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9mm Ammo Quest: Gold Dot 115+P Underwood vs DoubleTap test



This is Thirty-Fourth test in a series of a quest to find the overall best defensive ammunition for modern 9mm pocket pistols (such as the Sig Sauer P938, Taurus PT709, the Ruger LC9, Kahr CM9, Beretta Nano, Kel-Tec PF9 or S&W Shield or any other popular 9mm micro-pistol using a barrel length of approximately 3"). The test pistol for this review was a Sig P938.

In this installment, I am testing two "+P" versions of ammo using the 115-grain Speer Gold Dot bullet. Speer themselves makes a 115-grain Standard Pressure version, but they don't offer the 115 in +P version to the public. Accordingly, I am testing the 115+P loadings from Underwood and DoubleTap, two smaller ammo companies that use the Speer Gold Dot bullets in some of their offerings.

The DoubleTap product tested here is labeled "9mm +P 115gr Bonded Defense JHP". The Underwood product tested here is labeled "Item 135, 9mm Luger +P 115 gr. GD JHP".

I decided to combine these two tests to verify a) if they are indeed using Gold Dot bullets, and b) what performance differences we can see between these two similar offerings.

I am chronographing the rounds as well as firing multiple rounds per block so that we get a more statistically relevant result, rather than the typical ammo test where only one round is fired. Ammo can behave a bit unpredictably, and the results of any one bullet are not necessarily representative of how the ammunition performs overall.

The purpose of this testing is to find which rounds of ammo perform well enough from a short 3" barrel that they can reliably deliver the penetration (with expansion) that has been documented and proven necessary in order for the bullet to be able to reach the vital organs of an attacker and deliver an incapacitating hit.

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