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Guy Neill

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About Guy Neill

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    Calls Shots
  • Birthday 09/04/1951

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    Oregon

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  1. 9mm SAAMI question?

    Much has to do with the shape of the bullet nose. SAAMI allows OAL up to 1.169, as stated above, but some bullets cannot be loaded that long as they will contact the rifling in the barrel. You need to determine the length the bullet will contact the rifling during initial load development, then shorten the load to a suitable OAL. Look first at any load data from the maker of the bullet, if such is available. For example, Speer lists an OAL for their loads using their 147gr bullets in the 9mm Luger as 1.130". This is considerably shorter than the SAAMI allowed maximum OAL, and is very likely due to the bullet contacting the rifling if loaded much longer. It should be some 0.020" off the rifling generally. Guy
  2. Pen foster smithing coarse

    Are you looking for general gunsmithing or specialized? General gunsmithing seems to take the avenue of attending one of the various schools for a multi-year program. As I understand it, the general full AGI gunsmithing course comes from what was originally one of the college courses and the intent to preserve it since the instructor was retiring. It may be that the Penn Foster is similar though offered online instead of DVD. Specialized courses may be either DVD stuff like from AGI (build a Limited pistol or such), or attend some of the week long courses offered by several, such as that from Cylinder & Slide. While this costs a week plus the course fee and tools, you are left with the tools, and the gun you build after the fact. It's an intense week though. I believe the NRA or other groups have also offered spot type courses such as that from Cylinder & Slide, or even more specialized such as trigger jobs. So, how good or bad, or suitable, a particular course is, depends greatly on what you are looking for. I thought the Penn Foster course description could be better as it seems broad when reading it. It may be a great course, but hard to tell. The various colleges offering on-campus gunsmithing courses generally have good reputations, but require years of investment. Or you get with a gunsmith and apprentice to him/her, but this is also a long haul. I have only done the specialized courses from Cylinder & Slide, Nowlin and Shuey, with each having it's own perspective (all on 1811's). I've not taken the full AGI course, but Shuey has done some of the specialized videos for them, such as the Limited gun build mentioned, and I've met several of hte other smiths doing videos for them and they seem to be a most accomplished group with respect to their abilities. Videos or online will always have some limitations compared to hands on with an instructor looking over your shoulder. Guy
  3. Pen foster smithing coarse

    I don't know about that course, but you might check it against the video training course from AGI (American Gunsmithing Institute) Guy
  4. I calculate directly, beginning with finding the gun velocity with a momentum balance. The gun momentum equals the ejecta momentum (bullet plus powder gases. Once the gun velocity is obtained, insert it in the kinetic energy formula to get the free recoil energy. It's described in Hatcher's Notebook as well as some other sources. I've attached a brief description.Momentum balance I put it into a spreadsheet some time back. I hope it's helpful Guy Recoil Calc 6-23-17.pdf
  5. With the 36 ounce gun, and the values you give, I find; Cartridge 9mm 40 40 Minor Minor Major Bullet 147 180 180 Velocity 925 725 950 Charge 3.5 3.2 4.2 Momentum 0.67 0.64 0.84 Gun Velocity 9.5 9.1 11.9 Recoil (no charge) 2.6 2.4 4.1 Recoil (with charge) 3.2 2.9 5.0 Guy
  6. Do these values include the powder charge? Did they way what gas velocity they use? My numbers vary a bit - though it is generally a relative comparison. Looking at the Major load, for example, using your 36 ounce (2.3 pound) gun, I have the momentum as 0.85, as they show, but the gun velocity I show as 12.1 fps. The corresponding recoil energy using the bullet alone, with no powder is 4.1 ft-lbs. Assuming 5 grains of powder and a gas velocity of 4000 fps, recoil becomes 5.1 ft-lbs by my calculation. Did they list the equation? The calculation as shown in several references is a momentum balance to determine the gun velocity, then using that in the energy equation. Thanks. Guy
  7. If you want numbers yo compare, I need the following; bullet weight bullet velocity powder charde gun weight for each Guy
  8. power factor

    Power factor is the bullet weight, in grains, times the velocity, in fps, divided by 1000. As I recall, in Limited, to qualify for Major, it must be at minimum 40 caliber. You can use 9mm, but it will score as Minor no matter the actual power factor. Equipment would be a scale to weigh bullets, a chronograph to measure velocity and a calculator to do the calculation. Some chronographs will do the calculation for you Guy
  9. 7.62x39 Bullets?

