6.5 creedmore?

[Foggy47]

I don't see it that way. 6.5x55 is too long to optimally seat long bullets and fit in a short action. It has a lot of case taper and shallow angled shoulders which contribute to much faster case stretch which results in shorter brass life and more brass trimming to reuse cases. Most of all there's the SAAMI max pressure thing - ammo manufacturers don't want to load it to modern pressures and get sued when someone blows up their old mauser with it. Because the x55 case is bigger, it takes more powder to reach the same velocity, which equals more recoil for same velocity.

Basically it got created to compete or improve in some aspects on David Tubb's 6xc that was dominating across the course competition at the time but with less wildcatting headaches with inconsistent chamber specs, brass, load data, and better barrel life. The background story:

Interesting how American gun nuts continue to improve on perfection. Over the past few decades a number of improvements in cases have come about: Basically, Short, fat, lower taper, cartridges with a more pronounced shoulder angle has been found to improve performance while longer, low drag, bullets have improved accuracy at long range. (and a whole lot more).

These are really not new things.....as P.O. Ackley was converting many old chambers back in the 50's into what is commonplace today. I used to shoot allot of PD's......and my favorite cartridge for shooting prairie dogs was the 22-250. One problem with the 22-250 tho is that it really extrudes the brass upon firing...thus constant trimming and thinner brass and head separations are a concern. I converted mine to an Ackley improved chamber and the brass stretching became far more manageable while adding some additional speed. Nearly eliminated the need for trimming.

The sacrifice is the reliable feeding of these cartridges with low body taper and abrupt shoulders can be some concerns for big game hunters.....especially if chasing the toothy varieties, I suppose..

At one time I really liked to experiment with the latest and greatest new bullets and cartages as that was a "labor of love" for the sport. ......but that has worn off for me. BT/DT I suppose. Now, I'd just like to purchase some factory ammo that can do the job and call it a day. It's a lot of time and effort to reload for wildcat or specialty guns with tight necks and such. Can be fun.....and there is so much to learn.

Edit: .......or, a PITA. lol

 

[Wind Gypsy]

Interesting how American gun nuts continue to improve on perfection. Over the past few decades a number of improvements in cases have come about: Basically, Short, fat, lower taper, cartridges with a more pronounced shoulder angle has been found to improve performance while longer, low drag, bullets have improved accuracy at long range. (and a whole lot more).

These are really not new things.....as P.O. Ackley was converting many old chambers back in the 50's into what is commonplace today. I used to shoot allot of PD's......and my favorite cartridge for shooting prairie dogs was the 22-250. One problem with the 22-250 tho is that it really extrudes the brass upon firing...thus constant trimming and thinner brass and head separations are a concern. I converted mine to an Ackley improved chamber and the brass stretching became far more manageable while adding some additional speed. Nearly eliminated the need for trimming.

The sacrifice is the reliable feeding of these cartridges with low body taper and abrupt shoulders can be some concerns for big game hunters.....especially if chasing the toothy varieties, I suppose..

At one time I really liked to experiment with the latest and greatest new bullets and cartages as that was a "labor of love" for the sport. ......but that has worn off for me. BT/DT I suppose. Now, I'd just like to purchase some factory ammo that can do the job and call it a day. It's a lot of time and effort to reload for wildcat or specialty guns with tight necks and such. Can be fun.....and there is so much to learn.

Edit: .......or, a PITA. lol

Never had an ackley or 40 degree shoulder case but the 30 and 35 degree ones have all fed as well as anything else for me. I know there is some tuning necessary on some of those steep shoulder cases to feed nicely! The other thing besides case design is throat design. A lot of the old standbys dont really have any freebore but rather a constant taper throat starting in front of the case mouth. Most custom chambers focused on accuracy for a long time have had parallel freebore for a bit and then a 1.5 degree leade or throat. A lot of the modern cartridges have adopted that and IMO it seems to help with precision.

