260 Rem case problems

[Jim Tisdale]

"New" should have stated 1.553. It was a typo. The measurements with the tool I'm using are apparently indicated on the shoulder. Since the 26A insert I was (incorrectly:accidentally) using before is a bit smaller, it produced the exact same numbers because of where the insert takes its reading.
I have stated all along I'm neck sizing not fl sizing. The potential problem; in the form of a crack near the base shows up immediately after firing virgin Lapua brass with what everyone else seems to claim is a safe and even light load.
I've had my equipment checked and fired different brass with better/different results. You all have helped me determine my rig is probably in spec and safe to shoot. I'm NOT bashing the rifle maker or the brass maker, but at this point, I do suspect the brass.
I do take handloading very serious and fully understand the dangers associated with the process. That's why I here trying to figure this out with your help. I've loaded thousands of rounds for 223, 6mm, 308, 40s&w, 300 BO supers and subs, 20 and 12 ga. Never an issue until this happened.
I apologize for typos and mistakes I may have made relaying information. I want to thank you all for your professionalism, patience, and help to this point. I really appreciate it.

 

[Sheldon N]

It seems like you have slightly too much headspace on your virgin Lapua brass, between .010 and .013 based on what your two comparators are measuring.

Try treating it as though you were fireforming brass, as previously suggested. Jam a bullet into the lands by around 0.030 with good neck tension (ie factory lapua neck tension). This will hold the case head against the bolt face during firing, and will let the upper portion of the case stretch out properly without stretching the base/web/case head. Then the brass should be good to go for many firings into the future.

PS. You should be full length sizing and bumping the shoulder .001-002 rather than neck sizing, but that's a different conversation.

 

[dskogman]

I have the same gun and have over 10+ reloads with Lapua brass as do many others. Sounds like yours is set to the loose side on head space but since you have a Savage it's easy enough to tighten up the chamber if you want to. I set mine to a tight fit on the go gauge (+.001).

 

[jlow]

I have the same gun and have over 10+ reloads with Lapua brass as do many others. Sounds like yours is set to the loose side on head space but since you have a Savage it's easy enough to tighten up the chamber if you want to. I set mine to a tight fit on the go gauge (+.001).

"New" should have stated 1.553. It was a typo. The measurements with the tool I'm using are apparently indicated on the shoulder. Since the 26A insert I was (incorrectly:accidentally) using before is a bit smaller, it produced the exact same numbers because of where the insert takes its reading.
I have stated all along I'm neck sizing not fl sizing. The potential problem; in the form of a crack near the base shows up immediately after firing virgin Lapua brass with what everyone else seems to claim is a safe and even light load.
I've had my equipment checked and fired different brass with better/different results. You all have helped me determine my rig is probably in spec and safe to shoot. I'm NOT bashing the rifle maker or the brass maker, but at this point, I do suspect the brass.
I do take handloading very serious and fully understand the dangers associated with the process. That's why I here trying to figure this out with your help. I've loaded thousands of rounds for 223, 6mm, 308, 40s&w, 300 BO supers and subs, 20 and 12 ga. Never an issue until this happened.
I apologize for typos and mistakes I may have made relaying information. I want to thank you all for your professionalism, patience, and help to this point. I really appreciate it.

Sorry keep missing that you are only neck sizing. OK let’s start over.

First, about the load, you have said that you are using 39 grains of H4350. Again, that number means little unless we known what bullet you are using. For example, I am shooting a 140 gr Berge Hybrid out of my .260 and I am using 43.3 grains of H4350 with no problem, but if I was using a heavier bullet, I would need to use less powder so…

I am hearing that your problem is your case head is expanding and causing a crack and the crack is not caused by the case lengthening. You case does lengthen from new 1.553 headspace to fired 1.566 so it is lengthening by 13 thousands which is quite a bit so even though it is not a fault of yours in terms of sizing, it could be your chamber.

But if you think your case head of your Lapua s also expanding too much, have you measured the diameter of the case head of a new and fired round?

 

[Jim Tisdale]

I'm using 139 Secnars just into the lands. Loaded round measures .293 neck dia. and I'm using a .292 bush with the numbers down in a Redding comp neck sizer and seating with a Forster comp seater die. Neck tension, while I have no scientific way to quantify it, feels good. 210FedM primers. Powder is metered on an RCBS chargemaster to .5 gr under and trickled by hand the rest of the way onto a stock RCBS 505.
Primers look good; not cratered, not smashed flat after firing.
I'll measure the neck dia of a fired case when I get home and post.

