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6.5 Mauser Thought.


ghost95

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Hello all, I have begun yet another project. Maybe one day I'll get one of these completed. Anyway, it's a Mauser 6.5 sporter on a Swedish '96 action.

 

I was reading about the load and I came across a picture of a Mauser bolt where both lugs had been sheared off. It was on a castboolits forum. There was no other info available but it appeared to be a classic overpressure just by looking at the brass. What got me thinking was all the comments from people who handload for this cartridge.

 

I know the rifle used lower pressure rounds between 45k and 50k psi but everyone talks about loading until they see pressure signs and then backing it off a little bit. That didn't seem right.

 

To me it seems that pressure has to do with the round not the rifle that it is fired from so...how would pressure signs in a 6.5 differ from those of a '06? If it takes 65k psi to show as pressure in a Remington 700 wouldn't it take 65k psi to show pressure in a 6.5 Mauser. I know that there are pressure curves that may partially explain this but a flattened primer is a flattened primer (assuming you are at the top of the loading data) right?

I felt that I was pretty competent in reloading but now I have questions that make me a little unsure of myself.

 

It seems like working up to signs of pressure in a 6.5 will take you out of the design spec in a hurry. With the pressures that this round was designed to operate at should you ever see pressure signs?

 

Thanks for any light you all can shed on this.

 

C-

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Even tho there are defenant start and stop limits with hand loading, they should be worked up to in small steps. Lets say you have what looks like on the outside to be two, identical rifles, you may see pressure signs at different load charges between the two. If one has a longer headspace than the other it may make a differane when reaching the upper limit of a load charge. one may be throughted longer than the other, there are a lot of factors to figure in. Thats why no two like rifles will like the same exact loading the best. A low powder charge can in a lot of cases, be more distructive than an over charge, that's taking for granted you are using the right powder for the cartridg you are trying to load and didn't get it mixed up with another powder, like H-4895 VS IMR 4895. Without knowing all the details it's hard to say why the bolt sheered the lugs off. A taylored hand load is just that, and for the rifle you worked it up in, not your neighbors or friends rifle. My dad has been loading for over 40 years, and it used to piss me off that he wouldn't give me the exact charge weight he was using, all he would give me is the type of powder and which bullet he was using and would tell me I'd just have to work up and find out what my rifle liked. It took me many years to understand why he did it that way.

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Thanks for the reply. I think I may not be explaining my self well.

 

I understand that there are different loads to reach pressure signs but are there different pressures that make them appear?

 

Let's say it takes 65k psi to flatten a primer in a 6.5 x 55 Rem.700. Wouldn't it still take 65k psi. to flatten the primer in a 6.5 x 55 mauser?

 

It doesn't make sense that pressure signs would appear at lower pressures in different rifles and yet there is a ton of advice to load to pressure signs and then back off a bit regardless of the rifle. It may all be internet BS but there is so much of it out there that it gets confusing.

 

It seems to me that the small ring action, if loaded to the pressures it was designed to handle, should never be capable of showing pressure signs. Or am I wrong?

 

I hope I helped explain my question a bit better.

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First compairing a 96 Sweed to a Rem 700 is like compairing a VW to a chevy. They all function kinda the same, how are they throuted, the one with the longest throught=free bore, will usually show the less pressiour signs .

 

The rifle with the loosest headspace will probably show pressoiur signs first when getting on the high side or going slightly over the loading data stop point

 

Always look at what was used to reach this published data, they will usually say what rifle they used, and sometimes how long the barrel was, OR they will say data was collected using a test barrel. Which is not a rifle, as we know it

 

If you know anyone that has used a crony and try to match certin velositys bublished in any book, they are very lucky if they did. their are people that have sold their guns because they didn't reach the same speeds published in some book.

 

And last no one wants to admit they made a mistake, because usually in the first paragrapf that comes with every new rifle, it says something like always make sure gun is pointed in a safe direction, and not recomended to use hand loads and if you do it voids the warrenty among other things. But we all know that things get shot that were not ment to, and guns sometimes blow apart, but 99% of the time no one did anything wrong?

 

I don't have a book in front of me so I can't say what SAMMI calls out for 6.5x55 pressiour, I know the rem 700 can hold most anything you can fit into it correctly. The 96 sweed was chambered for the 6.5x55 and all small ring actions have pressiour limits, even given the action and barrel are in good shape. but if all is good the 96 action should hold up if the ammo is loaded correctly within the published limits. Seeting the bullets out into the lands can make pressiour shy rocket.

