Primer ignition testing.
Posted: Sat Dec 01, 2012 6:37 pm
Today was partly ear marked for primer ignition tests on the C.G Delta prototype I have here. The plan was really just to make sure it all went bang nicely which was never in doubt however when I had the chance to bring in a high speed camera and very technical type person I jumped at the opportunity and we thought it would be interesting to compare a couple of makes of primers.
For us this was always going to be looked on as initial testing and I am very aware that this was an incredibly limited test however it did raise a lot of questions.
The test.
Essential equipment included a high speed camera on a bipod facing down onto the action at a distance of 1,25m at an angle of approximately 30 degrees, plus a laptop for control and data storage, a black cloth backdrop to prevent any spurious reflection and a fixture to hold the action. The action itself is the C.G Delta LMR (Light Metal Repeater) fitted with a dummy barrel and chamber, the 'barrel' extending for 18,0mm from the front of case neck. Brass was Federal primed with Fed210M and CCI BR primers and that was it other than the obligatory coffee or two for myself plus tea for the cameraman.
First step after getting everything in place was a test firing to confirm the camera was pointing in the right direction and that the exposure was correct. The system we used was running at 28,000fps which uses around 4Gb of memory a second so the process is to start the camera which films in a two second loop and the 8Gb memory is overwritten every two seconds, instead of trying to guess the start point we simply test fired and then stopped the camera which would give us the primer ignition sequence plus some blackness. The shots were then edited back to only show the activity.
First test was with the FED210M primer followed by CCI, followed by FED and finally CCI so a total of four filmed test shots. This photograph shows the four test firings, the top two being the CCI BR and the bottom two being the FED210M. For scale the muzzle diameter of the test 'barrel' is 25,0mm for scale and the vertical white line is at approximately 125,0mm from the muzzle.
Initial observation is the FED210M Primer is visibly brighter. If you look at the background you will see it is lit up slightly, also the muzzle has been lit up where as with the CCI BR this is not the case. These tests were conducted under as near as we could get to identical lighting and temperature conditions and the action and camera position remained constant.
One thought is the addition of an IR filter is worth looking at for the next tests and it would also be worth adding a second overhead camera filming in colour to look at the flame colour itself.
If you have not guessed by now this was a far from scientific test and the whole purpose was solely to test fire the action to confirm the ignition of the primer which was proved. We simply moved on to testing with a couple of brands of primers. The action itself was fitted with a conventional coil spring to activate the firing pin so we will need to test again with the Belleville washer stack at a later date and it will be interesting to throw a couple more brands of primers into the equation and include the Lapua Palma (Small primer) brass.
The videos are on my Journal if anyone is interested in the slowmo video
For us this was always going to be looked on as initial testing and I am very aware that this was an incredibly limited test however it did raise a lot of questions.
The test.
Essential equipment included a high speed camera on a bipod facing down onto the action at a distance of 1,25m at an angle of approximately 30 degrees, plus a laptop for control and data storage, a black cloth backdrop to prevent any spurious reflection and a fixture to hold the action. The action itself is the C.G Delta LMR (Light Metal Repeater) fitted with a dummy barrel and chamber, the 'barrel' extending for 18,0mm from the front of case neck. Brass was Federal primed with Fed210M and CCI BR primers and that was it other than the obligatory coffee or two for myself plus tea for the cameraman.
First step after getting everything in place was a test firing to confirm the camera was pointing in the right direction and that the exposure was correct. The system we used was running at 28,000fps which uses around 4Gb of memory a second so the process is to start the camera which films in a two second loop and the 8Gb memory is overwritten every two seconds, instead of trying to guess the start point we simply test fired and then stopped the camera which would give us the primer ignition sequence plus some blackness. The shots were then edited back to only show the activity.
First test was with the FED210M primer followed by CCI, followed by FED and finally CCI so a total of four filmed test shots. This photograph shows the four test firings, the top two being the CCI BR and the bottom two being the FED210M. For scale the muzzle diameter of the test 'barrel' is 25,0mm for scale and the vertical white line is at approximately 125,0mm from the muzzle.
Initial observation is the FED210M Primer is visibly brighter. If you look at the background you will see it is lit up slightly, also the muzzle has been lit up where as with the CCI BR this is not the case. These tests were conducted under as near as we could get to identical lighting and temperature conditions and the action and camera position remained constant.
One thought is the addition of an IR filter is worth looking at for the next tests and it would also be worth adding a second overhead camera filming in colour to look at the flame colour itself.
If you have not guessed by now this was a far from scientific test and the whole purpose was solely to test fire the action to confirm the ignition of the primer which was proved. We simply moved on to testing with a couple of brands of primers. The action itself was fitted with a conventional coil spring to activate the firing pin so we will need to test again with the Belleville washer stack at a later date and it will be interesting to throw a couple more brands of primers into the equation and include the Lapua Palma (Small primer) brass.
The videos are on my Journal if anyone is interested in the slowmo video
, you could have used some of mine but never mind :goodjob: