FL resizing questions

[OmegaRed]

New to reloading. Reloading a .270 6br.

I'm a bit confused as just about everything I have read has another thread somewhere that is conflicting. Some people say neck size, some people say FL to bump the shoulder .001-.002, some people say FL won't size all the way down. So in that case, do they FL to bump the shoulder and then neck size in another operation?

It doesn't make sense to me that FL resizing gets you more life out of your case, as I've read it in other threads. After you fire your case, isn't it a close to your chamber size as it could get? Isn't this essentially fireforming?

Also, I have a set of dies that came with the gun. I'm not seeing any bushings, is there a way to tell if it's a bushing die or not, or if it has been sent away to be honed for this gun?

 

[Lapua40X]

Brass "grows" when it is subjected to pressure (e.g. chamber pressure). Put a piece of brass on an anvil and hit it with a hammer; it's larger than it used to be. It also has a "memory" that allows it to spring back, if only slightly, to approximate it's former shape and size. As it is shaped and reshaped by pressure in becomes harder (straing hardening, aka work hardening) and less capable of recovering its former shape and size. That's why reloaders anneal their brass to restore its ductility. But I'm sure you can imagine that, because only the neck and shoulder are annealed, the remaining portion of the case does not share the same characteristics (hardness) as the top end.
Some reloaders prefer to size necks and "bump" shoulders back rather than full length resize the case ("top end" resizing). As I understand the theory, whereas full length resizing of cases over stresses the brass throughout its entire length (strain hardening) and shortens the life expectancy of cases, if we only neck sizie and shoulder bump we can lengthen case life because periodic annealing restores that portion of the brass that is work hardened in each "top end" resizing process. There other reasons but I don't personally subscribe to any of them.

IMO, your remark that "It doesn't make sense to me that FL resizing gets you more life out of your case" is credible because repeated compression and expansion of the case should (at least theoretically) strain harden the brass. Nevertheless, I prefer to FL resize because I want uniformity in all my loaded ammunition. IMO it assures more consistency in performance and I can be confident that ever round will chamber.

Not all sizing dies use bushings. Some are reamed to honor SAAMI specs, others are custom reamed for a particular custom rifle, some are made to SAAMI specs with an enlarged area at the top of the die where a bushing (usually available in increments of .001) can be inserted to provide the neck clearances preferred by a user.

If your dies came from a commercial supplier (RCBS, Hornady, etc.) they are probably factory dies reamed to SAAMI specs. If they are bushing dies the top of the sizing die will be removable and a small round bushing http://www.midwayusa.com/product/888336/redding-neck-sizer-die-bushing-336-diameter-titanium-nitride will be inside the void.

 

[barefooter56]

New to reloading. Reloading a .270 6br.

I'm a bit confused as just about everything I have read has another thread somewhere that is conflicting. Some people say neck size, some people say FL to bump the shoulder .001-.002, some people say FL won't size all the way down. So in that case, do they FL to bump the shoulder and then neck size in another operation?

It doesn't make sense to me that FL resizing gets you more life out of your case, as I've read it in other threads. After you fire your case, isn't it a close to your chamber size as it could get? Isn't this essentially fireforming?

Also, I have a set of dies that came with the gun. I'm not seeing any bushings, is there a way to tell if it's a bushing die or not, or if it has been sent away to be honed for this gun?

OmegaRed,
The neck and /or the full length die will have an "S" like "S neck die" In the description found on the die. As far as any other customization of the die you will have to contact the previous owner. When you fire a cartridge it does get fire formed to your rifles chamber ( it may take more than one firing though ). The full length sizing being done is "minimal" full length sizing so you don't over work the brass and it chambers every time. Hope this helps!
Take care,

 

[OmegaRed]

Brass "grows" when it is subjected to pressure (e.g. chamber pressure). Put a piece of brass on an anvil and hit it with a hammer; it's larger than it used to be. It also has a "memory" that allows it to spring back, if only slightly, to approximate it's former shape and size. As it is shaped and reshaped by pressure in becomes harder (straing hardening, aka work hardening) and less capable of recovering its former shape and size. That's why reloaders anneal their brass to restore its ductility. But I'm sure you can imagine that, because only the neck and shoulder are annealed, the remaining portion of the case does not share the same characteristics (hardness) as the top end.
Some reloaders prefer to size necks and "bump" shoulders back rather than full length resize the case ("top end" resizing). As I understand the theory, whereas full length resizing of cases over stresses the brass throughout its entire length (strain hardening) and shortens the life expectancy of cases, if we only neck sizie and shoulder bump we can lengthen case life because periodic annealing restores that portion of the brass that is work hardened in each "top end" resizing process. There other reasons but I don't personally subscribe to any of them.

IMO, your remark that "It doesn't make sense to me that FL resizing gets you more life out of your case" is credible because repeated compression and expansion of the case should (at least theoretically) strain harden the brass. Nevertheless, I prefer to FL resize because I want uniformity in all my loaded ammunition. IMO it assures more consistency in performance.

Not all sizing dies use bushings. Some are reamed to honor SAAMI specs, others are custom reamed for a particular custom rifle, some are made to SAAMI specs with an enlarged area at the top of the die where a bushing (usually available in increments of .001) can be inserted to provide the neck clearances preferred by a user.

If your dies came from a commercial supplier (RCBS, Hornady, etc.) they are probably factory dies reamed to SAAMI specs. If they are bushing dies the top of the sizing die will be removable and a small round bushing http://www.midwayusa.com/product/888336/redding-neck-sizer-die-bushing-336-diameter-titanium-nitride will be inside the void.

Bravo. Clear and concise. Thank you very much for your post!

 

[OmegaRed]

OmegaRed,
The neck and /or the full length die will have an "S" like "S neck die" In the description found on the die. As far as any other customization of the die you will have to contact the previous owner. When you fire a cartridge it does get fire formed to your rifles chamber ( it may take more than one firing though ). The full length sizing being done is "minimal" full length sizing so you don't over work the brass and it chambers every time. Hope this helps!
Take care,

The former owner passed, so no luck there.

Just so I'm clear then, if you FL resize, then you don't need to neck size correct?

 

[Lapua40X]

The former owner passed, so no luck there.

Just so I'm clear then, if you FL resize, then you don't need to neck size correct?

Look inside your FL die. If it looks like this:
http://bulletin.accurateshooter.com...th-dies-neck-sizing-dies-and-small-base-dies/
it resizes the case body, shoulder and neck simultaneously.

 

[ireload2]

OmegaRed
You probably need to get someone to look at your dies and rifle and sort out the die and chamber dimensions for you.
Reloading a bench rest rifle can be very simple if everything is right. If it is not right you will need to change something and you cannot tell right from wrong without gauge pins and a micrometer or 3. You might be better off loading a few rounds for a common hunting rifle to get the knack of it. If you have never loaded any ammo before you will not have a good appreciation of the precision or even what .001 means in the real world.