Good read

 

Thanks Mark. Reminds me to add this step in my reloading process.

 

This is the reason I signed up. I could not care less about all my arguing with others about other things... clicking on threads like this is the real reason for being here. Thanks!!

 

The paper clip method is tried and true. It works. You will wonder what it really feels like till you hit your first one.

 

I use a dental pick to check for that instead of the paper clip method, same thing just different tool. Harbor freight sells a pack of picks pretty cheap, like 5 dollars. So far I have not seen this happen or start to happen in my medium rifle cartridges even after up to 6 reloadings.

 

Great thread. Overworked brass is an issue for sure.

Another culprit seems? to be that chambers in some guns being not quite tight enough then combined with repeated high-end load & full-length sizing ... had seen seperation signs a few times in a friends gun after 2 or 3 sizings. To my knowledge, my rifles have had decently tight enough factory chambers tho think seperation could still happen. Even the belted case chambers I have been lucky with.

But will check with great ideas mentioned.

Have had some wildcat projects but if ever found a loose factory chamber would be thinking about a chamber conversion before a new barrel.

Speer 11 also provides some info on seperation topic with images but dont remember paper clip mentioned?

After a couple of sizings, have been known to switch to less pressure loadings for other experiments combined with neck sizing instead of full length - especially with brass that is more challenging to acquire. Have tried to improve accuracy with neck sizing but good groups remained unchanged.

Have had a few split cases over the years but different topic.

 

Another culprit seems? to be that chambers in some guns being not quite tight enough then combined with repeated high-end load & full-length sizing ... had seen seperation signs a few times in a friends gun after 2 or 3 sizings

I don’t see it as a chamber issue, SAAMI specs are SAAMI specs. The issue is how folks set up their resizing die. All die manufacturers instructions basically have you mashing your brass so it will chamber in ANY rifle. Once you’ve fire formed a piece of brass to your chamber that’s no longer a concern. What becomes the concern now is case length and the forward positioning of the case shoulder. If the case is to long you can pinch your bullet possibly causing the pressure to spike. If the shoulder has moved to far forward you will either have a hard to close bolt or no closure at all. I set all my F/L dies to only bump the shoulder back .002 of an inch so the size of the chamber is now irrelevant.

After a couple of sizings, have been known to switch to less pressure loadings

Again, this comes back to resizing die set up. I run full loads in my 7 Mag and I have only had one in the last 20 years that stretched to point where it had to be tossed. Generally loose primer pockets are the culprit.

Have tried to improve accuracy with neck sizing but good groups remained unchanged.Have had a few split cases over the years but different topic.

I neck size for a lot different calibers and it’s not always a fix for accuracy. Consistent/uniform neck tension and concentricity are whats going to really make a difference. Annealing will fix neck tension and remedy split necks.

 

mark204,

Thats really great info ... and like that 'fire form' approach in 'any' chamber as I think you said as well. Have fire formed for 358win & 450 belted mashburn for conversions mainly but some others too, for other reasons.

Will think about your comments on a straight wall case too. Have two SBL 4570s 'that settled on personally to work with' where one chamber is more snug than the other with identical factory ammo. The non-rail SBL has a 3×9 scope for longer range use BTW, then the railed SBL has a 2x long relief.

Have never slugged but generally the snug chamber gun 'seems' to be more accurate naturally with identical ammo but not necessarily attributing that to the chamber, there are many variables. But what I have noticed is that the same new brass consistently has different dimensions after firing than in the snug chamber.

Interesting thread.

 

Over sizing is the big culprit as mark204 said. I have some .30-06 brass that is paired to one Rem 700 that I bought my senior year in high school. I have bras that has been loaded 12 times. About every 3rd loading, I will bump the shoulder back. Case head separation is from the push/pull working of the brass.

 

That 'push-pull' working of brass an excellent illustration of whats happening.

Have never had head come apart either but have had blown/expanded primer pockets in addition to a few split cases. And will remember the brush method for sure, re: head.

 

Again, good info as mark204 and then yourself said.

Thanks for discussion.

