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Qball-16

Qball-16

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Background - I took part in the Thundershot Long Range Challenge (Details Here) and worked up what I thought was a safe load at/near max. I was trying to safely maximize muzzle velocity so I could detonate the target (with the minimum 2000fps required) from as far away as possible.

Load info:
Federal Brass (saved from factory loads) fired 3x
Sierra 69 grain TMK
Varget 26.4 grains (max in the Sierra load data)
CCI 450 Primer

There were no obvious pressure signs (hard extractions, flattened/cratered primers, soot leaks around primers...) during the load development, testing and shooting for the contest, but when cleaning up the brass, I found a suspicious looking ring on some, but not all, of the brass.
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Using my RCBS Case Master to see what was going on inside, I found a very pronounced groove.
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The few unfired rounds I had left from this Challenge have now been pulled. My question to the Reloading guru's on here - was this just an overpressure situation, or is there potentially anything else going on here that I should be aware of???
 
It's an expansion ring and is caused by over-sizing your brass.

In all honesty though if you got 3 full-power loads using the Federal brass you have done well.
 
I find it kinda odd that it's so high up. It's normally near the bottom of the case for me. Does the web go way up? Maybe that's just where it happened to be softest so it stretched there.
 
LUTNIT said:
I find it kinda odd that it's so high up. It's normally near the bottom of the case for me. Does the web go way up? Maybe that's just where it happened to be softest so it stretched there.
Click to expand...

That was one of my initial concerns as well - especially after the recent thread on Otokiak's .223 case failure...

When checking cases that are still OK on the Case Master, the thickness of the brass from the web to the rest of the case is quite a long and gradual taper. It appears that the expansion ring is pretty close to the point where the taper stops.
 
If the ring is where the taper stops, that makes sense. It's the lowest point of relative weakness to the rest of the case. Odd that the taper is that long. If that's the case it's just case stretch and nothing related to the rifle. I'd toss the brass in the scrap bucket if it thinned out more than I like. Once the stretched area becomes the thinnest part of the case wall, I usually toss the brass in the scrap box.

Do you FL size your brass? Once it's fire formed there should be negligible stretch in the web if you're neck sizing or partial sizing.
 
Readjust your fls/ body die,,,I suspect you are oversizing, pushing the shoulder of the case back more than necessary,,
 
LUTNIT said:
If the ring is where the taper stops, that makes sense. It's the lowest point of relative weakness to the rest of the case. Odd that the taper is that long. If that's the case it's just case stretch and nothing related to the rifle. I'd toss the brass in the scrap bucket if it thinned out more than I like. Once the stretched area becomes the thinnest part of the case wall, I usually toss the brass in the scrap box.

Do you FL size your brass? Once it's fire formed there should be negligible stretch in the web if you're neck sizing or partial sizing.
Click to expand...

Yeah, this whole group of 100 Federal cases are going in the scrap pile. Being fairly new to reloading, I figured I'd use the cheap brass from factory ammo I'd been saving, so it wouldn't be a great loss if/when I screwed them up. I think it's probably time to buy some new, decent quality brass.

Based on a recommendation from Jerry (Mystic) I use a Lee collet neck sizer and a Redding body die. I used the body die on their 1st reload, since some had been shot from my current rifle, and some from a previous rifle. For their 2nd loading, I just neck sized but had some that were a little stiff to chamber, so ran them through the body die again for their 3rd (and final) loading.

Really appreciating all the info/advice here, thanks!!!
 
liberty said:
Readjust your fls/ body die,,,I suspect you are oversizing, pushing the shoulder of the case back more than necessary,,
Click to expand...

The Redding instructions state the body die "should make light but firm contact with the shellholder", which is how I set it up. Do I just back the die out slightly to reduce the shoulder bump? I'm using a Hornady Lock-N-Load press & collars, so fine tuning should be fairly straight forward & once it's set, it's set. Otherwise, I guess I could consider getting one of the Redding Competition Shellholder Sets.

Again, I truly appreciate the info/advice!!!!
 
Buy the headspace gauge found here.
http://www.larrywillis.com/
There may be other ways to do what it does, but I love my setup. Use this to set up your resizing die, or body die so that you bump the shoulder about .001" maybe .002"
Measure a fired case, from your rifle, set up your die by measuring sized brass. Adjust die as required.
This way you aren't overworking your cases, and it ensures they will chamber easily in YOUR rifle. Most dies, and their explanations for setting them up are to make sure the reloads fit any rifle SAAMI specs.
 
^^^this is the best way to go,hornady also makes a gauge,,

there are some who resize their brass, and try it in their chamber and close the bolt, feeling for light resistance as the bolt is turned down, but a gauge is best and 001~002 thou bump,,will extend your brass life and likely improve accuracy,,

imo, flsized brass makes the most accurate ammunition,,
 
Qball-16 said:
The Redding instructions state the body die "should make light but firm contact with the shellholder", which is how I set it up. Do I just back the die out slightly to reduce the shoulder bump? I'm using a Hornady Lock-N-Load press & collars, so fine tuning should be fairly straight forward & once it's set, it's set. Otherwise, I guess I could consider getting one of the Redding Competition Shellholder Sets.

Again, I truly appreciate the info/advice!!!!
Click to expand...

The die does not need to touch the shellholder. Why Redding would say this in their instructions is silly.

From your description, you have fired the case, it is now stiff to chamber.... . Set up the body die so it doesn't touch, chamber... still stiff.

Rotate the die in small (say 1/4 turn) increments in your press until the brass chambers but you can feel contact just before you completely drop the bolt handle. This is what I call ZERO headspace.

From this point, I would turn the die again maybe an 1/16 to 1/8 turn more. When sized, the case will chamber without any hint of contact but a piece of masking tape on the base makes it hard to even start chambering.

Voila, you have 1 to 2 thou clearance between the case and the chamber headspace. This will function fine and not overly stretch the case.

The goal is to just bump the shoulder so the case will chamber without issues... not any more. On moderate pressure rds and the die set up properly, you may not feel anything when you run the case into the body die but it will go from stiff to easy chambering.... you are moving the case shoulder about the thickness of a hair

Note: this tightness in tolerance is not ideal for a hunting or working set up. But for target shooting, ideal and maximises case life.

Jerry
 
Mystic Precision said:
The die does not need to touch the shellholder. Why Redding would say this in their instructions is silly.

From your description, you have fired the case, it is now stiff to chamber.... . Set up the body die so it doesn't touch, chamber... still stiff.

Rotate the die in small (say 1/4 turn) increments in your press until the brass chambers but you can feel contact just before you completely drop the bolt handle. This is what I call ZERO headspace.

From this point, I would turn the die again maybe an 1/16 to 1/8 turn more. When sized, the case will chamber without any hint of contact but a piece of masking tape on the base makes it hard to even start chambering.

Voila, you have 1 to 2 thou clearance between the case and the chamber headspace. This will function fine and not overly stretch the case.

The goal is to just bump the shoulder so the case will chamber without issues... not any more. On moderate pressure rds and the die set up properly, you may not feel anything when you run the case into the body die but it will go from stiff to easy chambering.... you are moving the case shoulder about the thickness of a hair

Note: this tightness in tolerance is not ideal for a hunting or working set up. But for target shooting, ideal and maximises case life.

Jerry
Click to expand...

Thanks (as always) for the extremely clear explanation and instructions Jerry, and thanks as well to everyone else who chimed in with suggestions and advice!!! I have learned, and continue to learn, so much from the veteran shooters & reloaders here on CGN - many, MANY thanks to you all on this Thanksgiving long weekend!!!!
 
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