 

[Telemark]

I don't see it that way. 6.5x55 is too long to optimally seat long bullets and fit in a short action. It has a lot of case taper and shallow angled shoulders which contribute to much faster case stretch which results in shorter brass life and more brass trimming to reuse cases. Most of all there's the SAAMI max pressure thing - ammo manufacturers don't want to load it to modern pressures and get sued when someone blows up their old mauser with it. Because the x55 case is bigger, it takes more powder to reach the same velocity, which equals more recoil for same velocity.

Basically it got created to compete or improve in some aspects on David Tubb's 6xc that was dominating across the course competition at the time but with less wildcatting headaches with inconsistent chamber specs, brass, load data, and better barrel life. The background story:

Fair enough. But for the average hunter, which is probably 90+% of users for both cartridges, they perform nearly identically.

For the relatively few users who shoot extreme long range and reload all their ammo, I'm sure all that makes a significant difference. So I take back the bit about marketing.

 

[Jerry-B-WI]

These are really not new things.....as P.O. Ackley was converting many old chambers back in the 50's into what is commonplace today. I used to shoot allot of PD's......and my favorite cartridge for shooting prairie dogs was the 22-250. One problem with the 22-250 tho is that it really extrudes the brass upon firing...thus constant trimming and thinner brass and head separations are a concern. I converted mine to an Ackley improved chamber and the brass stretching became far more manageable while adding some additional speed. Nearly eliminated the need for trimming.

Why would the 22-250 have anymore case stretch than any other cartridge hat headspaces on the shoulder?

Case stretch should be able to be controlled with proper sizing die adjustment.

 

[Wind Gypsy]

Why would the 22-250 have anymore case stretch than any other cartridge hat headspaces on the shoulder?

Case stretch should be able to be controlled with proper sizing die adjustment.

More case taper and shallower shoulder angles = more case stretch.

 

[Wind Gypsy]

Fair enough. But for the average hunter, which is probably 90+% of users for both cartridges, they perform nearly identically.

For the relatively few users who shoot extreme long range and reload all their ammo, I'm sure all that makes a significant difference. So I take back the bit about marketing.

Agree, functionally what happens when the primer is popped between the two will be indistinguishable by most anyone. Just wanted to point out that there are useful differences that matter to enough people to justify the creation of the creedmoor.

 

[Jerry-B-WI]

More case taper and shallower shoulder angles = more case stretch.

Doesn't case stretch happen when the firing pin forces the case forward into the chamber seating the case shoulder against the chamber shoulder. Then the primer ignites blowing the case sides out to grab the chamber walls and forcing the case head back against the bolt face.

If the case is sized so that the difference between the case headspace dimension and the chamber headspace dimension (clearance) is kept to a bare minimum case stretch is kept to a minimum. I under stand this would be more difficult with a semiauto action than a bolt action because of cycling function of the semiauto. This is why you can neck size for a bolt action but not a semiauto.

 

[Wind Gypsy]

Doesn't case stretch happen when the firing pin forces the case forward into the chamber seating the case shoulder against the chamber shoulder. Then the primer ignites blowing the case sides out to grab the chamber walls and forcing the case head back against the bolt face.

If the case is sized so that the difference between the case headspace dimension and the chamber headspace dimension (clearance) is kept to a bare minimum case stretch is kept to a minimum. I under stand this would be more difficult with a semiauto action than a bolt action because of cycling function of the semiauto. This is why you can neck size for a bolt action but not a semiauto.

I don't know all of the mechanics of it other than it made sense to me in theory that a steep shoulder at the end of a low taper body would make it harder for brass to flow forward into the necks and less case stretch has always been mentioned as a primary benefit of steeper shoulders.

 

[Foggy47]

Doesn't case stretch happen when the firing pin forces the case forward into the chamber seating the case shoulder against the chamber shoulder. Then the primer ignites blowing the case sides out to grab the chamber walls and forcing the case head back against the bolt face.

