Eye sight or lack thereof, lighting, sight size & shape, target size, colour and shape, & almost most importantly, your load, all effect group size at any range.
Added to that, is the bench shooting technique - sitting position, feet position, height, comfort, chest touching bench, holding forend or letting it bounce, sand bags- tightness
of softness - it all makes a difference.
The further the range, the more "weight" each of these had on potential groups size. Poor combinations,as in not enough powder, too-thin patches, poor anything else adds
up to have little chance of shooting well at longer ranges.
For instance, I shoot much better at 50yards if I am using a 4" black circle - or, a target with 1" thick rings of black on a white page. For some reason, this allows a much
more accurate, 6 o'clock hold on one of the 1" black bands with a post, as well as an 'aperture' effect when using a front bead & holding centre. With the .69, I like holding
the forend in my left hand, resting the back of my hand on the front bag -- no rear bag. Other guns, like the .36 and .50, like to have the forend resting on the bag, no rear
bag. The point of rest for both of those, is just back of the entry pipe. Some guns are particular where they are rested.
I used targetz.com(various targets) for most of my copied targets for BP as well as modern guns.
Black circle just over 1/2 way down this page, target Target No: 10098.
http://www.targetz.com/targetzlib/10098.pdfCircles = Target No: 10142
http://www.targetz.com/targetzlib/10142.pdfFor 100 yards, my best shooting was on one of the commercial targets with red bullseyes - big one in the middle and 4 smaller ones, in the corners.
This made it easy to aim with my Express sights on the .69. The 200yard target we used for the postal match, was good for 200yards. I do not
have our benched practice targets, but both Taylor and I managed 5 shot groups at 200yards that were less than 2 moa (4") on that target. It had a 12" square black
bull's eye, with a 5" square white centre. He was shooting his .62 Hawken with 127gr. 2F and a tightly patched .615" ball while I used 165gr. 2F and
as tightly patched .682" ball.
The load is VERY important when shooting past about 30yards. That is where having an accurate load makes a very big difference. If interested in this type
of shooting, looking up chunk shooter's loads (shot at 60yards), or plank shooters loads (also shot at 60yards) or if interested in longer ranges, check out
round ball bench rest shooter's loads. That will give you an idea what works - out there.
This is a 10 shot group, 8 off the rest and 2 offhand shots) shot at 50yards with, for this rifle, is a light load, developing 1,200fps. I noted on the target that
this load also shot into 2" at 100 meters. Also, the measurements were wrong as I subtracted the .684" round ball's diameter, instead of .675" which was the ball I used. Thus, the C to C
measurement should have been 1.105" for the 10 shots.
The patch was my normal 12 ounce denim that I measured at .025" with mic, and .030" with calipers. The ball was .675" and pure lead.
This combination runs .735" using the calipers measurement and .725" using the mic's measurement, both being will over the rifle's .714" groove to groove measurement.
This target was an experiment to see if I could get a grossly undersized, 16 bore ball to shoot, and it did fairly well using 2 .017" (8ounce denim) patches.
Some of the patches seemed in good shape, while others were cut and burned after firing with this light 82gr. 2f load. I increased the charge to 110gr. 2F and both of the patches were
incinerated, completely burnt up or almost so from the flames going past, due to the increased pressure of the load. Too much for the loose combination to contain. The WW ball, with no
obturation, relied upon the patch only, for maintaining it's integrity. It failed. That combo only adds up to .696". The groove diameter in this rifle is .714". I found it quite interesting that it shot
as well as it did, at 50yards - about 1 3/4" with the low shot. The shot far right was the first shot fired and a horrid flinch.