reloader901 Posted October 7, 2012 Share Posted October 7, 2012 I'm shooting some Federal 5.56 M855 in a Stag Arms AR15 copy. The cases appear to gain about .005 - .010 in length. Just plinking... don't care about accuracy. Is .005 to .010 acceptable for reloading, or MUST they be trimmed? Link to comment Share on other sites More sharing options...
Retread1911 Posted October 8, 2012 Share Posted October 8, 2012 The short answer is yeah I recommend trimming every reload. The long answer is it depends. Every barrel is different As the throat of your barrel erodes you will be able to take longer brass which is a bad thing. If you are not set up to process .223 there are a lot of us out there that will do it for ~30$ per K. Link to comment Share on other sites More sharing options...
warpspeed Posted October 8, 2012 Share Posted October 8, 2012 There is a max length and then a trim to length. 1.76" is the max you want. 1.75" is the length you trim to so that as it grows that 0.001, it is still ok. So the magic question is, how long are they ? Link to comment Share on other sites More sharing options...
reloader901 Posted October 8, 2012 Author Share Posted October 8, 2012 (edited) There is a max length and then a trim to length. 1.76" is the max you want. 1.75" is the length you trim to so that as it grows that 0.001, it is still ok. So the magic question is, how long are they ? A *quick* check of 20 of them this morning 9/8/12. Most 1.764". A couple a little longer 1.767". A couple 1.687" For plinking what's wrong with .005" over? I can trim them, but want some compelling reason to do so...... *** Edit.... Just called Dillon. There is a compelling reason. If the case is too long it will extend into the rifling causing the case pressures to be too high. So my next question was: Since I don't care about accuracy for plinking can I undercut them 10 or 15 thousandths so they maybe I can get a few uses out of them without having to trim them every time. They said yes. Any reason I shouldn't under cut them? (remember... this is just for plinking). Edited October 8, 2012 by reloader901 Link to comment Share on other sites More sharing options...
392heminut Posted October 8, 2012 Share Posted October 8, 2012 I trim mine to 1.750 with no problems at all. Link to comment Share on other sites More sharing options...
steel1212 Posted October 8, 2012 Share Posted October 8, 2012 Typically I find that when I trim to 1.750 it will take a couple shootings before it gets to where I need to trim again. Then again I always use the same setup to load rifle so they always go past the trim die if they need it or not. Link to comment Share on other sites More sharing options...
Alaskapopo Posted October 8, 2012 Share Posted October 8, 2012 There is a max length and then a trim to length. 1.76" is the max you want. 1.75" is the length you trim to so that as it grows that 0.001, it is still ok. So the magic question is, how long are they ? A *quick* check of 20 of them this morning 9/8/12. Most 1.764". A couple a little longer 1.767". A couple 1.687" For plinking what's wrong with .005" over? I can trim them, but want some compelling reason to do so...... *** Edit.... Just called Dillon. There is a compelling reason. If the case is too long it will extend into the rifling causing the case pressures to be too high. So my next question was: Since I don't care about accuracy for plinking can I undercut them 10 or 15 thousandths so they maybe I can get a few uses out of them without having to trim them every time. They said yes. Any reason I shouldn't under cut them? (remember... this is just for plinking). If you trim them too short you will lose neck tension and your bullets will get pushed back inside the case. (Ask me how I know lol) Don't do it. There are reasons the specs are 1.750 to 1.760. Get a dillon auto trimmer and run it each time you reload. Thats what I do and its fast. pat Link to comment Share on other sites More sharing options...
reloader901 Posted October 8, 2012 Author Share Posted October 8, 2012 Really? 10 - 15 thousandths of an inch isn't very much. Guess I'll have to experiment with this later this winter. If you trim them too short you will lose neck tension and your bullets will get pushed back inside the case. (Ask me how I know lol) Don't do it. There are reasons the specs are 1.750 to 1.760. Get a dillon auto trimmer and run it each time you reload. Thats what I do and its fast. pat Link to comment Share on other sites More sharing options...
