Need help reloading 6.5CM... Case head separation

[Wykyd]

Howdy guys!

I may have dropped the ball on this one, but I'm not exactly sure and need some advice.

I took out the 6.5 Creedmoor for the first time in a a few years. this is a bone stock Ruger Precision Rifle with 80ish firings. Half of that was was new Hornady match ammo and the other was reloaded once. So this was the third firing on the Hornady brass and the previous load was started at min working up with H4350 to just over Hodgdon website max of 40gr. I did reference multiple sources and the hogdon site was the lowest. I never saw pressure signs but that's very subjective I know!

Well today on the third firing I had some ammo loaded from 2020 to confirm the nodes I found and I started at my min of 39.2 with a 140 Barnes Burner. On the fifth and final round at that charge I had a case head separation. after looking back at the other 4 cases they did have a visible ring on the outside. When I tried the paper clip trick to check the inside I CANNOT feel anything abnormal but I am going to cut open a few of them to check. I do have a hornady comparator set and checked the headspace on the 4 fired pieces of brass then resized them and the avg difference was .0035-.0040 so its a little long. Would 4 thou be enough to stretch and ruin the brass after only a few reloads? I checked a few pieces of new Lapua brass and the avg headspace difference was about .005.

The Dies are Redding FL sizing and I do remember fighting with these dies a lot. I use dillon case lube and these dies do not have a vent hole and dent the brass with too much lube. None of my other dies have this issue and so I was wiping off most of the lube trying to leave enough to not dent the brass but still enough to not stick a case. I remember the sizing process was not smooth at all and maybe I stressed the cases pulling them out of the dies.

So I guess my question is how much of a headspace gap is too much? Should I buy a set of go no go gauges to see if my rifle has an out of spec chamber? Anyone ever have issues with the dies and dillon lube? Any help is appreciated im really at a loss right now!

Cheers,
Matt

[smoothy8500]

4 fired pieces of brass then resized them and the avg difference was .0035-.0040

The Dies are Redding FL sizing and I do remember fighting with these dies a lot. I remember the sizing process was not smooth at all and maybe I stressed the cases pulling them out of the dies.

So I guess my question is how much of a headspace gap is too much?

You only need size them back about .002" to ensure easy chambering without excessive case stretch. Unscrew/Back out your die a little.

As for the difficult sizing, some dies need a little "seasoning" or breaking in. Lube inside the die and let dry before use. Maybe even polish the interior with steel wool and case lube on a dowel.

[baih777]

My Redding dies are the same. I have to wipe off half inch from the shoulder and neck to stop.the denting.

Not sure about the case head. Your load is still on the low side.

[Wykyd]

You only need size them back about .002" to ensure easy chambering without excessive case stretch. Unscrew/Back out your die a little.

As for the difficult sizing, some dies need a little "seasoning" or breaking in. Lube inside the die and let dry before use. Maybe even polish the interior with steel wool and case lube on a dowel.

Ya I am not sure what happened I always try for .0015-.002 bump. Maybe the original fire wasnt quite enough to fully form the brass so when I set the die it was a bit much? Probably just a brain fart on my end

I may try and polish the die that cant hurt. I appreciate the response!

My Redding dies are the same. I have to wipe off half inch from the shoulder and neck to stop.the denting.

Not sure about the case head. Your load is still on the low side.

Even when I wipe it almost all off it still dents and the pressure to cycle the press is much more than any other caliber I have loaded. Im going to try some imperial wax maybe polish it like smoothy suggested.

I have seen some hot loads around 42.5 - 43 posted but the highest published data I have seen is 41.9 and I tend to stay on the conservative side anyways. Thanks for the reply brutha!

EDIT: I just re-read that you wipe down half an inch from the shoulder I just wipe off the neck and shoulder I will try that thank you!

[Wykyd]

736D06EE-C837-4DED-B252-C8507459A343.jpg

[baih777]

Hornady brass.
That outside ring !! Trash them.

[pacrat]

[ATTACH]1114447[/ATTACH]

THAT RING is not the sign of an eminent case separation. That is simply the lowest point that your sizing die "burnished" the case. Perfectly normal.

ETA .....

Ya I am not sure what happened I always try for .0015-.002 bump. Maybe the original fire wasnt quite enough to fully form the brass so when I set the die it was a bit much? Probably just a brain fart on my end

The underlined in quote are cause of your issue.

Once fired cases are rarely if ever fully fireformed to a chamber. I always fireform at least twice, with midrange loads before I consider them "fully formed".

[G38xOC]

did you just resize those to shows us or do you usually resize cases in that condition . Your inside die wall maybe scratched causing those rings ?

[Wykyd]

THAT RING is not the sign of an eminent case separation. That is simply the lowest point that your sizing die "burnished" the case. Perfectly normal.

ETA .....

The underlined in quote are cause of your issue.

Once fired cases are rarely if ever fully fireformed to a chamber. I always fireform at least twice, with midrange loads before I consider them "fully formed".

