Incepient case head seperation after 3 loads.

[Mtstalker]

Ok ill look for some diffrent brass. This rifle shoots great but if im only going to get 3 reloads outta brass its going to drive me nuts.

 

[Mtstalker]

Does anybody have some new lapua or ppu brass that they can measure?

 

[fguffey]

One side? I have many cases that have the appearance they are not centered in the chamber, I also have rifles that have large extractors; sometimes called 'THE CLAW'. When the bolt is closed on a case the claw pushes the case to the left side of the chamber. If I ever wondered about the dent on one side of the case and the what the claw had to do with it I would index the round when chambering; not a problem for me but many shooters could have trouble jumping the ejector/claw over the case head rim.

Using the sinclair comparator. The brand new brass is only .003" shorter than fired

What does that mean? I am sure there are many members on this forum that know exactly what you are talking about; I am the exception. If I was measuring the effect the chamber had on the case when fired I would be measuring the length of the case from the shoulder of the case to the case head. The length of the case from the end of the neck to the case head as a priority is less than nice to know.

F. Guffey

 

[Mtstalker]

F Guffey i measured the brand new brass from the head to the datum line and the fired brass the same way. I was trying to say the new brass was .003" " shorter from head to datum line than the fired brass to make sure it wasnt a excessive headspace issue.

 

[joed49]

I had a Remington 700 that did the same thing with the ring on one side of the cartridge base. Mine turned out to be a bedding issue though I don't recall what specifically. All I can remember was it did it after I took the action out of the stock and adjusted the trigger.

 

[Brians356]

I would contact Browning. From the pictures it looks like your chamber is too large or maybe out of round. Your full length sizing setup and procedure looks sound.

I doubt it's out of round, but it could well be sized at the outer limit, or beyond, of a SAAMI chamber. When there's plenty of room, the case is free to expand asymmetrically at the web. I've seen this before in factory rifles, just not as severe a raised ring on the one side. But bottom line: Somewhat lopsided head expansion is nothing unusual or necessarily a product deficiency issue from a rifle maker's POV.

OP, if you decide to contact Browning, I would first bite the bullet and buy a box of factory ammo to test fire. That way you eliminate any thoughts in the tech rep's mind about your reloading ability and knowledge. If factory ammo does the exact same thing, it will impress Browning more than your handloaded cases. My tip is all about them, not you, you understand?

OTOH it's possible factory ammo will not look exactly like your handloads after firing, which will shed a bit more light on the puzzle.

PS

What appears to be extreme expansion on one side it not an indication of incipient head separation! I do not see the tell-tale frosty-looking brass adjacent to the ring. The brass has necessarily thinned slightly under the ring, but the walls are thick there to start with, and it takes a lot of stretching and thinning to induce an incipient separation. Again, a ring appearing here is normal. This one is just unusually lopsided and pronounced on one side.
-

 

[Mtstalker]

When i bought the rifle they threw in 2 boxes of winchester super x. I remember when o fired them they had this just not as bad you had to look hard to see them. The wierd thing is that with them being fired 3 times and all of them are the same? Wouldnt it happen in diffrent spots if it was the camber? It would be one hell of a coincidence if all 50 were indexed the same for all three firings.

 

[Brians356]

When i bought the rifle they threw in 2 boxes of winchester super x. I remember when o fired them they had this just not as bad you had to look hard to see them. The wierd thing is that with them being fired 3 times and all of them are the same? Wouldnt it happen in diffrent spots if it was the camber? It would be one hell of a coincidence if all 50 were indexed the same for all three firings.

After they have been fired once and expanded, the cases assume the same off-center position when subsequently chambered. No additional visible expansion is likely taking place.

I do not believe the chamber is out of round. Otherwise the indexing you refer to could cause a change in a particular case upon subsequent firings. I'm not a gunsmith, but it seems to me extremely difficult to make a significantly out-of-round chamber, even if you tried to intentionally produce one.
-

 

[Mtstalker]

Brians356 there is head seperation happening i can feel it with a pick and the case i cut in half has a thin ring right above the ridge. I hear you on the out of round it would be hard. It has to be a combo of large chamber and the undersized brass with the claw extractor.

 

[Brians356]

Brians365 there is head seperation happening i can feel it with a pick and yhe case i cut in half has a thin ring right above the ridge.

