Patterning a new gun?

[4-Liberty]

Just a quick question. What is the process that you all use to pattern a new gun in terms of finding the correct ball size, patch thickness, and powder charge? Where do you begin, and what do you do next? Do you jump back and forth? Does this process change from a rifle to a smoothbore? I have yet to pattern my Tulle, and would like to know, through your experiences, what works best for you. I also have an up-and-coming Lancaster build that should be ready within the year (hopefully). I understand that smoothbores are different due to other factors such as using a wad, overshot card, etc., but just would like to know generally what order you all use.
Thanks!!  

[Sneakon]

I basically use the "Dutch Schoultz" method for muzzleloader rifle.  I'm a scientist, so I look at the process as an experiment with many repetitions. There are a number of variables to test:  patch lube type, patch thickness, ball size, powder type, powder charge, powder grain size, etc?.  The goal is to find the best combination of variables that provides the best shot accuracy.  I make things a bit easier by using only one patch lube and one powder type.  So then I'm testing only patch thickness, ball size, charge and grain size.  I start with a thin patch thickness, smaller ball size and say FF grain size.  Keep those three variables constant, but change powder charge starting low and increasing in 5 grain increments.  I shoot three shots at one target at each different powder charge, same grain size, starting at a low amount and increasing to something like a hunting load.  Then I change the patch thickness and repeat the three shot trials.  Then change the ball size and shoot.  Then change the grain size and shoot.  Obviously, this takes allot of shooting, but eventually it does produce the optimum combination for a particular rifle, and all the shooting is fun.  Also try to keep the barrel clean between shots to remove any fouling variable.
I'm sure I've left info out and my description is confusing, but others will clarify.

[Sir Michael]

First off I have to say that with a rifle you are trying for the tightest group.  For a smoothbore you can try for the tightest group with a single ball and consistent even pattern with shot.

As previously stated, with a rifle the key is what the gun performs best with (ball dia., patch thickness, patch lube formula, powder grain size, powder charge).  These are a lot of variables to deal with not to mention you.

With a rifle it is essential that you remove or minimize the variations you input into each shot.  This is best done with a good rest and a strong focus on the point of aim (POA) don't worry about the point of impact (POI) just the distribution of where the shots hit, you can move the POI to the POA after you get the best group.  Here is the best rule of thumb I've come across for this process.

Rifle starting point
Ball Size - Barrel Bore Land dia minus .010 - .015
Patch Thickness - .010
Patch Lube - Your choice (liquid e.g. moose milk or solid e.g. wonder lube) note:  don't change during grouping process
Powder Grain Size - The published sizes are <.50 cal - fffg, >.50 cal - ffg, >.70 cal - fg.  (note:  I shoot a .62 rifle that really likes ffg.  Go figure)
Powder Charge - Starting point go both up and down from here.  Target load measure grains = caliber of ball.  Hunting load 1/3 the weight of ball in grains.

Above all remember that the goal is the smallest group.  And every gun likes two charges one light and one heavy.  (This is the result of shock wave harmonics, ball velocity in the barrel, and barrel length)

Smoothbore ball starting point
Ball Size - Barrel Bore Land dia minus .020 - .010 depending on whether you are going to use patches or wadding
Patch Thickness - .010
Wadding - enough to hold the ball in place with the muzzle pointing down.
Patch Lube - If you use patches.  Your choice (liquid e.g. moose milk or solid e.g. wonder lube) note:  don't change during grouping process
Powder Grain Size - The published sizes are <.50 cal - fffg, >.50 cal - ffg, >.70 cal - fg.  (note:  I shoot a .62 trade gun that really likes ffg.)
Powder Charge - Starting point go both up and down from here.  Target load measure grains = caliber of ball.  Hunting load 1/3 the weight of ball in grains.

The hard part of grouping a smoothbore is that that usually doesn't have a rear sight (if it does use the rifle process).  Therefore consistency in the sight picture of the front sight and the POA is critical.  You may want to create a rear sight/reference point to ensure the necessary consistency.

To pattern a smoothbore with shot the process is somewhat different.
Use ffg Powder
Select Powder Charge - 68 grains - 90 grains
Over powder card to fit bore
Wad to fit bore
Select Shot size - e.g. No. 5 - No. 8
Select Shot volume - Use the same measure for the shot that you used for the powder
Select shot size - e.g. No. 5 to No. 8
Over shot card to fit bore.

The goal here is the most consistent shot pattern.  

Each process requires the adjustment of the above one item at at time.

This takes a lot of time but gives you the best consistency and teaches you just how your gun works.  It also instills a lot of confidence in you that when you pull the trigger you will hit what you are aiming at.

[4-Liberty]

Good stuff fellas!
So, as I'm working my way up through he powder charge by 5 grain increments, there will be two charges that will have the tightest group; the low being the "target load" and the high one being the "hunting load"? Do I understand that correctly?
Sir Michael; what exactly do you mean when you say "Powder Charge - Starting point go both up and down from here."?
Also, at what distance do you pattern a gun, both rifle, and smoothbore (ball & shot)?

