RE-sizing query

[adam]

I have just read an article about re-loading and its prompted some thought. It says that you should run your cases into a full length re-sizing die, to return the case to its original dimensions. I thought you needed to fire form the cases, to match your rifles internal chamber dimensions, so surely re-sizing them will defeat the object of fire forming?
Please enlighten me or put me right!!
Thanks again
Adam

[foxwhistler]

Are you using brass you`ve allready fired in your rifle?

[skipper]

New brass or brass fired in someone else's rifle may or may not fit your rifle chamber. It may be too fat or too long from base to shoulder. This is when you want to full length size. Then, once you fire it in your rifle, it is custom fitted and you don't want to full length size it again.

If you shoot a black rifle you might want to full length size every time so it will feed reliably. Aside from that, you are correct in thinking that you want to preserve the fire formed fit by just neck sizing.

[adam]

foxwhistler:
I'm not yet re loading its just im doing some reading up before I buy the equipment and start. I'm hoping to use the rem brass I have kept from my factory ammo. The only question mark i have over those is that they have a funny sort of cimp! Almost like little notches around the neck. The few Hornady cases I have dont have this.

This question to all;
I noticed that the factory bullets have a step down in diameter to which they are pressed down to in the case. On new bullets for re loading they dont have that step down in diameter. Does this mean I will have to open up the inside neck diameter of my cases to accept the new bullets for re load?
Sorry if these questions are trivial!!!

[skipper]

The only question mark i have over those is that they have a funny sort of cimp! Almost like little notches around the neck.

That is a little scary and possibly dangerous if it's what I believe it is. My first thought was that your brass is long enough to be shoved into the leade to the lands. The leade is where the lands are tapered off to the diameter of the freebore. If your brass is entering this section of your barrel those marks are from the lands themselves. That would mean that the lands are clamping down on your bullets as you close the bolt. I've let some of my Remington brass grow until I saw those marks and it scared me to think that I let the brass grow that much without checking. My Remington brass stretches a lot every firing. The bottom line is that if those marks are what I fear they are, that's dangerous. If your brass is being forced into the leade and clamping down on the bullet, the pressure is going to spike before the bullet breaks the grip. Please, check it out.

I puzzled because you said you don't reload so I'm wondering how your brass could be long enough to even reach the leade. Is this factory brass that has the marks? If you have a set of calipers, measure one of those Remington cases and let us know how long it is.

I'm not aware of any bullets that have a step down in diameter. You may be looking at a cantilever groove in your bullets used for crimping. This is just a groove and not a step down in diameter. See the picture below.

[foxwhistler]

Adam,I`ve sent you a p.m.

[jo191145]

adam
If those funny little notches are horizontal it sounds as if your Remington factory ammo came with a factory/ military crimp. The two boxes of Remington factory ammo I have do not have any such crimp. That doesn't mean its not possible though. We must remember your on the other side of the pond and manufacturers do sometimes change things up. For instance.

Hornady factory ammo I bought in 2004 all came with a roll crimp. This might be what the step down is you are referring too. I had four cases of ammo and never bought more until I ran low on 40's. I bought one box just to see if it shot as well as the old stuff. It came with no roll crimp. Not actually sure if Hornady has done away with the crimp or it was a fluke or they simply were trying without it.
It sure did'nt shoot very well at all compared to the old stuff in side by side tests.

Be that as it may you will not be crimping when you roll your own. Yes it is possible to crimp with the correct dies but I repeat. You will not be crimping when you roll your own

Bad news is, if in fact I'm correct and your Remy brass has been factory/military crimped its reloading usefulness is somewhat diminished. Yes you can definitely reload and shoot it but personally I would prefer to use something else.
The Hornady should be fine.

If the notches are not horizontal and do not appear on an unfired round then you've got a problem.

[WrzWaldo]

foxwhistler:
The only question mark i have over those is that they have a funny sort of cimp! Almost like little notches around the neck.

How many notches are there? I know the 17 Firball Remington factory loads I have shot were crimped. There were 4 "little notches" if I recall correctly.

[skipper]

Can you post a picture of those notches?

[foxwhistler]

I`ve got some 40 grain Remi V-MAX in my cabinet but unfortunatly my camera wont focus down far enough for a decent picture.
The only lines i can detect on my ammo is where it is crimped,and there are impressions where there are gaps between the 4parts of the crimping collet.
I hope this makes sense to other people,because when i read it back it dont make a lot of sense to me.

[jo191145]

foxwhistler
Makes perfect sense. Thats a factory/military crimp. Can you confirm this is 204 Ruger ammo?

FWIW I'm calling it a factory/military crimp because Lee calls it a factory crimp. Lots of military fodder uses the same crimp also. The other style crimp is a roll crimp. Does much less permanent damage to your brass. Normally used in conjunction with a canellured bullet such as in Skippers picture. Not always though.

[foxwhistler]

Yes,.204 ruger 40 grain remington accutips.

[jo191145]

Thanks foxwhistler. Now if Adam will verify he also has these marks before firing we'll know hes safe. Brass measurement would be nice too. Seeing as hes not yet reloading he might not have a caliper though. I sure never had the need for one before reloading

[LilCal]

Adam, I think I know what you are talking about concerning the factory remington crimp marks. Take a look at this picture I took of a 17 Remington factory load using 25 gr. Hornady bullets.









LilCal