.300 WSM resizing question

[boobap]

OK...I have a Lee aniversary press, with Lee shell holder and a RCBS full length resizing die but i keep getting a ring around the bottom of the case like it is not resizing the entire case??? If you look between the two red lines you will see the issue. The cases will not fit into my rifle and it is pissing me off. Is it the incompatability between Lee and RCBS, or is it that RCBS is not all it is cracked up to be...? The case is traveling its full length and the shell holder is bottoming out on the die, but... please help if you can.

Thanks

 

[moosehunt]

From l-r, cases 2, 4, & 5 sure look to be exhibiting case seperation from excessive stretching. Generally, you expect to see this after several reloads, particularly if full length sizing. Based on what you have said, I surmise that these are once fired grass? Are they from your gun? If so, they should chamber without sizing--they came out, didn't they? Check the length of fired brass before trimming, sizing. To be meaningful, you really need to pull a bullet on one of the originals and measure it's case length. You may have a bad (long) chamber that allows excessive stretching--but they should still chamber. All this comment is based on the idea that the brass is your once fired factory brass from your gun. I conclude that based on this being a new set-up for you. If those speculations are not correct, clarify and we can go from there.

Dies don't size clear to the bottom of the case, and based on your photo, it appears they are sizing down to about the proper area--can't tell for certain, but looks OK.

 

[USSR]

boobap,

First, the ring at the web of the case is normal; that's the furthest point on the case that the die is sizing. When a resized case doesn't chamber in your rifle, it's usually one of two things: either the shoulder is not back far enough; or the web portion of the case is too big. So, to determine which it is, mark one of your resized cases that don't fit with a magic marker in the web portion of the case (where the "ring" is), and on the shoulder. When you then try to chamber it, it will "scuff" the part of the case which is causing the problem. If it turns out to be the shoulder, then you must screw your die down further into the press. If the web portion of the case is being scuffed, then again, you must screw your die down further into the press, but I would check your case headspace with a tool such as the RCBS Precision Mic to be sure you are not bumping your shoulder back too far.

Don

 

[boobap]

It is not my brass, i bought it as "once fired" brass. My gun is a Tikka, not sure if that makes a difference. Tonight after work i will go home and take some measurments and post that...anything else that would be helpful to know that would make this easier to troubleshoot? Thanks for the help.

 

[Doug b]

Whats your trim length?

 

[boobap]

I always trim after sizing...should i do it the other way?

 

[USSR]

I always trim after sizing...should i do it the other way?

Nope, always trim AFTER sizing. But that has nothing to do with your problem. As previously stated, use the magic marker to find out where on your resized case is preventing the case from chambering.

Don

 

[moosehunt]

Based on the info supplied, I'd wager that the once fired brass you purchased was fired in an oversize chamber and the bases are expanded beyond where your die will reach (not just your RCBS; any die). One fellow suggested lowering your die, but you already pointed out that the shell holder was bottoming on the die, so lowering the die does nothing. If the brass didn't come from an oversized chamber, another remote possibility is that it was loaded way hot and expanded the web, which again, is below where a die can reach to size. Good example of why to buy new brass, or at least factory ammo to get your brass. In fact, I'd suggest that you buy a box of factory--I know, it takes a mortgage--then try loading that brass after firing it in your gun.

Another possibility, and it's not bad, is that you have a tight chambered gun. If so, it will become extra important that brass only be fired in your gun.

Incidently, if you had access to the rifle that brass was fired in, I'll bet it will fit in it.

 

[boobap]

Based on the info supplied, I'd wager that the once fired brass you purchased was fired in an oversize chamber and the bases are expanded beyond where your die will reach

What is an oversized chamber? Do they do this on purpose, or is it just the differences in manufactors?

 

[moosehunt]

Two ways to answer. Everything has what are called tolerances. One can say that an entity is supposed to be a specific size, but it is never exact, actually, it can't be. Generally, things are to be a measurement X +/- (plus or minus) Y. Y is the tolerance. Hypothetical example: 0.750 +/-0.003. Everything that measures 0.747 to 0.753 is "in tolerance", i.e. acceptable. Rifle chambers, as everything, have tolerances. A chamber on the small end of the tolerance (maybeso yours) likely may not accept cases fired in a chamber on the large end of the tolerance (maybeso the source of your brass), but both chambers are in tolerance, i.e. acceptable. Secondly, a chamber may well be outside of the tolerance, but still goes out the door, a true oversize chamber.

Actually, from a machinest standpoint, firearms manufacturing uses very "loose" or "open" tolerances, at least basic factory guns. Some custom stuff tightens tolerances considerably, but even then, they are generally rather loose from the viewpoint of a machinist. The top end custom gunsmiths are just good, finicky machinests that apply their trade to guns.

 

[boobap]

Since that brass is useless to me and all appears to be in good condition, should i try and sale it, or just scrap it? It is roughly 300 pieces, so it could make someone really happy. Or would you guys think that it would be a "scam" to sale it? .300 WSM "once fired" brass is kinda difficult to come by cheaply, so I really wouldn't want to scrap it, but on the other hand I don't want some one to have the same issue i am having. Let me know what you guys think.

Also, since my dies (RCBS full length) will not size it back to "normal" size, does this mean that the brass will not work for anyone, or just the "undersized" chambers?

 

[moosehunt]

Pretty hard to answer--not enough info known. What you really need to do is some measuring--this brass and some fired in your gun. You need a micrometer to do this right, not just calipers. Your chamber may be very selective because maybeso it is extra tight, or maybeso this brass came from an extra large chamber. No way to know without some good measurements. The brass might be trash (where did you get it?) or it might be fine for most folks.

 

[Sergeant Sabre]

I had a similar problem when I was loading for my .300WSM. The problem ended up being me. I found that the .300WSM required a lot of force for the die to re-size the final 1/16" or so of the case. I would pull the lever on the press and apply "normal" pressure until it felt like it bottomed out. Then I really leaned on it, and it would move just a touch more. Problem solved.

Perhaps you are having a similar problem?

P.S: The problem I had was with "once fired" Winchester brass purchased on eBay. The brass, according to the seller, came from some testing facility. Many of the primer pockets were a little loose, making me think that either A)It's more than once-fired, or B) The "testing facility" used it for proof loads. Maybe you bought the same stuff I did?

 

[USSR]

So, boobap, where on your brass (web or shoulder) is preventing it from chambering?

Don

 

[Vern Humphrey]

What is an oversized chamber? Do they do this on purpose, or is it just the differences in manufactors?

In this case, "oversized" means "too big for your rifle." Chambers, like any other part of a rifle, have tolerances, that is they can be slightly larger or smaller than the nominal dimensions. I suspect your rifle has a very tight chamber (on the "minus side") and the chamber these cases were fired in is on the "plus side."

You might look for someone else who has a .300 WSM of a different make and see if these resized cases will chamber in his rifle.