Thursday morning it looked like I was going to get some time to get to shoot, so I grabbed some of the .500x350 gr. Lehigh's and ran them between to files to knurl them. I am still trying to really perfect this process although I continue to think it does not have to be as precise as I thought it might need to be. When I do it - it is a pretty simple operation. I was at first using two mil files for the operation and found that they did not provide the knurl I needed so I have switched to two wood rasps.
After completing the knurling I gatherer up things up and headed to the farm. The purpose of this visit was to clock the velocity of the bullets from my ULite. I attempted this last week but the Chrono battery was dead. That has been fixed.
I set the target at 75 yards and set the chrono 25' ft. off the muzzle. Shooting of the same portable bench and rests that I always do. I began the operation. Again I ended up shooting 15 rounds, that is all the Barnes box that I am using will hold. Same load as last week 120 grains of T7-2f, MMP Sub-base, and W209's.
I shot 8 of the marred gold bullets at the target for velocity collection and the rest at birds placed in the field at various ranges. I had not intended to adjust the scope at all - just leave it set for my normal load, but after the first two shots I could not resist, so I made two scope changes during the shoot.
What I did find, was that I may have done a better job knurling this group. Most all bullets during the velocity test went down with about the same amount of loading pressure, not short starter needed. The lone exception was shot #5 - it did require a short starter and a very firm push on the range rod to seat it. Surprisingly, it stayed in the group and the velocity was right with the rest of the shots. 'I think' this is the value of the MMP Sub-Base - providing a complete seal on the gas behind the bullet.
Here is a composite picture of the shoot with additional information dropped in...
The powder loads were thrown in my trusty old TC brass volume measure and it seems to show a very constant velocity. One of the things I am bad at is waiting... I just load shot after shot.. not really waiting for the barrel to cool. It seemed evident to me as the barrel warmed - velocity would drop slightly.
One thing I did for get was the BH-209... I really wanted to shoot it also with this load - I am sure that it would have given me a velocity increase of 150-200 fps. Not really enough difference to make a huge difference but for some it might be significant.
The last thing I did was to run a ballistics' sheet for the load. I use a 6" PBR when sighting in. That allows me a large range of yardage that the bullet will never be any greater than 3" high/low - through the range. No need to adjust anything in that range.
As it now appears to me, this is a viable hunting bullet and load. I really might have to give it a try.
At this time I think my next test will be to repeat this process using a Mountaineer with the longer barrel and open sights. The Mountaineer I will use is set up with a NECG scope base mounted peep sight. It will be interesting to see how it does and IF there is any effect on velocity...
