Before I get into the results of the testing I want to let everybody know to take these results with a grain of salt because they are not completely accurate regarding velocity numbers. To make a long story short I was a bone head and did not have my breech seal in during the testing so while I think the accuracy tests will be unaffected, the velocity numbers should be much better with the breech seal in place. Needless to say I am going to redo these tests with the breech seal in and report back here with updated results.

The tests were done while shooting from bench rest with a red dot sight at a target that was 17 yards (51 feet) away. I used standard output HPA (~900 psi) for the testing and Daisy zinc coated BBs. My batteries were Energizer Lithium AA's that have had plenty of use on them.

Target 1: First up was the 15" smooth bore prototype with .174" bore diameter and after shooting a 6 inch Shoot-N-C target 25 times I was able to achieve a 3 and 3/8's inch grouping. Velocity over the first 10 shots was 661.7 fps as the high and 642.2 fps as the low with average velocity being 652.8 feet per second.

Target 2: Next up was our 15" rifled barrel prototype with very deep rifling and a 1:16 twist rate. 25 shots at the target produced a 6 and 3/4 inch grouping with velocities ranging from 630.4 feet per second to 646.8 fps and an average velocity of 637.7 feet per second.

Target 3: Last in line for the 15" barrels was the JimC 15" rifled barrel. We wanted to see how we compared to what everybody is already using. With this barrel we achieved a 6 inch group at 17 yards with velocities of 615.7 fps as a low and 637.1 fps as a high. The average velocity was 629.1 feet per second.

Target 4: Now we did the same test of 25 shots at the target with the first 10 shots being measured for velocity but this time we used our 23" smooth bore prototype. The accuracy was a 3 and 3/4 inch grouping. Velocity was 722.5 fps as a low, 757.9 fps as a high and the average was 739.4 feet per second. When compared to the 15" smooth bore that is another 100 fps of more power!

Target 5: Same tests but this time with our 23" rifled barrel prototype. The results are a 6 inch group with 685.5 fps as a low 701.9 fps as a high and 690.2 feet per second as the average.

Target 6: Again, same tests just this time we used a JimC 23" rifled barrel for comparison reasons and we achieved a 6 inch group with velocities ranging from 687.5 fps as a low and 708.2 fps as a high with an average velocity of 697 feet per second.

Below is a picture of all 6 targets side by side.

Conclusion : These tests need to be redone with the breech seal in this time to get more reliable numbers but you can clearly see that smooth bore barrels produced better accuracy with almost a 100% increase in accuracy as compared to the rifled barrels. Another thing these tests show is that our prototype rifled barrels are not any more accurate than JimC's rifled barrels and in fact they are a little slower compared to the JimC barrels. I believe this is because the rifling in our prototype barrels is of high quality and is much more pronounced thus increasing drag on the BB as it travels down the barrel and the rifling in the JimC barrels is far less deep and in my mind probably grabs less on the BB as it is traveling. It would be interesting to test which rifled barrel is more accurate when using lead shot instead of steel BBs.

That's it for now be sure to leave any questions or comments that you may have.

Ray

These are the same length as the JimC internal barrels (15", 23") so they will be a direct replacement and should work with all of the JimC barrel kits that are in use. If/when these smooth bore barrels are released for sale it will be mandatory to center the BB in the magazine and properly center everything to the bore of the barrel due to the tight tolerances otherwise there is a high risk of getting a BB jammed in the breech. Everybody should be doing that already anyway regardless of what barrel they use. One other thing, these barrels probably should not be used with copper BB's because those measure slightly larger and there will be a higher risk of jamming.

I will post back soon with pictures and some other data like velocity and accuracy when compared to rifled barrels. Also check out the Drozd BB Machine Gun Forum for testing and reviews of these barrels by "camracer" I sent him some samples of the new internal barrels and he will be putting them through the paces too. It should be interesting.

More to come soon....