ffgats Posted December 14, 2012 Share Posted December 14, 2012 There is a max length and then a trim to length. 1.76" is the max you want. 1.75" is the length you trim to so that as it grows that 0.001, it is still ok. So the magic question is, how long are they ? A *quick* check of 20 of them this morning 9/8/12. Most 1.764". A couple a little longer 1.767". A couple 1.687" For plinking what's wrong with .005" over? I can trim them, but want some compelling reason to do so...... *** Edit.... Just called Dillon. There is a compelling reason. If the case is too long it will extend into the rifling causing the case pressures to be too high. So my next question was: Since I don't care about accuracy for plinking can I undercut them 10 or 15 thousandths so they maybe I can get a few uses out of them without having to trim them every time. They said yes. Any reason I shouldn't under cut them? (remember... this is just for plinking). If you trim them too short you will lose neck tension and your bullets will get pushed back inside the case. (Ask me how I know lol) Don't do it. There are reasons the specs are 1.750 to 1.760. Get a dillon auto trimmer and run it each time you reload. Thats what I do and its fast. pat Pat, what do you think with regards to the RCBS X DIE, as per instruction,initial trimming is .o2 from max lenght which is 1.740. any opinion on this Link to comment Share on other sites More sharing options...
Akkid17 Posted December 16, 2012 Share Posted December 16, 2012 I am curious about this as well, I am currently in the process of 223 load development for bulk and long range ammo both. I plodded around and haven't found any reason this far to trim a little extra, especially when you crimp the bullet in as well. I'm not going overboard by any means taking it down to ~1.745" to accomodate for a potentially more finiky chamber. Let me know what you think Link to comment Share on other sites More sharing options...
gunther Posted December 24, 2012 Share Posted December 24, 2012 If you check the cartridge spec's 1.738 is the absolute minimum case length, anything shorter than 1.740 I chop up for 300 blk. Link to comment Share on other sites More sharing options...
Aircooled6racer Posted December 24, 2012 Share Posted December 24, 2012 Hello: One of the best AR-15 shooters I have seen for long range stuff told me to trim the cases to 2.735" OAL. He told me you trim to that length and I will not have to trim them again if shot in the same rifle. Thanks, Eric Link to comment Share on other sites More sharing options...
Tom Freeman Posted December 25, 2012 Share Posted December 25, 2012 I trim all mine to 1.740. Its easy and I dont have to trim them again. They split, fail or get lost before I need to trim them again. Link to comment Share on other sites More sharing options...
ffgats Posted December 27, 2012 Share Posted December 27, 2012 I trim all mine to 1.740. Its easy and I dont have to trim them again. They split, fail or get lost before I need to trim them again. using Rcbs X die,? or just std. die. thanks Link to comment Share on other sites More sharing options...
Tom Freeman Posted December 27, 2012 Share Posted December 27, 2012 Standard old DIllon Carbide size die. Link to comment Share on other sites More sharing options...
mpeltier Posted December 29, 2012 Share Posted December 29, 2012 With your longest at 1.767 I would not bother trimming. I never trim my once fired cases and they often mike as long as 1.769 after sizing. The important dimension as it relates to trimming is the neck length vs the chambers neck length not including the leed. For 5.56 chamber neck length of all chambers I've had we're .218" and .223 rem was .220". Commercial ammo neck length is .203 for a case who's OA length is 1.760. That's a whopping .015" of extra space. The longest fired cases I've had measured 1.769" with a neck length of .212. Loaded and fired many many rounds like that with absolutely no signs of over pressure or reliability issues. I'm not saying you or anyone should change their reloading practices, but if you do some research you may find it unnecessary to trim with that relatively small growth to your cases. Link to comment Share on other sites More sharing options...
Boxer1 Posted January 7, 2013 Share Posted January 7, 2013 I use one of the Little Crow trimmers on my high volume 223 and trim to 1.750 every time. It helps if you are crimping them to keep the crimp the same on all of the rounds. Link to comment Share on other sites More sharing options...
JACKIE40X40 Posted March 31, 2013 Share Posted March 31, 2013 Boxer is correct on the crimp, but the biggest problem if you crimp? and you have some too long, you will build extreme pressure because your crimp being too heavy! And little or no crimp On others, you put undue stress on the weapon and especially the brass.. If gets a lot too long the action might not lock up, or jam the brass in the rifling resulting in extreme pressure. Having a case a few k's under in my opinion is safer. Link to comment Share on other sites More sharing options...
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