consistent trim lengths?

[trigga]

I have been using the lee stud cutter for trimming 223 cases. Very consistent except for when I chamfer and debur. some are as high as 1.758 and some as low as 1.735 with more than 50% under 1.740. All within spec. I have sorted them according to their trimmed lengths and plan on loading them in batchs according to their lengths. just wondering if it is critical to keep and sort case lengths the same? mostly if not all will be for target ammo. will the different trim length be enough to affect accuracy? i plan on keeping the OAL the same regardless of the trim lenth. any inputs? (i know the crimp will vary with the length of the case.. could be a factor)

i have specifically kept all my 1.750 length batch for loading varmint rounds should i feel the need arise. that will be for another day.

 

[redbullitt]

Just depends how anal you want to be about it. Variation is bad no matter how you slice it. BUT does it make a difference to YOUR shooting? That is what you need to find out.

Keep them safe and in spec and then see how picky you have to be. FWIW I shoot a lot of long range and I have never really had much trim trouble. I cut them all to where I want or close to it and then again whenever they need it. I do not even sort them as you did, yet I still get good enough results.

IF I were going to shoot a match I would be a bit pickier I suppose. No sense in giving myself something to blame poor wind calls on lol.

 

[trigga]

yea this is no match grade ammo I'm trying to make here, just plinking/target ammo. usually about 100 yards at most. maybe 200 if I find a big enough range. keeping the AOL the same even with different trim lengths, will the accuracy be minimal at these ranges?

 

[rcmodel]

Very consistent except for when I chamfer and debur

Chamfering & de-burring should have no effect on case length unless you are over doing it.

All it should do is break the sharp in & outside edges left from the trimmer cutter.

And that cannot change the case length if done properly.

rc

 

[trigga]

i chamfer and debur on the drill so that might have something to do with it. the cases seem to "stick" to the case length gauge if I don't chamfer and debur well. It tends to leave a "lip" on the case mouth.

 

[rcmodel]

i chamfer and debur on the drill

Well, Theres your case length problem!

Get a Sharp chamfering tool.
And give it a simple hand twist inside & out to remove the sharp edges left from the trimmer.

rc

 

[amlevin]

Unless you are a bench rest shooter where EVERYTHING is a big deal, there are only two critical dimensions on a trimmed case. It has to be long enough to hold the bullet and short enough to not run into the "second shoulder" (the front of the chamber where the throat begins) when the case stretches under firing pressures. Most chambers have an extra .020" or so extra, above the design case length.

For most shooters, varying trim lengths have no bearing on accuracy when you take into consideration that the pressures involved in a .225 start around 50,000 PSI and go UP from there.

 

[Sunray]

Yep, using the drill is overkill for chamfering and deburring. Chamfering and deburring shouldn't remove much metal.
However, the only complication of having different length cases will be the crimp might get missed altogether. Your AR might not care if there's crimp or not though. Operative word being 'might'.

 

[gamestalker]

I trim, ream, and chamfer on the drill with the Lee thingy. I just figure why handle the brass twice since it's already chucked in the drill. You just have to be careful not to over do it with the R&C tool is all. If done correctly, or rather not over done, the length of the brass shouldn't change at all.

If you wind up with a razor sharp edge on the case mouths, than you are over doing it with the R&C tool. All you want to do it knock off the rough edge the trimmer leaves behind, no more.

GS

 

[trigga]

thanks guys, yes the cutting process brings it to around 1.750-1.755. maybe i am overdoing it because it's bringing it down pass 1.740. maybe use a little less pressure while on the drill as i don't want to handle the brass twice. i'm talking over 5k+ cases i gotta do. I've only done like a couple hundred so far.

i have notice that chamfering and deburring by hand takes off the least material and less likely to reduce the case length. again that is a lot of work...

 

[jwrowland77]

I use the hand tool to chamfer and deburr. Yes, you have to handle the brass more, and yes, it's more laborious, I find it rather relaxing myself. I generally grab a big bag of brass and an extra bucket, sit on the couch with my wife (they like that type stuff), and hand chamfer and deburr my brass. Plus, while it's hot here in Arkansas, it's nice to go inside and cool off a bit.