#swinglockbulletdies

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Bullet Sizing, Live Fire Comparison: Smooth-Form vs Wads

I shot the Smooth-Form bullet test first. I wanted to baseline them before I shot the Full-Form test. I also do not own wads and and did not have time to order veggies so had to get them from a friend. He supplied me with a .060″ thick, .460″ diameter vegetable fiber wad. I am unsure of the brand. I purchased a package of Traditions Wonder Wads at Gander Mountain while I was in town one day.

I had the breech plug out of the gun a couple of days earlier so I cleaned the bore. I have found that powder fouling can cause you to need a few rounds to settle in when changing powders so I cleaned the carbon out of the gun but left the copper as I believe it makes a larger difference based on testing I have seen. I had decided that if there were any wildly out of place numbers I would add shots until it normalized. Luckily, the muzzle velocity of the first shot fit with the rest (although the point of impact was quite low) and a similar velocity was found again on the eighth shot.

The control group target only has seven shots on it: cold/clean bore through the X-ring and a 6-shot group in the 8-ring. The wind was blowing 12-20mph and the target backers had just been replaced with Coroplast. It is a corrugated plastic sheeting and my staples were not securing the target well as a result. The target blew down twice during the 6-shot group and the two other shooters on the range were kind enough to go cold and let me re-hang it. When it blew down again I decided to just shoot shots 8, 9, and 10 through the chronograph and into the berm.

Control group without wads:

When I pulled my target after shot 10 I used a screw gun to secure my cardboard sheet to the Coroplast. That solved the falling target problem and I was able to finish out the test. All I had to do was switch out target sheets after testing the Vegetable Fiber Wads and shoot the Wool Wad.

Variable group with Vegetable Fiber Wads:

The lubed Wonder Wads were shot last as they could possibly have had an effect on any testing after them in the event the lube left any residue in the bore.

Variable group with Lubed Wool Wads:

Analysis of Velocity Statistics and Precision:

Velocity:

A vegetable fiber wad produced higher average velocity, with roughly half the extreme spread, and roughly half the standard deviation of identical Smooth-Form bullets shot without a wad or with a wool wad. It won on all accounts.

There was not an extreme difference between performance without a wad compared to performance with a wool wad. Nonetheless, a wool wad appears to offer no advantage over a bullet without a wad. If I had to choose wool or nothing, based on this test, I would choose nothing.

Precision:

Due to technical difficulties with wind blowing down my target I didn’t get all ten shots on target for the “No Wad” group. We will never know what that group would have turned in although I did re-shoot it in the next test for a head to head comparison with Full-Form (you’ll get that in the next installment). The potential for precision looks very good but it looked that way for the “Veggie Wad” until I had one each out of group, high and low. I know from shooting match rifles that as shot count goes up so does group size so nothing new there. Law of Averages.

Conclusion:

The performance of a load employing a Smooth-Form bullet can be improved by the use of a vegetable fiber wad.

[kineticperformancellc]

Bullet Sizing Live Fire Comparison: Setting up the test

Preface: I have seen some pretty heated debates over Full-Form vice Smooth-Form over the years. You got my take on it last time based on my preconceived notions. Proponents of both sides always have a slew of reasons most of which are little more than opinion. This is my modest attempt at offering you something more objective.

I am, by nature, a very curious person. I also have an overwhelming need to understand things. From the time I was a child to the present the answer, “Because,” has never been adequate for me. Everything has to be qualified and substantiated or I am not having it as anything more than opinion. I also learn best by doing. When a shooter who I’m acquainted with started struggling with Smooth-Form at long range I became curious as to why. While I do not have the resources that big companies like Berger have I began to devise some testing to come to a better understanding of why we might be seeing what we have been seeing and determine if some claims stand up.

Following the Scientific Method, I began to make observations. I drew from the fact that I have seen a lot of guys see an improvement with wads and that Jeff had bullets failing to stabilize at long range. I also took three key statements from Swinglock’s statement in the provided link: A much better seal is produced because the bullets form fills the rifling grooves, Full formed bullets do not require the use of over powder wads, and Full formed bullets produce higher velocities with less pressure.