 

[jlow]

I'm using 139 Secnars just into the lands. Loaded round measures .293 neck dia. and I'm using a .292 bush with the numbers down in a Redding comp neck sizer and seating with a Forster comp seater die. Neck tension, while I have no scientific way to quantify it, feels good. 210FedM primers. Powder is metered on an RCBS chargemaster to .5 gr under and trickled by hand the rest of the way onto a stock RCBS 505.
Primers look good; not cratered, not smashed flat after firing.
I'll measure the neck dia of a fired case when I get home and post.

Well if you are jamming then that makes a difference even though you are using a slightly lighter bullet and more than 4 grains lighter in load than me. The Hodgdon website don’t have the 139 gr bullet so I used 140. For H4350, the starting load is 39 grain, so you are basically at starting load and for a lighter bullet, not even that. I don’t jam and so I can’t speak for your load (perhaps someone can?) but I doubt you are over max at the load even jamming. I would think a conservative reloader working up a jam load would start at around 39.

So based on what most of us use and the Hodgdon data it’s hard for me to believe that you are max out with that Lapua brass. To me, your problem is likely the chamber headspace being too long causing your case to stretch out too much. You said in the OP that you had a smith check the headspace and he said its GTG, did he give you any details?

I can’t discount your thought about case head expansion but measuring the HEAD diameter (not neck diameter) at the base should tell you if your case head is expanding too much.

The other thing is you mentioned in reply 12 that the base gets a very pronounced crack in it. Was the crack around the circumference of the case or longitudinal?

 

[Jim Tisdale]

You said in the OP that you had a smith check the headspace and he said its GTG, did he give you any details?

I can’t discount your thought about case head expansion but measuring the HEAD diameter (not neck diameter) at the base should tell you if your case head is expanding too much.

The other thing is you mentioned in reply 12 that the base gets a very pronounced crack in it. Was the crack around the circumference of the case or longitudinal?

Headspace was checked twice.
I thought someone had asked for a neck dia. dimension.
The base or head gets a ring/crack around the circumference of the case about 1/4 inch up from the base. Enough that one can feel it with a finger nail.
It measures .470-.471 in that area after being fired.

 

[savagedasher]

I don’t think we (and the OP...) are talking about the same thing. First, charge weight means nothing without bullet information.... Second headspace with Hornady tool in my AI AT with a .260Rem barrel is also 1.624” so the OP must be using the wrong tool, it’s no wonder the bumps are way off and the heads are coming off....[/

 

[savagedasher]

The head space of the gun isn't the problem with the brass. The problem is your pushing the shoulder back to far and over working the brass . The head expanding is can come from over pressure loads. Larry

 

[jlow]

at

Headspace was checked twice.
I thought someone had asked for a neck dia. dimension.
The base or head gets a ring/crack around the circumference of the case about 1/4 inch up from the base. Enough that one can feel it with a finger nail.
It measures .470-.471 in that area after being fired.

Here’s the thing, with my Bartlein Dave Tooley chambered .260Rem barrel. The headspace of the new Lapua case started out with a length of 1.620” (16 cases and an ES of 1.5 thousands). After firing once, the headspace length was 1.623” (again 16 cases with ES of 1.5 thousands), so it got longer by 3 thousands.

Your physical numbers are different because you are using a Sinclair gauge but the actual numbers are unimportant, just the relative change after firing which is a growth of 13 thousands. To me, it really does not matter whether this conforms to SAAMI spec because the reality is your brass has grown in length by 13 thousands which is a lot and could be completely responsible for your case head separation. FWIW, case head separation due to this type of case stretching looks exactly like what you describe i.e. a ring/crack around the circumference of the case.

Here is a question for you. Why do you think you are getting case head expansion? Is it because of the above case head separation? If it is, then I can tell you the separation is most likely not a case head expansion but due to the case stretching because your chamber headspace is too long. Regardless of what your smith tells you, the case cannot stretch 13 thousands if it is not that much longer.

What basically happens is when you fire the gun, the firing pin hits the primer, push the case forward so that the shoulders are up against the front of the chamber. The powder goes off and expands the case, since the bases of the case is now un-supported, it expands and push backwards until it hits the bolt head. If the whole case stretch evenly, there will not be a problem but the reality is that never happens but what actually happens is it stretch only in that area where you see the crack, thinning it and weakening it so that it fails and that is what you are seeing.

