So I bought some fired bra brass. I have Peterson that only I have shot and it measures 1.550”. Bought some Lapua once fired. Somebody trimmed it like it owed them money. Some are 1.39”. Some shorter. Pics for reference. Is this going to be a problem? Before anybody says just shoot it until it grows, I’ve got three firings on my Peterson and it hasn’t grown any. Junk it or what?
-
Having trouble using the site?
Contact support
Bra brass trimmed too much.
- Thread starter L2bravo
- Start date
Just shoot it.
I hate trimming cases so I usually trim undersize so I don’t have to trim a second time.
I hate trimming cases so I usually trim undersize so I don’t have to trim a second time.
When I used to shoot a 308, trim length was 2.005. I trimmed 2.000. So while I do get it on some level, I think .030” seems a bit much. Do you chamfer and debur your brass before loading?
The BRA case doesn't really grow (one of the advantages of the cartridge), its a function of changing the shoulder angle. Some people have claimed to have gone through the entire life of the brass without needing to trim them.
If some are 1.520” and some are 1.390”, I would be hesitant to assume they will shoot interchangeably with each other if tested. That’s a big difference in neck tension and/or bearing surface contact.
If you trim them all way down to the same length, be prepared to monitor and clean the chamber of carbon regularly. Having the neck be 0.150” short of the chamber design means there’s a lot of room for carbon to deposit and harden before reaching the bore.
If you trim them all way down to the same length, be prepared to monitor and clean the chamber of carbon regularly. Having the neck be 0.150” short of the chamber design means there’s a lot of room for carbon to deposit and harden before reaching the bore.
They have blue pills for that problem.
My standard BR (no neck turn) grows about .002 each sizing.
My neck turned ones hardly ever grow in length.
This is pretty much right on. I just trimmed mine for the first time since the first new trim (6+ firings). Nothing really moves - I just trim to get to the same length. They had hardly grown. The BR/BRA really is a magic cartridge...
Consider:
- The force due to neck tension is force on the bearing surface times the surface area times the coefficient of friction. If you assume coefficient of friction and bearing force are uniform down the length of the neck (they're not, but you have no way of accurately measuring), then the neck tension changes linearly with the length of the neck.
- The neck length on the BRA is nominally .322".
- If you shave off 150 thousandths, that's a ~46.6% reduction in length, which is a ~46.6% reduction in neck tension (give or take).
One of the many things that amazes me about this round is how consistent the seating force (correlates to neck tension) is. I've got data on another thread about how that consistency translates to ES/SD. @samb300 is right about not shooting the two different lengths together. Why would you want to screw up one of most beneficial traits of the round?
Always wondered about this. Got some 6 Dasher Peterson brass that from the factory, SAAMI dimensions, the necks seems short. Always wondered if i can trim them too much.
Does brass eventually stop growing in case OAL? How about neck chamfers? Will 15-20 firings cahmfer away too much neck eventually?
Does brass eventually stop growing in case OAL? How about neck chamfers? Will 15-20 firings cahmfer away too much neck eventually?
I don't chamfer unless I trim the case - which is one action for me as I use a 3-in-1 from Forster. There's no practical need otherwise.
That was the "old" 6mmBR dimensions I believe. Regardless, .150" short is a lot of difference in neck tension and potential carbon build up.
Just to clarify, the short pieces are 1.539 or 1.39? Huge difference.
If you're talking about just 0.020" of trim discrepancy, then I wouldn't sweat it. I might set my trimmer to 1.545 to shorten up the long pieces, leave the slightly shorter ones in the 1.53x range alone and let them grow slowly (like 0.001-2 per firing in my experience). If there were really short ones <1.525 I might toss them.
An alternative would be to make two piles... shorter neck brass and longer neck brass and run different trim lengths. If you've got a large lot with a couple hundred of each that might work.
