The Accurate Reloading Forums
Trimming brass
30 April 2011, 09:03
olguyTrimming brass
Couple days ago finished up batch of reloads for .300WM. When I was trimming brass (once fired) got a few too short before getting trimmer adjusted where I wanted it. Min. trim length is 2.610; cut these few to 2.608"-2.609",
under by .001"-002".
Never gave it much thought before; have always discarded brass if I trimmed it .003" or more too short, or used for dummies. When they are .001"-.002" then I use them for min. charge fouling rounds.
What do you all think of my approach? Is there
a safety issue I am overlooking? Am I nit-
picking? I know that, from a quality control standpoint, you should keep everything consistent. The loading manuals I have(Hornady, Nosler, Speer, Barnes & Lyman) are
silent on this specific subject (or, have I overlooked it?).
30 April 2011, 09:12
bartsche
Use them!!! They'll grow. Really

roger
Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
30 April 2011, 09:31
SR4759Good grief man you are throwing away money.
Most chambers are already .030 to .040 longer than the brass. Another .001 to .003 will not be noticed.
30 April 2011, 12:50
OddbodI've used brass trimmed 0.020" short without noticing any difference whatsoever - all you're trimming is the neck, so it makes no difference to headspace, only to tension on the bullet.
As bartsche says; they'll grow.
30 April 2011, 16:58
BNagelMy problem is inconsistent trim length. Guess my RCBS unit needs a new cutter...
_______________________
30 April 2011, 18:04
Jim C. <><quote:
Min. trim length is 2.610; cut these few to 2.608"-2.609",under by .001"-002".
Actually, there is no "minimum" trim length. There is a "max length" but only a suggested "trim to length"; that's not a critical measurement.
30 April 2011, 19:22
graybirdolguy,
To eliminate the time it takes to adjust your trimmer to the length needed, I have a dummy cartridge for the exact length I want per caliber. This dummy round is trimmed to the length desired. Then, when needing to adjust the trimmer, I just pop it in, move the cut flush with the dummy round and tighten the set screws. So, basically it only takes one time of continuously checking the trim to length to get the dummy round correct.
Hope this helps!
Graybird
"Make no mistake, it's not revenge he's after ... it's the reckoning."
30 April 2011, 21:23
Hunt-ducksquote:
Originally posted by Jim C. <><:
quote:
Min. trim length is 2.610; cut these few to 2.608"-2.609",under by .001"-002".
Actually, there is no "minimum" trim length. There is a "max length" but only a suggested "trim to length"; that's not a critical measurement.
+1
Your worrying over 001 & 002 I always trim .010 under min. unless it has a real short neck like a 300 sav. it will grow.
30 April 2011, 21:58
Jay Gorskiquote:
Originally posted by BNagel:
My problem is inconsistent trim length. Guess my RCBS unit needs a new cutter...
Contact RCBS, they'll send you a brand new one free of charge, ive done it twice now since Ive had my trimmer.
30 April 2011, 22:57
BISCUTquote:
Originally posted by graybird:
olguy,
To eliminate the time it takes to adjust your trimmer to the length needed, I have a dummy cartridge for the exact length I want per caliber. This dummy round is trimmed to the length desired. Then, when needing to adjust the trimmer, I just pop it in, move the cut flush with the dummy round and tighten the set screws. So, basically it only takes one time of continuously checking the trim to length to get the dummy round correct.
Hope this helps!
After over trimming a few times I do the same as you! Saves some headache
quote:
Originally posted by Jay Gorski:
quote:
Originally posted by BNagel:
My problem is inconsistent trim length. Guess my RCBS unit needs a new cutter...
Contact RCBS, they'll send you a brand new one free of charge, ive done it twice now since Ive had my trimmer.
Thanx!
_______________________
quote:
To eliminate the time it takes to adjust your trimmer to the length needed, I have a dummy cartridge for the exact length I want per caliber. This dummy round is trimmed to the length desired. Then, when needing to adjust the trimmer, I just pop it in, move the cut flush with the dummy round and tighten the set screws. So, basically it only takes one time of continuously checking the trim to length to get the dummy round correct.
Me too. Great timesaver.
LWD
02 May 2011, 20:53
CouchTaterAmazing; I logged in today for the purpose of asking a general question about neck trimming.
My question came from reading about the shortened cases used in Hornady's Leverevolution ammo, as well as some of the tricks being used by folks running wildcat cartridges in the AR-15 platform. In both cases, AIUI, the motivation is housing a very long bullet within magazine or feed limits and not having the ogive fall within the neck.
It seems to me that the neck mainly does two things; guides the bullet into the lands, and provides a crimp and/or neck tension to keep the bullet properly positioned until launch. I guess providing a repeatable amount if initial bullet resistance for good powder burn is secondary.
If the chamber is cut properly, and you've got at least a caliber of remaining neck length, am I wrong in thinking that the neck can safely be trimmed back several hundredths from spec? Assuming that the jump to lands is normal.
02 May 2011, 21:32
StonecreekThere is no safety issue with short necks.
At some point there may be a change in point of impact if the case is significantly shorter than other cases since this might marginally influence total neck tension and possibly the barrel harmonics somewhat, perhaps similarly to the way changing the bullet seating depth influences harmonics. I wouldn't want the cases I use for a benchrest match to vary by .02", but it's unlikely you could tell the difference in hunting ammunition.
03 May 2011, 01:10
rcamugliaI recently bought the Sinclair chamber length gauges.
Found that the recommended trim length for my two .300WM's was about .040" short of my actual chamber length of 2.650" on one and 2.655" on the other rifle.
I'll be able to let the brass grow to within .015" of max safely and get better accuracy as well.
03 May 2011, 17:24
Hot CoreIf you get them too Short and fire bunches of them like that, it is possible to Erode that part of the Chamber neck area. Or Carbon can build up in the gap, which is difficult to remove without employing non-conventional Cleaning Techniques.
Then is becomes an issue if you begin firing longer Necks, because they can Hang a bit.
If however a person just uses the Lee Case Length Gauge/Trimmer after every shot, it never becomes a problem and the Cases are never Trimmed too short.

