>> 6.5 mm -- is this the "perfect" caliber ?

Started by LLANOJOHN (deceased), January 14, 2005, 03:22:22 PM

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sakorick

Quote from: 2ndtimerThis brings up the question of just how hot the loading manuals loads are. Most of them don't say what pressure their 6.5x55 loads are, and leaves us wondering if they are held down to "prudent" 6.5x55 pressure levels, hence can be safely exceeded within reason by shooters using modern bolt actions. For instance, one manual lists 46 gr of IMR-4350, standard primer, 129 gr Hornady bullet as a maximum load. What it doesn't say is whether that is a 50,000 cup load or a 44,000 cup load..
So, what is a modern bolt action????? I just don't get it....Have you ever seen a sweedish 6.5/55 bolt? My goodness, it has 3 huge locking lugs made of steel that is every bit a good as the stuff they are using now....maybe  better. The germans used the highest grade steel on the planet with 3 locking lugs not counting  the bolt in the mod 98.....looked at a rem 700 bolt lately????  Common sense says these Mauser rifles are up to the task. I have reloading manuals that range from 1965 to now......a constant dumb down. I shot some factory 170gr 8x57mm Rem bullets that chronied at a whopping 2250'/sec. Someone please help  me here.....does everyone have to junk their Mausers......does that mean all the HVA, PH's Bruno's and Zavodi's of the world can't shoot decent loads safely?? IMHO...Ludicrous.  You have a better chance at action failure with a new Tikka or Remington with dumb down factory ammo than a 50 year old Mauser.......the  last rifle I heard of that blew up was a Tikka, 1 year old!! Regards, Rick.
Talk to yourself. There are times you need expert advice.

CAfrica

The only "standard" downloaded ammunition for Mauser rifles that I know of is the 8mm loads (8X57).  The reason for this (apparently) is that the original J mausers had the smaller bore (.318) as opposed to the later S (or JS models .323).  USA being what it is with law suits, the manufacturers are natuarally concerned that some dolt will fire an S in an old J rifle and blow it up in his face.  Thus, factory loaded 8X57 loads are loaded very mild. (That explains those low 2000ft/s velocities Sakorick relates).
 
By the way, every "failure" I have ever heard of concerned the bbl, not the action But then I don't keep tabs on these things and maybe someone can enlighten me to the "action" failures that occur in Mauser rifles.
 
Regards.
 
C

overbore

2ndtimer,  Hot off the computer  is this data:
 
  I entered the program with this data:
  Hornady 129grsp (sp2620)
  6.5 X55 Sweede
  H-4350 powder;
  charge 46.0 gr
  26" barrel ( optimistic ) ; SUBTRACT ABOUT 26FPS/ SHORTER INCH
 
  PROGRAM SAYS:  "MV= 2,825'/SEC
  CHAMBER PSI IS  48,764 , WARM LOADING
 LOA IS 3.150" FOR LOADING DENSITY OF 91.1%. iT APPEARS WARM BUT SAFE UP TO 75 DEGREES. ALL CAUTIONS APPLY. OVERBORE
 

overbore

May I respectfully refer all to the following link:  for all to evaluate for themselves the 10 shot throat errosion  with dangerous pressure rises in a 6.5.. Mauser.  In today's litigous environment, none are immume from law suits and especially the providers of reloading info.  You should see the Quick Load warnings in red and the agreement one must ascribe to before going to data.  CYA is the name of the game. Overbore

2ndtimer

Quote from: overbore2ndtimer,  Hot off the computer  is this data:
   
   I entered the program with this data:
   Hornady 129grsp (sp2620)
   6.5 X55 Sweede
   H-4350 powder;
   charge 46.0 gr
   26" barrel ( optimistic ) ; SUBTRACT ABOUT 26FPS/ SHORTER INCH
   
   PROGRAM SAYS:  "MV= 2,825'/SEC
   CHAMBER PSI IS  48,764 , WARM LOADING
  LOA IS 3.150" FOR LOADING DENSITY OF 91.1%. iT APPEARS WARM BUT SAFE UP TO 75 DEGREES. ALL CAUTIONS APPLY. OVERBORE
   
