Thread: Do you always need to case trim?

I haven't yet trimmed.
I've Norma 223 cases that are on their 7th load and Lapua Palma 308 cases on their 6th load without trimming (or annealing).
223 cases have only been neck sized. 308 cases have been neck sized and full length sized.

I would trim all cases after first firing just enough to get them all the same length and possibly cull any very short cases.....eg FC brass.

Overall case length and how that relates to the chambers maximum length depends on the reamer used in that rifle and is nothing to do with headspace or jump to lands.

I personally would mark brass and size for each rifle as required.

If brass is to be used in two different rifles with the same load then basicly you are going to have to size and trim for the tightest chamber which WILL stretch your brass in the looser one and cause these cases to grow lengthwise and if the difference is more than a little case head separation is inevitable.

I use Sinclair chamber length gauges, have for over thirty years. They're inexpensive and give an accurate reading. You'll need calipers though.

https://www.youtube.com/watch?v=JKnXJxaAw2U

Originally Posted by 10-Ring

I use Sinclair chamber length gauges, have for over thirty years. They're inexpensive and give an accurate reading. You'll need calipers though.

https://www.youtube.com/watch?v=JKnXJxaAw2U

+1 Ditto, and the reamer drawings. Have 5 of them. Made the last one myself out of brass though rather than go to Sinclairs - I had nothing else I wanted off them at the time and the shipping would have been shit.

I trim every firing. I neck turn my cases before the first firing and use Redding bushing dies to get consistent neck tension and low ES. If the cases are not all exactly the same neck length there will be variety between cases, so I trim to just over book max length. Yes, the difference from one case to another is tiny, but it's all about eliminating tiny differences and they all add up. My last load of .300 WM reloads had an ES of 4fps over 5 shots.

I also think it's important to use a good trimmer that supports the case well. I use an LE Wilson jobby.

Just going through first time case prep for the 223. Brass is, what I assume, now on its second firing as it was H&F ammo. Primers and projectiles had been crimped. As an afterthought, yes I’d missed a step, I measured the case lengths after all the prep and they’re generally within .002-3”and no longer than 1.760”. Would you bother trimming??

Originally Posted by Sidetrack

Just going through first time case prep for the 223. Brass is, what I assume, now on its second firing as it was H&F ammo. Primers and projectiles had been crimped. As an afterthought, yes I’d missed a step, I measured the case lengths after all the prep and they’re generally within .002-3”and no longer than 1.760”. Would you bother trimming??

Nope


I mainly load 1x fired .223 brass and I haven't trimmed a case in years

Some calibers seem to need trimming more than others. In my particular case Ive found different rifles same cal seem to need it as well. My 22 hornets require regular trimming more than likely because the brass is thinner. I have three x55s running same loads, for some reason the mill sporter doesnt need trimming where as the t3 does same brass so dont know why that is not that it bothers me.

What I don’t get is why crimp the bullets (55’s with cannelure) and stake the primers on these. Was it a gas gun thing or a bulk production on used brass requirement.

Ive only ever seen it on mil type ammo, prob what mil spec requires if you want to sell ammo to them

Originally Posted by Sidetrack

What I don’t get is why crimp the bullets (55’s with cannelure) and stake the primers on these. Was it a gas gun thing or a bulk production on used brass requirement.

A lot of .223 ammo has this. Most of the mixed brass I have has crimped primers in one way or another

Possibly manufactured on same line as milspec stuff so crimping is desired. Hornady superprefomance stuff was crimped last time I checked any. Quick whizz with case mouth deburring/ champhering tool and no more crimp burr( makes seating primers a breeze too) job done.

Originally Posted by Sidetrack

Just going through first time case prep for the 223. Brass is, what I assume, now on its second firing as it was H&F ammo. Primers and projectiles had been crimped. As an afterthought, yes I’d missed a step, I measured the case lengths after all the prep and they’re generally within .002-3”and no longer than 1.760”. Would you bother trimming??

That is milserp brass,this the crimp thing.

I have heaps of commercial hunting ammo brass that also has crimped primers. Federal, Hornady, etc