Case dimensions change after bullet seating

[kilotanker22]

Well today I realized there was a problem with my seating die for my 6.5 creedmoor.

I have used the same die all throughout load development for multiple rifles. A couple weeks ago I sat down and loaded about 400 rounds. Now I find that not all of them even fit in the chamber.

No it is not the bullet depth, the case itself is not fitting into the chamber. Not even close. Only about the first half of the case fits. Of course this is all brand new never fired Hornady brass.

So I was scratching my head trying to figure it out. So I took a new piece that was not loaded, measured the length and dropped it into the chamber. Fit just fine. Then I ran it through my sizer die and dropped it into the chamber. Again, fit was perfect. So I chamfered the case mouth, seated a primer, weighed a charge and seated a bullet. Double checked the OAL and the CBTO. Went to drop it into the chamber and nope! The center of the case is too large diameter to fit into the chamber and come back out without pounding the bolt open. When I say only half the case. I literally mean only the first half of the case fits the chamber after seating a bullet.

Since after my step by step test proved that whatever action was causing this was happening I side the seater die. I took the die apart and wouldn't ya know there was a thin ring of brass right where the die transitions from the neck area to where the bullet seating stem sits.

I am assuming that this build up of brass inside the seating die was smashing the case as I seated a bullet.

The only problem now is what to do with 300 rounds of ammo I have to force into the chamber.

I can pull the bullets I guess and re size them, but dang.

So there this advice. Keep your does clean!! Don't load a thousand rounds without at least checking your dies and dimensions. Out of the thousand rounds I have loaded in the last 4 months. This problem only developed in the last 300 rounds.

[kilotanker22]

I am also assuming that the brass left in that seater die was probably due to me not deburring a case when I sized and trimmed all of those new cases.

[HiBC]

Well,maybe its just as you say about the brass buildup.

But I have something else for you to check.

Its one of those things lots of folks...."discover" along the way.

You seem to have isolated the problem to seating. I'm curious...how do you set up your seating die in the press? Do you screw it in to contact the shellholder?

If so,thats your problem. Or,at least,its the cause of your problem. You have more problems.

Your seater die has a built in crimp function.In order to not crimp,the die must be backed off from the shellholder a bit.

If you did bring the die to the shellholder, You applied max crimp to your ammo. Just for education purposes,take one round of sized but unprimed brass.No powder,no bullet.Just the brass. Set your seater up just like you did before,and run it into the die full stroke. Look at the case mouth.

Hmmm.

Now,if your bullet does not have a nice,deep crimp ring,that crimp has no place to go.

So,you put tremendous end load on the case mouth.

Something has to give. The seater die does not closely support the outside of the case at the shoulder.

The shoulder collapses a bit. That messes with the head clearance.

And the shoulder to case body sort of cantilevers outward.

The case diameter gets larger at the shoulder. Check it with your calipers. Then look really close.

If you try to force them in the chamber they will get real stuck.

400 of them,huh? Not happy news.

Here is the harsh lesson. See f you read the directions that came with the dies...can you find where they covered it? Its probably in there. Reading the old instructions!! Sometimes makes life easier.

I won't say there is nothing you can do.

I'm sure you will get plenty of suggestions.

But most all of your options suck one way or another.

You are paying your dues at Reloading University. I'm sure it won't happen again.

Tell you what,next time,you write this lesson to the next guy.

Now,grab another piece of sized brass. Back off your seater die about two turns. Put that piece of brass in the shellholder Run the ram up all the way.

Now,slpwly turn the die down into the press till you feel the crimp contact the case mouth. OK,now look at the gap between the shellholder and the die.
Suppose if you had something like a washer just a little thicker than that gap,maybe .015 in. thicker. You could keep that in your die box to se as a setting gauge,so you can easily repeat your die setting.

Oh,one more thing.

Suppose a machinist has 400 parts to perform an operation on. Say,drilling a hole.

A lot of shops insist he get a "buddy check" on the first part before he runs the 400. Boss can fogive you messing up one part. You mess up 400,...They are going to make sure you don't do that again.

Run a few samples and check them.

[kilotanker22]

How I set my seater die is this. I put a sized and trimmed case in the shell holder. Put the ram all the way up. Screw down the die u til it touches the case and back it off a half turn. Normally I do not have this problem, but apparently there just was not enough space left. And when I presumably missed deburring one case. That small amount of brass left was enough to cause the problem. How I intend to resolve it is to back the die off further.

[kilotanker22]

I went through the entire 400 rounds I loaded. I have 97 that fit the chamber. The rest do not.

I am wondering if instead of pulling all of these bullets. I should buy a body die and size the body of the loaded rounds. Can this be accomplished?

[Colorado Redneck]

Is the 6.5 Creedmoor that these loads were made for the only rifle you have in that round? I had a similar problem crop up in one of my 204 Rugers. My issue stemed form neck sizing only. Some of the rounds wouldn't chamber completely, I foolishly tried to force the bolt to close, and had to pound the bolt open. Those bulged rounds would work in my other rifle. In my case that was the solution to relieve me of pulling down the rounds. Just a thought. Obviously the chamber is slightly more forgiving and would work for those loads. Mine were bulged a whopping 0.001 inch over spec.