Larry, he is not FL sizing, just sizing the neck.

 

[AndyA]

I had the exact same problem with the Lapua brass and forming them to 260AI. They seem to be undersize on the headspace dimension. If I didn't jam the bullet they would form a ring at the base. Its a brass thing.

 

[jlow]

I had the exact same problem with the Lapua brass and forming them to 260AI. They seem to be undersize on the headspace dimension. If I didn't jam the bullet they would form a ring at the base. Its a brass thing.

I think what happens is when your fire the round, the case is suppose to expand and grip the chamber wall, and it does. However, if you look at the thickness of the case, it is thickest at the head and thins as you go forward towards the neck. What I think happens is the crack is where the case is thick enough that it resist gripping the chamber. So if it does not grip the chamber then everything after the area that grips will expand and move backwards towards the bolt face and that area where it starts to not grip is the area that stretch out and thins. When you jam, it cannot move forward initially and so cannot stretch out except at the shoulders. This is the whole reason people use false shoulders...

 

[M-61]

The head space of the gun isn't the problem with the brass. The problem is your pushing the shoulder back to far and over working the brass . The head expanding is can come from over pressure loads. Larry

Aside from a mess of numbers, I see the OP said he is neck sizing. How (never mind how much) is the bumping occurring? What does the DIE say on it?

 

[savagedasher]

at

Here’s the thing, with my Bartlein Dave Tooley chambered .260Rem barrel. The headspace of the new Lapua case started out with a length of 1.620” (16 cases and an ES of 1.5 thousands). After firing once, the headspace length was 1.623” (again 16 cases with ES of 1.5 thousands), so it got longer by 3 thousands.

Your physical numbers are different because you are using a Sinclair gauge but the actual numbers are unimportant, just the relative change after firing which is a growth of 13 thousands. To me, it really does not matter whether this conforms to SAAMI spec because the reality is your brass has grown in length by 13 thousands which is a lot and could be completely responsible for your case head separation. FWIW, case head separation due to this type of case stretching looks exactly like what you describe i.e. a ring/crack around the circumference of the case.

Here is a question for you. Why do you think you are getting case head expansion? Is it because of the above case head separation? If it is, then I can tell you the separation is most likely not a case head expansion but due to the case stretching because your chamber headspace is too long. Regardless of what your smith tells you, the case cannot stretch 13 thousands if it is not that much longer.

What basically happens is when you fire the gun, the firing pin hits the primer, push the case forward so that the shoulders are up against the front of the chamber. The powder goes off and expands the case, since the bases of the case is now un-supported, it expands and push backwards until it hits the bolt head. If the whole case stretch evenly, there will not be a problem but the reality is that never happens but what actually happens is it stretch only in that area where you see the crack, thinning it and weakening it so that it fails and that is what you are seeing.

Larry, he is not FL sizing, just sizing the neck.

Just sizeing the neck doesn't let the brass flow and cause head seperation . Larry

 

[jlow]

Larry, please read my post today.

 

[savagedasher]

Larry, please read my post today.

Sorry wasn't responding to you . My bad
Larry

 

[jlow]

Sorry wasn't responding to you . My bad
Larry

No sweat, it's confusing....

 

[Sheldon N]

What basically happens is when you fire the gun, the firing pin hits the primer, push the case forward so that the shoulders are up against the front of the chamber. The powder goes off and expands the case, since the bases of the case is now un-supported, it expands and push backwards until it hits the bolt head. If the whole case stretch evenly, there will not be a problem but the reality is that never happens but what actually happens is it stretch only in that area where you see the crack, thinning it and weakening it so that it fails and that is what you are seeing.

+1

This is the answer. We know he's not jamming the bullet into the lands and having pressure problems because if he was jamming the bullet into the lands then it would hold the case in place and he wouldn't have headspace problems with associated case head failure.

OP, the solution to the problem is to find out how far out you have to seat a bullet until it touches the lands, then go 0.030" farther than that with good neck tension on the brass. Virgin unsized lapua brass has plenty of neck tension so you can just load and shoot. The bullet will hold the case head against the bolt face, there won't be any stretching of the web and you'll have brass that you can safely reload without any further need to jam the bullet.

 

[Jim Tisdale]

Ill do that and report back.

 

[Cuando]

Headspace issues on a Savage? You don't say?

Lapua .308 brass with a false shoulder is the way to go and will save you some coin.