Hornady 6.5CM Bulge?

[perdurabo]

I've got a lot of 3x-4x fired Hornady 6.5CM brass where aboit 10% or so seem to have a .0015" bulge at the bottom of the web near the head that's just enough to make it stick in my Sheridan cutaway case gauge. I'm already bumping the shoulder about .003 with the Hornady FL match bushing die completely grounded out into the shell holder with a little bit of cam over, so I can't seem to size the last bit of the web where the bulge is. The sized cases that fit easily into my gauge measure .4700" whereas the "sticky" ones that wouldn't drop freely in the gauge measured .4715". I colored in the web of the case with sharpie and put it back in the gauge to prove where the high spot was and got the rub marks right below where the die sizing ends.

As for my actual chamber, the bulged ones chamber just fine with slightly more force required but not so much its a big deal (I think min reamer spec is .4714 for the web area). They seem to group more or less the same as the unbulged ones with the same load. I flame anneal all my brass before every resize. I use imperial sizing wax for lube and have never had a stuck case.

I've read this can be a sign of overpressure but I have a REALLY hard time believing that. My match load is nowhere near max (140gr RDF, 43.5gr StaBall65, CCI 200 @2750fps). The cases showed ZERO other signs of pressure. No primer cratering or flattening out. No loose primer pockets. No hard extraction.

I don't really wan't to toss brass that's only had 3x-4x loadings, especially when they still chamber and shoot more or less the same as other brass, but I can't really figure out why I can't get them to size like all the other brass to the point they'll drop in my gauge unassisted.

Any ideas what's going on? Am I gonna have to shave down my shell holder to get my FL sizer to actually size the whole damned case?

 

[mgoodrich]

It looks more like it is showing that you are going to have case head separation pretty soon. How much has the brass grown between firing? You may be bumping the shoulder back too far.

Take a paper clip with a slight bend in it and run it down the inside of the case. You are feeling for a slight indent in that area all around the brass.

This looks like what I had on my 220 swift brass when I was firing the same brass in 4 different guns that had slightly different head space between them and I wasn't paying attention to how much I was sizing the shoulder back.

 

[supercorndogs]

Yep expansion at the .2 line is usually from pressure. 2750 with a 140 isn't stupid fast, but it's not low pressure either. I don't have RDF load data, and don't know what brass you are in. I see one 140 maxing at 43g and 2711, and with another 44g and 2800. I think hodgdon data for 6.5 creed is in a hornady case. It depends on your brass, bullet, chamber, barrel and primer.

 

[TheOfficeT-Rex]

You may not feel like you’re near max, but the brass is telling you that you are for that barrel. And some just run slow.

There are a couple options to bust the bulge (ring die, small base body, different sizer die, EC mandrel die) but IMHO that’s not addressing the root cause.

 

[Supersubes]

Seems like a die issue to me. .4714 is spec chamber diameter at that location. Your die should be sizing that area to .4705-.4710. Not a pressure issue.

Your caliper isn't the ideal tool to measure that area either. Edit: case head separations happen above the bottom of that bulge, this is not a separation about to happen.

 

[supercorndogs]

10% out of how many cases? Did you do load work up in these cases? How many did you shoot with a charge over 43g during load work up?

 

[Haney]

Is the gauge cut to minimum SAAMI specs ?

 

[perdurabo]

Is the gauge cut to minimum SAAMI specs ?

According to Sheridan, the gauge is cut to minimum chamber spec:

"The diameter of the gauge is SAAMI min chamber spec, which is larger than the max spec of the cartridge. The length of the gauge corresponds to the max length of the cartridge."

https://sheridanengineering.com/product/65-creedmoor-ammunition-gauge/

 

[perdurabo]

10% out of how many cases? Did you do load work up in these cases? How many did you shoot with a charge over 43g during load work up?

Not 10%, maybe 10-15 cases were fired over that charge/velocity in my ladder testing. I've got maybe 50 with that problem.

 

[perdurabo]

Your caliper isn't the ideal tool to measure that area either.

Exactly what tool is ideal to measure that diameter?