[kilotanker22]

Originally Posted by Colorado Redneck

Is the 6.5 Creedmoor that these loads were made for the only rifle you have in that round? I had a similar problem crop up in one of my 204 Rugers. My issue stemed form neck sizing only. Some of the rounds wouldn't chamber completely, I foolishly tried to force the bolt to close, and had to pound the bolt open. Those bulged rounds would work in my other rifle. In my case that was the solution to relieve me of pulling down the rounds. Just a thought. Obviously the chamber is slightly more forgiving and would work for those loads. Mine were bulged a whopping 0.001 inch over spec.

I have two 6.5 creedmoor rifles. Also these are brand new, never fired cases that were run through my sizer die prior to loading.

[Colorado Redneck]

I realize that you have a different issue, but perhaps those loads would chamber in the other rifle?

[kilotanker22]

Originally Posted by Colorado Redneck

I realize that you have a different issue, but perhaps those loads would chamber in the other rifle?

Nope, the other rifle is from when the Creedmoor first came out. It's chamber is even tighter than this one. Tried both

[cpa22]

i don't think you are resizing your cases right.you need to set your shoulder back a little more. try this and see if it works.

[kilotanker22]

Brand new cases already full length sized. Besides like I said in my opening post. The cases chamber just fine after sizing. After seating the bullet the case body was bulged. The shoulder of the cas was no where near the shoulder of the chamber.


I did a step by step test to determine where the problem was. Then I fixed the problem. It is not my sizing die ..... The purpose of this post was to share my mistake. Not to try to troubleshoot a problem that I have already solved.

[HiBC]

I take it you discovered the die needed to be backed off a touch more,and you do have collapsed shoulders.

Its a bummer and I don't know of an "instant puuding" fix.

Look at the case drawings to check case taper,but I suspect if you have access to a sizer die in 308,7mm-08, 358,etc it might size the shoulder dia so you can chamber them. Pull the spindle so its just the die bodyLube the cases and try. See what happens.

Those dies are longer,case head to shoulder. The die won't toich the shoulder or neck.

The shoulder/head clearance ? I don't know. It won't be perfect,but it might shoot.

When you run them through the press,just consider,in the extremely unlikely event a primer ignites,a bullet is going through the ceiling.

[kilotanker22]

Originally Posted by HiBC

I take it you discovered the die needed to be backed off a touch more,and you do have collapsed shoulders.

Its a bummer and I don't know of an "instant puuding" fix.

Look at the case drawings to check case taper,but I suspect if you have access to a sizer die in 308,7mm-08, 358,etc it might size the shoulder dia so you can chamber them. Pull the spindle so its just the die bodyLube the cases and try. See what happens.

Those dies are longer,case head to shoulder. The die won't toich the shoulder or neck.

The shoulder/head clearance ? I don't know. It won't be perfect,but it might shoot.

When you run them through the press,just consider,in the extremely unlikely event a primer ignites,a bullet is going through the ceiling.

I have considered that. I just ordered a Redding body die from Midway. Where the cases are hanging up is behind the shoulder about halfway down the body of the case

[kilotanker22]

My Redding body die is out for delivery today. Any advice? I am hoping that using the body die will size the case and push the shoulder forward when it squeezes the body, then put the shoulder back where it belongs.

My plan is to set this die up to fully size the case.

One concern I have is that after this ordeal the concentricity of these rounds will be way out there. Although this may be an opportunity to test an awesome shooting load with bad concentricity. To see how much of a difference it will make in how the load shoots.

[marchboom]

I hope you have luck with your Redding body die.

But if you have to pull bullets (been there, done that with almost 400 rounds), use a puller with a collet that grips onto the bullet. MUCH FASTER than using a hammer type puller. Especially after you get a rhythm going.

And after you finish pulling bullets you can use the collet type puller as a mandrel holder if you decide to size the necks using this method.

[kilotanker22]

Update

The Redding Body die worked beautifully. Although after using it, the shoulder was pushed forward and I had to reseat the bullets to the proper depth.

[HiBC]

If you have saved the ammo, great!! You may now want to use what is calleda "Bushing type cartridge headspace gauge" to check the,also.

If you squeeze a banana in your hand,it gets longer.

Your ammo might be fine. But its possible your cartridge length ,base to shoulder has grown.That may not work out with the rifle's chamber headspace.

The bushing gauge will sort them out for you.

[kilotanker22]

Originally Posted by HiBC

If you have saved the ammo, great!! You may now want to use what is calleda "Bushing type cartridge headspace gauge" to check the,also.

If you squeeze a banana in your hand,it gets longer.

Your ammo might be fine. But its possible your cartridge length ,base to shoulder has grown.That may not work out with the rifle's chamber headspace.

The bushing gauge will sort them out for you.

Yep, I use the Hornady tool for checking shoulder location and cartridge base to Ogive measurements. That is how I knew that the shoulder was set back and also how I knew that the shoulder was pushed forward when using the body die.

Using that particular tool I have recorded in the past the reading from fire formed brass and from new and fully sized brass so that I have a control group to compare measurements with