Best of luck to you.
03 May 2011, 21:06
vapodogquote:
the Cases are never Trimmed too short
uuhhhh....jus wonderin.....how short would that be?

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03 May 2011, 21:22
Ghubertquote:
Originally posted by Hot Core:
If you get them too Short and fire bunches of them like that, it is possible to Erode that part of the Chamber neck area. Or Carbon can build up in the gap, which is difficult to remove without employing non-conventional Cleaning Techniques.
Then is becomes an issue if you begin firing longer Necks, because they can Hang a bit.
If however a person just uses the Lee Case Length Gauge/Trimmer after every shot, it never becomes a problem and the Cases are never Trimmed too short.

Best of luck to you.
+1
The Lee trimmer and an electric drill is quicker over a hundred cases for me than the RCBS hand lathe thing and I don't need to worry about keeping a sample case safe.
If one doesn't crimp case length isn't too critical but if the case is so long that it pokes into the lands, you can get some very impressive pressure signs.
I've ground my lee stuff to trim between 5-10thou under the recommended max.
04 May 2011, 02:30
Hot Corequote:
Originally posted by vapodog:
quote:
the Cases are never Trimmed too short
uuhhhh....jus wonderin.....how short would that be?
Beats me. Never bothered wasting my time measuring it. I spend that time
Uniforming Primer Pockets.

04 May 2011, 03:01
rcamugliaquote:
Beats me. Never bothered wasting my time measuring it. I spend that time Uniforming Primer Pockets.
You may be concentrating on the wrong step if accuracy is important.
amann posted a youtube link for a video by a big time bench rest guy. Out of the entire hour video, the biggest thing he believed and proved that affected accuracy (one hole benchrest accuracy) was making sure all of his cases were trimmed to the exact same length

04 May 2011, 03:23
ramrod340quote:
If however a person just uses the Lee Case Length Gauge/Trimmer
Hey where can I get on for a 400PDK, 380PDK ..... All well and good if you shoot std. Wildcats of different lengths the Lee don't hlep a bit.
As usual just my $.02
Paul K
04 May 2011, 17:27
Hot Corequote:
Originally posted by rcamuglia:
You may be concentrating on the wrong step if accuracy is important.
amann posted a youtube link for a video by a big time bench rest guy. Out of the entire hour video, the biggest thing he believed and proved that affected accuracy (one hole benchrest accuracy) was making sure all of his cases were trimmed to the exact same length

Surely you didn't believe that? Come on Grasshopper,
you know better than that.

I suppose you need a U-Tube video of me explaining Neck Turning - while backing-up the truck!

04 May 2011, 17:28
Hot Corequote:
Originally posted by ramrod340:
quote:
If however a person just uses the Lee Case Length Gauge/Trimmer
Hey where can I get on for a 400PDK, 380PDK ..... All well and good if you shoot std. Wildcats of different lengths the Lee don't hlep a bit.
Lee will make any size you want - maybe.

04 May 2011, 21:01
rcamugliaquote:
Originally posted by Hot Core:
quote:
Originally posted by rcamuglia:
You may be concentrating on the wrong step if accuracy is important.
amann posted a youtube link for a video by a big time bench rest guy. Out of the entire hour video, the biggest thing he believed and proved that affected accuracy (one hole benchrest accuracy) was making sure all of his cases were trimmed to the exact same length

Surely you didn't believe that? Come on Grasshopper,
you know better than that.