The easiest hypothesis to test is the null-hypothesis. It assumes no difference between states. The hypotheses become:

1. There is no difference in load performance between a Full-Form and Smooth-Form bullet.

2. The performance of a load using a Smooth-Form bullet is not dependent upon using a wad.

Now I had to devise the test. One thing that immediately invalidates a test is slanting it in favor of a particular outcome. You also have to ensure you only change one variable at a time until you have tested all variables. Only then can you combine variables. I did not intend to ever combine variables, just do two tests that built upon one another with different variables.

I have loads that are dialed in for my guns using the bullets I make and my preferred powders. While they all shoot very well some are better than others and if gamed things accordingly I could rig this test. I wanted to test with something I had no reason to see succeed over something else. I needed to do this test with some unknowns. Those unknowns would be powder and bullets suspected to succeed but never tested together.

I took a look on my powder shelf and saw that I had a pound of Hodgdon’s H322 I bought a year or so back and never used. I shoot a lot of H4198 with the 302gn BOMB and IMR3031 with 344gn BOMB. H322 falls between those two in burn rate so I ran it through Quick Load to compare it’s pressure and efficiency to the others using a 317gn bullet which falls between the two bullet weights I frequently use. Everything looked good so I chose a charge weight that should put me in the velocity band where I expected good accuracy.

I decided to make no changes to my dies for this test. They are set up to size the BOMB 302gn and 344gn so I expected they would work just fine with the 317gn BOMB. Both the Smooth-Form and Full-Form bullets were sized with two passes through the respective sizing die.To check the potential of this load I needed to range test it with a known quality. Since the 302gn bullet looked better than the 344gn bullet based on computer predictions I hit the range with the 302gn bullet sized in the Swinglock Smooth-Form Die and the 76gn of H322 I intended to use for the test.

H322 showed plenty of promise with a known bullet:

Everyone has a pile of scrap. As a bullet maker I have scrap bullets. I happened to do a custom run of bullets a while back for a guy in 317gn and while they were structurally sound they had some cosmetic blemishes in a ratio that made them not worth pursuing. I shot some of them with H4198 when I first made them just to see if they would shoot but since I could never make one pretty enough to sell they have been sitting on my test shelf. Using my standard 70gn of H4198 they were sub-MoA to 300yds (as far as I shot them) so I felt like they would work for this test since I had only ever shot 9 of them and never with H322. I sorted out 50 of them that were good to go and set them aside for testing.

The 317gn bullet with H4198 from proof testing at 100yds and 300yds back in Feb2016:

At this point I had all the hardware components for the test: an accurate and precise rifle, a dependable optic, a powder that showed good precision with a known and similar bullet, and a bullet that showed good precision with a known and similar powder. Research finished, I could set parameters to test the hypotheses.

Test #1:

Shoot three groups, 10-shots each, using Smooth-Form bullets and 76gn of H322. The first group would be with shot without a wad as the control group, the second group with vegetable fiber wads, and the third group with lubed wool wads.

Test #2:

Shoot two groups, 10-shots each using 76gn H322. The first group will be shot with a Smooth-Form bullet as a control group. The second will be shot with a Full-Form bullet. Neither group will be shot using a wad.

Each test was conducted to completion in one range session and each test was shot on a different day but with the same rifle. I shot every group. I always shot the control group first, so that I was fresh, after a solid dry firing session. All groups were shot prone with a bipod and rear bag. A bench and bench-rest equipment would have allowed for more repeatable position but I shoot well from the prone. More importantly, I have shot several hundred rounds of heavy loads over the past few months conducting SML testing from the bench and it started to give me recoil anxiety. Going to the ground has cured it. Both days the atmospheric conditions (temperature,barometric pressure, and humidity) were nearly identical. Both days winds were 12-20mph (half value) and skies were partly cloudy (good for the sky screen chronograph).