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Posted: 3/23/2014 5:57:18 PM EDT
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Help needed. I'm resizing once fired LC 308 brass. After resizing brass with my Hornady die I check to see if it fits my Lyman case gauge, it does. I then check it with my RCBS 308 precision mic gauge, the RCBS mic reads 0 which should be 1.630 perfect reading. I then trim case to 2.005. This should be a perfect fit, but when I put the case in my Rem 700 the bolt is hard to close WTF. I tried the case in my friends Howa 308, same thing.
I have a small base die, I then run the resized case through the SB die and then check headspace. The SB die pushes the headspace back 10 thousandths, for a reading of 1.620. My case will now work in my Rem 700 and the bolt closes easy. Why is the SB die pushing headspace back 10 thousandths, it is a straight walled die no neck sizing. This is bugging the shit out of me, what say the hive. |
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Are you full length resizing or just resizing the neck?
RCBS Small Base 2-Die sets are useful for reloaders loading for semi-automatic, pump action and lever action rifles to help ensure that proper functioning. Small base sizing dies size brass to minimum specifications and help to ensure that cartridges will chamber every time. Due to the fact that this product sizes more than regular dies, it is crucial to have a sufficient amount of high quality lubricant to prevent stuck cases. •Small base sizer dies are usually required for reloading ammunition to be used in automatic, semi-automatic, pump, slide and some lever-action rifles. •These dies size the case somewhat smaller in diamter and also set the shoulder back slightly more than a Full-Length sizer die to ensure poper functioning in the actions of these rifles. •NOT RECOMMENDED FOR AMMUNITION IN BOLT-ACTION RIFLES. |
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Quoted:
I am full length resizing. Check your dies, make sure it says full length (FL) I bought a set of dies and assumed they were full length and was having the same problem. It wasn't until I rechecked my dies that I realized I was using the wrong type. Once you resized your brass using the small base and fire them thru your rifle. The brass will fire form to your chamber and than you should only have to resize the neck. |
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Using an RCBS SB die? If so, they do neck size, and will bump the shoulder back. At least mine does.
I have both the RCBS SB FL set, and a regular RCBS FL set. I use the SB set on the brass I saved from when I had an M1A, then after firing in my 700, I use the regular set. |
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Quoted:
I just checked my SB die. It is a Redding die and it does have neck sizing. I'll back out the SB die until I get the proper headspace. I will be shooting these rounds thru my DPMS 308 GII hunter. I am using my Rem 700 as a gauge. The chambers in your two rifles will be different. Using your 700 as a gauge, unless you have measured the actual chambers, and know them to be equal (HIGHLY unlikely), what you ought to be interested in is whether the rounds feed and chamber in the rifle you intend them to be shot through. For the semi-auto, you always need to full-length resize, and you only need to set the shoulder back perhaps 0.003" or so from a case fired in that chamber. For the bolt gun, once a case has been fired in the chamber, you can neck size for at least a few iterations before having to set the shoulder back. If your SB die is properly adjusted, the case should feed just fine in any proper chamber. Does your 700 chamber factory ammo easily? Be sure to follow the instructions that came with the die, including turning the die a little past contact with the shellholder in order to cam it over, removing all dimensional slop from the press-ram-shellholder-die assembly. |
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Why is the SB die pushing headspace back 10 thousandths, it is a straight walled die no neck sizing. IIRC, SB dies are not straight wall dies. Where did you come up with that? The SB dies that I use, push the shoulder back to whatever I intend by establishing where the dies sits elevation-wise in the press frame (to the point where the shell holder pushes into the bottom of the die body.) |
| Bumping the shoulder back an .010 is useless if it is stretched .020. You need to bump it "all the way". Turn the die a full quarter turn past touching the shell holder and try again. The shoulder may end up need bumping much further than .010 the first sizing after being shot in a loose machine gun chamber to get it back into spec. |
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You might try trimming the brass a little shorter.
Right now you are at the max length. SAAMI specs for .308 case length is 2.005''. If your 700 chamber is tight the case mouth might be getting pinched. Measure the length of a case before and after you run it through the SB die. You said it is setting the shoulder back .010'', it may be shortening the case by that much too, which is why they chamber afterwards. |
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