 

Get a copy of the Lyman loading manual and read the first section about reloading, and then reread it, there is a lot of good information in there.

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OK, given it some thought, and here is my take.

 

You have a very relevent question regarding the fired primer condition as pressure indicator. And IMO anyone who uses only that as the upper parameter for their loading is just waiting for a bolt in the face. Because they are baseing their loading safety on the structural integrety of a primer as opposed to that of their rifle. Just as you suggest.

 

It is also a very straight forward question. But I don't have a simple straight forward answer. Because my head just doesn't work that way when pondering a subject that is influenced by a plethora of variables, all of which are relevent.

 

People who purposely load up to the level of imminent primer failure are just damn fools. I personally put them in the same class as internet EGG-SPURTS who live in their Mom's basement and giggle uncontrollably while making things go BOOM.

 

That pressure indicator is a usefull EARLY WARNING system. Not a GOAL TO BE REACHED.

 

If while following PROPER SAFE loading technique of choosing compatible components for the round assembled and starting at start level by reputable loading manual and working up slowly with small weight increases you experience hard bolt lift and flattened primers before getting anywhere close to Max published data. Something isn't right. If you intentionally sit down and purposely start loading until something goes wrong. Then you aren't right. In the head.

 

The difference between magnum and standard primers isn't a stronger cup, it is only a slightly longer flash time to light heavier loads of slow powder.

 

Big stomper magnums operate close to 70k psi. Small Ring Mauser ammo is rated at about 50k psi. Same primer cups are used in both type ammo. Consistant loads with flattened primers may cause no harm in a modern rifle designed for sustained fire with magnum cartridges. But the same loads in a SR Mauser are causing unseen damage to lug seats, lugs, ring stretch, excess headspace, etc, etc. Accumulated over time these things will eventually cause a catastrophic failure. Usually though damage is caused by head separations, blown primers, etc all of which can and will damage rifle and shooter alike before a catastrophic failure.

 

Don't exceed maximum charges listed in reputable loading manuals. You have to trust that the actual ballisticians with engineering degrees who work for rifle, ammo, and component makers know more about structural integrity of rifles and ammunition components than the basement giggler. They have millions of dollars worth of tricky toys to measure pressure curves and max levels that loaders can't afford or know how to use if we could.

 

JM2c

 

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Thanks guys. I'm really not interested in hot loads, just accurate ones. I know that sometimes the most accurate loads are a little on the hot side sometimes on the low side. My question was more specifically about pressure signs in general. I think I'm getting a bit of an idea between here and conversations among friends at work. I do tend to get a lot of answers about which action is stronger and how you can't compare a Rem.700 to a 96 Mauser. That part is academic.

 

Also I'm not hung up on the primer thing but rather any sign of excess pressure.

 

I am still having a hard time wrapping my head around the pressure thing though. I understand the effects of excessive headspace and seating bullets into the lands and such but those things CAUSE high pressures. Im trying to get my brain around what happens after the pressure develops because that instant is what will do the damage.

 

Let's say a case will show pressure signs at 65k psi with load A.

 

Then we make up load B which also develops 65k psi but with a slower powder.

 

Will load B also show signs of pressure because 65k psi is 65k psi or, is it possible that it will not show signs because the time to develop the 65k psi was slower? (assuming all other variables are the same)

 

C-

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I guess you could use this same question for velocity.

 

If load A develops 60k psi and pushes a 150 grain bullet at 3000 fps...

 

Would load B that also develops 60k psi but at a slower rate still produce a velocity of 3000fps with all other things being equal?

 

60k is 60k right?

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I think yes, their are a lot of things hapening all at the same time and very fast as to interiour ballistics, powder is very complex in it's makeup it's self you could read for weeks everything you could find and still leave your self asking questions.

 

Each cartridg has it's own pressiour limit set baised on a number of things. The brass may be thicker inside on say a 30-30 than on say a 22-250, as the cases were built different for the different aplacations / lever action VS modern type bolt action. Still even tho the action may be able to with hold the pressiour, the case will fail when loaded to hot for the particular case. Find a Hornady loading book and look at the 257 roberts, and or 45-70 pages and read the first page in each and it will let you know a little about thy the loadings are what they are, now they also have a section like for the 45-70/TC hotter loadings NOT ment for the old Trapdoor type 45-70 guns.