If the case is sized so that the difference between the case headspace dimension and the chamber headspace dimension (clearance) is kept to a bare minimum case stretch is kept to a minimum. I under stand this would be more difficult with a semiauto action than a bolt action because of cycling function of the semiauto. This is why you can neck size for a bolt action but not a semiauto.

Yes that is one way cases stretch. But at the high chamber pressures upon firing.....the brass also "flows" or is extruded due these pressures and the more taper the more the brass will flow. The only direction it can flow is toward the rifling. Thus reducing taper in the cartridge can have a significant change in brass life.

 

[Foggy47]

I don't know all of the mechanics of it other than it made sense to me in theory that a steep shoulder at the end of a low taper body would make it harder for brass to flow forward into the necks and less case stretch has always been mentioned as a primary benefit of steeper shoulders.

Also sometimes those steep shoulders can make brass to flow into the junction of the shoulder with the case neck. This can cause what is called "the dreaded doughnut". The doughnut can impede proper bullet seating (especially in longer VLD bullets). The only solution to remove the doughnut is to ream the inside of the case. This can be tricky as the brass can (does) have a thick side and a thin side and the reaming may not be concentric within the case neck . (cliff notes version)

 

[Wind Gypsy]

Also sometimes those steep shoulders can make brass to flow into the junction of the shoulder with the case neck. This can cause what is called "the dreaded doughnut". The doughnut can impede proper bullet seating (especially in longer VLD bullets). The only solution to remove the doughnut is to ream the inside of the case. This can be tricky as the brass can (does) have a thick side and a thin side and the reaming may not be concentric within the case neck . (cliff notes version)

Is it the steep shoulders that caused the donut or the brass specific to that case? I thought the issue was primarily thicker shoulder brass becoming neck brass when it flows or bushing dies not sizing the full length of the neck and then having build up in the donut area. If it's shoulder flowing into neck, a shallower shoulder would allow that to happen quicker.

It also seems to be notorious in necked up cases where shoulder was made into neck during the neck up process. Example - Lapua 6.5x284 necked up to be straight 284 brass. 6 PPC would be the same if necked up from 220 russian but i'm not familiar with the PPC and if donuts are a frequent issue.

 

[Foggy47]

Is it the steep shoulders that caused the donut or the brass specific to that case? I thought the issue was primarily thicker shoulder brass becoming neck brass when it flows or bushing dies not sizing the full length of the neck and then having build up in the donut area. If it's shoulder flowing into neck, a shallower shoulder would allow that to happen quicker.

It also seems to be notorious in necked up cases where shoulder was made into neck during the neck up process. Example - Lapua 6.5x284 necked up to be straight 284 brass. 6 PPC would be the same if necked up from 220 russian but i'm not familiar with the PPC and if donuts are a frequent issue.

Been a long time since I visited this topic. Just did a google and here is what Boyd Allen says about the Doughnut (below). I have had this issue in a few of my guns......after repeated reloading the rounds.

There seems to be a widely repeated and incorrect idea of where doughnuts come from. When a case if fired for the first time there is more clearance than is the usual for a properly resized case (for a bolt action). The firing pin strike knocks the round forward in the chamber until the shoulder of the case is stopped by the shoulder in the chamber. From that point the ignition of the powder and attendant pressure causes the case to expand, creating sufficient friction between the body of the case and that part of the chamber that any stretching of the case back to the bolt face happens toward the back of the case. (Look up incipient separation if you want to know more about this.) This causes a slight thinning at the back of the case in a narrow zone, but if you are careful setting your die for shoulder bump, it should not be a problem....except that for every cycle of firing and FL or body sizing brass from the body is moved forward in the case. This is caused both by the bump and the reduction of the diameter of the body of the case. This is what causes cases to grow in length, and require trimming. As a part of this process the thicker brass at the top of the shoulder is moved into the base of the neck and when that happens we have doughnuts. It is not a matter of brass flowing during firing. Some may have noticed that their unturned necks are thicker at their base than at their mouths. This is normal. If you section a case lengthwise you will see that it has a continuous taper in wall thickness from the head to the mouth. That is why most factory chamber drawings show taper in the neck, so that if the bearing surface of a loaded bullet is seated deep that chamber clearance will not decrease toward the bottom of the neck. On the whole neck sizing only thing, if you are loading to normal pressures, eventually cases will become excessively tight. When they do, it will not happen on the same firing for all cases and if you shoot tight with not tight, your groups will be enlarged over what they would be if they were all tight or all not. You can also end up with lug galling issues from running tight brass, especially if your lugs are not lightly greased on their rear surfaces on a regular basis.