If you look up from the sizing die ring (bottom one) you can see the second ring about 2mm up from the lowest point of the FL sizing die ring. Its hard to see in the pic I know maybe enlarge it a bit if you can. I will try to post a better pic tomorrow. I attached the same pic just zoomed in so you can see the jagged line above the FL sizing die line.

The more I research fireforming and head spacing I can see how I goofed but would that really cause a case head separation and the second ring on the brass?

did you just resize those to shows us or do you usually resize cases in that condition . Your inside die wall maybe scratched causing those rings ?

Well I should have taken pics first thing but I didnt think about it. I took a headspace measurement on the fired brass cases then I used my resizing die with the lock ring set to where it was last to see how much of a delta there was between the two. The die wall did not make the second upper ring. It was very prominent before I resized the cases. I attached the same pic just zoomed in so you can see the jagged line above the FL sizing die line.

[pacrat]

[1] ... If you look up from the sizing die ring (bottom one) you can see the second ring about 2mm up from the lowest point of the FL sizing die ring. Its hard to see in the pic I know maybe enlarge it a bit if you can. I will try to post a better pic tomorrow. I attached the same pic just zoomed in so you can see the jagged line above the FL sizing die line.

[2] ... The more I research fireforming and head spacing I can see how I goofed but would that really cause a case head separation and the second ring on the brass?

[1] ... I saw it/them. I also zoomed to 250% looking for a thinning of case wall at that point. On the cut case. NO THINNING is the reason, I stated that the external burnishing is normal die rub. And not a sign of eminent failure.

A shiny ring CAN be indicative of eminent failure due to web thinning. But YOURS ISN'T. The more frictional pressure applied to the case by the die the shinier [burnish] the the brass gets. The top ring is where the burnishing starts due to frictional pressure. Bottom is where it ends.

Use a decent case lube. And be sure the web area of your cases are coated. 6.5 CM cases aren't all that big. Your complaints of HARD sizing, and neck dents are related to your lubing procedure. Too much lube becomes "hydraulic fluid" inside the die. And when the pressure increases, as you pull the handle far enough to FL size a case. You get dents.

[2] ... Second ring on brass already covered. "Would that really cause separation?. IT CAN. To more fully understand the reasons why it can. I suggest you read this thread in its entirety. https://www.calguns.net/calgunforum/....php?t=1798278 . Lots of solid input on causation of separations, even with just a couple of firings.

And then compare the dimensions between ammo/chamber for the CM here https://saami.org/wp-content/uploads...sting-Copy.pdf . To save a bit of time, scroll to pg 39 on the pdf for your CM.

To quote Randal in the linked thread Post 6

Sometimes as little as 0.015" to 0.020" TOTAL headspace over the life of the case can cause it to fail.
That's not a SINGLE firing, but over multiple firings.

KEEP in mind, that ammo makers don't give a crap how many reloads you get from your factory ammo cases. Their primary concern is that every round they sell, fits ALL the guns on the market. That is why they make it SLIGHTLY SMALLER than Min. SAAMI spec.

Do the comparative math using the SAAMI drawings. Consider the smaller than SAAMI case Dim of factory ammo. And you will see that in some instances, MORE than 1/2 of expected case life was gone as soon as you pulled the trigger first time on the factory ammo.

Dropping back to your OP.

So I guess my question is how much of a headspace gap is too much? Should I buy a set of go no go gauges to see if my rifle has an out of spec chamber? Anyone ever have issues with the dies and dillon lube? Any help is appreciated im really at a loss right now!

IMHO, anything over .001" is too much in a bolt gun. Your barrel is what it is. You don't need HS gages. Tune your loading procedures to IT.

I gave up buying factory ammo in the 1970s, a few years after I started loading in 1968. I buy new cases in lots of 100. And fireform them to fit my rifles. I don't even size them first time if they already fit my chamber. As I said in post 35 of linked thread.

I buy new unfired cases and incrementally fireform them to my rifle chambers. With a powder charge, and corn meal filler, with the neck full of hot wax. TWICE.
Only then do I seat a bullet for FINAL fireform.
All three steps are done NECK SIZE only. So as to not disturb the shoulder at all, during the process.

JM2c

[Wykyd]

[1] ... I saw it/them. I also zoomed to 250% looking for a thinning of case wall at that point. On the cut case. NO THINNING is the reason, I stated that the external burnishing is normal die rub. And not a sign of eminent failure.

A shiny ring CAN be indicative of eminent failure due to web thinning. But YOURS ISN'T. The more frictional pressure applied to the case by the die the shinier [burnish] the the brass gets. The top ring is where the burnishing starts due to frictional pressure. Bottom is where it ends.

Use a decent case lube. And be sure the web area of your cases are coated. 6.5 CM cases aren't all that big. Your complaints of HARD sizing, and neck dents are related to your lubing procedure. Too much lube becomes "hydraulic fluid" inside the die. And when the pressure increases, as you pull the handle far enough to FL size a case. You get dents.

[2] ... Second ring on brass already covered. "Would that really cause separation?. IT CAN. To more fully understand the reasons why it can. I suggest you read this thread in its entirety. https://www.calguns.net/calgunforum/....php?t=1798278 . Lots of solid input on causation of separations, even with just a couple of firings.

