New Brass + Borescope + Fired Brass + Borescope - didn't learn a thing.

[Taxman1002587]

I religously measure my brass -when there new, when fire formed, after each firing, after each reloading. I only shoot .223 & 6mmBR. I then pitch .223 at 10 firings and 6mmBR's at 7 (Just my Rule). I just looked inside new cases with a borescope, I then look inside 6mm's that have been fired 7 times (cleaned the inside with acetane as best I could) and I learned nothing (not even sure what I was looking for). I use Lee Collet neck sizing dies and bullet seating dies and Redding Body dies to bump the shoulders. I try for loads that in my judgement are 90% of max at a temp of 80-90 degrees, because of where I shoot the temp can be anywhere between 40 to 100+ degrees when I'm shooting and I had a bad experience with with a 100% max load developed at 80 degrees when I shot it in South Dakota and the temp was North of 100 degrees.

Is there something (other than the obvious ring by the web signaling potential head separation - which did not exits in the cases) that a person looking inside a fired case with a 6X borescope would be able to see that would tell them anything about the quality of the case?


Second question - I have 10 unfired brass for the 6mmBR from the same lot as the ones that have been fired 7 times. If I were to section lengthwise and crosswise five of the fired and five of the unfired are there specific measurements of the, primer pocket, head, extraction groove, web, body, shoulder, neck or mouth that would indicate the amount of diminishment in the quality of the fired brass? I currently always measure the head expansion (outside measurement) each firing but it never has exceeded .0012 greater then the new unfired after either 10 or 7 firings.

The reason for the second question is I have to means to very easily section the brass and the tools to accurately measure the sectioned brass but it would be much like me looking inside the brass with the borescope - not a clue what to look for or what the measurements would tell me.

 

[Mikem]

Well, first, I didn't know that the Redding body only die bumped the shoulder back, but you didn't use the word "Only" so maybe we have different dies. But after 7 firings, something must be bumping them back.
Since your not FL sizing, nor do I, I get at least twice the reloads, like 14+ and my first sign of a problem has been when the primer pockets start to get loose. And if you prime with a hand primer, you will notice this right off. I have never had a 6BR Lapua case have head separation, or cracking, and only a few old ones have cracked in the neck.
Cutting them would be a wast, load and shoot them, I dont think you have a problem, yet.
And put the bore scope down for a while, and go shooting.
Mike.

 

[Taxman1002587]

I'm sure your body die and mine are the same. They do, besides bumping the shoulder resize the body somewhat (not a heck of alot though based upon my measurements) which is fine with me as I don't want over work the brass. The questions I asked were academic - whether at 7 firings or 14 or 24 would sectioning the brass and comparing the measurements to new unfired tell a reloader anything? Can inspecting the inside of the brass with a borescope tell a person anyting (again assuming you don't see the ring suggesting impending head separation).

I am not having any problems with the brass and my pitch after 7 or 10 has more to do with the fact that my family for Christmas, my birthday and fathers day buys me nothing but brass, bullets or powder as gifts - somtimes I get all three so given my age and the amount of components I now have I may already have a lifetime supply of brass.

Thanks for your response.

 

[Bob3700]

OK, So you have way too much time and energy on your hands plus you may have a touch of OCD and the tooling to enable it. (no offense intended)

Ask yourself, what causes head separations? It is a reloader pushing the shoulder of the case back too far and creating space between the chamber and the cartridge.

So with this excess space, the firing pin strike drives the cartridge to the forward most end of the chamber. As pressure builds, it expands the brass, the case grabs the chamber walls and the head of the case moves/stretches until the case contacts the face of the bolt.

So excessive shoulder set-back is what will cause the brass to stretch each time that it is resized. For a bolt gun you don't need to push shoulders back more than .001" - .002". You want the bolt to close with little to no downward pressure.

Instead of using your borescope, take a piece of wire and sharpen it to a point. Then bend the end to 90 degrees. You need this bent portion to be short enough to insert into the case neck. You can now take that point and start at the case head, run the point up the wall of the brass and if you are thinning the brass (due to stretching) you will actually feel the point at which the brass is thinning/yielding.