 

[Wind Gypsy]

Been a long time since I visited this topic. Just did a google and here is what Boyd Allen says about the Doughnut (below). I have had this issue in a few of my guns......after repeated reloading the rounds.

There seems to be a widely repeated and incorrect idea of where doughnuts come from. When a case if fired for the first time there is more clearance than is the usual for a properly resized case (for a bolt action). The firing pin strike knocks the round forward in the chamber until the shoulder of the case is stopped by the shoulder in the chamber. From that point the ignition of the powder and attendant pressure causes the case to expand, creating sufficient friction between the body of the case and that part of the chamber that any stretching of the case back to the bolt face happens toward the back of the case. (Look up incipient separation if you want to know more about this.) This causes a slight thinning at the back of the case in a narrow zone, but if you are careful setting your die for shoulder bump, it should not be a problem....except that for every cycle of firing and FL or body sizing brass from the body is moved forward in the case. This is caused both by the bump and the reduction of the diameter of the body of the case. This is what causes cases to grow in length, and require trimming. As a part of this process the thicker brass at the top of the shoulder is moved into the base of the neck and when that happens we have doughnuts. It is not a matter of brass flowing during firing. Some may have noticed that their unturned necks are thicker at their base than at their mouths. This is normal. If you section a case lengthwise you will see that it has a continuous taper in wall thickness from the head to the mouth. That is why most factory chamber drawings show taper in the neck, so that if the bearing surface of a loaded bullet is seated deep that chamber clearance will not decrease toward the bottom of the neck. On the whole neck sizing only thing, if you are loading to normal pressures, eventually cases will become excessively tight. When they do, it will not happen on the same firing for all cases and if you shoot tight with not tight, your groups will be enlarged over what they would be if they were all tight or all not. You can also end up with lug galling issues from running tight brass, especially if your lugs are not lightly greased on their rear surfaces on a regular basis.

That aligns with what @Jerry-B-WI was saying about brass growth yet it seems basically universally accepted that steeper shoulders = less brass growth/trimming. I have some ideas why but its kind of hard to put in words in short order..

 

[Jerry-B-WI]

That aligns with what @Jerry-B-WI was saying about brass growth yet it seems basically universally accepted that steeper shoulders = less brass growth/trimming. I have some ideas why but its kind of hard to put in words in short order..

If you get yourself the 3rd edition of the Hornady Handbook it has a very good explanation of this, complete with illustrations. I can't say I've heard of the "doughnut" but Hornady explains what happens upon firing and what happens when you resize cases, whether it's full length, partial length, or neck sizing.

And this is why I preach learning about handloading. Not just dumping powder in a case and seating a bullet. Get a good manual read and understand the front half of the manual before ever looking at load data. It can keep your ass out of trouble. There's allot of pressure in that receiver that 's right next to your cheek and inline with your face. It's going somewhere and if you've done your homework it'll be down the barrel and out the muzzle not back at you and everyone goes home safe.

 

[Foggy47]

If you get yourself the 3rd edition of the Hornady Handbook it has a very good explanation of this, complete with illustrations. I can't say I've heard of the "doughnut" but Hornady explains what happens upon firing and what happens when you resize cases, whether it's full length, partial length, or neck sizing.

