6.5 Credmoor vs 7mm-08

[BEEMAN]

I don't feel that I am in danger of blowing up any of my rifles. I am not the expert that some of you guys are but I don't feel I am a beginner. toddc I totally agree with what you say about top end components. My 300 WM shoots the 215 Berger at 2995 fps but I also had BROZ help me with the reamer specs. I feel this combined with the Borden action and Brux barrel gives me these velocities. This 300 WM will actually shoot the 215 Berger almost as fast as my 300 RUM Sendero. Did a quick search and my X47 is right in line with other guys loading 42 gr of H4350. This is a great site for guys like me trying to learn. Hope this hasn't highjacked the thread to bad. Sorry if it did, that was not my intention when I brought up the 6.5X47.

 

[catamountsierra]

I think for deer or with factory rifles either caliber would be great. My experience is with the 7mm-08 in a factory R700 ADL. My go-to hunting load has been a 140gr AB at around 2800ish; though I haven't yet had a chance to chrono it. I am also looking to work up loads and see what it will do with 150gr ABLR and 162gr ELD-X bullets. I think the 162 is about as heavy as I would recommend for the 7mm-08, and even then I think it best to load them as long as possible so you aren't losing as much case capacity. In a couple years I will need to get a rifle for my kids to start hunting with, and am toying with both of these caliber options in something like a Ruger American. Recoil in my 7mm-08 is very tolerable but with good bullets it should be enough for even elk out to 3-400 yards, as long as the shooter can do their part; the same would be arguably true of the 6.5CM too.

 

[adam32]

Because they are wringing out that PARTICULAR barrel, action, brass, primer and powder combo. Just like the manuals say "These are recommended loads not necessarily safe in YOUR rifle". Why should someone running Lapua brass, custom action, fast barrel and HBN have to run the same loads as a guy shooting RP on an action with only one lug touching at 25% contact, a patchy barrel and a lot of oversize bullets?
There are too many variables present for a book max to be safe OR be anywhere near any particular rifles max.
I guess that's why we work up loads.

They shouldn't have to run the same loads.

All I'm getting at is that if you want to keep up with a bigger casing then get the bigger casing to start with. I'm all for getting the most out of a cartridge, but everything has it's limits and if 50 fps slower in a x47 compared to a .260 or Creed is that big of a deal then get the bigger casing to start with and be even happier gun)

 

[Dgd6mm]

how do you know that? Because you run under a max book load? Really doesn't mean anything other than you are under max book load. This whole thread devolved into a discussion of visible pressure signs, none of which will accurately show the psi you are at. My ar creed will run 2 gr over max of superperformance and yet 1gr under max of rl17 scares me to death. Without an accurate pressure system we are all running in the dark to some extent. Book max is a guideline as always and nothing more.

never mentioned book.....todd.....you make me laugh..... You act like no body but you knows anything..... About reading pressure ..... You have not taught me a thing in this thread yet.....

 

[toddc]

never mentioned book.....todd.....you make me laugh..... You act like no body but you knows anything..... About reading pressure ..... You have not taught me a thing in this thread yet.....

Just saying we are all running in the dark when it comes to actual PSI unless we are spending the $$$ on a measurement system. Wildcatting and reloading in general is STILL the wild west. A lot of stuff we think we know, we don't have any real proof of and the factories won't involve themselves to any real extent other than saying "Work up loads to max blablabla". Same stuff they have been saying since the 20s.
Yeah I jerked your chain a bit. Sorry.

 

[J E Custom]

I'm just not sure why anyone would want to push the envelope that hard...if you want to push a bullet faster then step up to a bigger case...

+ 1
Well said !!!!!

When I was young and bullet proof I pushed many cartridges to and beyond there limit. The end results were always predictable But I lived with it and thought it was necessary to get the velocity and trajectory I wanted. Some of these rifles actually liked the overpressure loads and shot better the faster I pushed them.

As I got older and wiser, I realized that there was a better way than sacrificing brass on a single loading and washing out a barrel after 6 or 700 rounds. The simple solution was to increase case capacity, bullet weight and lengthen barrel length to get everything I wanted without trashing brass, and setting the recoil lugs back.