    I believe Hornady and Speer have bullets intended for the 7.62x39. Guy
  10. primer seating depth

    Did any of the light primer strikes fire on a second try? The 0.003" should be suitable unless the anvil legs are not against the bottom of the primer pocket. This could be that primers are on the shorter side and/or the primer pockets are on the deeper side. You might try one or two things. First - how does it do with factory ammunition? If factory ammunition gives the same problems you may suspect the gun, Alternately, load a batch of ammunition and sort by primer seating depth, looking for a group 0.005 - 0.006 inch deep see how they work in the gun. Guy
  11. primer seating depth

    With normal tolerances, the primer face should be 0.003 to 0.005 inches below the case, though I have seen factories allow anything from 0.000 to 0.008 inches. Overall, what you want is the primer anvil legs against the bottom of the primer pocket. The three to five thousandths usually gives reliable performance. Guy.
  12. Low Flash powder for 9 and 45

    I don;t recall all the powders I tried some time back, with photos in the dark, but my experience with HS-6 was like a flash bulb going off in front of my face. If I'm remembering right, the Vihtavuori powders were fairly low flash, and I don't recall 231 being too bad. Guy
  13. Low Recoil Loading Data needed for S&W 40

    Never having used one, I'll defer to those with experience with a Ransom rest. Do slower burning powders tend to rotate it more? Or is there a guideline? Thanks. Guy
  14. Low Recoil Loading Data needed for S&W 40

    You may want to shoot for a velocity of 945 fps with your 180gr bullets. This would give a 170 power factor that should be good most anywhere. What online calculators are giving different values? Guy
  15. Low Recoil Loading Data needed for S&W 40

    Trying to use the values listed for Titegroup and WSF, here’s the difference. Using a 3 pound gun and equal velocities of 865 fps for 230 grain bullet, and 5.2 grains of Titegroup and 6.7 grains of WSF. Charge Velocity Recoil Acceleration Force PF Titegroup 5.2 865 5.3 1795740 1834 199 WSF 6.7 865 5.6 1795740 1834 199 Since the bullet is accelerated to the same muzzle velocity, the acceleration value, and subsequent force must be equal. Recoil is in ft-lbs using the gun velocity and mass. Force is in pounds, acceleration is fps2. Power factor is a form of momentum with inconsistent units (grains-feet/second instead of pounds-second) resulting from wv instead of mv. Another aspect of what we feel ins the moment. This is the force times the distance between the bore and our hand. In the case of the Ransom rest, it is the distance between the bore and the pivot point of the rest, likely greater than the distance between the bore and the pivot point of our hand. If, for the sake of argument, we assume the distance between the bore and the pivot point of our hand is one inch, the moment arm would be 153 ft-lbs with the force determined earlier. This seems a lot, but it is applied very briefly (0.0005 seconds). I tend to expect the moment is more a factor in the rotation of the Ransom rest than recoil (though obviously they are not totally unrelated). For equal power factors (resulting in equal force) the rotation should be equal, though there will be variations just as we see in load tests with velocity variations. It seems likely approximations could be calculated, though I find angular calculations more tedious than linear ones and have not pursued it further at this time. While all this is interesting, it still comes down to how the shooter perceives the recoil – the combination if the actual recoil plus the muzzle flip caused from the moment arm. In my own shooting, if I’m doing my part, the load doesn’t seem to matter much other than accuracy. I’ve done some of my best shooting with heavier loads. As such, I select components that are available and satisfactorily economical, develop an accurate load – and go shoot. No particular worry about finding the mathematically lowest recoil load. Others may find they are more prone to the recoil feel and should experiment to see what works for them. Guy
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