I have habitually trimmed and chamfered my cases as part of the handloading process. I recently bought a bore scope and after removing the carbon ring from the chamber I can clearly see a fired case has room to grow before it contacts the end of the chamber cut. if the neck was allowed to contact the end of the chamber is it a big deal? It would seem logical that case life would increase. Of course if chambering the case would become difficult then a little trim would be in order. How say you?
Who does not trim their brass?
- Thread starter savagefan
- Start date
- Location
- Delta B.C.
If the case grows too long it can stick in the chamber. Not ideal in a hunting second shot scenario.
Hand Skills
CGN Regular
- Location
- In the 'heartland', southern SK
I'll take Ackley Improved cartridges for $1000, Alex.
Brass grows most during the resizing process.
Carefully setting up the Resizing die to only bump shoulders 0.0015-.002" considerably improves case longevity and reduces trimming.
Seep shoulder angles (like 40° AI cartridges) hardly grow at all.
Brass grows most during the resizing process.
Carefully setting up the Resizing die to only bump shoulders 0.0015-.002" considerably improves case longevity and reduces trimming.
Seep shoulder angles (like 40° AI cartridges) hardly grow at all.
- Location
- Blaster land, Okanagan BC
Only pistol brass I’ve trimmed is 10mm, I started checking case mouths after the first firing. None of them were square, nor to listed case length. After trimming I noticed accuracy improved off bags while I was shooting through a chronograph, I figured a more consistent crimp with the case mouth square to the wall helped. Groups improved and I had less fliers.
Can’t say I’d bother trimming any other pistol brass I load for though.
Rifle brass I trim off f it needs it, check it periodically but I’m not loading excessively hot so it seems minimal that I need to trim.
You can buy the little caliber specific plugs to check your actual maximum brass length. Most of the "maximum brass length" SAAMI numbers are much shorter than what a chamber allows.
I think they may be made by Stoney Point, but I can't recall off the top of my head, sorry!
I think they may be made by Stoney Point, but I can't recall off the top of my head, sorry!
- Location
- Blaster land, Okanagan BC
Blazer mainly, Fed and S&B was more consistent in having the case mouths square with the wall. I trimmed it all while I was clean/prepping one evening, have the drill attachment for my Lyman universal so it didn’t take long to trim them. I figured having an even crimp wouldn’t be a bad thing, have picked up a Lee factory crimp die in the meantime but haven’t been loading much 10mm lately.
Have a bunch of new 10mm Starline but I haven’t checked how uniform the case mouths are, I’ve just been shooting my small primer 10mm brass more than the lg primer brass I have.
nowarningshot
CGN Ultra frequent flyer
Trimming brass is like drying silver cutlery when you had 12 for Christmas diner. Has to be done, fight turkey coma, fight turkey coma.
Development of a awesome tuned load for your rifle is fun, in hindsight. At the time, measuring, trimming brass is as fun as cleaning a barracks floor with a toothbrush.
The two steps I've invested the most money for reloading? Undoubtedly, trimming and powder measuring. Eventually everything works out. It's a hobby unto itself, been saying that 35yrs. Might actually believe it in about another 10yrs. Zero chance I ever believe it possible for pistol brass. Life's to short to trim pistol brass.
Development of a awesome tuned load for your rifle is fun, in hindsight. At the time, measuring, trimming brass is as fun as cleaning a barracks floor with a toothbrush.
The two steps I've invested the most money for reloading? Undoubtedly, trimming and powder measuring. Eventually everything works out. It's a hobby unto itself, been saying that 35yrs. Might actually believe it in about another 10yrs. Zero chance I ever believe it possible for pistol brass. Life's to short to trim pistol brass.
I find with several different cartridges that after they are fired they are still below the max trim length. Once I resize them they are either very close to the max trim length or are over by a couple thou. Most of the problem is from the full length sizing die and pulling the expander ball back through the neck and stretching it.
Since I started using bushing dies with no expander ball and using a comparator to make sure I have less than .002 shoulder bump it has significantly reduced the amount of trimming I have to do.
Since I started using bushing dies with no expander ball and using a comparator to make sure I have less than .002 shoulder bump it has significantly reduced the amount of trimming I have to do.
You will find that brass of various lengths, say minimum and maximum, together in the same batch can lead to unexplained flyers on paper and in the field.
I'm not going on about a bullet going a couple of inches off the group, but especially in accurate rifles, it can open nice consistent sub moa groups by half, in extreme cases more.
I usually trim after every third shot, depending on the rifle. In the No4 MkI Long Branch, I'm not so fussy and only trim when the cases won't fit through the gauge.
For most hunting situations, it's not important until the cases exceed what the chamber will allow, but as mentioned, take care when cleaning your rifle to remove any carbon rings which may build up in front of the case mouth.
Trimming depends on if it needs it or not, I usually set the trimmer for .005 under max and check them all in the trimmer. Damned if you do and damned if you don't, have to check them all with a caliper anyway, so, I use the trimmer instead. I do have a couple of guns I want all brass at the same length for. Have one batch of brass I set the trimmer to min on, as new brass was .010 under to start with. If you are sizing properly and not running hot loads, you won't find many in a given batch that needed trimming after say two shots on most new brass. Always seems to be one or two in a batch though, even when it seems there probably shouldn't be any in that batch, because you are usually 3/4 of the way thru before you hit on them. But, I'm disciplined about it, so I just do it for peace of mind. Meh.
Set your own max length by visually seeing the case throat relationship. Utilizing your borescope.
It’s simple!
My new 22-250 has this much room with a brand new virgin case.
How much that is will be pretty much a visual thing until the gap narrows, then measure, record and voila my actual max case length.
Sooner or later you’ll need to trim cases, the saami spec is just a number somebody said will work, but is most often too damned short.
It’s simple!
My new 22-250 has this much room with a brand new virgin case.
How much that is will be pretty much a visual thing until the gap narrows, then measure, record and voila my actual max case length.
Sooner or later you’ll need to trim cases, the saami spec is just a number somebody said will work, but is most often too damned short.
This is exactly what I am seeing hence the post, the thinking is if there is less distance between case mouth and chamber, there will be less carbon ring to clean out. Very clean chamber BTW, what do you use?
