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Posted: 5/28/2010 1:55:23 AM EDT
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When to trim?
6.8 SPC is overall case length is 1.676 according to Hogdon (and other sources) So I have some at 1.683, 1.688, 1.693 etc When do you all make the decision to trim? Ideally all would be trimmed to perfect length - but in practice - do you all actually do that? Where is the threshold you set for trimming? I hope to load some live ammo this weekend. Thanks in advance. |
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When to trim? 6.8 SPC is overall case length is 1.676 according to Hogdon (and other sources) So I have some at 1.683, 1.688, 1.693 etc When do you all make the decision to trim? Ideally all would be trimmed to perfect length - but in practice - do you all actually do that? Where is the threshold you set for trimming? I hope to load some live ammo this weekend. Thanks in advance. Sir, I generally use my reloading books to tell me what the maximum case length is for the cartridge I intend to reload. Remember the length you are measuring is the length of the shell after it has been resized. If the case length you mention of 1.676" in the maximum case length after resizing then you will need to trim all cases that exceed that length. My normal procedure when preparing cases to reload .223Rem is to resize all of them on my Rockchucker press and then trim all of them with my Giraud trimmer. The Giraud trimmer is set to trim each case to a finished dimension of 1.758" which is .002" less than the maximum case length specified in my Hornady reloading manual of 1.760". I'm not sure what you mean when you use terms such as "perfect length" and "threshold". If the case length exceeds the maximum specified in my reloading manual for that cartridge after I have resized it then it needs to be trimmed, no ifs, ands, or buts, about it. HTH, 7zero1. |
Whatever trimming method is employed will not trim a case that doesn't need it. With this in mind I run every case through every time. This gives better consistency and guarantees I will never have a case which exceeds the maximum. Reloading is about safety (first!) and consistency––not "getting away with" anything. 
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It is called "maximum" for a reason.
I don't have a fancy Gracey or Giraud trimmer  , but I still put each case through the trimming process each time. If material is removed, great. If not, I wasted a few seconds.
Beekeeper is right. It is all about consistency. Rob Robideau Personal Armament Podcast |
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Quoted:
Whatever trimming method is employed will not trim a case that doesn't need it. With this in mind I run every case through every time. This gives better consistency and guarantees I will never have a case which exceeds the maximum. Reloading is about safety (first!) and consistency––not "getting away with" anything. +1... this is exactly what I do. - AG |
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Whatever trimming method is employed will not trim a case that doesn't need it. With this in mind I run every case through every time. This gives better consistency and guarantees I will never have a case which exceeds the maximum. Reloading is about safety (first!) and consistency––not "getting away with" anything. That's what I was looking for. Thanks |
| You can either run each case through the trimmer every time, or measure each case every time after resizing (x-die users notwithstanding). It's just a matter of which one you'd rather do, but you have to do one or the other or you will end up with overly long cases. I trim mine to 1.750, and then after they're fired and resized I measure them - anything under 1.760 is GTG, anything over gets trimmed back to 1.750. If I had a Giraud trimmer or something similar, I'd probably just run all the cases through that, but for my purposes, it's easier to hit each case with a calipers and just trim the ones that need it. I can do that watching the boob tube. |
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For routine reloading that's fine. Trim so that you never shoot a piece of brass over max length listed in the manuals.
BUT.......you may go over IF you can measure where YOUR chamber ends and leave a margin of room for expansion so the brass neck doesn't ever enter the throat with the bullet. Sinclair sells a tool to measure your actual case chamber length. It utilizes a case that is trimmed extra short and a metal plug that you insert like a bullet. You chamber the doo hickey in the piece of extra short brass, and the plug will stop at the end of the chamber's neck and not enter the throat. That will give you your actual chamber length and sinclair has a number shorter than that you must not go beyond. Brass needs some room to expand to release the bullet. AND conversely there are times when you are to trim below the minimum length.......RCBS X die instructions have you trimming well below minimum. That said, unless you're a bench rest shooter who really knows what they're doing......trim below the book max and above the minimum.. You'll have your best results just by having consistent brass. ETA- Case in point; I just F'd up and started loading some 2x fired winchester 7.62x54russian cases in mid workup before realizing that i didn't check length again. Saami max length is 2.115" and the trim to length is 2.105". A quick check of my brass showed some over max. I pulled out my sinclair chamber length checkers and made a dummy case out of a drilled out and resized berdan casing and measured the actual chamber length of 2.147". The sinclair instructions say to have a minimum clearance of 0.024". That would give MY PARTICULAR RIFLE A MAX LENGTH OF 2.123". Well I still had to trim in my particular case but If If I was still under that 2.123" I would have just loaded and shot and trimmed the next time. Anyway I trimmed to saami specs since I had to trim. |
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Quoted:
You can either run each case through the trimmer every time, or measure each case every time after resizing (x-die users notwithstanding). It's just a matter of which one you'd rather do, but you have to do one or the other or you will end up with overly long cases. I trim mine to 1.750, and then after they're fired and resized I measure them - anything under 1.760 is GTG, anything over gets trimmed back to 1.750. If I had a Giraud trimmer or something similar, I'd probably just run all the cases through that, but for my purposes, it's easier to hit each case with a calipers and just trim the ones that need it. I can do that watching the boob tube. This is what I used to do before I got the guaird trimmer. Now I set up the guaird to trim .005 back from max case length and make sure that all are trimmed to the same length. |
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Quoted: Whatever trimming method is employed will not trim a case that doesn't need it. With this in mind I run every case through every time. This gives better consistency and guarantees I will never have a case which exceeds the maximum. Reloading is about safety (first!) and consistency––not "getting away with" anything. I trim all mine every other time. Haven't been able to measure a difference in groups between the two groups (freshly trimmed vs trimmed last time). Admittedly, I'm big on testing to see what matters and what doesn't as far as accuracy. |
,used to use a rotary Lyman and still did it
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I don't load 6.8, only .223, for rifle.
But I'll tell you, I only trim a case if it's at or over the max. length, if not, I leave it. If you're not crimping, and not trying to load that "super-duper most accurate match round ever", it's not an issue, in my experience. |
| I just finished trimming 500 pcs of .223 once fired with a manual Lyman trimmer. I modded the crank handle on the trimmer by replacing it with a wooden cabinet pull and that made a huge difference in speed and comfort, but I'm waiting for my Possum Hollow trimmer to come. That will speed it up a lot for the other 1k or so that I have in need of trimming. |
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