If you're talking about just 0.020" of trim discrepancy, then I wouldn't sweat it. I might set my trimmer to 1.545 to shorten up the long pieces, leave the slightly shorter ones in the 1.53x range alone and let them grow slowly (like 0.001-2 per firing in my experience). If there were really short ones <1.525 I might toss them.
An alternative would be to make two piles... shorter neck brass and longer neck brass and run different trim lengths. If you've got a large lot with a couple hundred of each that might work.
I'm lost too on the actual variance range.
The pictures show 1.524 to 1.552 (rounding to highest spread).
So deltas of 0.028"(pictured) vs 0.160" (narrative)
The pictures show 1.524 to 1.552 (rounding to highest spread).
So deltas of 0.028"(pictured) vs 0.160" (narrative)
OK so here’s where I’m at. I have got 3 firings on Peterson brass. It grows lengthwise, none. I use a giraud trimmer. I have my case holder set, where it barely, and I mean micro, touches the case to put a mini bevel on it. I’m not a fan of the recommendations to cut it short and roll with it. Neck tensions going to be all over the place, case volume is going to be all over the place. This will make numbers be all over the place. Never mind and almost guaranteed carbon ring.
Just going to ask the guy if I can return the brass. Seems like the prudent thing to do.
Just going to ask the guy if I can return the brass. Seems like the prudent thing to do.
I agree that your fighting an uphill battle with inconsistent brass that's been trimmed too short.
The key to reloading is keeping everything as consistent as possible.
Getting new brass will probably save a lot of potential headaches.
If you're talking about 1.524" through 1.550", now you're exaggerating a little.
But hey, if you don't have confidence in your stuff then it will mess with your mind and make you miss.....almost guaranteed.
Volume may not change much, possibly true. Neck tension on the other hand, will assuredly be.
I’ve got a ton of new Peterson, the one I showed @1.551, is one of mine. I bought this as a deal. Lesson learned.
Maybe for you, but for some reason I find my 6 dasher needs chamfering or else I have inconsistent seating of bullets, sometimes the copper gets burrs peeling up and it takes way to much force. Chamfer each time eliminates that for me.
My Lapua dasher is short already too so I never trimmed, only chamfer.
I chamfer every time as welll. It has nothing to do with trimming and everything to do with bullet seating.
I used to. But I took a careful look and enuf chamfer was there after firing to see I don't need to chamfer every time. Just need to make sure that hard, squared edge isn't there on the case mouth. Don't ned a full funnel mouth.
YMMV. But scraping away brass will eventually end case life.
Not exactly. When you trim, you square off the case mouth. This creates hard edges that necessitate a chamfer in and out. During/after the shot, no such hard edge is being created.
Still, do what you do if it works for you. I get seating forces falling within a 3-5lb range on my 6mm, and within a ~10lb range on my 30 cals. Being data-driven in my reloading process, with my next 300 loads I'll chamfer 10 cases, and measure the difference in seating forces and post here.
I don’t go for hell on the chamfer. My brass is growing none, so I barely touch it. So little I highly doubt I’ll affect case life. A little clean up, I feel helps get my seating/tension where I want it.
Attachments
I’m also with you on data. Let us know what you find on that. I’m truly interested. See my post above.
Chamfer if ya need it. But don't if ya don't. Chamfering when ya don't need to removes brass you can never put back.
Sure. If it works for you, then keep at it. I'd also like to see how many firings ppl who chamfer every time get out of their brass, on average. Its undeniable they are removing case neck length EVERY SINGLE TIME. That's not a debatable item. Its fact.
I also know there's ppl on the internet who know everything and can never learn anything from anyone.
If you are such, then yer awesome, dude.
Last edited:
I run a Giraud trimmer which chamfers the case mouth as it trims, and I trim every firing. All my 6BRA and Dasher brass (~ 1k pieces) is between 15 and 20 firings and no signs of giving up. The Giraud is set to a fixed length so it only trims off case growth, the cases always measure the same length after trimming. From prior measurements I know that case growth with these 40 degree shoulder cases is about ~1 thou per firing, which is barely moving.
FWIW, you're not going to shorten case life by trimming to length or chamfer/deburring. Case stretch happens from the cycle of firing and sizing the brass which squeezes the case forward. Eventually the case wall thins and you get case head separation. Happens way more slowly to almost not at all with these 40 degree shoulder cases.
FWIW, you're not going to shorten case life by trimming to length or chamfer/deburring. Case stretch happens from the cycle of firing and sizing the brass which squeezes the case forward. Eventually the case wall thins and you get case head separation. Happens way more slowly to almost not at all with these 40 degree shoulder cases.
I do the exact same thing using the exact same equipment although I am new Ish to the BRA, all of my friends doing exactly what we are doing are getting 20+ loads. Thank you for chiming in.
I also use a Giraud, and have my trimmer set for my 6BRA to chamfer with as minimal as possible trimming. I do this every time I reload - I try to keep my process between every reload identical.
For those that do want to trim with the Giraud, a good tip is to use the Hornady Sure-Loc Lock Rings on your case holders. Keeps your case holder locked into the same position, no need to dick around getting the right trim height each time you go to use it.
One of the biggest things that I am concerned with is neck tension and bullet seating pressure. The chronograph that I posted is pretty much in the ballpark of what I get all the time. That was not cherry picked. If your results are better, please post them I’m interested to see. As far as somebody that willing “to learn“.
I’m literally arguing with some guy on the internet, worrying about me chamfering, which is funny. Then you go so far as to act like I’m a jackass for not listening to you. Talk about awesome.
If you are such, then yer awesome, dude.
All I said was "trimming when ya don't have to is removing brass you can never put back. And that will definitely shorten brass life. That's a fact. Not an opinion." Eventually you'll remove enuf brass you cannot seat bullets.
So when I tell you facts, and also recommend you do what works for you...what part of all that is treating you like yer a jackass? The ONLY way that's treating you like yer a jackass is ***IF*** indeed you do in fact think you already know everything and cannot learn from anyone else. ***IF*** you think that, the jackass treatment is warranted.
So.... I don't get what yer all upset about. IF you also MUST have the last word... its yours. I'm out.
Last edited:
If ya remove enuf brass thru re- chamfering (when it isn't needed, i.e., a chamfer already exists) , such that ya can't seat bullets , that will end the life of the case. Whether that happens b4 or after case head separation....is anyone's guess. But I know ppl that got 20+ firings per case. (So they claim anyway.) Removing 0.010" some 20x may render the case neck unsuable before the case head separates. That's 0.2" removed from the case neck...almost 1/4" ..... even if its less than that...why unnecessarilty remove brass that you can never put back?
Anyway....why chamfer when ya don't need to? I reload to shoot, not to prep brass.
If ya remove enuf brass thru re- chamfering (when it isn't needed, i.e., a chamfer already exists) , such that ya can't seat bullets , that will end the life of the case. Whether that happens b4 or after case head separation....is anyone's guess. But I know ppl that got 20+ firings per case. (So they claim anyway.) Removing 0.010" some 20x may render the case neck unsuable before the case head separates. That's 0.2" removed from the case neck...almost 1/4" ..... even if its less than that...why unnecessarilty remove brass that you can never put back?
Anyway....why chamfer when ya don't need to? I reload to shoot, not to prep brass.
Attachments
Hmmmm, am I the only one here reloading 6mmBR (ok, it's not Ackley I know) and not needing to trim this much?
You are absolutely correct. You quoted the reloading guru (self appointed). My brass has not grown not one .001”. I’m only retouching the case mouth. That dude went full retard.
Recall I'm the one arguing for not chamfering unless you need to. OTHERS are arguing for chamfering EVERY SINGLE LOAD. They are the chainsaw jockeys.
Last edited:
We agree. And You make my point...(1) unless you've trimmed your brass, you likely don't need to re-chamfer it at all and (2) you only need a tiny chamfer, not a funnel mouth case.
The brass you remove you can never put back on.
Why remove brass from your case by chamfering EVERY SINGLE TIME when you DO NOT NEED TO? This is obvious to all but one guy here who has to throw insults like "full retard" and win the internet, and then whine about him supposedly getting the "jackass treatment" (his words) that he so richly deserves.
Last edited:
Yeah only you’re talking about trimming .010 every pass which, sure, obviously would be bad, no shit sherlock…but that’s not what anyone here is claiming they do nor advocating for. It would take a concerted effort to be that bad at trimming (but really just chamfering) and take an entire case neck off. You seem to be missing all of the details and finesse of what they are saying and doing and instead believe that they are converting 223 to blackout with a chop saw.Recall I'm the one arguing for not chamfering unless you need to. OTHERS are arguing for chamfering EVERY SINGLE LOAD. They are the chainsaw jockeys.
And removing neck length has absolutely nothing to do with case head separation nor brass life.
Last edited:
Let’s get this straight sunshine. I tried to actually end this with a little bit of class in reference to my results. I’m not whining, and I’m about as concerned with your opinion as I am your haircut.We agree. And You make my point...(1) unless you've trimmed your brass, you likely don't need to re-chamfer it at all and (2) you only need a tiny chamfer, not a funnel mouth case.
The brass you remove you can never put back on.
So let’s put the proof in the pudding. Put your numbers up or shut up. Pretty simple. We’ve seen my results let’s see yours. I’m not winning the Internet, I’m dealing with somebody who has gone full retard, complaining that I don’t take somebody’s advice off of the Internet. That’s not true, I just don’t take yours.
In your effort to bandwagon against me, you may notice that literally nobody agrees with you. Some people call that a clue.
You are going to ruin your brass kid! I’m going to guess that he does not anneal either.
Why anneal when you’re just gonna chop it off entirely 2 steps later.
Me: "Check to see if you already have a chamfer before re-chamfering. Why remove brass when you don't need to? "
Him: "Chamfer every single time, whether you need to or not. Chainsaw that extra brass off !!!"
Why are we still discussing this? Cuz he's a petualnt child who uses insults like "goes full retard" cuz winning the internet is necessary for his self esteem. I had an uncle and several friends who are learning disabled. Insults like his are the lowest form of humanity. Childish, gutter language no decent person should use. The fact he doesn't see this proves intelligent discussion is not possible with him.
To your question, I say anneal first. Then check for a chamfer to see if you actually NEED to chamfer. If you already got a chamfer, Don't "chop off" brass unnecessarily.
Seems the simplest of concepts to me.
I mean....right ?!?!?!?!?! Anyway.... I'm outta here. Really. The ones willing to "get it" ....will. The rest never will.
If ya remove enuf brass thru re- chamfering (when it isn't needed, i.e., a chamfer already exists) , such that ya can't seat bullets , that will end the life of the case. Whether that happens b4 or after case head separation....is anyone's guess. But I know ppl that got 20+ firings per case. (So they claim anyway.) Removing 0.010" some 20x may render the case neck unsuable before the case head separates. That's 0.2" removed from the case neck...almost 1/4" ..... even if its less than that...why unnecessarilty remove brass that you can never put back?
Anyway....why chamfer when ya don't need to? I reload to shoot, not to prep brass.
Just pointing out how a Giraud trimmer works...
It is set with a lock ring to a fixed depth, indexed off the shoulder. Every single piece of brass comes out at the same length (assuming same shoulder bump). So it won't trim off anything unless the case has grown. Put a piece of brass that's 1.550" in it and it doesn't touch the case mouth. Put in a piece of brass that's 1.551" and it trims/chamfers to 1.550".
It trims/chamfers every firing because the case grows every firing.
The idea that you would take the entire neck off a case with chamfering/deburring10 thou at a time is nonsense.