 

If you ever get a case head separation that leaves the body of the case in the chamber and extracts only the case head, here's what to do: Use a bore brush that is slightly larger than the inside body of the case and screw it on your cleaning rod. Insert the cleaning rod from the rear and push it inside the case body. It should pull out easily. This technique requires access to the the rear of the chamber so the bolt or BCG must be removed.

For rifles that don't have easy access to the rear of the chamber (lever, pump, or some autos), you can insert a cleaning rod from the muzzle then screw the bore brush on after the rod protrudes from the chamber. Just pull the brush into the case then push the rod out far enough where you can unscrew the brush. BTW, I always take a 3-piece GI cleaning rod and a couple bore brushes in my range box, just in case. 38 cal works good for stuck 223 Rem, 45 cal brush works well with most larger rifle cartridges

 

Fortunately I’ve never had a case come unglued but I know some that have......the brush trick works every time.

 

BTW, teaching my son to big game hunt at fairly close quarters 'first' (with the different SBL leverguns I mentioned), as we did near Blanca peaks last fall when 200lb lion snuck up on us, that I actually saw tho know its happened before.

Want my son to have good ideas of whats happening on the ground before he gets into longer range hunting with bottle necked bolt guns (that I enjoy), especially on 'public' wild lands. That was 'a' good lesson.

Also to note on one of my bottle-neck bolt guns ... something to learn from(for me), about 20 yrs ago had a 700 Classic feeding issue (in the field) while on a nice bull, from a handload that was both fireformed/neck sized plus it was longer than the SAAMI spec'd round. I was not a happy camper though ended up with a different bull later that week, thankfully.

My test cycling was much slower than when in field on a nice elk, man's plans sometimes.... whew!

 

What normally causes case head separation is excessive headspace. Most bottleneck cases are designed for a headspace not to exceed .005", so each time the case is fired, the walls will expand about .005" then when full length sized, they contract about .005". The junction of the case walls and the solid brass head is the most vulnerable place for case head separation for a couple reasons. First, that's where heat is the most intense and second, the longer walls expand more than the shorter head. If you just neck size each time after the first firing, you can easily extend the life of a case. Why? when the case fireforms, headspace is at a minimum, which is the root cause of head separation.

For informal target shooting I like to use neck only sizer dies but for hunting where chambering can be a challenge, I always use a full length sizer die with once fired cases.

 

I think this is worth adding. I stated I set my dies to bump the shoulder back .002”, but that’s only after I have established how “long” my chamber is. Depending on the length of your chamber one firing may or may not completely fire form your brass to your chamber. My point being you may still be mashing your cartridges more than necessary. I haven’t seen a one shot fire forming in any of the Ruger’s I own.

As stated I do neck size for most of the calibers I shoot. But I don’t size the entire neck, probably 50% of it or less. I can usually get 5 or 6 firings out of most calibers before I encounter a “hard” bolt, I do like a stiff bolt though. At that point I run my brass through a body die, which will do the same thing as a F/L but it leaves the neck undisturbed. For the calibers I don’t neck size I do something else. First I take a fired case and see if it can be re-chambered, if it can there’s still room for the shoulder to move forward and fill the chamber. Now I’ll take my F/L and back it out, I’ll then take a case and cycle it, I’ll then check to see it the case mouth will hold a bullet. If it does, I’m done, if not I’ll screw the die down a little and repeat. Once the case mouth will hold a bullet I’ll load it up and fire it. After the next firing I’ll repeat this process, I’ll continue to do it until I encounter a stiff bolt on a fired case. Once the bolt meets my level of stiffness I’ll hit it with a headspace gauge, record that number and then reset my F/L or body die to push the shoulder back .002” from where it was. At that point my die is set and never moved again. If you only neck size or use a collet die you will eventually have to push the shoulder back, there’s no getting around it.

I know some like to do a complete F/L sizing on their hunting loads, I get that. I generally hunt with one in the chamber and two in my pocket. Back up shots are nonexistent for me, if I miss I lose. If I burn more than three shots on a daily deer hunt I’m the problem not my rifle.