 

Gi brass is thicker than commercial brass is built, so if you are loading each the same you may be loading the gi brass a little on the worm side. I always thought my dad among other things was to ANAL about his reloading, because he seperated each piece of brass by brand, and worked up loads seperate just to make sure if their was a difference he didn't get in a bind and have a miss hap. You need to keep notes of everything you have tried and what worked and what didn't for future refferance, or you may be repeting the same test later, or taking your life in your own hands, which is the reason why I won't shoot other peoples reloads.

 

All I can say is read, read and read more, but read good published material, not something that was just posted on some fourm with no details on how they found out what they found out.

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This is a post I made quite some time ago on another forum in relation to a protruding primer and "low pressure" causation question. But thought you might find it relevent because it explains what happens to a cartridge internally during ignition.

 

 

 

It often helps in evaluating whether a problem is pressure or headspace related to know the sequence of events that happen in the chamber in the small part of a sec. at time if ignition.

1- primer is struck by firing pin pushing entire cartridge as far forward as possible. " forward and back motion governed by headspace"

2-primer ignites powder, and pressure starts to build.

3-bullet starts to move forward with pressure as case starts to expand.

4-as bullet moves forward, primer starts to move back, then case moves back as it continues to expand. When case has moved back as far a possible against bolt face it has reseated primer and case expands to max. sealing chamber completely. It remains so until bullet has cleared muzzle and pressure drops to zero.

5-Without internal pressure, case contracts and no longer seals chamber. Allowing easy extraction.

With a to low in pressure load, as case moves back and bullet moves forward. The case does not move back far enough to reseat primer and allow base to contact bolt face before case expands to max. and grips chamber walls. Hence protruding primer. Another low pressure indicator is smoky/sooty case necks after firing.

A rough or pitted chamber can cause same condition. As case starts to expand { bullet moving forward, primer moving backwards} if chamber is rough, brass grabs irregularities in chamber walls as it starts to expand and does not move rearward as much as it should to reseat primer.

 

 

 

 

I am still having a hard time wrapping my head around the pressure thing though. I understand the effects of excessive headspace and seating bullets into the lands and such but those things CAUSE high pressures. Im trying to get my brain around what happens after the pressure develops because that instant is what will do the damage.

 

Let's say a case will show pressure signs at 65k psi with load A.

 

Then we make up load B which also develops 65k psi but with a slower powder.

 

Will load B also show signs of pressure because 65k psi is 65k psi or, is it possible that it will not show signs because the time to develop the 65k psi was slower? (assuming all other variables are the same)

 

Lets deal with the common misconception that excessive headspace causes higher pressure. It does not. If anything it slightly decreases internal pressure because it creates a larger pressure vessel. What it does do is allow the improperly supported brass case to be over stressed and fail causing the misconception.

 

Your load A to load B comparison is correct. 65k is 65K and max. pressure level is not time related even thought it happens at different times with different powders. MAX is MAX. It is an absolute.

 

 

 

I guess you could use this same question for velocity.

 

If load A develops 60k psi and pushes a 150 grain bullet at 3000 fps...

 

Would load B that also develops 60k psi but at a slower rate still produce a velocity of 3000fps with all other things being equal?

 

60k is 60k right?

 

NOPE

 

Max pressure is Max pressure. It is an absolute. But even though the MAP or "max absolute pressure" remains the same for A and B. You have now added "time" to the equation in computing "velocity". That is where the "pressure curve" you mentioned earlier comes into play. Because it is time/pressure related and governs "velocity" in a given rifle. As does a third factor which is "plasma" generated. Plasma is the superheated expanding gases generated by the combustion of the powder in the case.

 

Over simplified example would be.

 

Large capacity rifle case loaded with enough "Bullseye" to create 60k MAP psi with a 150 gr boolit. Compared to same case/boolit but loaded with enough IMR 4831 to create 60k MAP psi.

 

A-Bullseye load would reach MAP extremely fast with a short PC and very little plasma generated. Likely the boolit would have reached max velocity within a few inches of leaving the case and actually be decelerating before it reached the muzzle.

 

B-4831 load would reach MAP slower creating a longer PC and do so while creating many times more plasma in the process and continue accelerating the bullet to the muzzle.

 

JM2c


 

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Ok, I think I have a better idea about what I was asking. Thanks pacrat.

 

What I conclude form this is that in a Swedish Mauser, with a properly sized chamber and good bolt, and a properly sized case and seated bullet, I should probably not ever see pressure signs if loading to the published data for the older actions. Even to max loads.

