223 Giraud triway trim issue

[chwithad]

I've been having a lot of trouble getting my Giraud tri-way trimmer to trim my cases to anywhere near consistent lengths. I'm out of brass fired from my AR15 so I've been working on a bucket of mixed headstamp brass my friend gave me. I have my die set to bump the shoulders back 0.003" and I'm using a Dillon 550 press. I don't anneal - I understand the benefit, but life's expensive and I'm trying to save up for an optic for my AR10 . The inconsistencies range from 1.763ish - 1.735ish. My goal is to trim them to 1.750. I do spin the case before removing as I've heard is almost necessary.

1st question - would sorting the brass resolve this? If so, I'm assuming I'd have to adjust my die and resize them again? If it wouldn't, any other ideas?

2nd question - what's the shortest case trim length you consider safe to load in an AR?

Last question - is there an overall trim length spread that you like to maintain when reloading? (i.e. 1.748"-1.752" MAX?)

 

[straightshooter1]

I've been having a lot of trouble getting my Giraud tri-way trimmer to trim my cases to anywhere near consistent lengths. I'm out of brass fired from my AR15 so I've been working on a bucket of mixed headstamp brass my friend gave me. I have my die set to bump the shoulders back 0.003" and I'm using a Dillon 550 press. I don't anneal - I understand the benefit, but life's expensive and I'm trying to save up for an optic for my AR10 . The inconsistencies range from 1.763ish - 1.735ish. My goal is to trim them to 1.750. I do spin the case before removing as I've heard is almost necessary.

1st question - would sorting the brass resolve this? If so, I'm assuming I'd have to adjust my die and resize them again? If it wouldn't, any other ideas?

2nd question - what's the shortest case trim length you consider safe to load in an AR?

Last question - is there an overall trim length spread that you like to maintain when reloading? (i.e. 1.748"-1.752" MAX?)

I also use a Tri-Way. There are 2 key things that contributes to consistency, or lack thereof. As you are aware, the Tri-Way indexes off the shoulder, so if your cases head spaces are not consistent, your trim lengths will not be either. Add to that the second thing: the amount of pressure as you cut to trim can result in a couple thousandths difference. I've learned to have consistent pressure by not pressing too hard and just enough to stop the bearing from spinning (you know, the bearing you stick the case through into the Tri-Way). When you don't anneal, you can have quite a variance in case headspace due to spring back and variance in that with various case thicknesses (mixed brass will have a LOT of variance that way). Therefore, for the brass you intend to load, it'd be a good idea to sort your brass by your case's headspace after sizing and before trimming to help get a more consistent trim length.

 

[chwithad]

I also use a Tri-Way. There are 2 key things that contributes to consistency, or lack thereof. As you are aware, the Tri-Way indexes off the shoulder, so if your cases head spaces are not consistent, your trim lengths will not be either. Add to that the second thing: the amount of pressure as you cut to trim can result in a couple thousandths difference. I've learned to have consistent pressure by not pressing too hard and just enough to stop the bearing from spinning (you know, the bearing you stick the case through into the Tri-Way). When you don't anneal, you can have quite a variance in case headspace due to spring back and variance in that with various case thicknesses (mixed brass will have a LOT of variance that way). Therefore, for the brass you intend to load, it'd be a good idea to sort your brass by your case's headspace after sizing and before trimming to help get a more consistent trim length.

Thank you. Could you help with the headspace part? I have a Hornady headspace comparator tool - but what differences should I sort them by after full length resizing?

 

[Lawnboi]

The giraud trims off the shoulder, not OAL which is what you’re measuring.

Your likely seeing inconsistency in your sizing/brass prep process, which is likely unavoidable being your shooting mixed headstamp unknown what it’s fired from brass.

If you want to achieve what a more reasonable spread in sizing you may need to start with more consistency, specifically likely same head stamp preferably same rifle fired brass.

 

[straightshooter1]

Thank you. Could you help with the headspace part? I have a Hornady headspace comparator tool - but what differences should I sort them by after full length resizing?

If you sort by your case's headspace, each batch should have a pretty consistent AOL =<.001", if you sort them in groups with .001" difference. But, of course, there'll be more difference between the batches. And since you don't anneal, there can be variance in springback that can add an additional +/- .0005". So, I'd sort them into batches .001" apart, if I wanted decent uniformity for each batch.

I should point out that a case's AOL is not as important as the case's headspace. And it's not just how it fit into the headspace of the chamber. Consistent case headspace contributes a lot to consistent results from your loading. . . as much or more than bullet seating depth. Getting consistent case headspace would be something better focused on than case OAL's. Solve that issue and you solve your trimming issue with the Tri-Way.

 

[DownhillFromHere]

I use a Tri-Way for .223; my experience tracks with previous posts. I bought 1000 new same-lot Starline cases a few years ago; I have found that I get satisfactorily consistent trim lengths as long as I'm using brass from that lot fired from the same rifle. I anneal after every firing. If I try to use mixed-lot (range brass) or brass fired in some other rifle - especially ARs - my 1.750" average length goes out the window.

Since the vast majority (>98%) of my .223 shooting is handloads from that 1000-count lot, the Tri-Way works fine. I've learned that other lots fired in other rifles will almost certainly require a trimmer adjustment.... and subsequent adjustment back to where it was. Pita. So, blaster ammo for my AR tends to be once- or twice-fired brass from factory bulk ammo, then I just recycle the brass. I don't mess with trying to get "precision" (MOA or better @100) out of my AR, although it seems capable.

 

[vwpilot]

I spoke to Giraud about the Tri-way and Doug himself said there could be up to 0.010 of variance depending on how much pressure you're putting on it. He did not recommend it for precision work. Between the variance stated above and any variance you have in your sizing process, it could account for the ranges you're seeing.