Thanks for the information.  I checked the latest Nosler  Manual and they listed 45.5 gr as maximum with their 125 gr Nosler Partition bullet for 2910 fps out of a Lilja test barrel.  Pretty close to your computer estimate.  I read a post somewhere that mentioned using ones chronograph as a reasonable estimator or pressure levels.  Since velocity and pressure are directly related, if your velocity is way less than the manual shows (like with my Howa), chances are your pressure is also less than what the loads were generating in the test rifle in the manual, accounting of course for different barrel lengths.  Since my Howa is a 22" barrel and factory as opposed to a 23" Lilja test barrel that is probably minimum chamber dimensions vs my sloppy Howa factory barrel, it sounds reasonable to me that my chronograph indicates that my 46 gr load of IMR-4350 is generating less pressure than Nosler's load with their partition since mine only chronographs around 2650.  Figure 100 fps for barrel length and tighter chamber and I am still 160 fps below Nosler's numbers.  So can I cautiously try increasing my load?  Probably, but I am pretty reluctant to "boldly go where no loading manual has gone before".  
 So unless I can set up my own ballistics lab with pressure testing equipment (come on Lotto!), I guess I will be content with the highest published load that gives no excess pressure indications in my rifle.  I still may be able to hit 2700 fps with that Hornady 129, or maybe even 2800 with a Nosler 120 gr Ballistic Tip if I use the right powder ( or rebarrel to a custom short throated chamber with a 24 or 25"  barrel, come on Lottery again)
 Anyway, thanks again for the computer estimate.  I think it is probably pretty accurate, and I am very confident in the Howa's ability to contain even higher pressures than you indicated.  After all, they use the same action and (I think) barrel contour for the .270 Win. 7mm Rem Mag and .300 Win Mag, all of which operate at well above 52000 cup or higher.  I have enjoyed the discussion.

gitano

Based on past experience, I feel the following 'disclaimer' is called for:
overbore, please do not take this personally, my 'crosshairs' are not on you on this matter. Glad to have you aboard here at THL, and I look forward to your future posts.
 
Quote from: overboreMay I respectfully refer all to the following link: for all to evaluate for themselves the 10 shot throat errosion with dangerous pressure rises in a 6.5.. Mauser. Overbore
I went to the above link and read the entire article including the rebuttal. I found the rebuttal more valid than the article, but I give the author credit for including the rebuttal on his site.
 
I had a difficult time reading any farther than the sixth paragraph in which the author makes the following comment:
 
QuoteThen a "spontaneous disassembly" occurred that destroyed the action but left the barrel undamaged.
Which is absurd. The bbl is threaded INTO the receiver. The BARREL contains the chamber. The receiver envelopes the barrel AND the chamber. If there was a "spontaneous disassembly" (which may be cute wording, but is nonetheless incorrect terminology), due to excessive pressure, the only way the action could be "destroyed" and the barrel left "undamaged", would be if the bolt blew straight out the back of the receiver. The picture at the top of the article clearly shows the receiver's front ring, that part that surrounds the bbl's chamber, is in pieces. This sort of misrepresentation makes the rest of the article "extremely suspect", to put it nicely.
 
If this "solves the mystery" for the author, good for him. As far as I'm concerned, it is simply another in a very, very long list of "I told you sos", and has precisely the same 'value' as all of the other ones.
 
There are just as many "Chicken Littles" on the Net as there are "Anything Goes" goof-balls. They both have credibility 'issues'.
 
To those wondering "What's right?", I respectfully suggest the following:
1) Shoot what you feel comfortable with.
2) Do not go past your "comfort zone" just because someone on the Net says you can.
3) By the same token, do not deny your own eyes, personal experience, and training just because someone on the Net says, "It's dangerous".
4) If you don't have personal experience and training... get some.
 
2ndtimer,
QuoteSo unless I can set up my own ballistics lab with pressure testing equipment (come on Lotto!),
You can have that for less than $500 from Recreational Software Inc. http://www.shootingsoftware.com/ptsupport.htm
 
Finally, hasn't this wandered a bit "far afield" of the original topic?
 
Paul
Be nicer than necessary.

firebird

Trying a different scope before you tinker with the bedding is not a bad idea. In my younger days I bought a very nice little rifle in .22 hornet including scope but was at my wits end trying to get any accuracy from it. I sold it to a friend that took it off my hands for half of what I paid for it.  He took the scope apart and found one end of the horizontal cross wire had come loose. A tiney drop of epoxy and the rifle shot very well for him. I should have kicked myself for that one.!!!Scope mounts can also cause inacurracy if they are not very secure in any rifle with even a mild recoil. I had that problem with a used .357 with 4" barrel. It came with a beautiful leopold 4x hand gun scope. It took about 50 rounds of dissapointing accuracy to realize the scope was moving. I couldn't  budge it by hand but the recoil was too much for the cheap scope mount that came with the gun. A new scope mount that used 3 mounting screws instead of two screws solved the problem.

LLANOJOHN (deceased)

Gents,

I believe we have pretty well covered the subject and the thread has become quite lengthy.  Since I started this thread, let me thank everyone who has contributed in this discussion...lets end it here.
 
Thanks again folks!  I have certainly enjoyed the discussion.
 
Ol' John...:D ;)
Life Member-NRA-TSRA
Riflesmith-Bolt & Lever Centerfires Only
Left-Hand Creek Rifles
Mark Twain was right-"There is no such thing as too much good whiskey!"
My best advice.."Best to stay outta trees and offa windmills!"

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