Now when I build or wildcat a cartridge, I decide what performance level I want for it's intended use, with the bullet I would "Like " to use and go from there with a max PSI pressure of 63,000 PSI that will achieve that level of performance. With these parameters decided it is easy to pick a cartridge that will fill my needs without over stressing the cartridge.

Every cartridge has its limits and if you stay within those limits they are very dependable and safe.
with as many different choices of cartridges as we have today, There is no reason to push a cartridge
beyond safe pressure levels unless the shooter knows the risk and excepts them.

Sometimes the person only has a couple of rifles and feels the need to push one to get more velocity
and exceeds max pressure. In reality the difference in performance is very little from near max pressure to over pressure but the problems increase as pressure goes up.

Just the opinion of someone that has been there and done that.

J E CUSTOM

 

[WildRose]

Exactly because of what I have been saying. Wildrose's point which is 100% correct is that the two cartridges loaded to the same pressures yields the 260 outrunning the 47. It's math.
The real world reality is that the 47 can run REALLY close to the 260 because of brass design, thickness and primer/flash hole, without SHOWING pressure. The pressure is there, we just don't see it.
Lots of guys run the 47 almost as fast as a 260 because they CAN. They are over pressure but there are no SIGNS of it.
Build a 260 with brass with the same thickness, hardness and a small primer hole and pocket and you can compare apples to apples. That isn't the real world most live in however.
Guys running the 47 in the same area as the 260 are doing it by relying on the brass to hold over SAAMI pressure and are getting away with what would cause issues in a 260 or Creed.
This kind of stuff is more common than many realize. There is Wildrose's version of internal ballistics which is THEROTECIALLY and ABSOLUTELY CORRECT and your version of real world ballistics which is REALISTICALLY CORRECT.
You can run your 47 nearly as fast as a 260, however you are doing it at a higher pressure than the 260 and the brass is masking your pressure signs. Happens every day. Doesn't make it smart and there is always the chance that ONE particular piece of brass or primer out of 1000 won't handle it and you will have primer in your eyes.
I have seen this stuff many, many times. Not only does brass MASK pressure signs, but actions, primers, barrels and powders do also.
Lots of guys are running over SAAMI to achieve the velocity that they do. Some combinations ALLOW this and others won't. A stock non trued action will USUALLY show pressure before a custom. Some chambers because of finish will SHOW less pressure than others. Tons of variables that allow people to REALISTICALLY achieve that which is THEORETICALLY impossible by CHEATING the pressure gods.
Wildrose is RIGHT. The 260 loaded the same way as the 47 will outrun it. Just a lot of guys run the 47 hotter than the 260 and get away with it for the most part due to a lot of different factors.
Run both loads thru Quickload and actually MEASURE pressure not pressure SIGNS and the 260 is faster.
Load both to show pressure SIGNS and who knows which will cry uncle first.
Unfortunately the real world we load to SIGNS not PRESSURE. If we had commonly available pressure testing systems that EVERYONE used there would be a lot less talk of the 47 running in the same league as the 260. Until we do, guys will hotrod stuff and SOME will pay for it sooner or later.

We don't have to load the 260 to dangerously high pressures to get higher velocities, we can achieve higher velocities with slower burning powders and higher volumes of those powders.

 

[WildRose]

You are dealing with exactly what I have been talking about. Your setup will MASK pressure incredibly well. If you are running MUCH over published data you are PROBABLY over. You will most likely be fine but anytime you are running faster than you should be, there is a risk. The only way a 47 will run with a 260 is by being over SAAMI. You can realistically get away with it but as Wildrose has pointed out there are no free lunches. Loading to pressure signs and backing down a bit has been done forever. It works but results in a lot of guys running over THEORETICAL max.

No, if you are running good, reliable reloading data you can see what the MEASURED pressure of the recommended loads are.

They also give you their data on the test barrels used.

 

[toddc]

No, if you are running good, reliable reloading data you can see what the MEASURED pressure of the recommended loads are.

They also give you their data on the test barrels used.