[Sir Michael]

For a rifle, there are generally two amounts of powder that will produce the minimum size group.  One will be somewhere in the range of the number of grains of powder equal to the diameter of the ball being shot.  This amount of powder could be anywhere from 15-20 more or less than that number e.g. if you shoot a .50 caliber ball your light load may be anywhere from 30 grains to 70 grains.  There will also be a heavier load that will be anywhere from 15-20 grains more or less than the 1/3 the weight of ball you shoot e.g. if you shoot a .50 caliber ball your heavy load may be somewhere from 43 to 83 grains or more.  (NOTE:  both of these values are purely for example your gun will have its own likes they may be more or less than these values)  Also you may find that 5 grain increments may miss the optimal charge and that it may be half way between two of the 5 grain increments.  What ever it is that should be what you use.

As for finding the two optimal charges, you should experiment with both heavier and lighter charges from your two starting points because there is no way of knowing whether the optimal charges are higher or lower that those points.  Personally, my .62 cal rifle likes 62 grains of fffg and it also likes 100 grains of fffg.  I've seen people shooting as much as 80 and 130 grains is their .62 cal rifles.  Every gun is different.

To make it easy to work up a load for a rifle 25 yds is a good distance.  However, remember that once you get the optimal groups, you need to move the target out to 50 to 150 yds to adjust your sights.  The distance you decide to use for your sight adjustment to achieve POA=POI is up to you and depends entirely on what range you intend to shoot the most.  It is also a good idea to fine tune or confirm your powder load at that distance as well.

As for patterning a smoothbore, the typical distance used is about 40 yds with a pattern board of at least 50 in. square.  Again the idea in patterning is to get a uniform a distribution of shot over the board as possible.  You don't want to have any gaps or wholes in the distribution.

[4-Liberty]

That certainly is a lot of shooting! I'm looking forward to it! But with all of that shooting, that barrel has to get pretty warm. Does a hot barrel effect the POI?

[Sir Michael]

Between the time required to reload, set new targets after every five rounds (I prefer a five round group to a three round group to make sure I've not thrown things off, three rounds is just too few in my experience), and making decisions for changes the barrel doesn't get that hot.  Even of a hot day you will introduce more variation in POI firing off-hand than a heated barrel.

One more thing.  In all this process, only change one thing each five round session.  Powder charge is generally first, then Grade of powder, then patch thickness, then ball diameter, lastly there is patch lube.

[4-Liberty]

So, in finding a hunting load, I should start about 20 grains less than 1/3 of the weight of the ball in grains? Is that correct? For instance; my .62 Fusil shoots a .600 RB that weighs 325 grains, 1/3 of that is 108, minus 20 equals about 85 grains. Is that a good starting point to work up from, or should I start lower?
Thank you for the help so far! I'm still somewhat of a greenhorn and never really understood the patterning process!

[Two Steps]

4-Liberty, ya might like to read this;
Sighting-In the Black Powder Rifle
Good luck getting a good tight group (I'll get one some day   )
Al

[Sir Michael]

The short answer is yes.  Don't forget that after finding the best load you will have to sight in your rifle at the range you expect to shoot the most.

[ridjrunr]

For what I see as one of the most asked questions concerning ml shooting, this has got to be the best thread on the subject that I have ever read. Thanks to all who contributed. VERY well explained.  

[4-Liberty]

Yes, very well, indeed! This certainly has cleared up a lot of questions that I have had. Now, if only the weather would change a bit so that I can get to the range. It's either dumping snow or sub-zero!
Feel free to contribute any more information that you might have in regards to patterning! This is good stuff!

[Sir Michael]

One more thing.  I don't know if I made this clear but when working up your load it is of paramount importance that you shoot from a solid bench with a brace and remove as much of you from the equation as possible.  Also, use the exact same aiming point for each group of shots without regard to where the POI is.  The goal here is reducing the size of the group not getting the POA = POI that is a latter function.

[Bigsmoke]

Anlother thing to be aware of is that what is the magic formula for one person's rifle probably won't be for yours.
Example, Michael talks about his .62 liking 62 or 100 grains of Fffg.  Compare that to my .62 which seems to prefer 135 grains of Ffg for plinking and 200 grains of Ffg for more serious work.  Which interestingly enough is the same heavy charge my .69 likes, however it wants 150 grains of Ffg for target work.  Both have 1:104 twist.
And to emphasize, as has been said before, only change one variable at a time.  That cannot be over emphasized.
Have fun getting to know the gun.
John

[4-Liberty]

Wow! 200 gr is a lot of powder!!!
That brings up my next question. Is there a formula for the maximum amount of powder that a specific caliber can safely handle?