Full length sizing problem

[LRRPF52]

Is that PPU brass?

[dega37]

Is that PPU brass?

My brass is AA or Lapua, which I believe is the same thing.

How can I bump my shoulder .003" without full length resize?

[LRRPF52]

My brass is AA or Lapua, which I believe is the same thing.

How can I bump my shoulder .003" without full length resize?

Can't. You need to full-length re-size for auto-loaders. Something is going wrong with your sizing operation. Looks like excessive Imperial wax when I have done that before. I use spray-on lube now.

[dega37]

Which part looks wrong? I use Dillon case lube, but if I dont use Dillon's, nearly every case has a problem. Only some cases have the bad shearing - which i think was caused by over pressure. What is also weird is that the brass fits in the lee case gauge until the shearing has occurred then it no longer does.

[Klem]

Could be over-pressure. Try spinning the cases that wont go into the gauge in a drill press while holding a fine file against the web. Sometimes in hot loads brass bleeds into the unsupported gaps down at the base end of the gauge. This includes the gap where the extractor claw sits.

You can check with the gauge with the top half of the case still held in the drill press by introducing it from the base first (i.e. upside down). That way you don't have to keep taking it in and out of the chuck.

[dega37]

Klem I don't think I understand, the case does fit into the gauge. I think the resizing is not working properly and shaving brass instead of sizing it.

[Klem]

OK, I understand now. A fired case goes into the gauge but after sizing it's not a clean fit. it jams at the point of the 'shearing' marks.

Given dies squeeze the case I can only imagine it is being squeezed to the point it is displacing brass below where the mouth of the die is on the uppermost part of the press stroke.

If that is the case is being squeezed way too much.

Might be the wrong dimensions from the factory or even the wrong die.

[JASmith]

...Might be the wrong dimensions from the factory or even the wrong die.

I am very sure that the die problem is centered in either this OR the factory failed to properly chamfer the entry into the die.

Sharp edges WILL scrape softer materials...

Some have commented that the case may have expanded too much on extraction. One way to tell is to note the presence of a bulge just above the base.

Another is to measure the case diameter 0.2" in front of the base and compare that with the SAAMI maximum chamber (0.4426 + .002 = 0.4446"). If the fired case diameter is greater than the max chamber, then your rifle has an out of spec chamber AND your pressures are a bit high.

If the fired case at this point is LESS than the max chamber, the odds are your die is out of spec.

[Mav714]

Yes I've had to cam over all my brass to get it to chamber correctly. However there are some that will still not work. Frustrating.

[Rickc]

If it were me I would.just order.me a.forster full length sizing die and a set of hornady headspace gauges

http://ads.midwayusa.com/product/479704/hornady-lock-n-load-headspace-gage-5-bushing-set-with-comparator?cm_mmc=pf_ci_google-_-Reloading+-+Metallic+Reloading+Equipment+(Not+Presses)-_-Hornady-_-479704&gclid=CjwKEAjwnebABRCjpvr13dHL8DsSJABB-ILJ3ScSfl7uJ9eGSIGr0yldv4GJ2N6_onoPfqoV49YnVRoCFdjw_wcB

And set the die up as clem said with a .003 shoulder bump.

If you really suspect the rifles chamber then make a cast and compare the measurements to saami specs.

http://www.sinclairintl.com/GunTech/Casting-your-Chamber-using-Cerrosafe/detail.htm?lid=16061

[dega37]

Here are few more pictures and notes
Sized not over-cammed: http://imgur.com/eqRoINm
Sized over-cammed: http://imgur.com/trzrFID

Both have same overall length; Left -Fits in Gage but possibly over bumped; Right - slightly protrudes from bottom: http://imgur.com/nH3Wjf9
In a comparator the left is .012" longer than right, and the case gauge has a difference of .015" between the go and no go.

Better view of bulge starting to shear: http://imgur.com/Ua6b5Z7
.442" vs .446 - .004" difference in the web bulge - remember both of these fit in the gauge
If I complete full cam, the sheer becomes too wide to even fit in the case guage and is unuseable

[wheelguner]

What was the load that you used when these cases were fired?

[Klem]

From your latest photos it looks like the die is squeezing the life out of those cases.

This is what they should look like after sizing


In the photo the case sits proud of the gauge by just a fraction. You can feel it when running a straight edge like a set of calipers over the top. For other guys their sized cases are likely to be shorter and sit within the gauge. If you bump your cases back .003" they will feed fine through your gun regardless of whether they sit proud of, or within the top that rifle gauge.

But, it is not the headspace of your chamber that is causing the squeeze - it is your sizing die.

[dega37]

Klem, you just blew my mind with that case gauge picture - I went to buy one but they are out of stock. Thanks for all the info, I am going to send the die back to redding with some fired cases to get checked out. I'll post the results.

Wheelguner, I thought I was loading 30.5gr of AA2520 on 123gr A-MAX, but it turns out my dillon scale/powder dropper combo weren't that accurate.

[just_john]

Have you tried cross-sectioning a sized and an unsized case to see if it is brass flow from the shoulder down or a step in sizing diameter?