“RAPUD” on the ASSRA Forum wrote:

“Recently I acquired a CPA chambered for the .32 miller, a #3 bbl with 1/14" twist. Had no problems with the making of brass from .357 Max cases and am breech seating the .32 Hoch bullet at 30:1 alloy. Using 11 gr. AA#9 the rifle shoots consistently into 2" at 100 yd, and many times will produce at 1" or less. I see these groups of .75 at 200 yd and am wondering should the twist be 10"? How does one contact Ron Smith about his infamous gain twist bbls?”

Dave Patterson (Schuetzendave) replied:

Your rifle appears to be shooting relatively well for you and most Schuetzen rifles do not do much better than what you say it is already achieving.

However there may be gains to be had by further tweaking of either your rifle or your shooting skills. For tweaking of your equipment:

The 1:14 RKS gain twist is ideal for 200 to 210 grain .32/8 mm cast bullets.

A 1:11.5 RKS gain twist is what we are using now with 230 to 235 grain bullets which many argue do better in the wind.

Most everyone is using a slightly harder alloy of 20:1 or 22.5:1.

I had tried 25:1 but found that 20:1 worked better. I believe 1:30 is definitely too soft.

If you are using the 1.470" long case you may not be using enough powder. However Tommy Mason would probably argue too hot of a load only leads to uncontrollable recoil.

You should be able to go up to 13.2 to 13.4 grains of AA#9 before you start encountering any pressure signs for either a 200 or a 235 grain cast bullet.

Some are even pushing hotter loads but I don't like to push the limits.

This only leads to reduced life of primer pockets, can result in pitting of your block/bolt face, and can result in significant throat erosion which is normally only a problem with high power rifles.

I have had four different 32 RKS barrels on various actions and they all shot better with more powder.

I found they all had a sweet spot every .3 grains of AA#9/H108 powder but the hotter loads were always better until I got to the point where you start getting primer pressure signs.

You may wish to start testing loads starting with 12.5 grains of AA#9/H108 if you are using the 32 RKS (.357 Max case trimmed to 1.470" and tapered with a .223 die).

If you are using the shorter Miller Short case you should consult with someone more familiar with the maximum powder loads for this case.

But most importantly do you have a Weber bullet seater or some other adjustable breach seater that allows you to fine tune your chamber volume as well?”

More on Dave and his shooting:

On May 8, 2007 Dave had a very good day and broke the 1996 Earl Hines Raton record of 1241(41x) for 200 yard 50 shot plain base cast bullet using a scope off the bench.

He shot a 1245 (45x) which included two perfect targets, at Tommy Mason's International Benchrest competition at Nine Mile Falls, WA.

     The pipe insulation is the black thick foam stuff they sell to insulate 3/4" copper pipe.

The thick wads are inserted to be level with the top of the 32 RKS case (357 Max @1.470 tapered with .223) to prevent the wrinkling/lube denting of the cases that occurs when you place wads on the powder column and use hotter powder loads.

The wad is pushed out of the barrel and looks like a big black bumble bee was in the barrel when you take a shot. Contrary to popular belief the wad material does not burn or melt.

There is no additional carbon build up or fouling of the barrel from use of this wad material.

However the use of JB's bore paste is the only effective way I know of for cleaning the carbon fouling that eventually builds up in all barrels that are only cleaned with bore cleaning solvents. Knowledge learned from having access to a good bore scope.

The longer wad also helps prevent lube blow back around the front edges of the case mouth. I believe it helps seal the side of the case mouth from gas blow around until sufficient pressure builds up for the brass to seal against the side of the chamber. The longer wad also prevents twisting of the elevated wads I struggled for three years trying to get my Miller to shoot the way I thought it was capable of. Three things that immediately tightened up the group size and contributed to the new record were.

1.    I went to a Weber bullet seater that is adjustable and has a longer throw. By being able to fine tune my chamber volume and having a seater that aligned the bullet straight every time, I increased my per target score by an average of 6.6 points.

2.    I bought a new Jones bullet mould since my bullets were coming out oval even after I tightened up the worn pins. Face it, bullet molds can wear out after more than 30,000 castings.

3.    I went to thicker elevated wads to prevent case wrinkling and lube blow back. I believe the thick wads also helps protect the base of the bullet from deformation and/or gas cutting due to the increased insulation from the thicker wad. Also I think the thicker wad helps wipe the barrel of excess lube and fouling resulting in a more consistent environment in your barrel for the next shot and when transporting or handling filled cases. Nothing worse than a powder spill in a Miller action in the middle of a competition.