charlie 7
Active Member
Very puzzling, the entry #1 does not correlate well with the following two, made only couple of days apart.
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First case head separation
- Thread starter Dmagna
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What r u talking about? Case head separations happen, just happens to be my first one.
Since no one has mentioned it yet, the middle casing in your pic has started to separate at the same location.
I can normally see the impending separation one or two shots before the case wall actually separates. And then throw out those cases.
I can normally see the impending separation one or two shots before the case wall actually separates. And then throw out those cases.
Yeah. I threw out most of the brass. I had a tool and could feel the separation inside the case. No big deal. Probably going to switch to adg brass
charlie 7
Active Member
Yes, you are right it happens all the time with poor reloading practices.
And you scalded the other guy for a lack of reloading knowledge.
charlie 7
Active Member
Headspacing belted cases on the belt could potentially separate any brass no matter what brand.
Tool? You mean a bent paper-clip, there's no need for that, just have a look at the case on right, there's imminent separation, possibly within 2 firing.
Case head separations are the result of too much headspace or over sizing. They don't just happen. There's a reason no go gauges are used to chamber barrels. If you dont make a false shoulder most belted mags will stretch 10-15 thou on the first firing. If you keep head spacing on the belt this is what happens. I'm not preaching. It happened to me as well before I knew any better. I measure every case with a comparator now before sizing.
I measured the case with the hornaday 400 gauge. Was resizing .002 of bump. **** happens.
Your rifle chamber could be somewhat oversized in diameter relative to your resizing die. I suspect that condition would place some extra stress/strain on the case web, over multiple firing and resizing events.
I think I had this large chamber / small resizing die experience, and experienced impending case web separations with a Ruger 77, chambered in 338 Winchester Magnum back in the late 1970s. Eventually ended up selling that rifle. It seemed I couldn't back the resizing die off the shell holder without difficult chambering of the cartridge. But that was many years ago, and I didn't have too much reloading experience at that time. There was no internet to learn from at that time. I did try to back my RCBS full length resizing die off the shell holder so as to only partially resize the necks. But that shoved the shoulders so far forward that I couldn't chamber the cartridges...
It also could'a been a rookie mistake on my part. Not knowing what I was doing, and not having cartridge shoulder headspace measuring tools at that time.
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Mike Matteson
Well-Known Member
The third one is showing too. Learn to read the brass.
Yes, too much case stretch from Full length sizing.
You have to determine if you need sizing at the web or shoulder to bolt face length. You can smoke the shoulder with a candle and be able to tell when you get shoulder contact, as the die will start to "print" on the case, kinda mashing in the smoke, prior to hard contact on the shoulder. Then find a case where the bolt is stiff, reduce the web dia screwing the die down in very tiny amounts, till you get easy bolt closing. Then measure the amount the shoulder is being pushed back at the point where you get easy closing of the bolt.
Factory chambers are all over the map in terms of dia, due to a lot of factors, how many chambers were on the reamer, how true the barrel was indicated in prior to the chamber, method of chambering, and reamer holder technique. Chamber variances of 0.0005 are an everyday occurrence, and this small amount is a night and day difference to deal with.
Standard Forster neck sizers will size the necks and bump back the shoulders only, the only brand of NON custom dies to do this that I know of.
In some chambers, there is a mismatch between the dies and the chamber. So, in order to reduce the web dia, you have to push back the shoulder too far, this is the case with most of my 7 Rem Mags. MY 7 Rem mags do not shoot their best until I full length size the cases....and I do not like this. I shoot the 140s at 3250-3300, 150s-154s at 3230, and 160-168 ~3100 fps. In my case, I just buy more brass, and I am shooting the accuracy node at peak pressures.
In my 257 Weatherbys, 9 & 10T with very, very short freebore of .030 I shoot:
100g TTSX, 100g Hornady flat base, 100g Speer Hot core, 100g Partitions, 100g Nosler ballistic tips at 3850 on 10T, 26" barrels
110g Nosler accubond at 3600 with R#22
115g Berger vld hunting at 3580 fps with R#22
87g Speer Hot core and 85g nosler ballistic tips at 4130 fps
A good friend has a 30" hart 12 twist chambered with my reamer, where he shoots the 100g Sierra Match King at 4000 fps into absolute bug hole groups, with basically the same load that I shoot. Rock Chucks take off like bottle rockets!
I, my brother, and my nephew have never shot a deer that has taken a step, they fold up like an accordion.
With the addition of a Gentry muzzle break, we all see the bullet impact on the deer, water vapor fly off, and depending on the terrain, see the bullet hit the hillside behind the deer or a tree #5 Contour, 25-26".
I have an older Krieger 12T, 25 cal barrel that I want to have chambered with this reamer and shoot 80g Barnes TTSX or a Hammer bullet. I shot the 80g Barnes TTSX in a 243 Win, 6 Rem and they are very accurate, just killing deer and hogs very quickly!
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MagnumManiac
Well-Known Member
Them something else is going on. You should not be seeing that at 5 reloads. How much is virgin brass stretching on first firing?
MagnumManiac
Well-Known Member
Wow, the movement at the shoulder has zero influence on what happens after the first firing. Head separations have one, and only one cause. Excessive headspace caused by the handloader.
This is what happens to a belted case after several firings when it is sized to fit the chamber…nothing happens.
Proof below.
This is what happens to a belted case after several firings when it is sized to fit the chamber…nothing happens.
Proof below.
