Who Trims When?

[mikecr]

I don't understand what "BR reloading" would have you trimming every time. BR cartridges, chambers, and dies should not have anyone trimming enough to invest so much concern.

You bump shoulders after firing, right?
You've measured chamber end to know your max trim length, right?
These are taken to case head, which there is nothing deficient about.
If you prefer to trim based on shoulders, they were set(in bumping) based off the case head, so your trimming is still w/resp to case head(Case OAL), which leads to simple max trim length.
When your cases actually need trimming, you'll see it in OAL, and no matter the tool, you trim to correct OAL.

Chasing shoulders makes no sense. Just trim under max trim length.

 

[savagedasher]

I don't see how someone can make a load the same without haveing the trim length the same trim every time . Larry

 

[Geronimo Jim]

Carbon ring is reason to have all brass same length.

 

[mikecr]

I don't see how someone can make a load the same without haveing the trim length the same trim every time . Larry

For the BR shooter wiping out 6PPC cases in 3-4 firings, running competitive extreme pressure loads, EXACT trim length is meaningless to results. It would make no difference whatsoever.
For the LR BR shooter, consistency is not just case to case, but match to match to match as well. What's the price in causing and engaging in continual trimming? Well, case capacity and neck thickness changing for sure. That brass trimmed away came from brass moving in cases you're relying on in the long run. By 5-6 rational trimmings your load is going somewhere. By 20-30, your original load is gone.
What do competitive LR BR shooters do to manage their loads in the long run? They make better plans than to continually trim away at their vested cases. They choose better reloading cartridges, chambers, and dies. Stuff like at least 30deg shoulders for .473 cases, small primers, tighter clearances needing less FL sizing, custom/chosen minimal sizing dies. It's rare that their trim length changes to a point of needing re-trimmed. Do you think a 6.5x47L or 6Dasher need much in trimming along the way? NOPE. Not with any plan.

But let's say you want every single case EXACTLY the same trim length. This trim length is measured with calipers (OAL).
You could simply trim to that exact OAL with anything. Pull out a file & hit it to scribe, jig to case head, jig to bumped shoulders, makes no difference.
You don't need to be trimming new/unformed brass to any exact length, because all that will change with fire forming anyway.
You do your precision trimming after fire forming, and the only things changing that trim length from there are your continued sizing actions.----Now, you're really liking your 6Dasher-----
Apply this to a 243Win or 30-06, and you should quickly hate your plan. All that trimmed brass piling up on the bench is pretty sad. That's cases you've invested resources in -changing. And oh yeah, check your runout on them lately..

Of trimming jigs to shoulders? No real advantage warranting the hassle..
If your shoulders are set(as they should be) they're just a different datum to case head and fully correlate the same to case mouths. There may be an advantage to the world's bestest trimmer or whatever, but only if it's the world's smallest trimmer (fits in a reloading drawer).

If you get the notion that trim length doesn't matter to me, the opposite is true. It's actually important enough to me that I plan for it, and consider it, while filling out a reamer print. I love improved cases, and tight chamber end clearances.

 

[savagedasher]

For the BR shooter wiping out 6PPC cases in 3-4 firings, running competitive extreme pressure loads, EXACT trim length is meaningless to results. It would be

For the BR shooter wiping out 6PPC cases in 3-4 firings, running competitive extreme pressure loads, EXACT trim length is meaningless to results. It would make no difference whatsoever.
For the LR BR shooter, consistency is not just case to case, but match to match to match as well. What's the price in causing and engaging in continual trimming? Well, case capacity and neck thickness changing for sure. That brass trimmed away came from brass moving in cases you're relying on in the long run. By 5-6 rational trimmings your load is going somewhere. By 20-30, your original load is gone.
What do competitive LR BR shooters do to manage their loads in the long run? They make better plans than to continually trim away at their vested cases. They choose better reloading cartridges, chambers, and dies. Stuff like at least 30deg shoulders for .473 cases, small primers, tighter clearances needing less FL sizing, custom/chosen minimal sizing dies. It's rare that their trim length changes to a point of needing re-trimmed. Do you think a 6.5x47L or 6Dasher need much in trimming along the way? NOPE. Not with any plan.

But let's say you want every single case EXACTLY the same trim length. This trim length is measured with calipers (OAL).
You could simply trim to that exact OAL with anything. Pull out a file & hit it to scribe, jig to case head, jig to bumped shoulders, makes no difference.
You don't need to be trimming new/unformed brass to any exact length, because all that will change with fire forming anyway.
You do your precision trimming after fire forming, and the only things changing that trim length from there are your continued sizing actions.----Now, you're really liking your 6Dasher-----
Apply this to a 243Win or 30-06, and you should quickly hate your plan. All that trimmed brass piling up on the bench is pretty sad. That's cases you've invested resources in -changing. And oh yeah, check your runout on them lately..

Of trimming jigs to shoulders? No real advantage warranting the hassle..
If your shoulders are set(as they should be) they're just a different datum to case head and fully correlate the same to case mouths. There may be an advantage to the world's bestest trimmer or whatever, but only if it's the world's smallest trimmer (fits in a reloading drawer).