I suppose you need a U-Tube video of me explaining Neck Turning - while backing-up the truck!
The guy's name is
Jack Neary and I guess he is a world class benchrest shooter and member of Team USA.
There is about an hour of video there. I watched it but don't know which video the information came from but it stuck with me as he stressed its utmost importance.
His example was while he was at a match and his one hole groups got bigger. He talked with a friend about it who reminded him of trimming each case to the exact same length between strings. He went out and one-hole accuracy returned when he made sure his cases were trimmed perfectly.
He does not weight sort at all and sees no difference in groups with not weight sorting.
Consistent neck length gives consistent tension
04 May 2011, 21:30
wasbeemanThat kinda makes sense but then his rifle was a one off made to shoot a particular cartridge of exacting specs. Would there be any significances if he was shooting a $300 Savage that he picked up at Walmart?
If it's someone's cup of tea fine and good , but folks spend (read waste) a whole lot of time performing nit picky things to their brass that has no real world effect on the rifle's performance. The rifle is just not up to it.
Did the fellow mention how much time he spends practicing?
Aim for the exit hole
04 May 2011, 22:36
rcamugliaquote:
Originally posted by wasbeeman:
Would there be any significances if he was shooting a $300 Savage that he picked up at Walmart?
If it's someone's cup of tea fine and good , but folks spend (read waste) a whole lot of time performing nit picky things to their brass that has no real world effect on the rifle's performance. The rifle is just not up to it.
I guess the shooter of the Savage in question would never know if there is a difference until he tries it.
The only thing you can do is experiment like we all do with handloading and as you know, sometimes you hit on a particular thing in brass prep or component choice that makes a difference in accuracy.
04 May 2011, 23:02
ramrod340quote:
Lee will make any size you want - maybe
Let's see at $20 a pop let me jump all over that. Why pay $200 for 10 wildcats when a dummy round a 2 minutes to set up and my forster does all of them.
I think there are a lot of things a shooter might do to his brass that might give a gain in benchrest but would pretty much be a waste of time with a normal hunting rifle.
I have a couple rifles that I tried all the little things to the brass shoot groups then simply cleaned sized and load. Trimmed when needed. I could see no measureable difference in my groups.
A .23" group over a .25" group might make a big difference in where you finish in a benchrest match. A .73 vs .75 group on a hunting rifle not so much. If it make a shooter feel better to do all the little steps them by all means do them. Me I'll live with the .75" group and spend my time on other things.
As usual just my $.02
Paul K
05 May 2011, 02:33
Hot Corequote:
Originally posted by rcamuglia:
He went out and one-hole accuracy returned when he made sure his cases were trimmed perfectly.
Hey Ted, That can be done with the Lee tool "more accurately" across a Lot of Cases than with a Lathe Style. Just measure some and it is obvious, not much, but there is Variation which does not have to be there.
quote:
He does not weight sort at all and sees no difference in groups with not weight sorting.
Obviously he still has a lot to learn. Does he use a M43 too?

quote:
Consistent neck length gives consistent tension
Plus Annealing. However, it can all be forgotten about, just like Concentricity, if the Reloader uses P-FLRing and Seats Bullets Into-the-Lands. Those two bits of Magic eliminate the need for a lot of stuff that has all kinds of Variations in it.
But...., you should use whatever you want.

05 May 2011, 10:13
wasbeemanquote:
Originally posted by rcamuglia:
quote:
Originally posted by wasbeeman:
Would there be any significances if he was shooting a $300 Savage that he picked up at Walmart?
If it's someone's cup of tea fine and good , but folks spend (read waste) a whole lot of time performing nit picky things to their brass that has no real world effect on the rifle's performance. The rifle is just not up to it.
I guess the shooter of the Savage in question would never know if there is a difference until he tries it.
The only thing you can do is experiment like we all do with handloading and as you know, sometimes you hit on a particular thing in brass prep or component choice that makes a difference in accuracy.
Right! By spending countless hours trimming your brass to an exact length and/or measuring how far the primer is seated into the primer pocket will change a 3" spray and pray into a bug hole shooter. Especially when the shooter spends only part of one day a month at the range and is shooting over a rolled up slicker. (no telling how many hours he spends in cybeerspace talking that talk however)
A Wally World special only has so much accuracy potential. While it may or may not be your cup of tea to try to shave the 1.5" groups down to a mere 1.25", in the real world, it don't make no difference. As I posted, you'll come closer to shaving those groups by practicing bench technique than you will shaving logs of 4350 in two.
And finally, the folks that want to take a single facet of ultra precision shooting and try to make a doxology out of it are really deluding themselves regardless of how they try to assume the high road.
Aim for the exit hole
06 May 2011, 01:17
rcamugliaHey wasbeeman,
My point is that the key to accuracy in any rifle is consistency.
Making the best ammo you can make is a huge part of the equation for accuracy. Everybody who handloads and not just reloads knows this and I know you do. To make the best ammo you possibly can entails making it consistent. Consistently weighed powder charges, consistent OAL, and consistent brass
Consistent brass has a lot of factors.
woods has shown me and I have demonstrated for myself in my own rifles what brass does does to accuracy that is inconsistently prepped or sized.
This thread showed how much variance in accuracy in my rifle occurs with brass in different states of preparation.
Some even weight sort to keep ammo consistentcy to the Nth degree.
If you've developed the most accurate load for your rifle and all of your ammo is perfect as you can make it, then all that is left is the rifle's accuracy capability and the shooter's accuracy capability.
If a rifle shoots 2 MOA with the best ammo you've made, all the practice in the world won't shrink your groups to 1 MOA