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Posted: 11/9/2008 9:55:41 PM EDT
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I have been reloading other calibers for a while with no real difficulties. I finally ordered my WOA varmint upper so I figured I should get all the stuff to reload for .223. I got the RCBS small base 2 die set and got it all set up. I full length resized the brass that I had put through a friends upper while waiting for mine to come in and everything looked good. I made a dummy round to help set up the seater and it looked good. I checked in the Sierra reloading manual and cross checked in the Lee handbook and picked out a good starter load for 68-69gr hpbt match bullets. I have sierra 69gr. MK hpbt, nosler custom comp. 69gr. hpbt, and hornady 68gr. hpbt. The load I picked is 25.3gr of Varget and is well below max pressure but when I go to seat the bullets the RCBS seater die is pressing a ring into the bullets about an 8th inch behind the tip. Also the load is not listed as compressed but it deffinately is.
Anyone know whats going on here???
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In 7.62, mil brass is thicker than 308. What kind of brass is it? I've noticed that some of my 5.56 milspec brass is thicker and slightly heavier than 223 umc?
Weight is a good way to check how thick a case is. I'm out of town or I'd throw up some case weights. |
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For me, anything over 24.5 gr of Varget is crunch time. By the time I get to 25.3 gr, there is major big time crunching going on. Reduce your charge or settle it into the case before seating. Basically, back off on the powder.
You can reduce the depth of the ring by regrinding the seater to conform to your bullet but what a pain! |
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Quoted:
ok, that makes more sense. either that or I need to switch to a ball powder. Anything I can do to make it not ring the bullet like that??? Other than get a comp seater.... Jer The problem is in the seater. If you take it apart, you will see the problem. The seater is made by drilling out the seater stem with a pilot drill, say 1/8". Then some arbitrary reamer is used to profile it to the bullet. Guess what? Most brands differ in ogive profile. That ring is the only contact and corresponds to that pilot hole drilled in the manufacture. What can you do about it? Polish it out? Sure! Get some fine valve grinding compound. Or some 400-600 grit aluminum oxide abrasive grit...valve grinding compound is easier, unless you also grind telescope mirrors, hint...apply this to a scrap bullet Chuck the bullet in a drill and force it into the seater stem, then turn it at a good pace. Just like grinding a valve, you will polish that seater stem. The copper bullet acts as a lap, holding the grit because it is softer. Every so often, recharge with fresh abrasive and remeber to PUSH, then turn. This forces the abrasive into the stem. You mighht need a fresh bullet, so be it. Just make sure it is the same bullet you will be using. Get additional stems for each bullet you want to use. Just do NOT use the bullets that were used with abrasive! Unless you want a scored bore! Make double damn sure to clean out the steating stem with paint thinner, ultrasonic cleaning or boil it in detergent, then oil. Keep abrasives away from reloading gear, save these bullets you will sacrafice. After polishing, crush the bullets to prevent use. |
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Quoted:
Thanks much guys. I'm thinking that with my 26" barrel I wont need quite so much powder to get the velocity I wanted. I'll be getting a copy of quickload and working from there but I might actually try reprofiling the seating stem. Thanks again, Jer Quickload is a means for estimating pressures, speeds, and so on. Don't use this for your primary or sole source of load information. If you believe your loads and guns produce the same pressure predicted by Quickload, I have a big ol' bridge up near San Francisco I'll sell you. You still have to approach the information with caution. Get reloading data manuals, or use the same ones I'll assume you already own since you've reloaded before this. Some compression of gunpowder is not necessarily bad in the right load combination. It probably improves accuracy in some combinations. But, it also pushes the bullets out of the case if the neck tension is too low, and that affects the length for feeding. You should also consider a more conservative start load, about below the maximum charge weight. |
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If you use a 4" drop tube with your charge Varget (note: your starting load is getting pretty close to max load) you will have no problem seating with the Nosler or Sierra match bullets, the Hornady 68's are real long for their weight and the jackets are very soft and easily crushed when trying to compress powder.
Larry |
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Did the lapping thing to my RCBS bullet seater and the ring reduced to almost nothing. And that was seating a 69 SMK over 26.6 grns of Varget at the high end of a OCW workup.
Wasn't overflowing the case, but it was pretty much full and the seating die needed to be adjusted to get the same seating depth as with lighter loads. OFG |
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ok, I got quickload and ran the numbers. I was looking for between 2750 and 2800fps. The sierra manual claims I need 25.3 to hit 2750. Now quickload, using my barrel length says I should be able to get 2792fps out of 22.99gr of varget with the sierra 69gr. Or with the hornady 68 I can get 2778 out of 22.53gr of varget. No, I am not using quickload as my sole source of data. I have the newest sierra manual and the lee book. I was using a hornady 68 in the picture. ok, so that is part of the problem. The hornady is almost .10 of an inch longer than the sierra 69. I will pull the 3 hornadys I loaded and dump the powder and try again at 22.2 - 22.4 - 22.6 for the hornady 68's and try 22.6 - 22.8 - 23.0 for the sierra 69's. Thanks for the help guys. I'll propably do the stem reprofiling myself. I have a drill press with vise so I can clamp the stem in the vise and the bullet in the chuck and between working the handle and reapplying the grinding compound it should go fairly quickly. Jer |
| If you do need your seater stem reworked in the past RCBS would fix it for you, I believe they still do. You just send them your seater stem and a sample of the bullets you are using and they rework it and send it back to you. Just and FYI in case you don't want to fix it yourself |
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Quoted:
You're cutting too deep when you chamfer the brass. You just need enough to take off the burr.
This has nothing to do with the ring on the bullet. But I don't think the ring will hurt anything.
Whenever I trim with the Giraud trimmer it chamfers like that, has no effect on the brass other than making it easier to seat the bullet; crimps still hold as well. |
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