17 HMR "MATCH" VELOCITY DATA
This is old info now, but remains valuable and steadfast. The Bullberry 17 HMR "Match" is still a well proven cartridge in both performance and accuracy.
It took three reamers to finally land on what Bullberry considers optimum accuracy, however. Initially we had our reamer made to Hornady specifications but were not happy with the results. The chambers were – by Bullberry standards – far oversized. A subsequent batch of about 8 barrels were chambered .002" smaller in diameter. Now, with our final reamer dimensions, our chambers are nearly .004" smaller in diameter than the original. This is giving us the accuracy we are always looking to achieve, without having a ruptured case problem as was predicted by Hornady early on, by shrinking the dimensions to just accept the ammo.
The 17 HMR "Match" has remained one of our most requested calibers, particularly for the Contender and G2 actions.
The high quality polymer-tipped bullets, along with just the right powder charge and bullet weight have lent to exceptional performance for many Bullberry customers. Many of our customers in the South have regularly chosen the 17 HMR for squirrel and other small game when they want maximum potency and minimal tissue damage.
With careful shot placement the Bullberry 17 HMR "Match" chamber is difficult to beat. Of course, wind will disrupt any 17 caliber bullet so take care to know your conditions.
Velocity Tests
Our test gun in the photo features the 3rd generation chamber dimensions as referenced above.
Velocity tests were conducted on this 11" barrel, as well as on a full length test barrel, both using Hornady's 17 grain bullet. Below is the chart based on this barrel. All velocity tests were conducted using a 5-shot group.
Note: The average velocity of this 11 inch barrel is only 132 fps slower than the 22" carbine barrel (data shown below).
About the Accuracy in the Pistol:
Fred previously put 200 rounds through the gun to make certain we did not have any pressure related problems.
Groups #1 and #2 were shot with about a 5mph crosswind, left to right, in a rather intermittent manner. Then, unusual for our area, the wind went dead calm for groups #3 and #4. Group #5 had an increasing breeze that was moving toward the target that caused the vertical lift on the last two shots, as Fred had his target box on an upslope of a sand dune.
Needless to say, he was and is happy with these results. He feels its a half inch shooter in calm conditions. Group #3, that is okay at .438", had him excited. First four shots into one hole that measures .178". Then of course, he pulled one out with a quarter inch gap. There will be those of you out there that will handily shoot one-hole groups.
All of these were shot at 103 yards from a solid bench, off the rest you see in the top photo. This system allowed Fred to have the crosshairs of his 6.5 x 20 Leupold rifle scope dead still on target. The pistol was also tested with the 3" wide target forearm photographed. The rest is constructed to allow vertical adjustment of sight picture by simply pulling or pushing the grip forward and back on the "incline" of the rest. Pretty good system.
Test Barrel – From Rifle to Pistol
The below tests were performed April 20, 2002 in the Bullberry Test Pit using a Dr. Oehler Sky Screen Chronograph Model 33 with Sky Screen III system. The first screen was set 6 feet in front of muzzle. Screens are spaced EXACTLY 10 feet apart. The test began with a new production 17 HMR "Match" Bullberry bull barrel 22" long. The purpose was to determine velocities at this length, and every inch shorter down to the practical minimum length of 10". After each group of 5 shots, we cut the barrel by one inch, recrowned it, and repeated the velocity test until we had reached our 10" pistol.
Fred had predicted higher velocities than were being reported at the time from Ruger and Marlin rifles, based on our tighter chamber tolerances. While this did not occur, it did prove his other theory that we would possibly see a maximum velocity in the 17- or 18-inch range. You will see in the performance breakdowns below that the maximum velocity was actually achieved in our 19-inch barrel test.
The HUGE surprise was in the short pistols having velocities so near the carbine length barrel. Our early accuracy test barrel in stainless shot only 132 fps slower than the original 22" blued chrome-moly carbine barrel. When we finished the test at the 10" length, we found the chrome-moly barrel to be only 241 fps slower than the 22-inch length.
Summary
This 10" barrel produced a velocity average of only 241 fps slower than the 22" length, and only 262 fps less than the best average of the 19" length.
Patches dampened with Eezox™ were pushed through the bore after the cutting and recrowning processes, and to assure a clean bore for each test group.
