April 30, 2005, 08:27 AM | #1 |
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Join Date: February 8, 2005
Posts: 180
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How short is to short?
I am still a rookie in reloading, so here is my question.
I decided to try my hand at reloading .223 for my AR and when I was measuring my brass, I noticed a fairly wide variation in length. The long ones can be trimmed, but what length is to short? According to the manual I checked the length is 1.760. Some of the brass I checked is measuring up to .015" shorter. Thanks for your help. Will |
April 30, 2005, 08:44 AM | #2 |
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Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
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The maximum length is 1.760". That's the point to start thinking about trimming if the cases get a little longer than that.
.015" shorter than max is not a problem. |
April 30, 2005, 09:00 AM | #3 |
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Join Date: February 8, 2005
Posts: 180
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Thanks MalH, I will just sort by length, and trim the over length ones.
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April 30, 2005, 08:34 PM | #4 |
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Join Date: July 14, 2001
Location: State of Confusion
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Trimming brass
Checking your manual, there should be a "max length," and a "trim-to length." If they're over max, you trim 'em down to the trim-to length. You load all the rounds to a COAL or a COL (Cartridge over-all length) so the amount of space inside the case will be the same regardless of exactly how long is the neck of the case.
Whenever you trim a bottleneck case, you have to chamfer (cut an angle) on the inside and outside of the trimmed edge. Probably you knew that. Now, the shorter the case neck, the less the bullet is held in by the case neck (case neck pressure on bullet affects the pressure accumulating in the case when the powder starts burning, but before the bullet begins to move) but I agree, 0.015" difference in total case length is not enough of a difference to notice at your stage of the game. When you get to competition bench-rest shooting and reloading you can worry about it. The only time case neck length variations become a problem is when you're crimping the mouth of the case on the bullet's cannelure. If you are crimping, then all the cases want to be as exactly the same in length as you can manage, so the crimp is uniform on the bullet. Variations in crimp affect in-case pressure, too, but much more so than variations in neck-hold pressure.
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