And then compare the dimensions between ammo/chamber for the CM here https://saami.org/wp-content/uploads...sting-Copy.pdf . To save a bit of time, scroll to pg 39 on the pdf for your CM.

To quote Randal in the linked thread Post 6



KEEP in mind, that ammo makers don't give a crap how many reloads you get from your factory ammo cases. Their primary concern is that every round they sell, fits ALL the guns on the market. That is why they make it SLIGHTLY SMALLER than Min. SAAMI spec.

Do the comparative math using the SAAMI drawings. Consider the smaller than SAAMI case Dim of factory ammo. And you will see that in some instances, MORE than 1/2 of expected case life was gone as soon as you pulled the trigger first time on the factory ammo.

Dropping back to your OP.


IMHO, anything over .001" is too much in a bolt gun. Your barrel is what it is. You don't need HS gages. Tune your loading procedures to IT.

I gave up buying factory ammo in the 1970s, a few years after I started loading in 1968. I buy new cases in lots of 100. And fireform them to fit my rifles. I don't even size them first time if they already fit my chamber. As I said in post 35 of linked thread.



JM2c

Thank you I appreciate you taking the time to write up and provide that amazing reply. I have some reading material to keep me busy in this heat!

The one problem bugging me is that the "2nd" ring is not present on the prepared brass (loaded ammunition) that is ready to shoot. That ring only appears after the case has been fired. Also, the case head separation that happened was in the exact spot. hopefully some of the links you provided can help me wrap my head around that. Either way this has been a great learning experience and brought up some deficiencies in my load workup.

[pacrat]

Thank you I appreciate you taking the time to write up and provide that amazing reply. I have some reading material to keep me busy in this heat!

The one problem bugging me is that the "2nd" ring is not present on the prepared brass (loaded ammunition) that is ready to shoot. That ring only appears after the case has been fired. Also, the case head separation that happened was in the exact spot. hopefully some of the links you provided can help me wrap my head around that. Either way this has been a great learning experience and brought up some deficiencies in my load workup.

The underlined would have been helpful to know from the get go.

You may have a rough circumferential area from when the chamber was reamed. And the ring magically appears when the case expands against it, then as the case is extracted. Opposite function of the sizing die, but the resulting ring appearance is same.

In relation to your original separation. Watch a video of cases in a factory being drawn to shape. At this point I gotta say, odds are pretty good you just had the misfortune of getting that funkyfied one in a million bad case that made it past QC.

[ar15barrels]

Howdy guys!

I may have dropped the ball on this one, but I'm not exactly sure and need some advice.

I took out the 6.5 Creedmoor for the first time in a a few years. this is a bone stock Ruger Precision Rifle with 80ish firings. Half of that was was new Hornady match ammo and the other was reloaded once. So this was the third firing on the Hornady brass and the previous load was started at min working up with H4350 to just over Hodgdon website max of 40gr. I did reference multiple sources and the hogdon site was the lowest. I never saw pressure signs but that's very subjective I know!

Well today on the third firing I had some ammo loaded from 2020 to confirm the nodes I found and I started at my min of 39.2 with a 140 Barnes Burner. On the fifth and final round at that charge I had a case head separation. after looking back at the other 4 cases they did have a visible ring on the outside. When I tried the paper clip trick to check the inside I CANNOT feel anything abnormal but I am going to cut open a few of them to check. I do have a hornady comparator set and checked the headspace on the 4 fired pieces of brass then resized them and the avg difference was .0035-.0040 so its a little long. Would 4 thou be enough to stretch and ruin the brass after only a few reloads? I checked a few pieces of new Lapua brass and the avg headspace difference was about .005.

I have written in other posts that brass can fail in as little as 0.020" of excess headspace.
That could be 1 firing of 0.020" or that could be 4 firings of 0.005" or that could be 10 firings of 0.002" or 20 firings of 0.001" headspace.
It does not seem to matter much how you get there but the 0.020"+ excessive headspace adds up from multiple firings and you get case head separations.

[fguffey]

Do the comparative math using the SAAMI drawings. Consider the smaller than SAAMI case Dim of factory ammo. And you will see that in some instances, MORE than 1/2 of expected case life was gone as soon as you pulled the trigger first time on the factory ammo.

My cases do not have head space, When I chamber a round, I know the difference in length between the chamber and the case when measured from the datum to the bolt face and datum on the shoulder to the case head. You guys have too much head space on everything. All I have is clearance, I off set the length of the chamber with the length of the case from the datum to the case head.

F. Guffey

[kcstott]

My cases do not have head space, When I chamber a round, I know the difference in length between the chamber and the case when measured from the datum to the bolt face and datum on the shoulder to the case head. You guys have too much head space on everything. All I have is clearance, I off set the length of the chamber with the length of the case from the datum to the case head.

F. Guffey

do you bump the datum in your chamber or do you bump the datum on the case, or did you make a die with a bumpable headspace datum with analog settings?