck]

26.0 grs. of H335 and a 55gr.bullet puts you over max. by .7grs. according to Hodgdon Data Center.

Yea but I believe it's way under according to Lyman, if i remember right. I'll check.

 

[Walkalong]

Speer #13 goes to 26.0 Grs H335 with 55 Gr bullets.

 

[ole farmerbuck]

I dont have my manual here at the house but i think Lyman shows 27gr for the 55.