Hello all
I am starting this thread to address the tests I am conducting with the 6.5x55 Swede cartridge with cast bullets shot at high velocity (2200 – 2300+ fps) using medium and slow burning powders with a shotgun buffer filler. It has been posted that excellent accuracy can be obtained with this cartridge and it’s fast twist barrel in that high Velocity (HV) range. It is also stated by those who developed this technique that it is dangerous as high pressures can result if the loader doesn’t know what he is doing. These tests I have and am going to be conducting are because I am interested in such HV loads in the 6.5 Swede and I have the mechanism (an Oehler M43 PBL) to measure velocity, muzzle velocity, downrange velocity (100 yards), Ballistic Coefficients, MAPs (Maximum Average Pressure), and can record the time/pressure trace. The objective is two fold; first to develop accurate (minimal 1 ˝ moa in capable rifles) HV (22-2300+ fps) cast bullets loads in issue milsurp 6.5x55 Swede barrels using the described technique with shotgun buffer as a filler. Second is to determine if dangerous pressures do happen and where they happen.
I will conduct numerous tests over the next several months. I have already conducted the first test. As the tests are done other sub-tests will be done along the way to give data or reach a conclusion on a point. Observations on what is working and what is not working will be obvious through the group size, the velocity and the pressure data. On the two main objectives (can the claimed accuracy really be had by other cast bullet shooters and is this technique dangerous) I will not make any conclusion until I have completed all of the tests. I would ask that all of you do not reach any conclusions before then also.
Obviously this thread is a different track from starmetal’s “Milk Jug” thread. As such I am asking everyone to ask pertinent questions or make pertinent remarks. However lets just let the results of the tests and the data speak for themselves. Derogatory remarks and/or criticism without an explicit constructive answer to the criticism are not wanted. We want to progress here in as straight forward manner as we can. That means we must all cooperate toward this goal. If you can not do that then please don’t post. You are always open to start your own thread and criticize and complain to your hearts content there. Here we are trying to accomplish something in a meaningful way so please assist if you can.
Thank you all for your cooperation.
Larry Gibson