If you are bumping your shoulders the min amount, it will take a dozen reloads or more to begin to see any brass stretching. As someone else stated, you will see your primer pockets enlarge first. Also, if you are not annealing the shoulder and neck of your brass, the necks will be prone to splitting long before the heads separate.

I have given up looking for head separations years ago as I watch my shoulder set-backs closely and anneal my brass. The primer pockets dictate the life of the brass.

HTHs

Bob

 

[fdshuster]

I'm with bob on this one, and don't get wrapped up in the condition of brass, unless/until I see signs of impending failure(s). 223 Rem, fired in a factory chamber is usually good for 14 or so loadings before I see the first split neck (in a box of 20). I may continue to use that "lot" of brass, with caution 'til 1 or 2 more fail, then will throw it away. Lapua 223 Rem with a tight no-turn neck chamber (?) don't know, have never thrown away one yet. Lapua 6BR with tight, no- turn, (.272"), and tight fitted (.265") have been loaded as many as 30 times, and still going strong. Control headspace lengths very closely with all the cartridges, including those for the AR-15, and cannot remember the last indication of a case head seperation. Split necks are my first case failures, they never make it to the point of head seperation.

 

[jo191145]

I'm with Bob and Frank.

What you've just learned is your throwing away perfectly good brass.

 

[Taxman1002587]

Bob and Frank - Sorry I am not making the question clearer. It is not about head separation - no turn vs tight neck - headspace or bumping the shoulder or making sure you only miminally work the brass. Although your responses are appreciated and insightful. I plan on pulling 10 cases that have been fired 7 times and putting in a zip lock bag, pull 20 more of the cases that have been fired 7 times and keep shooting them until they have been fired 12 times then put 10 of those in a zip locked bag and keep shooting the remaining 10 until they have been fired 17 times (or if they show serious sign of giving up the ghost I will stop) All the loads will have been with the same powder, weight of charge, same brand of primer and same bullet seated to the same length. I will then have 10 new -10 fired 7 - 10 fired 12 and 10 fired 17 times. Then I am going to section five of each (a couple crosswise and sum lengthwise) and mesure the heck out of them to see just what if anything I can learn I also plan on looking at the ones I dont cross section with the bore scope just for the heck of it. As you gentlemen pointed out 7 firings, if you take care of your brass will probably not show much of anything.

However I had 6.5X284 years ago that would without a change in the load or the shooting conditions at the third firing (of the same case) start showing serious signs of pressure. First time I reduced the powder charge an seated the bullet a few 1/1000 shorter and used new brass form the same lot -third or fourth firing serious pressure signs again. I section the brass lengthwise and found out that the brass on one side of the case body and shoulder was substantially thicker(don't know if that was the problem or not). I unfortuantely did not section any of the unfired brass to see if they started out that way - the gun spooked me so I pulled the barrel and had it rebarrelled in 6mmbr.

Again thanks for your responses.

 

[NorCalMikie]

"I had a 6.5 x .284 years ago"??
Could be that the brass you were using wasn't the same quality (or brand) as the newer stuff that's available now?
I've got 7 boxes of "new" brass under my bench and have no reason to open them up and start using them. My brass (Lapua) has at least 15 firings and no indications of "even starting" to go south.
Sounds like you're looking for problems and indications that arn't there? I've never seen a piece of 6BR brass with a seperated case head.
Maybe one out of 200 with a split neck. Mine get fired, resized and reloaded as soon as I get home from the range. I've lost track of how many times they've been reloaded. (And I'am not worried about it either)
If you're not moving the shoulder more than needed, and the primer pockets are tight, I see no reason to pitch the brass.
If you didn't have new brass available, would you still be sectioning and looking at the brass like you are?
7 to 10 times fired brass is just getting broke in.
(when you pitch your brass let me know and I'll take it and neck it down for my 22BR )
Stash the bore scope and new brass.
Sounds like you've got too much time on your hands and you need more trigger time. Go shoot some bug holes or something. JMHO. Mike.

 

[SmokinJoe]

I would have to agree with the others, Taxman, that you are wasteing your time & throwing away perfectly serviceable brass. I have reloaded 30BR Lapua brass 55-60 times & still had a winning combo in IBS Score shooting. If you start with good brass & treat it right, it'll go a very long time. Use your borescope to learn to clean your barrels effectively & efficiently, or check the leade wear or crown condition.