Virgin vs x1 fired brass
- Thread starter hitman44
- Start date
We dont alter charge weights to control group size....Your node is your node and you need to be in the center of it... Yes, you will most likely have to tweak your load with 1x brass vs virgin. Thats why I only do load development with 1x. You tweak seating depth to adjust group size.
If understand your statement correctly, if you're in the middle of your node you're saying you shouldn't see a significant change in group size between 1x fired and virgin? As in the fireformed case volume increase, shouldnt affect much?
I load virgin brass with my known load and shoot it to bang steel. If you're new to shooting or new to that caliber than you start low and shoot your brass, clean it, size it, etc then do load development.
Typically, your charge weight isnt going to be in the middle of a node with virgin and 1x brass. It will be close, but you need to check and tweak your load. Again, group size has nothing to do with being in the center of your node..... Group size is tweaked after your found your node and load up charges in the center of that node.
Read Dan Newberry's OCW and follow it and you will be set
Typically, your charge weight isnt going to be in the middle of a node with virgin and 1x brass. It will be close, but you need to check and tweak your load. Again, group size has nothing to do with being in the center of your node..... Group size is tweaked after your found your node and load up charges in the center of that node.
Read Dan Newberry's OCW and follow it and you will be set
Dan Newberry's OCW Load Development System
Dan Newberry OCW or Optimal Charge Weight Load Development method or system for handloading, reloading, bullets, brass, powder, primers, accurate handloads.
optimalchargeweight.embarqspace.com
Padom is correct. Its those subtle distinctions that matter.
You want to find a region of where your rifle centers the bullets across a couple charge weights in the same spot so if its hot/cold, harder/softer, dirty/clean etc you wont start sending bullets to a different unintended location.
Once you find that consistent region (your optimal charge weight) you can adjust your seating depth to time the bullets exit for smaller groups.
Changing the internal volume of the case changes the equation and the results so you cant automatically assume anything will correlate between virgin and 1x fired.
I will develop a crude load for virgin brass so that I dont pigeon hole myself into loading a couple hundred cases that shoot horribly.
Then once the brass has all been fired in my barrel I will start load development in earnest.
I find that usually the 1x fired has a hair more internal volume so you can put in a tad more powder before over pressure issues.
Thats not a hard rule, Ive also had it not make any appreciable difference.
The issue is that you dont know until you test it for yourself in your particular configuration.
So what do you guys recommend for the person who puts 4-500 new pcs of brass into service? It's one thing to use up barrel life fire forming with a false shoulder and still have accuracy, another just banging away so you can do load dev with 500 rds down the tube. I have yet to find any Norma or Lapua brass that is not accurate the first firing. I've also made slr brass from Winchester garbage and did fine, sometimes you may have to adjust your charge is all.
The only diff from new to once fired brass is the energy wasted on initial case expansion, so more energy goes out the barrel on the 2nd firing.
This is not some insurmountable issue. Unless you fire new brass at it's upper limits.
The only diff from new to once fired brass is the energy wasted on initial case expansion, so more energy goes out the barrel on the 2nd firing.
This is not some insurmountable issue. Unless you fire new brass at it's upper limits.
You can develop a plinking load using Trailboss powder and a cheap bullet. This will let you shoot plates at 300 yards simulating 1000 yard trajectory and it wont put any wear on your barrel. Plus they kick and sound like a 22.
Id recommend you go with fewer cases for that barrel
I guess if that were the case I would go with a more in depth load development for the initial firing.
You're still going to be able to determine what the gun likes with regard to bullets, powder, etc. I don’t use large lots of brass because I’m not a match shooter, but I’d have no problem using a developed load in virgin brass and tweaking (only slightly) the charge to match the fired brass velocities, and running with it. Virgin shoots great, you just have to treat the necks exactly as you would your fired cases.
Sometimes duplicating neck tension or seat force of new Lapua brass can be next to impossible, lol
Like many, I try to buy enough brass to last the life of the barrel. As mentioned above, I'm not going to waste barrel life or components just to use once fired brass for load development. As Supersubes states, "Virgin brass shoots great" and I agree. I may have to tweek the load when all of my brass has been once fired but I've never seen it take more than a tenth or two +/- once all the heavy lifting has been done. Let me also add that the biggest difference between virgin and once-fired is neck tension. This can be controlled somewhat by using a mandrel on virgin brass.
I don’t think it’s that bad. Maybe it’s just me. If I cared a little less, id shoot virgin 100% of the time and sell the fired stuff.
The whole concept of Dan Newberry's OCW is to find a node where minor variations have little to no effect on the accuracy (POA and POI) so that variations such as virgin vs fired, powder lot variation, bullet lot variations, etc still give acceptable accuracy. Its more about hitting what you aim for than shooting the smallest possible groups.
AS far as pressure is concerned, the volume of a fired vs unfired case is very subtle and the The volume that affects pressure is the chamber volume, not the case volume.
AS far as pressure is concerned, the volume of a fired vs unfired case is very subtle and the The volume that affects pressure is the chamber volume, not the case volume.
If it was only chamber volume that affected pressure, there’d be no difference between virgin and fired brass with regard to pressure. That isn’t the case though.
I do agree the volume difference between fired/unfired is subtle.
New brass as much undersize to fit 99% every chamber..being undersize not chamber formed..brass will absorb some of the pressures while being fired the first time..IMO this is why fps slower with new brass same load after formed and resized..