And this is why I preach learning about handloading. Not just dumping powder in a case and seating a bullet. Get a good manual read and understand the front half of the manual before ever looking at load data. It can keep your ass out of trouble. There's allot of pressure in that receiver that 's right next to your cheek and inline with your face. It's going somewhere and if you've done your homework it'll be down the barrel and out the muzzle not back at you and everyone goes home safe.

Take a look at the cover of that Hornady Manual. See those hands holding the calipers and tools in the pic? Those are my hands. lol.

Edit: My bad. Wrong edition. The below edition are my hands. Your right....getting a good grasp on those pages is really a must for reloader. I think those pages are largely unchanged over the years.....and those pages in the third edition served as the basis for my product(s) development a long time ago. The manual I was referring to is this one:

I have not looked at recent editions of the Hornady Manuals. I ASSUME that all the editions would have this same basis of reloading know-how?

 

[Wind Gypsy]

We've got a legend in our presence gents!

 

[Foggy47]

We've got a legend in our presence gents!

No legend. Down here in OZ.....I play golf with allot retired guys that we call "PIPs": Preveiously Important People. Many of these old codgers are used to telling other folks how to do things.....so we call them PIP's. Mostly out dated, irrelevant retired folks now. lol.

 

[Foggy47]

A little story......'cause all us old guys like to tell stories. grin.

In the 80's I spent most of one winter doing "cut and try" efforts to make a bullet seating depth gauge. And I found the means to do so with some refinements needed. The biggest refinement being to make a rifle case that could be threaded onto the tool I made. I had to get some extra fine threads in order to have enough brass left to not break on the smaller cases like 223 Remington.......so that took some effort to arrive at a solution. Also had to be universal in nature and relatively affordable. I spent allot of hours perfecting the various tools that go along with what is now known as the OAL Gauge. I had to design and have built some aluminum extrusion dies and developed a relationship with a good machine shop to machine the parts.....etc, etc, etc.

First stop I made was to Camp Perry at the NRA National Shooting Matches. I set up a small stand and sold allot of product to some knowledgable shooters. I figured if anyone had doubts or concerns in the design I would learn from them. Nope....was good......so I went for a visit to Sinclair International (whom became good freinds to me) and sold them on the goods. They started to catalog the product soon after and my sales grew. Still I was working as a salesman for an aluminum mill days.....and assembling product nights and weekends.

I used the company car and hooked a U-haul trailer to it.....and went to Houston to the SHOT Show in Jan of 1990 (IIRC). I had lots of product along to sell.....and did not know that you really did not sell at the SHOT Show....but rather would show your products to the industry and take orders. Few people delivered goods at the show. I had a neat display with a cutaway gun to demo the product......and show folks how it worked. I felt like a "carnival barker" at times as the crowd would stand 5 or 6 deep and listen to me pitch these revolutionary tools. I told folks that if they filled out our order form and paid cash.....we could put together their order and have it ready for their pick up the next day. I needed the money....lol.

I had a barrel manufacturer from Australia whip off his money belt and buy several thousand dollars of product on the spot. Also had one guy with a fictional name badge watch my demo repeatably. That was Jim Carmichael from Guns and Ammo....and he wrote a fantastic piece that would sell allot of product for me. Had other writers do artlcles too and found our products in most all the gun magazines over the next few months with feature articles on this products. And I was off to the races. At that time I had the OAL Gauge, Bullet Comparators, early model Bore Guides (cleaning rod guides), and a target stand to sell. Revolutionary stuff back then.

Anyway.....I think I sold about $40,000+ in cash sales at that first SHOT show and had orders for lots more......and most importantly the free articles by some of the best gun writers in the industry. At that time most gun nuts were all about the monthly magazines we all would read. (later it was the TV hunting shows). At that time most of the reloading biz was quickly becoming "mail order" business's. And folks like Midway were just selling off a two-page flyer they would mail out. They were quite small at that time....mostly selling bulk bullets and brass.

