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July 12, 2008, 10:35 PM | #1 |
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Join Date: December 16, 2007
Posts: 73
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Titegroup grain count question?
I was curious about something. I am loading from a Lyman loading guide, using Titegroup powder. The question I had was that the guide says that the maximum grain count for a 147 Grain bullet (what I'm using) is 2.8. For a 115 grain bullet in the same material the grain count is 3.6.
Now I'm confused, wouldn't a heavier bullet require a higher powder charge? The only thing I can think of to explain is that the larger 147 grain bullet is seated deeper, and as such it achieves a higher chamber pressure rate, and that is the limiting factor in the equation. Does that sound about right? Any other thoughts on this? thanks zac. |
July 12, 2008, 11:10 PM | #2 |
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Join Date: May 12, 2008
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That is actually quite typical of smokeless powder. Smokeless powder normally burns faster, the higher the pressure it is under.
Since it takes more pressure to get that 147 grain bullet moving than it does the 115 grain... the 147 needs to have less powder in the case, or you risk over-pressure conditions. Assuming you are talking about 9x19mm: (If not, completely disregard the following.) Did you start at minimum and work up? Starting at a maximum charge is a dangerous proposition. However, 2.8 grains of Titegroup behind a 147 gr bullet (Lead or jacketed) is quite a light load. Was that a typo?
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July 12, 2008, 11:57 PM | #3 |
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it is a 9X19 load. I worked up from 2.4 where the load says to start. I have as yet to chrono any of the workloads, plan on doing that next week. The 2.8 gives a great grouping.
As to whether or not its a typo, your guess would be as good as mine. Load charts for 147 #2 alloy bullets are tricky to come by. I'll need to search around. In all its probably a moot point. I'm not working up a self defense round, I'm looking for an IDPA load, so I really want a pretty slow charge with little recoil, so a maximum charge probably isn't what I'm looking for. I bring the point up because I'm a bit concerned with it being a typo. I have some friends that shoot 124 encapsulated, and they are using 3.1. Maybe I'll go do some online research. |
July 13, 2008, 02:04 PM | #4 |
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Well, if the 2.8 grain load is working... there's really no point in trying to change it. Like you, I think I would just want to verify the data.
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July 13, 2008, 03:25 PM | #5 |
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Yes, pressure is always a primary consideration and usually the limiting factor in loads. Occasionally with small cases and large, bulky, slow burning powder, case capacity becomes the limiting factor. Rule of Thumb: If a given powder charge gives max safe pressure with one bullet, then the same powder charge with a heavier bullet would give more (unsafe) pressure.
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July 14, 2008, 10:27 PM | #6 |
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Heavier bullets always use LESS powder-all else being equal.
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