 

[hlee]

Throw away the case gauge. The cartridges need to fit in your rifle’s chamber, not the case gauge. But, use a hack saw or dremel to cut a couple of the offending cases open, to prove to yourself that you do not have a case head separation about to happen. And, the bent wire is a good way to check without destroying cases. Cut an angle on the end of the wire, so that you have a nice acute tip to probe with.

 

[perdurabo]

Throw away the case gauge.

Im not going to disassemble my bolt to remove the ejector then do a "bolt handle drop" test on EVERY piece of ~500 brass I have. To my knowledge, NOBODY does that. Thats why case gauges exist.

 

[LRRPF52]

Im not going to disassemble my bolt to remove the ejector then do a "bolt handle drop" test on EVERY piece of ~500 brass I have. To my knowledge, NOBODY does that. Thats why case gauges exist.

When I set up my sizing die, I use an extra stripped bolt for my gas guns that has the same lug lengths and face depth, just to check initial die set-up and to QC along the way.

Instead of case gauges, I use the Stoney Point (bought by Hornady) headspace comparator set with different bushings.

Too many case gauges out there were made by another shop than the one who cut your chamber with a specific reamer, so they are not the same. I’ve seen too many people have issues with case gauges to ever trust them for loading precision rifle. For pistol mass-produced loads on a progressive as a QC with confirmed dimensions, sure. For rifle, I use the Headspace Comparator kit.

I zero the calipers out on the base of the bushing and then can see exactly where my shoulder datum is for headspace.

 

[Rio Precision Gunworks]

Exactly what tool is ideal to measure that diameter?

You'll want to use a micrometer for something like this. Calipers are only accurate to about +/- 0.001" and that's if they are used perfectly.

 

[perdurabo]

For rifle, I use the Headspace Comparator kit.

I use the same comparator to measure shoulder bump, because that's really all its good for. It can't measure any other case dimensions because its decided NOT a measurement tool, its a comparator tool. Base to shoulder is all you get, and only in comparison to some other piece of brass, not as a primary measurement tool. A case gauge measures more than just base to shoulder index.

 

[Rio Precision Gunworks]

As far as the issue, does the unfired brass/cartridge fit in the chamber gauge? If so, and the chamber gauge is cut to .4714 (can measure the unfired brass/cartridges with micrometer if you have/once you have one), then there is over .001 expansion of the case head.

That means either it's fairly high pressure or the brass is soft. Hornady brass isn't known for lasting more than a handful of firings.

If it's taking 3-4 firings to grow .001 or so, then you can try either another die or a small base die and see how that goes. As your current die obviously isn't getting the brass sized down enough at the .200 line. Cutting the shell holder or the die down may work as well.

 

[LRRPF52]

I use the same comparator to measure shoulder bump, because that's really all its good for. It can't measure any other case dimensions because its decided NOT a measurement tool, its a comparator tool. Base to shoulder is all you get, and only in comparison to some other piece of brass, not as a primary measurement tool. A case gauge measures more than just base to shoulder index.

Tracking all that. I measure my case base ODs above the extractor groove as well to see if there is case head expansion, but if the sized cases fit, feed, and extract from the chamber without signs of incipient head separation and do so repeatedly, there is no need to question their longevity, sans any other signs of undue wear and tear.

 

[WasNH4X]

Is this a gas or bolt gun ?

 

[perdurabo]

Is this a gas or bolt gun ?

Bolt. Zermatt Origin, Straight Jacket Armory spun MTU 6.5 creed, 1:8.

 

[WasNH4X]

Bolt. Zermatt Origin, Straight Jacket Armory spun MTU 6.5 creed, 1:8.

Has Horn. Factory loads ever been shot in rifle.....if so ,what was fps? Also what length barrel ?

 

[Rio Precision Gunworks]

Also, FWIW, Hornady load data shows 43.7 of Staball 6.5 and 140 class bullets to be max load and at 2750. So, while you're likely not running incredibly hot, you can easily be flirting around max SAAMI pressures.

 

[perdurabo]

Has Horn. Factory loads ever been shot in rifle.....if so ,what was fps? Also what length barrel ?

