LOOSE??- perhaps, but a .662 was the normal ball for 14 bore smoothbores, with a .678 being right in Forsyth's day for the 14 bore rifles with patch. Both Musketman and I chose .684 for the .69 rifles. The common choice was a ball 1 bore size smaller for rifles and 2 bore sizes for a sporting smoothbore with ctgs. or (approx)3 bore sizes for military ctgs.
: The military was the one shooting loose balls, ie: .64 and .65 in the 14bore(.69cal) muskets, not us.
: Your .648 for the 16bore with a .007 patch will have .000 compression for a perfect fit without deforming the ball. With the .017 patch and the attendent excessive compression, your accuracy at 100yds. will be considerably larger than 8", I presume. With a bit of work might, perhaps, you might shrink your groups, striving for less deformation of the ball, yet with a patch thick enough for the fouling.
: We've been able to get the 20 bores and larger to shoot into the 8" category at 100yds. which I feel is max range for this group size on large deer. On smaller deer in the 200 lb. bracket, I'd think 80 yds. would be about max.with 5" groups.
: We did find it difficult to get the small bores, ie: 20 and 16 to shoot into such small groups at 100yds. but it is possible with much trial on patch composition and size. At times, plastic cups from shotshell wads will help - at other times, they imcrease groups.
: I even had a turn of the century doublegun, 12 bore that I shortened the tubes to 24"& resighted. The barrels were marked Whitworth Fluid Steel & were originally imp. mod. chokes of .702" I.D. at the muzzles and .727 for bores. At 24" and with BP loads, it would make the 8" circle with 2 lefts and 2 rights - perfect for moose or anything on this planet, within it's effective range. I used the light "African" load for the .725 balls(original old mould fitting the bores perfectly) at 150gr. 1F ICI powder. The Full charge of 193gr. listed in WW Greeners book Kicked like blazes and other than an initial right and left, wasn't used. Those two heavy loads both impacted the 10" gong at 100meters. The elevation nor horizontal dispertion didn't change from the lighter load. This was on a 2 1/2" thick plate that a 7mm or 300 mag wouldn't do more than barely swing. Those 650gr. balls had it dancing on it's chains.
Daryl