On the way home from that first SHOT show.....I gave two weeks notice that I was gonna quit the Aluminum company.......meanwhile driving their car and pulling a U Haul trailer with their trade show booth in the trailer and calling on their cell phone (bag phone at that time). lol. I though my wife was gonna kill me that day. But she soon learned that good days were to follow.

Fun telling old stories of the start up for Stoney Point. I digress.

 

[Catscratch]

A little story......'cause all us old guys like to tell stories. grin.

In the 80's I spent most of one winter doing "cut and try" efforts to make a bullet seating depth gauge. And I found the means to do so with some refinements needed. The biggest refinement being to make a rifle case that could be threaded onto the tool I made. I had to get some extra fine threads in order to have enough brass left to not break on the smaller cases like 223 Remington.......so that took some effort to arrive at a solution. Also had to be universal in nature and relatively affordable. I spent allot of hours perfecting the various tools that go along with what is now known as the OAL Gauge. I had to design and have built some aluminum extrusion dies and developed a relationship with a good machine shop to machine the parts.....etc, etc, etc.

First stop I made was to Camp Perry at the NRA National Shooting Matches. I set up a small stand and sold allot of product to some knowledgable shooters. I figured if anyone had doubts or concerns in the design I would learn from them. Nope....was good......so I went for a visit to Sinclair International (whom became good freinds to me) and sold them on the goods. They started to catalog the product soon after and my sales grew. Still I was working as a salesman for an aluminum mill days.....and assembling product nights and weekends.

I used the company car and hooked a U-haul trailer to it.....and went to Houston to the SHOT Show in Jan of 1990 (IIRC). I had lots of product along to sell.....and did not know that you really did not sell at the SHOT Show....but rather would show your products to the industry and take orders. Few people delivered goods at the show. I had a neat display with a cutaway gun to demo the product......and show folks how it worked. I felt like a "carnival barker" at times as the crowd would stand 5 or 6 deep and listen to me pitch these revolutionary tools. I told folks that if they filled out our order form and paid cash.....we could put together their order and have it ready for their pick up the next day. I needed the money....lol.

I had a barrel manufacturer from Australia whip off his money belt and buy several thousand dollars of product on the spot. Also had one guy with a fictional name badge watch my demo repeatably. That was Jim Carmichael from Guns and Ammo....and he wrote a fantastic piece that would sell allot of product for me. Had other writers do artlcles too and found our products in most all the gun magazines over the next few months with feature articles on this products. And I was off to the races. At that time I had the OAL Gauge, Bullet Comparators, early model Bore Guides (cleaning rod guides), and a target stand to sell. Revolutionary stuff back then.

Anyway.....I think I sold about $40,000+ in cash sales at that first SHOT show and had orders for lots more......and most importantly the free articles by some of the best gun writers in the industry. At that time most gun nuts were all about the monthly magazines we all would read. (later it was the TV hunting shows). At that time most of the reloading biz was quickly becoming "mail order" business's. And folks like Midway were just selling off a two-page flyer they would mail out. They were quite small at that time....mostly selling bulk bullets and brass.

On the way home from that first SHOT show.....I gave two weeks notice that I was gonna quit the Aluminum company.......meanwhile driving their car and pulling a U Haul trailer with their trade show booth in the trailer and calling on their cell phone (bag phone at that time). lol. I though my wife was gonna kill me that day. But she soon learned that good days were to follow.

Fun telling old stories of the start up for Stoney Point. I digress.

I've heard you tell the story before... and never get tired of it! Truly inspirational!

 

[Wind Gypsy]

I love it @Foggy47!

Creating stuff that truly has become standard equipment for reloaders and shooters.

And Hornady was smart enough to buy it!