The barrel is 26". I've shot 140gr RDF Nosler factory "Match Grade" loads and got around 2750fps out of an advertised 2650fps on the box. I've never shot factory Hornady.

 

[LRRPF52]

Hodgdon’s has data for 140gr A-MAX on top of StaBall 6.5:

140gr A-MAX

Winchester

StaBALL 6.5

2.820"

40.0

2,535

45,400 PSI

44.0

2,806

61,100 PSI

They also have data for the Swift A-Frame, which doesn’t like being swaged into the lands like common cup and core bullets, builds pressure faster:

140gr Swift A-Frame

Winchester

StaBALL 6.5

2.700"

38.7

2,468

46,100 PSI

43.0

2,711

60,100 PSI

Seems like you’re right around 60,000psi, depending on your COL and throat (how close you are to the lands). My guess with RDFs is that there is plenty of jump, unless you have a really short throat.

If you’re getting 2750fps from a 26” pipe with 43.5gr under a 140gr, I don’t think you’re into excess pressure. What’s your COL?

As for my actual chamber, the bulged ones chamber just fine with slightly more force required but not so much its a big deal (I think min reamer spec is .4714 for the web area). They seem to group more or less the same as the unbulged ones with the same load. I flame anneal all my brass before every resize. I use imperial sizing wax for lube and have never had a stuck case.

Are they loads for recreation or for matches? Do you have to exert more pressure to turn your bolt into a locked position, or is it something that can be done with finger pressure only?

Are you trimming necks down? The picture makes your necks look long for a Creedmoor.

If it isn’t that bad, I personally would just continue to load and shoot until primer pockets die.

I used to use Imperial Wax, but moved to Hornady One-Shot long ago and haven’t looked back. Imperial was giving me problems with over-working the brass and dented shoulders from hydraulic pressure (my fault I’m sure for using too much in certain places).

 

[hlee]

Im not going to disassemble my bolt to remove the ejector then do a "bolt handle drop" test on EVERY piece of ~500 brass I have. To my knowledge, NOBODY does that. Thats why case gauges exist.

What is the case gauge telling you? Any case that fits the gauge is a pass. And, as at least some of the cases that don't fit the gauge still fit the chamber, a "fail" is not really a fail.

Oh, and when its important that every cartridge chamber, I chamber check every case before it is loaded.

 

[longrange772]

If you have a borescope, you can inspect inside of brass for case head separation vs paper clip.

 

[Supersubes]

Im not going to disassemble my bolt to remove the ejector then do a "bolt handle drop" test on EVERY piece of ~500 brass I have. To my knowledge, NOBODY does that. Thats why case gauges exist.

He’s right, and case gauges frequently get people into trouble. It’s a lowest common denominator approach to a precision relationship. For example, you prioritizing case fit into the gauge vs the chamber, and considering shaving a shell holder to accomplish this despite already getting sufficient shoulder bump. Nobody should proceed this way, thats how you end up with case head separations. In fact thats how these threads usually start, with separations on new-ish brass. There is only .0084” of total case taper for the Creedmoor, you’d have to shave .1” off the shell holder to get roughy .0007” more sizing at the base. Totally unworkable of course.

Buy yourself another die(what I would do) or address the current die with the manufacturer.

A blade micrometer is what you should be using to measure the web expansion you're seeing. A regular mic would work too, but a blade will allow you to measure above the extractor groove(below the bulge) to roughly determine pressure.

 

[perdurabo]

If you’re getting 2750fps from a 26” pipe with 43.5gr under a 140gr, I don’t think you’re into excess pressure. What’s your COL?

1.910" using a Little Crow drill trimmer.

Are they loads for recreation or for matches? Do you have to exert more pressure to turn your bolt into a locked position, or is it something that can be done with finger pressure only?

PRS match loads, and the ones with the bulge take about 20% more pressure to close than a normal bolt throw (I never just let the handle drop anyway, always use some force).