I normally uses virgin brass for breaking in barrel getting scope zeroed and get data.so next time i shoot virgin brass from same rifle i can practice with it
I normally uses virgin brass for breaking in barrel getting scope zeroed and get data.so next time i shoot virgin brass from same rifle i can practice with it
It's not quite that simple, if so, if you small base sized brass, you could run hotter loads w/o ever getting hard bolt lift. It's still all pressure related, the more powder you stick in a case the more expansion you get, along with less springback.
Not trying to start an argument here, but have you measured pressure in each case? Different brands of brass will take up a different amount of chamber volume so pressure does very. But once you have sufficient pressure to fully expand the brass to fill the chamber the variations in pressure are minimal with the same brass. If you are looking at indications of overpressure, such as flattened primers or sticky bolts, you are already in an overpressure situation.
But, I should have stated that chamber volume is the primary factor and new versus fired brass is insignificant in normal cases.
Not sure I understand the small base die concept. My statement is that reguardless of sizing the maximum pressure will very only slightly, once there is enough pressure to fully expand the case to fill the chamber.
No, I don’t have pressure trace equipment. The purpose of this thread was to discuss load differences between fired and virgin brass. It takes nothing but a chronograph to tell there’s a difference between a previously fired/sized case in chamber, vs. a virgin case of the same make in the same chamber. Like I said in a post previous to the one you quoted, the difference is minimal, and I have no trouble getting good results with virgin brass. So I’m agreeing with you there.
Exactly. That's the biggest problem with virgin lapua, excess neck tension. I never just load it. I run them all through an expander mandrel otherwise that shit is like .005-.007 neck tension or more
Nobody said you cant/dont get good results with virgin brass. I do to.....but that's not my same load or center of the node with those now 1x cases which is exactly the OP's question...
Well let me throw this out there. My new .25cm alpha brass is very undersized, about .008 undersized. Undersized enough that the bolt wont extract an unfired case. Once you pull the trigger (empty case or not) it will extract. I have fired 20 cases and now the extract perfectly. I sized some 1x fired lapua cases to the same size as the virgin alpha brass and it does the same thing, wont extract unless the trigger is pulled so i know that the sizing is the issue. Now with that said, the 20 rounds that i fireformed (brand new barrel as well), the charge weight i used should have at least gotten me around the 2950ish mark if it were a broke in barrel. The average MV i got was 2840 at sea level. Is the under sizing of the case coupled with an un-broke in barrel the reason why its eating up so much MV? My SD was 5 and the ES was 13 so im happy with it, but that velocity is way way too low. What say ye?
Brass growing that much can eat up some velocity that should be going down the barrel, but I think once your barrel speeds up things will change in your favor.
Not quite, op just asked if he needed to add powder to retain what he had. Most of us said most likely you will pull powder. Also I disagree to some point, if you fire virgin brass at the low end of a node as you call it, it very well may end up being in the center or upper third of the node on once fired brass.
Developing a load before a barrel speed up will hose a guy more than virgin brass to once fired.
You're now adding info I never put out there. I never said anything about where his virgin brass load would be, low, high or completely out of a node, never stated any of that, you did. All I said was it "typically" youre virgin brass load isn't going to be in the "center" of the node with your 1x brass and may need some tweaking. You can disagree all you want but those are facts.
Now, how much it needs tweak all depends. Typically on caliber. For example, x47L shoots damn near everything good I put into it, no matter the bullet, virgin/1x, etc. vs say .223 or .308 which generally shows a noticeable difference on target down range shooting virgin lapua load vs 1x load in the center of a node.
Barrel speed up is also a whole different conversation. This is why I dont start load development until I have at least 100rds down the barrel. This is why Ill bang steel with a new box of lapua with a known load for that rifle with a new barrel.
My issue with Lapua virgin brass is the neck is too soft. After 2 reloads the groups shrink by 50%.
It’s not the powder charge but the bullet release that causes the inaccuracy.
It’s not the powder charge but the bullet release that causes the inaccuracy.
Thanks for the replies, whether it be to my specific question or slightly off, all the info is useful and appreciated.
One thing I hadn't considered was the barrel speeding up. Sending my stuff to the smith tomorrow, should have a 6.5x47 back in a few months.
300 pieces of brass on the way. Dies will be shortly after.
One thing I hadn't considered was the barrel speeding up. Sending my stuff to the smith tomorrow, should have a 6.5x47 back in a few months.
300 pieces of brass on the way. Dies will be shortly after.
Keystone Accuracy is a few weeks...
Keystone Accuracy – Accuracy starts here!
www.keystoneaccuracy.com
I do load development with 1x fired brass. Buy brass in bulk, then weight sort (put aside the bad outliers, very few in the case of Lapua and Alpha, likely other brands too), once you have a 2-3 grain weight delta in the batch of brass, the best load you managed to developed will work for the entire batch, at least until the lands erode enough to force you to re-optimize seating depth, or a new batch of powder arrive that is a little different. Then adjust powder charge to get back in the node (MV range where positive compensation helps you out).
I have heard stories of top level competitors who buy new Lapua brass who only shoot virgin brass (presume they FL size it to deal with Lapua’s typical bent necks), then sell it after one firing. Alha necks are not ever bent, due to far better packaging.
Urban legend or not, who knows!
