LongRifles Inc. second group session

Discussion in 'Gunsmithing' started by WesB, Jul 17, 2010.

  1. WesB

    WesB Well-Known Member

    Feb 3, 2008
    This morning was cool with no breeze so it would be a good day for testing new loads. After the first grouping session it appeared that this rifle liked the bullets seated to the lands. These were loaded with once fired Remington brass, Federal 215 primers, H-4831 powder, and Berger 168 VLD Hunting bullet seated .001 off the lands. The last time I would clean between groups. It was suggested to shoot without cleaning between groups to see if the rifle shot better fouled, so all groups were fired without cleaning. I fired 5 fouling rounds to adjust my scope then fired for groups. I waited about four to five minutes between shots to give the barrel a chance to cool. I loaded two different powder weights to check for pressure with an additional .5 gr. of powder.

    Group #1
    Load- 66.0 gr. H-4831

    Group #2
    Load - 66.5 gr H-4831

    Group #3
    Load - 66.0 gr. H-4831

    Group #4
    Load - 66.5 gr. H-4831

    There were no pressure signs with the additional 1/2 grain of powder.
    It appears to me that after eleven shots without cleaning the pattern started to open up. This could be me getting a little flinchy ?
    For this session I lightened the trigger a little and screwed the over travel adjustment screw all the way in, according to Shawn's trigger dwell time article.
    Comments, suggestions, interpretations and criticism welcomed.
  2. Chas1

    Chas1 Well-Known Member

    Feb 15, 2009
    It does appear that as time went on the groups seemed to openup irregardless of the .5 additional powder. I'm not so sure it was you getting flinchy as I would expect groups to be bigger...hard to tell only you can know if it was you.

  3. coyotezapper

    coyotezapper Well-Known Member

    Sep 26, 2009
    Good shooting! It appears you have an accuracy node in the 66 grain range. I would tweak those if the velocity is there. The only thing I might do different is to shoot three and then let the barrel cool. In a hunting situation I want to know what my shots will do back to back.