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  1. Doom

    6.5CM Development guidance

    OH, boy. All of the info you are seeking has its place so you aren't looking at the wrong information but you may be overanalyzing and may run the risk of going down the rabbit hole chasing things that don't make much of a difference. For instance you may see information on shoulder bump being...
  2. Doom

    Lee “Kit” Press to MEC Marksman

    If you search press and accuracy I doubt that you will see much conclusive evidence that one press is superior to another until maybe you get to large cartridges like the 50BMG or some of the larger sniper cartridges like the 338 Lapua Magnum. It certainly doesn't show up much in forums as a...
  3. Doom

    20” 6ARC bullet selection…

    The 6 ARC is kind of a strange cartridge. It is spec'd as a 1 in 7.5 twist but it is designed as a fairly low pressure (52KSI) round for the AR15 platform and is designed around a 108 Gr round at 2700 fps. Hornady has published higher pressure loads (62KSI) for bolt action rifles which would...
  4. Doom

    M118LR all the same regardless of the name on the box?

    Just to clarify what happens with Lake City and changes in operators like Federal or Olin/Winchester. The ammunition manufactured by LC doesn't change with the change in management. It means that supervision of the facility in managed by new company. The same people are on the production line...
  5. Doom

    6.5 Creedmoor Brass NOT CHAMBERING

    This is a typical problem when using a cartridge fired in a different rifle. Assuming that you setting the die up correctly usually what happens is the base of the cartridge isn't getting size enough at the 0.200" point above the base. It is also possible that the dimension called the datum...
  6. Doom

    .308 how accurate?

    Sort of sounded that way in the first sentence. If I mistook it, I apologize. You are correct that you don't have to run your brain numb and you don't have to shoot 30 rounds either, but it is important to understand what the basis of the numbers are. Of course someone can blindly go about...
  7. Doom

    .308 how accurate?

    Your point is well made and true. But if you are shooting at long range and in a competitive environment the velocity and standard deviation can and due matter, the degree to which the discipline determines and we have the tools to aide in improving those numbers. But in most cases the tools...
  8. Doom

    .308 how accurate?

    You bring up a good point about the response time and it applies to the Chargemaster as well. In the case of the ChargeMaster I have tested mine for consistency and it can be very consistent when I use the straw and some programming twerks. But trying to go with faster loading, >20-30 seconds...
  9. Doom

    .308 how accurate?

    Speaking of Rabbits and where they might lead. I'm going to comment on the planning and testing and what @staightshooter1 can expect from the results. This is kind of where the issue of statistical significance comes into play. This how a test engineer would look at the the data and what...
  10. Doom

    .308 how accurate?

    Check @straightshooter1 response #13. He posted his chronograph numbers for using different scales but that may are may not be the reason for the difference.
  11. Doom

    .308 how accurate?

    Considering that the resolution on the Fx-120i is 0.02 gn and his SD is the same on both scales then the scales are producing the same results.
  12. Doom

    .308 how accurate?

    I have to ask a question based on your scale comparison and the SD data you posted. The difference between the 120i and the DS-750 is essentially nothing yet you seem to be implying the difference in the SD is due to the scale. If I am correct how did you come to that conclusion?
  13. Doom

    5.56 AR reloading: Can Anyone ID what would cause these weird triangle shaped scrape marks/dents just below the shoulder?

    Dents like these usually have one source which is the load is too hot or the rifle is overpassed. Beyond the obvious the brass is probably not being ejected to the 3-4o'clock pattern. The brass is being flipped back hard into the deflector.
  14. Doom

    Dasher PSI & GRT Questions

    With wildcats there is no standard. The GRT max is probably taken from the 6BR-Norma which is the parent case. The 65KSI in QL is probably what experience and testing has demonstrated.
  15. Doom

    Weight ES for LR bullets ?

    To the point here. There are several things that come into play with a change in weight. It you change only the weight of a 168 gr 308 bullet in 308W in Gordens Reloading Tool by 1/2 gn you get about 2 fps. That estimate assumes ONLY the weight changes and nothing else. But for the weight to...
  16. Doom

    Advanced musings on powder humidity

    You put a hygroscopic matrrial (gunpowddr) in a hermetically sealed jar. And measure the humidity in the air which is being controlled by the gunpowder. Yes , gunpowder gave up a very small amount of moisture to keep the air at 56%RH
  17. Doom

    Neck/chamber clearance

    The minimum chamber dimension is 0.2933 per CIP. The maximum cartridge is 0.2913 so the expected minimum is 0.002 which what you have. As noted you actually exceed that due to springback.
  18. Doom

    Case sizing.

    Hey, don't mess with my 'plunk" gauge! Actually it is a good QC item when loading for a Semi Automatic because if it doesn't pass the the plunk test it may well become a stuck cartridge in the gun which makes for a bad day. That's especially true if you try the forward assist! :mad:
  19. Doom

    Case sizing.

    There are typically 2 measurements of interest in this instance. The first is the datum dimension that is the base of the case to the shoulder being too long. The other is the case diameter 0.2" above the case base. In some rare cases the problem can be the case body diameter at the shoulder...
  20. Doom

    308 brass question

    I am familiar with FGMM brass and as far as I can tell the difference is that the FGMM rounds (in 308) rounds all weigh within 1 gn of each other. Obviously the brass does also. I believe they are weight sorting.
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