 

Pressures signs don't seem to start showing on cases in properly sized rifles and components until pressures quite a bit beyond the max listed 50k to 52k are reached. Also, it is possible to have a load for a Swedish Mauser that shows no signs of excess pressure but is quite a bit beyond the "generally recommended" operating pressure of the action.

 

Basically, I can over pressure the action before I over pressure the components in an older action like this.

 

Thanks again. I think I have a clearer picture of this now.

C-

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What I conclude form this is that in a Swedish Mauser, with a properly sized chamber and good bolt, and a properly sized case and seated bullet, I should probably not ever see pressure signs if loading to the published data for the older actions. Even to max loads.

 

Correct as far as primer indications go. The wonderfull 6.5x55 does not rely on high pressure and big boomer magnumitis velocity loads for its much acclaimed efficiency and long range accuracy. It is an almost perfect balance all built around its long for bore dia high BC bullet design.

 

Other pressure indicators are a stiffer bolt lift. Shiny ring around web of fired case. Rough extraction. Sharp recoil increase with small increment charge increase. All of these things are telling us something. We just have to listen and use accumulated knowledge to intrepret what they are saying.

 

Best to remember a simple........"all things are variable, all variables are relevent." If you change one thing it also creates variables as to how the other components interact. Something as simple as changing from a Spitzer boolit to a RN design of the same weight will create different pressure levels with the same powder charge. Because of the variable of bearing surface.

 

An example of this is the new All Copper boolits. They are longer and have more bearing surface than lead cores because they are a lighter metal. Thus even when same weight they increase pressure. Even then another variable is Nosler E-tips v Barnes TSX in a 270 they are both 130 gr spitzers of all copper construction. Yet the E-tip creates much higher pressures than the TSX. Nosler made the E-tip just like a lead core with smooth sides and high resistance. The TSX has bearing bands on the sides and the rifling rides on these, lowering comparative pressure by lowering resistance.

 

 

Take Lemski's advice and read, read, read from reputable established sources within the shooting community. The Lyman Manuals are good books. I have several dating back to the 1950's. along with about a dozen others. Those folks with the actual ballistic laboratories and all the years of experience using them have your best interest foremost.

 

The giggler in Mom's basement making Big Booms and posting on the internet who thinks he's smarter than all those ballisticians and Paul Mauser................well he just isn't. :blink:

 

Be safe, load safe, shoot safe.

 

JM2c

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Thanks for the info. I think I'm back on track. The comments about pressures in the Sweed that I am building just got me to thinking. I mean I've talked to people who have loaded up hot pistol rounds that were beginning to show pressure signs and they were doing that at, I'm guessing, 25k psi. When I looked at things like that everything got a little fuzzy. Maybe they weren't true pressure signs but a manifestation of something else that is in handguns specifically.

 

The reading I was doing on the interwebz made it sound like the signs of excess pressure appeared at different levels for different rifles. I.E. signs appear in a Rem. 700 at 65k psi. but it only takes 57k psi. to show up in a Mauser. That seemed wrong, and it was. Pressure is pressure as far as the receiver is concerned.

 

Thanks again for the help. Maybe one of these days you all will get to see a picture of a rifle I actually complete. I'm getting close. C-

 

P.S. I still giggle when I make things go Boom. I just prefer it to be more than 1/4" from my nose. Tannerite is awesome!

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P.S. I still giggle when I make things go Boom. I just prefer it to be more than 1/4" from my nose. Tannerite is awesome!

 

OK Dude, go to Mom's house and blast off a pound of Tannerite in her basement and see how much SHE giggles.

 

:o;):D:lol:

 

Just kiddin...............Yes Tannerite is fun stuff............at a distance. ;)

 

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Yeah, not a good idea. Years ago she was highly unimpressed with the dry ice and a coke bottle thing.

 

I told her it was educational. We learned about in science class at school.

 

Even that was small compared to the time she caught me throwing the old glass 1ltr. coke bottles full of gas into a bonfire. I was 5.

 

I'm surprised she has managed to keep a grip on her sanity after all these years. Strong woman she is. :lol:

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  • 2 years later...

For wildcats I either get to the velocity I was after or I get sticky bolt. Sticky bolt tells me I'm at least a grain over. Loose primer pockets in the absence of sticky bolt is also a 1 grain over sign.

Every rifle is different. Some build pressure before you ever thought they would. Others you have a hard time getting enough powder in the case.

 

I'd never try to hot rod a semiauto or lever action. 'Tis a dangerous game we play (of course if it wasn't it wouldn't be worth playing).

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