The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading How important is it to weigh cases?Go | New | Find | Notify | Tools | Reply | |
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I have been scrounging up cases for a newly barreled rifle in .300WM. In doing so I have come up with some RP, WW, and DWM( Speer Blount) cases. I started weighing them to see how much difference there was between mfg. Real eye opener! I've never bothered to weigh cases as I usually get enough new brass together at once to not need to,... or so I thought. The Win & Rem cases are roughly the same weight. There is a big difference in weight though. I found variations of as much as 8.2grs within the same mfg. The DWM cases are much heavier than the others and look similar to Lapua or Norma in the brass still shows annealing color. Is the difference enough to be dangerous? I can see not mixing the heavy cases in with the lighter ones, but even within mfg there's over 8grs of difference. | ||
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Best accuray is with brass of the same lot number & weight. Brass that is heavy may produce more pressure than lighter brass. A rifles chamber has a volume running from the bolt face to where the bullet seals the bore. Place more mass in that volume, pressure and velocity may go up. | |||
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I could never understand how you would know where the weight difference is. You could have two pieces of brass that weigh exactly the same and one have a thicker base and the other thicker walls, I have had loads as much as 5.0 grs difference and shoot to the same point. same powder and bullet. I never much worried about the weight. light crimp to get consistent burn rates or not to crimp and used a lee collet die with the mandrel turned down a couple thousands. I had some issues with bullet set back full boat loads 220gr bullets. Dave | |||
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The only brass cases that I sort by weight are for my match guns that I shoot out to 1,000 yards. I only use one brand/lot of cases at a time for my hunting guns. Frank "I don't know what there is about buffalo that frightens me so.....He looks like he hates you personally. He looks like you owe him money." - Robert Ruark, Horn of the Hunter, 1953 NRA Life, SAF Life, CRPA Life, DRSS lite | |||
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I have killed lots of critters using mixed brass. It all depends on what you are looking for. | |||
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No one can really answer because you are talking in generalities. DWM is much heavier meaning 2 grains or 15 to 30 grains heavier? Keep in mind that brass is 8X more dense than powder so it takes 8 grains of brass to take up the same room as one grain of powder. | |||
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I don't worry much over case weight, life's too short. Anymore 'bout all I do is separate cases by head stamp. And, as the saying goes, your mileage may vary. | |||
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Yup. Aim for the exit hole | |||
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Headstamp, period. Prep them all the same way and forget the few grains difference. Ken.... "The trouble with our liberal friends is not that they are ignorant, but that they know so much that isn't so. " - Ronald Reagan | |||
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If you keep shots to under 250 meters, you should have no problems - an accuracy of 2" groups will kill any deer. BUT you have other potential problems with such mixed brass. 1. How many times was each case fired? You could get into trouble if you are using brass that someone has discarded after shooting many times. 2. What is the case capacity of each type? You will get variance in capacity & therefore pressure & velocity. Hot loads could become dangerous in some brands of brass unless you develop the loads for each brand of brass. 3. You will never get top accuracy with such mixed loads. Honestly - you are better off getting 50 or 100 new cases and developing your best load & using that lot of brass for 10 reloads! In the final analysis you will find that you save money by not wasting powder, bullet and time on mixed brass experiments. Good luck JMTBW "When the wind stops....start rowing. When the wind starts, get the sail up quick." | |||
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SR4759 Thanks did not know this. I agree buying new brass and tracking the number of firings is best. However, I have been unable to buy new as it has been unavailable. Win cases (10) 241.0gr to 249.8gr Rem cases (60) 240.9gr to 250.1gr Fed cases ( 4) 254.4gr to 254.7gr DWM cases ( 6) 273.3gr to 276.8gr I realize the sample size could be an issue but it is notable the range of weights within brand and from brand to brand. At this point I'd not be afraid of mixing Rem & Win but the Feds and DWM cases could be an issue. | |||
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if you weigh the cases, the bullets, the powder and the primer, convert it into pounds you can figure out just how many rounds it takes to weigh in at the 11#'s the airlines let you take    | |||
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Nakihunter touched on it but let me restate. It doesn't make any difference what one case weighs compared to the next, what matters is the volume difference. If you want to be exact weigh how much water or powder or sand or whatever fills each case and sort them out. Personally for hunting applications I typically use the same headstamp and lot and call it good so check the Rem cases you have and if they look good, use those for hunting Have gun- Will travel The value of a trophy is computed directly in terms of personal investment in its acquisition. Robert Ruark | |||
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Unless the weight difference is hiding in the rim on something like a .45-70 or .348, a heavier case is going to have less volume unless you manage to break the laws of physics. It is just more convenient to weigh a case than measure the water volume. And you can only get a good idea of the relative internal volume if all cases have been fired in the same chamber. As Nate showed above you can get a huge swing in weights with some brands. It has been known for more than 50 years that DWM is heavy and WW is usually light.