Maybe I am dense. Ok I am probably dense but how will that give anyone a real idea of pressure in their setup?
I understand it will give you a ball park idea but how would it do anything more?
The velocity may match, load may match, but powder, bullet size, case capacity, chamber, barrel surface and size, can all vary.
Yes you would probably be close but HOW CLOSE? 500 PSI? 1000? 50? 2500? IDK and don't really know how anyone would according to what the companies have always said.

If I run a lot of bullets that is .0001 larger, and a lot of powder that is 4% hotter and yet I load the exact same load, and it runs the exact FPS as the factory data, am I running the same PSI? Doesn't seem like I would be unless you simplify things and say that 63k under a certain bullet will always yield a certain FPS. I can buy that a certain area under the curve would yield a certain velocity with a certain load, but not that a peak PSI will.

And yes this stuff is over my pay grade which is why I always am happy to run near book and other guys data. I honestly cannot see how the factory pressure data will equal what I am really getting. Might be close BUT might not be. IDK Wildrose am I crazy or just thinking about it in the wrong way? And yes I do realize I am splitting hairs but math is math and if it was as simple as just matching the factory #s with dissimilar setups then why would we need to work up and why would velocity and pressure EVER surprise anyone?

Honest question also not trying to stir the pot.

 

[BEEMAN]

Very well said toddc. To many variables to know exactly what the pressure will be. As you said we just have to work up our loads and look for pressure signs the best we can.

 

[toddc]

Very well said toddc. To many variables to know exactly what the pressure will be. As you said we just have to work up our loads and look for pressure signs the best we can.

I wasn't saying, I was 100% asking. I may be wrong. I don't understand what WildRose was saying really.

 

[BEEMAN]

I think as mentioned earlier, without expensive specialized equipment we are all just guessing. But with that said starting near minimum and working up to pressure must still be done to be safe in my opinion. A good example I always think of is my 6.5 Sherman. Myself and a friend both have one and both used 270 Nosler brass. I spoke with Rich and started at his minimum loads and was blowing out primers!! Came to find out my lot of Nosler brass was 23 grains heavier than my friends lot. This combined with my barrel being a tighter bore resulted in me being way over pressure at starting loads. I know always start way low and weigh all my brass. Was a scary experience but a good learning experience at the same time.

 

[WildRose]

Maybe I am dense. Ok I am probably dense but how will that give anyone a real idea of pressure in their setup?
I understand it will give you a ball park idea but how would it do anything more?
The velocity may match, load may match, but powder, bullet size, case capacity, chamber, barrel surface and size, can all vary.
Yes you would probably be close but HOW CLOSE? 500 PSI? 1000? 50? 2500? IDK and don't really know how anyone would according to what the companies have always said.

If I run a lot of bullets that is .0001 larger, and a lot of powder that is 4% hotter and yet I load the exact same load, and it runs the exact FPS as the factory data, am I running the same PSI? Doesn't seem like I would be unless you simplify things and say that 63k under a certain bullet will always yield a certain FPS. I can buy that a certain area under the curve would yield a certain velocity with a certain load, but not that a peak PSI will.

And yes this stuff is over my pay grade which is why I always am happy to run near book and other guys data. I honestly cannot see how the factory pressure data will equal what I am really getting. Might be close BUT might not be. IDK Wildrose am I crazy or just thinking about it in the wrong way? And yes I do realize I am splitting hairs but math is math and if it was as simple as just matching the factory #s with dissimilar setups then why would we need to work up and why would velocity and pressure EVER surprise anyone?

Honest question also not trying to stir the pot.

If you stick with what they recommend and have a similar set up and components you should be extremely close.

Change components, start jamming it into the lands and yes, you'll very quickly find yourself well outside of the published results.

They go to a lot of time, money, and work to provide us that data all of which would be a complete waste if it didn't help us to be able to duplicate their results with a high level of confidence.

 

[gohring3006]

All very good points....

I have used start loads and worked up to max load in my rifle for years.
I watch velocity and the the usual pressure signs, and it has worked well.
Not sure what else we can do, short of pressure trace equipment..