I have never trimmed my new brass on my 454 because the trim to requirement in the manual was at least .005 longer than the raw length of my new brass. The trim to length mentioned in the manuals that I have most say 1.380 All of my brass which I measured when bought new measured 1.375 1.376 and 1.377 .SO I figured it would take several range sessions to get the cases to the point that they neded trimming. you guys like Mike G. are doing basically the same thing too you trim the new case and then never do it again. so eventually somewhere down the road I will have to trim them but, not for a while because I dont rev them up too hot I shoot medium hot loads and tend to mostly stay away from stressing my brass by max loading them all the time.

Let me know if you think this could affect my accuracy or if this is not a good practice.I find that they all still crimp nicely.I have shoot all my brass one time .

The School of Ammunition Nit-Pickers would say that those cases need to be trimed to the shortest dimension in the lot, or 1.375". When you trim new cases you are also evening up the mouth, some will not be perfectly perpendicular to the case body, and you will find a portion of the case mouth being cut back more than the rest. This will effect crimp and bullet pull. How much will this matter at the target? Probably not much, but Nit-Pickers are looking for the ultimate in accuracy and uniformity, so they trim away. Others will wait one firing to redistribute the brass and then trim to the shortest dimension. However, with the variation between revolver chambers this is the ultimate in wishful thinking, as to really benefit from this, one would have to fire each case in the same chamber each subsequent shot! Also, one needs to be careful not to trim too much away, as this may effect the degree of crimping available, too short and a heavy crimp can't be made. Short cases can also be unreliable or unsafe, especially on cartridges that headspace on the case mouth, such as the .45ACP.

Another technique for those Nit-Pickers with lots of time on their hands, that also buy brass in large bulk lots, is to separate cases by length and/or weight. Each batch is loaded separately.

Personally, I would lightly trim that brass to true up the case mouth as much as possible, and let it go at that. It would take many firings before they needed trimming again, and by that time they would be nearing the end of their life.

axlenut

You may find part of your answer in the Tech Notes:

http://www.beartoothbullets.com/tech_notes/archive_tech_notes.htm/20

Dan

It depends what you are looking for in your loads, myself I'm looking for the highest quality load, in saying this I take my time and doing everything single stage, trimming is very important to me, if you want quality in your bullets, if you don't trim you will have all different OAL's, to some reloaders this is not a problem, some reloaders are not looking for a finely tuned bullets, just something to shoot at the range and punch paper. I personally want each bullet to be alike, perfect as possible, I even hand trickle every load,after the 98% dump, chamfer and deburing is very important as well, I think every step in reloading must be done to achieve a well constructed load, and to operate properly, there is a reasons for these reloading steps, so if you are looking to better your factory load,trim your cases and follow the steps closely, I'm a hunter and every shot counts for me, if I need to take a pin point shot, I can using my reloads, and count on them hitting where I aim. So bottom line inhere to all the reloading steps and you will find many days of enjoyable shooting, with the utmost accuracy. Aim small hit small. RAMbo.

I have never trimmed my new brass on my 454 because the trim to requirement in the manual was at least .005 longer than the raw length of my new brass. The trim to length mentioned in the manuals that I have most say 1.380 All of my brass which I measured when bought new measured 1.375 1.376 and 1.377 .SO I figured it would take several range sessions to get the cases to the point that they neded trimming. you guys like Mike G. are doing basically the same thing too you trim the new case and then never do it again. so eventually somewhere down the road I will have to trim them but, not for a while because I dont rev them up too hot I shoot medium hot loads and tend to mostly stay away from stressing my brass by max loading them all the time.

Let me know if you think this could affect my accuracy or if this is not a good practice.I find that they all still crimp nicely.I have shoot all my brass one time .

Considering that your brass measures 1.375 to 1.377, you'd pretty well have to trim them all to 1.375" to get an absuolutly uniform crimp on each (having to go with the shortest and trim the rest to match as we've no good way to make the short ones longer). That .002" isn't enough to really be a problem...but if you want to get all nit-picky about it, then get them all the same length.

Have to measure indiviual chambers, but in general revolvers are more tolorant of longer than standard brass than other systems. Given a few fireings, and the cases will be uneven again (brass is never 100% unform...evens tarting out the same length and having the same number of firings, some of them will grow longer than the others)...and again I'll pick whatever the shortest case of the bath is to set my trimmer, and make them all that length. Don't much care waht that length is so long as it's under max. and over the minimum.