What you feel with a pick is perfectly normal. When there is a visibly raised ring on the outside (again, not unusual, in fact expected with a generous but in-spec SAAMI chamber) there must be a corresponding shallow groove under that ring on the inside of the case. Otherwise the wall would have to have gained thickness right there! Not very likely, don't you agree? Feeling a ring does not indicate the wall has stretched and thinned enough to be an incipient separation. If it was, I would have blown up several rifles over the years.
-

 

[Mtstalker]

I hear ya. On a few i do have the flaky looking ring with the corresponding thin groove directly below it.

 

[fguffey]

It would be one hell of a coincidence if all 50 were indexed the same for all three firings.

Yes it would be but I have no ideal how much effect the sizing die is having on the case head. The shell holder deck height is .125" meaning nothing below .125" is going to get sized, and then there is the radius of the die. Most of my 30/06 sizing dies have an opening of at least .470", meaning I can reverse a case and place the case head into the die.

And then there is case head thickness from the cup above the web to the case head, most of my case heads are .200" thick and then there are the others, some of my other case heads are .260" thick.

I know, there is one reloader out there that is wondering why I would do that. I can not stick a turned around 30/06 case head into a small base die. I have 30/06 dies that are mistakes or they are the smallest small base dies ever made because they keep every case I shove into them.

F. Guffey

 

[Mtstalker]

Just talked to a couple of companys and all said there brass is made to .462 + - .002" at the web so on the small side. They said sammi spec is .470 at the web.

 

[fguffey]

Just talked to a couple of companys and all said there brass is made to .462 + - .002"

Well I know what the dies were made for now, all I have to do now is find about what is happening to all of the 30/06 cases before they make it to me. Not a problem, I have more brass that will fit my loose sizing dies than I will ever need.

F. Guffey

 

[Brians356]

Just talked to a couple of companys and all said there brass is made to .462 + - .002" at the web so on the small side. They said sammi spec is .470 at the web.

SAAMI Max Case at the web is 0.4698" (-.008") so implied minimum is 0.4618". That means .462" would be in spec, but .460" would not be.

As for the chamber, SAAMI Min Chamber at that location is 0.4708" (+.002") so it could be .4728" and still be in spec.

So 0.4728 - 0.4618 = 0.011" total clearance (or .0055" all around). Get out a .011" feeler gauge to appreciate how much that is, and compare to the height of the ring on one side of your cases.

Few guys realize, I think, just how much slop (headspace and diameter) in the chamber is considered perfectly safe by SAAMI.
-

 

[Brians356]

Incidentally, I ran into a generous chamber in a custom R700 I had built on 250 Ackley Improved. Not only was the diameter generous in the web area (in part from the less body taper), but the gunsmith neglected to short the reamer intrusion to produce a crush fit on factory ammo at the neck-shoulder junction. When I fired factory 250 Savage ammo, I got the same lopsided ring you are seeing. But worse, even when I fireformed "bullet-less" from unfired 22-250 cases, I still got a lopsided ring. To cure that, I increased the charge of Bullseye slightly, and lighty lubed the body of the cases with Rem Oil. After that the cases had perfectly even expansion around the web, which made the ring appear quite innocuous. As a bonus, the 40-deg shoulders fully formed out to a nice sharp corner on one bullet-less firing.
-

 

[Mtstalker]

That is a lot of slop. I guess i wont worry about it to much just get new brass. The rifle shoots so good i dont wanna give it up. When you say crush fit what are you talking about?

 

[AckleymanII]

PPU brass measures .469

Here is the end of your problems, and the brass is cheap.

https://www.grafs.com/retail/catalog/search?keywords=ppu+270+brass

 

[Brians356]

. When you say crush fit what are you talking about?

Mr Ackley intended his improved chambers to be cheated short, to minimum headspace, producing a slight "crush" fit (and stiff bolt closure) where the neck meets the shoulder on the parent case. Since the "improved" shoulder angle is steeper than the parent case's, there is no longer the possibility of case-to-chamber contact on the shoulder proper in the improved chamber, so the case cannot "headspace on the shoulder" as rimless/beltless rifle cases should. By cutting the chamber ~.010" short, it forces the neck/shoulder junction to contact the chamber instead, holding the case firmly while the steeper shoulder and less tapered body are formed under pressure.
-

 

[MagnumManiac]

If you have a photo of the case you dissected, it would be appreciated if you could post it.
My 25-06 ALWAYS expands more on one side with WW-SUPER brass, but not with any other brand.

Cheers.