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Probably overly anal, but I've always weighed ten or so cases from every new batch to get an average, then sort the rest of 'em by weight. For my hunting rifles I try to get them within 2.5 grains of each other; 1.5 grains on the target rifles. Then I mark the ejector grooves of the cases within each weight range using different Sharpie colors. Dunno' if it makes a difference or not...  but it gives me one more thing to take out of the accuracy equation.  Typically, I've found R-P brass to be heavier than W-W. Federal and Lapua Match stuff is very consistent - one batch of Federal .223 had only one case in 100 that was more than 1 grain off the average. R-WEST Load smart. Load safe. Triple check everything. Never use load data from the 'net without checking against known, pressure tested load data. Typo's happen!! "the spotlight of truth will cause the cockroaches of deceit to run for cover every time" Rush Limbaugh "just because you're paranoid doesn't mean they aren't following you" "never turn on a blow dryer while holding a cat" "genius has limits, stupidity does not" | |||
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If you are loading a load that is so hot that even a 8gr swing in case weight is gonna put you in danger of missing fingers and hot, smoking shards of rifle barrel sticking out of your head, please don't sit next to me on the firing line. While I don't weigh cases, I don't mix head stamps. And I "fire cull" my brass as I'm shooting it. If I have an unexplained flyer, I mark the case and give it another chance. If it is unacceptable the second time around, it goes in the scrap bucket. How tightly you cull your brass is up to you and what applications you plan for it. Aim for the exit hole | |||
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Cartridge weight only makes a big difference if you are loading at or near maximum pressures. For every 7 to 8 grains of brass the powder charge should be reduced by 1 grain in the heavier cases. Using heavier brass is the same as seating a bullet deeper in the case - there is less room for the powder and as a result the pressures go up. Speer, Sierra, Lyman, Hornady, Hodgdon have reliable reloading data. You won't find it on so and so's web page. | |||
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Regarding this issue I agree with Blacktailer and this is why. Both my weighing and case volume measuring as well as the same conducted by RIP. Cases were all manufactured by Lapua, all have the relating yLapua headstamp. Only difference between the cases is that one random selection of cases were twice fired 338 Lapua commercial cases and one selection of cases were twice fired 338 Lapua military cases. The military cases were of a much harder material and weighed an average of 8grs heavier than the commercial case. The external dimensions of both sets of cases were identical with the same case by case average variance. Case capacity of both commercial and military brass were identical with the same case by case volume variance. All weights and volume measurements were taken after the cases were fire formed to .500 caliber, FLR'd, and trimmed to the same case length. RIP did all final firing using the same 430gr .500 caliber CEB MTH bullets, same Federal primers, and same charge of 100grs of H322 powder. Velocity delivered by both sets of cases fell into the same velocity and shot by shot variance; accuracy as well... So, I have to agree with Blacktailer that matching case volume is the most important factor. Jim  "Life's hard; it's harder if you're stupid" John Wayne | |||
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Who is RIP and why are you taking RIPs word for what you got? It seems that you did not do the work or the reloading. You based your agreement off of something that you did not do and took someone's word for it.
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Simple, RIP is Ron Berry and I know Ron Berry. You I don't know. I did measure, weight, and verify case volumes of once fired 338 Lapua - Lapua brand mfg - commercial and military brass that I purchased from a resale vendor. Plus my data matched RIP's once fired 338 Lapua data within the same case variance so why should I disbelieve his .500 caliber data using the upsized 338 Lapua case. Jim "Life's hard; it's harder if you're stupid" John Wayne | |||
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If the external dims between the commercial and military brass was the same and the internal capacity between the commercial and military brass was the same, where did the 8gr difference come from? Back in the day, most reloading books mentioned that military brass was heavier than commercial WITH THICKER WALLS AND LESS CAPACITY, and a reloader should reduce his loads a couple of grains or so. Perhaps this is where segregating your brass according to head stamp got started. Aim for the exit hole | |||
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wasbeeman, Generally I believe that you're correct, military brass that is heavier than relating commercial brass is due to thicker case walls and/or head. In our case, RIP sectioned a randomly selected a commercial and a military piece of brass and they measured no difference in head or case wall thickness; photos were posted in the 12.7x68 BB forum thread. Our supposition was that the exact mix of materials used in the manufacture of the commercial and military brass is slightly different. When both necks are freshly annealed the military brass was 'harder' than the commercial brass when run into the resizing die. I personally believe that reloaders would be best served by checking 'all measurement variables' relating to their cases if minimal velocity variance and maximum accuracy is their end desire. Electing to only go by one variable May lead to failure in this quest. Jim "Life's hard; it's harder if you're stupid" John Wayne | |||
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Wasbeeman the trouble is no one knows if that is the case, especially those guys that don't consider case weight of any importance. I have seen one brand of case vary 17 grains. It was clear from weighing them they were from two totally different populations.
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You need to consider the laws of physics are at odds with what you say. There is NO magic. I don't think you will find a cartridge brass alloy with that much variation in specific gravity. I think there was some variation in chambers, sizing dies or actual measurements.
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BigNate Try these guys http://www.reloadinginternatio...+mag&Search=+Search+ for your brass. They are very good to deal with as far as I am concerned - from NZ. They carry stock of CEB bullets - which Midway etc. do not. Good luck. "When the wind stops....start rowing. When the wind starts, get the sail up quick." | |||
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I don't mix brands or brass as some like Remington and some mil. brass is considerably thicker walled and will run pressures up if you use the same max load as say a WW case...I drop about 2 grs. for some milsurp brass I have and for Rem. cases in most calibers..I suppose were talking about max loads, it wouldn't make much difference with lesser loads. Years ago I weighed cases and nothing ever changed so have not done that in years..Maybe a good idea for bench resters where every mm may mean a win or loss, don't know.. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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I don't weigh my BR cases, but Lapua brass is very good. I'm like Ray, on my hunting rifles I use one brand of brass. Brass is such a small part of the loading price, so I use Lapua, Norma, RWS, and other premium brass if it is available for my particular chamber. Case weight is the least of my worries. I believe a good barrel, good bedding, great trigger, and great glass is most important other than range time. | |||
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The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading How important is it to weigh cases?
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