I am not at all new to reloading, I have all the tools and equipment. I have loaded for 6PPC, 6BR, .308, .280, etc., but am new to loading and reloading belted cases. I have NEW/UNFIRED 7mm Remington magnum Winchester brass that I need to get ready to load. I tend to be perfectionistic when it comes to reloading, so I wanna do it right. So can some of you list the step by step proceedure you go through to get new/unfired belted cases ready to load or tell me where I can find the information ?
This is going to sound weird, but it is true.
I full size for my 7mm Weatherby because many of my previously fired cases do not fit in the chamber without some serious cam action. My empirical, unscientific evidence indicates that nearly 48% of my fired Weatherby cases will not chamber correctly without a full-length resize. I performed the following test to determine why the cases would not chamber correct after a large number of neck sized reloads with a correct OAL failed to chamber without “cramming.”
My test was to chamber fired brass and determine if a fired case would easily chamber in my Remington 700 Classic. First, I selected 3 sets of 5 cases for my tests. All tests were conducted with clean fired Weatherby brass with a case length under 2.549”. I then put the muzzle to the floor and allowed the cases to slide into the chamber until it went no further. Next, I attempted to close the bolt. About 50% of my cases did not chamber. After I discovered that most chambering failures occurred with Weatherby brass, I re-performed using a 100% sample of the Weatherby brass. During my subsequent testing is when I derived the 48% number for Weatherby brass. The R-P and PMC fired cases seemed to be much better, but they still did not always work properly.
The cases that were tested had been re-loaded with 68.5 gr. IMR4831, CCI Large Magnum Rifle primers, and topped off with 140 gr. Ballistic Tips. During the reloading process I did not sort the cases and test by lot nor did I notice if any of the cases were difficult to extract. All primers (and I know that this is not fool proof) were still rounded.
Since I have not had this trouble with either the 308 Winchester, 30-06, or 25-06, I surmised that maybe magnums were not a candidate for neck sizing. But then that conclusion runs counter to the experiences shared on this forum.
Were your once fired brass fired in your same rifle. Unless you have some serious hot loads the fired brass should go right back into the same chamber no problem. I load for 3 different Weatherby's and they all will rechamber their own fired brass no problem and no camming. You do have to give it a good shove sometimes to get the extractor over the rim but once it's over you cam just run them in and out and the bolt drops shut with almost no effort. Now if I try to chamber a fired brass out of my son's identicle 257 Accumark into my Accumark you can't get it anywhere near closing and you will need a cleaning rod to get that brass back. They are different. That said I use Lee collet dies on all my guns including these belted cases. 257Wby, 7mm Rem Mag, 300 Wby mag. Eventually they all need a slight cam action to close but the never get worse. My 3650 fps 100 grain 257 bullets have test brass at 10 loadings and they still chamber with a little bolt closing effort. Same for all my guns after about the 3rd reload. I quit full length sizing 15 years ago. I just keeps my lugs cleaned and lubed and resize them in the gun if you will. Doing this has also all but stopped the growth of my brass so my trimmer is about on full retirement. To answer the question of how to prep my new brass. I would measure them all to be sure they are not to long. A light chamfer to help get the bullets in without scratching them. Run them through the collet die to uniform the necks and then after the first firing I would trim them all to a uniform length, chamfer and then back to the collet die from then on. I personally do nothing with primer pockets ever. I'd rather spend my time shooting than at the bench.
__________________ Build a man a fire and you heat him for a day. Set him on fire and you heat him for life.
I went back to my computer records. My memory was wrong and you're right. The load I cited was not the one I was using. And the load I was using was too high according to the latest IMR suggested loading data. At the time I made the loads they were OK per my Speer Manual. Now I know why the Crony gave me an average of 3375 fps for the 140 gr. bullet. Thanks for the help and advice.
If you look at the different reloading forums, you'll find that the questions you're asking (about resizing belted magnums) are VERY common.
A few years ago I found that reloading belted magnums is a bit different from reloading other calibers. The belt creates a problem that effects resizing. Take a look at our website (below) and you can see the difference - and the solution.