head stamp

[toot]

I have a 6.5 JAP. rifle that came with ammo that is head stamped-NORMA-220-SWIFT.my question, is this ammo safe to shoot in the gun? it is what was shot in the JAP. be fore I got it.

[Tatume]

Look here:

http://castboolits.gunloads.com/showthread.php?125003-Forming-6-5-Jap-from-220-Swift

[Wayne Smith]

If the brass resizes in the 6.5 Jap die and fits the chamber of your rifle use it. I would check for incipient case separation inside the case first though. When reforming brass head stamp doesn't mean much. All my 8mm-06 brass says 30-06 on the head stamp. All my 25 Krag AI brass says 30-40 Krag on the head stamp.

[Mk42gunner]

I don't like shooting other people's reloads, you never know for sure that they knew what they were doing. The safe way to do this would be to break down the ammo that you have and then load it yourself.

As for the .220 brass used as a parent case, it should work if it has been converted properly. If in doubt, Grafs still lists the proper brass for around $30/50.

Robert

[Der Gebirgsjager]

All I can go by is what you said, "It is what was shot in the JAP before I got it." So, if it worked then, it should work now, if you're sure of that fact. If you have empties, they should be fire formed to the chamber. But, new proper brass is always preferable.

[toot]

Der Gerbirgsjager, yes to your question. I have fired the 220 SWIFT remotely with no ill affects, reloaded them my self. thanks for the help all you guys have added to my query. one quick question, why do all 6.5 JAPS. have a small bulge near the base of the brass after firing? it seams to go away after re forming in the die then reappears when fired?.

[Tatume]

It's because the case wall expands to fit the chamber, but the solid case head does not expand appreciably. What you are seeing is very common and is not a sign of an abnormality.

[1hole]

.... why do all 6.5 JAPS. have a small bulge near the base of the brass after firing? it seams to go away after re forming in the die then reappears when fired?.

That fired pressure bulge is common to all ammo, not just the Jap. And the looser/larger the chamber is and the smaller/tighter the FL sizer is, the more observable the bulge will be.

[Tatume]

Actually, the size die has nothing to do with extent of the bulge. Even if cases are neck sized the bulge will be the same. The size of the bulge is determined by the difference in the diameter of the chamber and the diameter of the solid cartridge case head.

[1hole]

Actually, the size die has nothing to do with extent of the bulge. Even if cases are neck sized the bulge will be the same. The size of the bulge is determined by the difference in the diameter of the chamber and the diameter of the solid cartridge case head.

The issue here isn't how/why the bulge occurs, it's the fact that a minimum diameter tolerance FL die can and will reduce that solid case head bulge to its original (unfired) size.

[Tatume]

The issue here isn't how/why the bulge occurs, it's the fact that a minimum diameter tolerance FL die can and will reduce that solid case head bulge to its original (unfired) size.

It makes no difference if the case is sized a lot, a little, or not at all. That has nothing to do with the bulge. Unsized cases, neck sized only, still exhibit the bulge. The bulge is the difference between the diameter of the chamber and the diameter of the solid case head.

[1hole]

... The bulge is the difference between the diameter of the chamber and the diameter of the solid case head.

So, the actual fit between the case's heads (actually, the rapidly thinning part of the head's transition from the solid web to the body wall) and every FL sizer ever made doesn't matter so, in your world, no visible pressure bulge will ever change?? I disagree. :)

[Tatume]

The solid case head is not sized in the FL die. The case wall will always expand to fill the chamber. The case head will not. The difference is the bulge.

[Wayne Smith]

And one solution is to wrap the case head with a couple of layers of Scotch tape first. This centers the cartridge in the chamber and the expansion is equal all around. From then on neck size and your case will fit the chamber.

[1hole]

The solid case head is not sized in the FL die. The case wall will always expand to fill the chamber. The case head will not. The difference is the bulge.

Yes, that's the reason the case bulge occurs. No one has suggested sizing the solid head and, even if that could happen, it would make the bulge more pronounced the next time it's fired.

All that's needed is to size the swollen wall back to original size, not make the head smaller. The wall bulge is well forward of the head, the only reason it's there after reloading is because most sizers just didn't contact it. But, individual die and chamber tolerances occasionally do stack in ways that the pressure bulge will indeed be sized back to where it started; that's not common but it's not nearly as impossible as you suggest and sizing the solid case head plays no part in it.

I have to wonder, have you ever used a "Small Base/Small Head" sizer? Reducing, or eliminating, that pressure bulge is their reason for being but even they do not "size" the solid case web.

That's enough about case bulges, this issue is way off topic.