I used to use Imperial Wax, but moved to Hornady One-Shot long ago and haven’t looked back. Imperial was giving me problems with over-working the brass and dented shoulders from hydraulic pressure (my fault I’m sure for using too much in certain places).

I went the other direction. Hornady one shot was messy and slow so I stopped using it over 20 years ago. Well, I do use it now as a bedding release agent, but not for reloading. With imperial wax you just wipe some on your fingers and smear it on the case before you put it in the press. You can re-use the same smear on your fingers for 2-3 cases before needing to get more. Super simple and each little tub lasts me 3-5 years.

 

[supercorndogs]

Your primer seating can tell you a thing or two about case head expansion too. Since your pockets are staying tight, it's proabaly not pressure as you already assessed. A diffrent die is what I would try also. I would say your chamber gauge warned you about a problem about to pop up. As the unsized portion gets bigger than your chamber you will get clickers and tough extraction.

 

[supercorndogs]

Imperial faster and cleaner than hornady one shot. Surely you jest or maybe you forgot.

 

[Supersubes]

Imperial faster and cleaner than hornady one shot. Surely you jest or maybe you forgot.

I lol’d at that one too.

 

[WasNH4X]

Your primer seating can tell you a thing or two about case head expansion too. Since your pockets are staying tight, it's proabaly not pressure as you already assessed. A diffrent die is what I would try also. I would say your chamber gauge warned you about a problem about to pop up. As the unsized portion gets bigger than your chamber you will get clickers and tough extraction.

I'm of the same opinion about trying a different die ,after running this entire discussion back and forth through my little ole pea brain. I've used Hornady dies problem free ,loading quite a few different cartridges.... Except for one....308 ,shot out of a dpms . Small die / large chamber = too much handle force to size brass through die. Dug out rcbs die and sized at normal handle force. Who knowns, maybe Hornady 308 dies are "small base" without saying so ?
Depending on number of rds. through OPs rifle it may be prudent to send a fired case to a die maker and have a custom one made ?

 

[LRRPF52]

Imperial faster and cleaner than hornady one shot. Surely you jest or maybe you forgot.

I thought I was taking crazy pills too. Spray-lube has worked so much better for me not just for case bodies, but for inside of necks too.

I’ll never go back to Imperial Wax. I used to put my cleaned cases in a plastic tub and spray them, but then started spraying them in load trays so I could hit from multiple angles and get inside the necks.

 

[WasNH4X]

Hey, don't y'all one shot users known that we imperial users are listening to as we do "our thang"

 

[supercorndogs]

I thought I was taking crazy pills too. Spray-lube has worked so much better for me not just for case bodies, but for inside of necks too.

I’ll never go back to Imperial Wax. I used to put my cleaned cases in a plastic tub and spray them, but then started spraying them in load trays so I could hit from multiple angles and get inside the necks.

I stand them up in a Tupperware. I spray down at an angle to get the necks and bodies from two side. Then I shake them up and let the carrier evaporate for a minute.

I'm of the same opinion about trying a different die ,after running this entire discussion back and forth through my little ole pea brain. I've used Hornady dies problem free ,loading quite a few different cartridges.... Except for one....308 ,shot out of a dpms . Small die / large chamber = too much handle force to size brass through die. Dug out rcbs die and sized at normal handle force. Who knowns, maybe Hornady 308 dies are "small base" without saying so ?
Depending on number of rds. through OPs rifle it may be prudent to send a fired case to a die maker and have a custom one made ?

Did you try cleaning the hornady die out with bore solvent? Sometimes you need to season a die also. I.E lube a case start it into the die until its gets tough. Pull it out relube and work it in a little farther in. This helps work lube into the surface.

 

[WasNH4X]

I stand them up in a Tupperware. I spray down at an angle to get the necks and bodies from two side. Then I shake them up and let the carrier evaporate for a minute.



Did you try cleaning the hornady die out with bore solvent? Sometimes you need to season a die also. I.E lube a case start it into the die until its gets tough. Pull it out relube and work it in a little farther in. This helps work lube into the surface.

Yeah cleaned and did all that you mention . Still a no go . No big deal to me, had backup ,it works ......rockin on .