If you get the notion that trim length doesn't matter to me, the opposite is true. It's actually important enough to me that I plan for it, and consider it, while filling out a reamer print. I love improved cases, and tight chamber end clearances.

make no difference whatsoever.
For the LR BR shooter, consistency is not just case to case, but match to match to match as well. What's the price in causing and engaging in continual trimming? Well, case capacity and neck thickness changing for sure. That brass trimmed away came from brass moving in cases you're relying on in the long run. By 5-6 rational trimmings your load is going somewhere. By 20-30, your original load is gone.
What do competitive LR BR shooters do to manage their loads in the long run? They make better plans than to continually trim away at their vested cases. They choose better reloading cartridges, chambers, and dies. Stuff like at least 30deg shoulders for .473 cases, small primers, tighter clearances needing less FL sizing, custom/chosen minimal sizing dies. It's rare that their trim length changes to a point of needing re-trimmed. Do you think a 6.5x47L or 6Dasher need much in trimming along the way? NOPE. Not with any plan.

But let's say you want every single case EXACTLY the same trim length. This trim length is measured with calipers (OAL).
You could simply trim to that exact OAL with anything. Pull out a file & hit it to scribe, jig to case head, jig to bumped shoulders, makes no difference.
You don't need to be trimming new/unformed brass to any exact length, because all that will change with fire forming anyway.
You do your precision trimming after fire forming, and the only things changing that trim length from there are your continued sizing actions.----Now, you're really liking your 6Dasher-----
Apply this to a 243Win or 30-06, and you should quickly hate your plan. All that trimmed brass piling up on the bench is pretty sad. That's cases you've invested resources in -changing. And oh yeah, check your runout on them lately..

Of trimming jigs to shoulders? No real advantage warranting the hassle..
If your shoulders are set(as they should be) they're just a different datum to case head and fully correlate the same to case mouths. There may be an advantage to the world's bestest trimmer or whatever, but only if it's the world's smallest trimmer (fits in a reloading drawer).

If you get the notion that trim length doesn't matter to me, the opposite is true. It's actually important enough to me that I plan for it, and consider it, while filling out a reamer print. I love improved cases, and tight chamber end clearances.

Last br shoot I watch 2 of the best trim every . They took many of the trophy. .

 

[savagedasher]

Last br shoot I watch 2 of the best trim every . They took many of the trophy. .

I only have trimming a couple of years 1957 was my first. Press die and a file . Larry

 

[Ned Ludd]

Bob,
I have the same trimmer system that I use for 223 and 308 brass. For the 308, I purchased both (fired/unfired) case holders. I have only opened and used the 308 case holder for "fired" brass. For the 223, I have only one case holder that says "Standard". I bought this trimmer so long ago that honestly, I forgot what the unopened 308 case holder was even for. So I have actually been using the "fired" case holder for both virgin and fired (after FL resize) brass for several years and I don't know how many rounds. Both holders work just fine. There is a slight difference in how far the case head is sunk down into the holder when it is nice and snug, but it works for both virgin and fired/re-sized brass and hasn't made any difference in the trim length or consistency as far as I can tell. I always measure case length of the first few cases, especially after switching between 223 and 308. The micrometer setting is very consistent when you adjust it to switch between the two different trim lengths for 223 and 308 (1.750" and 2.005"), and it doesn't appear to be affected by using only the single holders for each caliber. Hope that helps.

 

[rkittine]

Thanks all and GS, I purchased a "Fired" Case holder for my 6.5x47L and found the same thing you are talking about. It will hold either a fired case or a virgin case fine, just has less base sticking out the back when inserting an unfired case. To start I guess I will just purchase the Fired Case holders for my other two BR calibers.

Bob

 

[GSPV]

Quit churching it up. Trim the danged cases. It takes the same time to trim them as it does to measure them.

If you notice that they don't trim till the third firing, then that'll tell you something and you can go from there.

Sheesh.

 

[amlevin]

I just trim after every firing, after neck sizing and shoulder bumping. My reasoning is that cases aren't perfect and "growth" is not uniform around it's circumference. When I trim this is somewhat supported by some cases only showing cutting on a portion of the case mouth circumference. Trimming gives me a nice, square, freshly chamfered, case mouth, every time. No need to keep count of how many firings or measuring. Just trim and be done. If it cuts it cuts and if it doesn't it doesn't. As GSPV said, takes the same time as measuring.

 

[DOGCAPPER]

+1 AMLEVIN

 

[LHSmith]

The key to accuracy is make everything that goes into the shot the same....reduce as many variables as possible. You CAN control brass length, you CAN'T control conditions ( at least not in competition to any great extent). Jack Neary, Benchrest Gold level in Precision Shooter points advises to keep the length of cases within 0.002". I put great weight into his advice. With his skill level using the very best equipment on the planet he can notice the difference on paper....YMMV

 

[amlevin]

The key to accuracy is make everything that goes into the shot the same....reduce as many variables as possible. You CAN control brass length, you CAN'T control conditions ( at least not in competition to any great extent). Jack Neary, Benchrest Gold level in Precision Shooter points advises to keep the length of cases within 0.002". I put great weight into his advice. With his skill level using the very best equipment on the planet he can notice the difference on paper....YMMV

It can cause one "brain cramps" trying to figure out what steps are important and which are not. Rather than kill brain cells I prefer to just "do 'em all". I've also noticed that when people start saying 'that doesn't matter', they often overlook the items that really DO make a difference in the overall accuracy.