From Hodgdon web site
Triple Seven In Cartridges: Use data specifically developed for Triple Seven FFG only. Cartridge loads should be used exactly as listed in this pamphlet. You may safely use a card or polyethylene wad up to .030" in thickness to protect the base of the bullet. Loading density should be 100% with light compression not to exceed .100". Testing has shown that Triple Seven will perform best when the bullet just touches the powder. Allow no airspace between the base of the bullet and the powder. Do not reduce loads by means of filler wads or inert filler material such as Grits, Dacron or Grex. Do not heavily compress powder charges. The use of filler wads, inert fillers or heavy compression may cause a dangerous situation, which could cause injury and/or death to the shooter, bystanders or damage property. Do not create loads for cartridges not listed. Contact Hodgdon Powder Company for recommendations concerning other loads. *See WARNINGS below.