Sierra 107 SMK vs Berger 105 Hybrid: Do Berger Bullets Have the Best Consistency

In the shooting community Berger Bullets are often regarded as the most consistent, often over Sierra bullets. Is this really the case? In this post I will compare the Sierra 107 SMK and the Berger 105 Hybrid.

Introduction

Both Berger Bullets and Sierra Bullets hold many world records, and many have argued about which are better. Berger bullets are often considered to be the most consistent, but is that the case? In this post I test both Sierra and Berger bullets, putting them head to head to see which deserves the title of most consistent. Due to a lack of time, tools, and money, I cannot test every aspect of the bullets. I can test the consistency of easily measurable things. I can measure and compare the lengths, weights, and diameters of both of the bullets. All testing is done between the Berger 105 Hybrid Target bullet and Sierra’s 107 grain MatchKing bullet.

Consistency

For years and years, shooters have known that consistency is important in their ammunition. The consistency of the bullet is known to be a major factor in the consistency of the load overall. Top Benchrest and F-Class shooters sort their bullets to give them an upper hand. Field shooters tend to want to be efficient, and avoid tedious tasks like sorting. When you are loading in the high volumes that many do, saving time wherever possible is vital. With this in mind, bullets that are more consistent out of the box would likely be the best choice.

Measurements

Testing and Sample Size

Weight Consistency With the Sierra 107 SMK and the Berger 105 Hybrid

My testing shows that Sierra 107 SMK bullets have more consistent weights than the Berger 105 Hybrids. However, the 105s had a more accurate weight. The SMKs have an average weight of 106.893, which is about a tenth of a grain less than the advertised weight. The Bergers have a more accurate average weight of 104.998 but have more variation. A more consistent weight is vastly more important than an accurate one. A consistent difference in point of impact can be corrected, but variation cannot. The Berger 105s had 77% higher SDs (standard deviations), and a 40% higher ES (extreme spread), when compared to the Sierra 107s. When I put the data in the calculator to see if it was statistically significant, I found that it likely was. The calculator said that given the sample size, averages, and SDs, at a 95% confidence level, there is a 98.4% chance that the variations are different. In other words, there is around a 90% chance that the Sierra 107s have more consistent weights than the Berger 105s. Many top Benchrest and F-Class shooters believe that weight consistency matters. They know that a higher weight means a higher BC, which affects POI. This means that if you want to save time by not sorting bullets, Sierras may perform better than Bergers in that aspect

Base to Ogive Comparison Between the Sierra 107 SMK vs Berger 105 Hybrid

My testing shows the base to ogive of the Sierra 107 SMKs are more consistent than the Berger 105 Hybrids. Once again, the SDs of the Berger 105s were 80% higher than the 107s, and the Bergers also had an ES which was 75% higher. The calculator shows that at 95% confidence, the variations have a 98% chance of being different. Again, it is up to you whether or not you believe this has an impact downrange, but sorting by base to ogive length is also quite common. The idea is that because the ogive is what engages the lands, the variations in length will impact the seating depth. This would mean that if you are shooting without sorting by base to ogive, the 107 Sierras may give you an upper hand.

Diameter

Diameter is not the most important measurement, but it was another thing we could test. The 107s have an SD that was almost half that of the 105’s SD. The ES of the 107s is also half of the 105s. The calculator says that with a 95% confidence level, there is a 98% chance that they’re different.

Length Consistency

Length is known to be a major factor that affects precision. The BC of a bullet is based on the bullet’s weight, diameter, and shape. The shape of a bullet is directly connected to the length, so it is bound to have an effect. Many F-class or Benchrest shooters eliminate variations in length by trimming or sorting. Brain Litz from Applied Ballistics tested in effects of bullet length in his books. His books, Modern Advancements in Long Range Shooting are some of the best on the subject of ballistics. The Sierra 107s has a length SD which was more than 3 times less than the Berger 105s. They also had an ES which was less than half than the Berger 105s. The calculator shows that at a 95% confidence level, there is a 100% chance of them being different! Even when I up the confidence to 99%, it still shows 100%.

Stacking Tolerances

These inconsistencies may not do much on their own, but all of them together lead to bigger effects. Variances in powder charge, paired with bullet length, diameter, BTO, and weight can all add up and affect your shots. This means that with Sierra Bullets you may be less likely to see a major effect from these stacked tolerances than you would with Berger Bullets.

Conclusions

All in all, the Sierras seem to be more consistent than the Bergers in each of the aspects that I measured. Whether or not you think this has a significant effect is up to you. This does not mean that Berger Bullets are bad in any way. It only means that in my sample of 20, in my lots, the Sierra bullets ended up being more consistent. I only tested a relatively small sample size between one lot of each bullet, and if you repeated this test your data may be the same, or it may not. For definitive results, I would have to take more measurements, from more lots, and test more bullets.

My Data

If you are interested in doing your analysis of the data or double-checking my work, here is a spreadsheet with my raw measurements.