We have already determined his bullet is not too long for his twist - instead we were indicating it was too short and spinning too fast earlier.

Ballistician Bryan Litz:

"There are potential precision advantages of keeping SG under 2.0.
The conversation above wasn’t addressing dispersion, only the flight mechanics of overly stable bullets.
In other words, additional drag is not a concern for SG over 2.0, elevated dispersion might be. Two different things."

I'm not sure that ANYTHING has been determined for certain from the scant information given, just a lot of conjecture that may or may not be apropos but does have validity in some circumstances.

I NEED to see the ACTUAL target to see the ACTUAL amount hole elongation,  the weather conditions and more about the loads/COAL/ETC...absent that, we're just blowing smoke about our favorite thoughts and aspects and speaking to the choir.

I would hate for a surgeon to use this limited  amount of into to operate on my brain when all that was wrong was an in grown toenail...

Have any of you actually looked at the RPM difference between a 1/14 and a 1/16 and run the numbers?  There are several good free software programs devoted to that particular subject.

A 0.410" dia bullet needs to be ≈1.70" long to have an optimum of 1/14...at ≈1450 fs fs - RPS 1228, ≈1.55" long for a 1/16, RPS 1038 at ≈1450 fs ....a 1.32" SAECO 740 bullet at 1/19, RPS 912 at ≈1450 fs, where it is optimum from ≈600 fs to ≈1500 fs...that is revolutions per SECOND...(went blind for a second)

At 1445 fs a 14 T barrel hits ≈1240 RPS and a 16 T hits ≈1085 RPS, ≈155 RPS DIFFERENCE...but it is an understood fact that it is hard to over-spin a good bullet, jacketed OR cast.

Basically it's all relative...relative to a ton of variables and no one sticks to the original premise...things go sideways VERY FAST. 

Enjoy

Flintlock,
Here is a bullet that has worked for 14 twist 40-65s
beltfed/arnie

See what I mean by "GOING SOUTH"...I don't think ANYONE ever said the 740 was PI**-poor bullet...the original posit was basically POOR ACCURACY with it in HIS RIFLE and that Flintlock was using it and he wanted some help to "fix an accuracy problem"...then a few posts down the road it all went to heck with posters positing THEIR FAVORITE CONJECTURES and no one listening to the others or even Flintlock...THAT'S WHAT I MEANT.   

What you or your cousins or all the rest of the world did in a PAST match doesn't mean squat doodley if the "rest of the story" is missing...we're NOT talking about YOUR GUN or YOUR fame...who cares what you did, I care what I can do for FLINTLOCK, HE'S THE ONE NEEDING HELP, YOU CERTAINLY DON'T...Flintlock was asking for help with HIS GUN and HIS problems...WITHOUT providing enough/adequate information. and so far NO ADDITIONAL INPUT.  This happens WAY to often on forums...one or two questions/posts then the poster disappears for good.

The major problem with ALL forums is everyone wants to talk about THEIR thing and only cursorily attentive to what others want to do/need/asking.

I was hopping this forum would be different...I should have know better.

Hobble on.

The load and fouling management seems pretty good to me.  At least the one with BP.  I have never tried smokeless in the .40-65 so I can't say.

The 20:1 alloy and lube are also quite reasonable to me. 

I had a C Sharps 1885 once with a freebore that was quite a bit over groove diameter.  Something like 0.005" over as I recall.  In order to make that rifle shoot well it needed the fattest bullet that I could fit into the case.   

Bill have you done a chamber cast by any chance to check the dimensions?

Chris.