As the test showed, Full-Form bullet sizing offers --at the very least-- advantages of higher and more consistent muzzle velocities. In that particular test it also showed the highest precision with a 10-shot group of 1.035 MoA. This was not a surprise to me because in several guns Full-Form sizing has proven to give up better precision than Smooth-Form sizing.

My Remington 700ML with McGowen .451″ barrel was pretty forthcoming with good precision. I could just Full-Form a bullet with a single pass, push it down with one hand, and shoot little groups. That barrel did not require indexing of the bullet; if you are unfamiliar with the term it means aligning the bullet at the muzzle so that the formed bullet is matched to the exact groove corresponding to it. This was not an issue; just push bullet through brake, twist until it dropped into the barrel, and push to seat.

Having said that, it did not happen that way with my Hankins gun. Full-Form sizing for that Brux barrel would leave some bullets hard to seat. It turns out that on the lands of this barrel one or two of them have a small flat. If you look at the picture below you can see what looks like a groove just above the green dot on the punch. That is a flat in the land, the grooves are lined up with the red dots on either side of the green dot.

Some makes of dies seem to be better (Swinglock namely and it’s patented) and so do some barrels. Brux makes good barrels but not every barrel is going to be perfect. I had to figure out a work around to get this die and barrel in concert because I was determined to make Full-Form work in this gun due to the performance advantages it offers.

I began to index all the bullets but it was still spotty as to how consistent my bullets fit the barrel. On the range it was causing mayhem with my precision and accuracy. I might shoot three or four shots through one ragged hole then pitch one or two shots an inch and half or two out of the group. Being the kind of guy who immediately looks at myself instead of my equipment when I fail I let this go on for a few weeks trying to work through it. I spent a lot of time with a small bore gun working fundamentals and hit the range again to no avail. Certain it was not me I began tweaking bullet sizing and powder charge. I completely re-assembled the gun to make sure there were no issues. Nothing improved. 

Whenever I can’t figure something out I talk to people who are smarter and more experienced than I am. I usually find out there is still nothing new under the sun and that there is a viable solution someone else has figured out. In this instance the recommendation from my buddy Rob was to size the bullet two to three times, rotating the bullet each time. The idea is that it is still Full-Form so a much more occlusive seal than a Smooth-Form but by rotating it you eliminate the sensitivity to indexing. You can just find a land/groove orientation, the bullet pushes past the crown, then you ram it home.

The question I had was, “How do you do this without having a bullet with twelve to eighteen grooves in it?” After a brief explanation via text message I had a grasp on how to get it done.

If you take a look at the punch (protruding from the top of the die) you will see one green witness mark and two red. The green lines up with the witness mark at the bottom of my die where the bullet enters (couldn't get a good pic). Luckily, I had my Full-Form bushing inserted in the die where a land was lined up facing me. If you have a fixed bushing die you just have to mark it where you can see a land to work with.

When you mark your punch I recommend that you spot drill it. If you don’t your mark will wipe away. Drill it or punch it then paint it. You need to mark your bullet the first time as well (I used green since my first dot was green). After you size the bullet you can re index the two marks (one in punch and one in a land) then mark your grooves. Again, I recommend that you spot drill your grooves and paint them or you will lose your marking.

If you look at the two red dots both are aligned with the left edge of the groove they correspond to. That is how far the bullet rotates in one pass. When I make the second pass I turn the bullet 180° (or half the total number of grooves in your barrel) and line those two red dots on the inside right edge of the rifling to take into account how they enter the die. If you feel any resistance that feels like initial forming stop and use a dowel to punch out from the top instead of cutting a larger groove. Another technique is to use a piece of tubing and run it through the top of the die towards the ram, force it over the bullet tip, then pull up and index it into the die before applying force with the ram. Either way, if you index it into the rifling it will just sail smoothly through on the second pass.

That said, if you cut a larger groove I have not found it to be a deal breaker. I have shot a slew of sub-.5 MoA groups using bullets that had a slightly enlarged groove from 2 passes from the FF die. I still segregate them though if I mess it up and will use them as my cold bore bullet (I actually believe it is usually a “cold shooter” but more on that another time) or bullets I use for shooting from alts even though there is no practical difference in precision or accuracy.

Loading does not require the removal of a brake as some think. You either have a funnel made/modified for full-form use or if you are stuck with a break made for smooth form bullets you improvise by using a pieced of tubing. You stick the bullet nose into the tubing and use the tubing (run through the funnel) to pull the bullet ogive into the base of the funnel so that you can use the funnel to insert the bullet through the brake, index it to the rifling, and lightly seat it before using the ramrod to finish the job.

I shot the Smooth-Form vs Full-Form test three days after the Smooth-Form vs Wads test. I established a baseline for Smooth-Form bullets with and without wads to see if Swinglock’s statement that a Full-Form bullet did not need a wad for superior performance was a truism. In this test I re-shot the Smooth-Form bullet without a wad again to see if velocity and precision were comparable plus it kept this comparison fair since I was collecting data for Smooth-Form vs Full-Form under the exact same conditions rather than trying to extrapolate data taken under ever so slightly different conditions.

Control Group shot with Smooth-Form sans wad:

Variable Group shot with Full-Form sans wad:

Analysis of Velocity Statistics and Precision:

Velocity:

With all else being equal the Full-Form bullet produced 24fps more velocity on average than a Smooth-Form bullet, with nearly half the Extreme Spread, and nearly half the Standard Deviation.

Comparing the Smooth-Form without wad in Test 1 to Test 2 velocities were nearly identical. The differences in high velocity were 6fps, low velocity 5fps, average velocity 4fps, extreme spread 1fps, and standard deviation 1fps.

Precision:

With all else being equal the Full-Form bullet produced 50.9% better precision than the Smooth-Form bullet.

While this is more accuracy than precision, the point of impact on this round of Smooth-Form, No Wad is lower than the last test with the same load. All other groups, including Full-Form, No Wad, had nearly the same point of impact which is in the 8-ring between 12 and 1 o’clock.

Conclusion:

With all else equal, there is a discernible performance increase with a Full-Form bullet over a Smooth-Form bullet.