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  1. #41
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    The Missus did not take this one well - Cody and I were looking at the rifle's pictures, she came in,"what you looking at ?" - - - - - I always thought the South Pole was as far south as shit could go !.
    Just finished eating, we had Impala and kudu meat in 3 forms with "she did not make " and some "she did not make", we had some " f*** Y*** for desert", I did not know you could burn "fU", evidently you can.
    Moer ? ...................... this is a first, I is confused ??????
    My boy just stated " I think we going to battle this week end Dad".
    ...................... etc.

  2. #42
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    Quote Originally Posted by driepootx View Post
    Most 303 bullets are .311, but Hornady make a 312.

    The difference between the 284 and 285 bullets might just be 1 or 2 grains of propellant. I would not get my knickers in a twist about that. Safe reloading practice will take care of it.
    If you have a look at the published Somchem 7mm Rem Mag load data, you will see data for bullets of different diameters. PMP 7mm bullets usually measure .283". Then read the little paragraph below the data and compare the .283" loads with the .284" loads of the same or similar weight. The difference seems to be somewhat more than just a grain or 2.

    I witnessed a friend shooting a starting load through his brand new custom built 7x64 rifle, built on a .284 barrel and shot with .284" bullets. The Somchem load data is for .283" bullets in a .285" barrel. Guess what? The start load blew the case and damaged the rifle. Guess what? He had to back down by 5 grains below the recommended start load, after repairs to the rifle, to get a safe load.

    The 303 is a poor example to reference, as the barrel groove diameters can vary wildly between .312" and .318". Actual .311" barrels are quite rare. Additionally, the max pressure spec is significantly lower than that of a modern 7mm, so the margin of error is quite a bit wider.

    Safe reloading practise is not to disregard any possible issues, even if considered relatively small. You may get away with it most of the time, but we have seen enough disasters to take the matter of reloading safety much more seriously.

    My reference to the relationship between the bullet and barrel diameters of the 7-08 cartridge was more to point out that we have a better match here than usual, with smaller chances of any accuracy, safety or barrel life issues than with slightly mismatched combinations.

    When it comes to playing with 60 000-odd PSI peak pressure toys, a little perfectionism may just be good occasionally, I think.

  3. #43
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    Quote Originally Posted by A-R View Post
    If you have a look at the published Somchem 7mm Rem Mag load data, you will see data for bullets of different diameters. PMP 7mm bullets usually measure .283". Then read the little paragraph below the data and compare the .283" loads with the .284" loads of the same or similar weight. The difference seems to be somewhat more than just a grain or 2.

    I witnessed a friend shooting a starting load through his brand new custom built 7x64 rifle, built on a .284 barrel and shot with .284" bullets. The Somchem load data is for .283" bullets in a .285" barrel. Guess what? The start load blew the case and damaged the rifle. Guess what? He had to back down by 5 grains below the recommended start load, after repairs to the rifle, to get a safe load. That points to a serious gunsmith error

    The 303 is a poor example to reference, as the barrel groove diameters can vary wildly between .312" and .318". Actual .311" barrels are quite rare. Additionally, the max pressure spec is significantly lower than that of a modern 7mm, so the margin of error is quite a bit wider. New barrels have been fitted to many old 303's and I would presume that they have been built to the correct diameter.

    Safe reloading practise is not to disregard any possible issues, even if considered relatively small. You may get away with it most of the time, but we have seen enough disasters to take the matter of reloading safety much more seriously.

    My reference to the relationship between the bullet and barrel diameters of the 7-08 cartridge was more to point out that we have a better match here than usual, with smaller chances of any accuracy, safety or barrel life issues than with slightly mismatched combinations. I might have misunderstood your notes on this issue, but the American designers surely knew that 285 bullets migt be used in the caliber.

    When it comes to playing with 60 000-odd PSI peak pressure toys, a little perfectionism may just be good occasionally, I think.
    You make it sound as though I do not take safety seriously. Rifles only blow when pressures reach 100K psi+. They are tested to 80K psi. An overload of 2 grains should not get you there and even then you will have clear signs of too much pressure.

  4. #44
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    CreedMOOR.
    - GAMER -

  5. #45
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    Quote Originally Posted by driepootx View Post
    You make it sound as though I do not take safety seriously. Rifles only blow when pressures reach 100K psi+. They are tested to 80K psi. An overload of 2 grains should not get you there and even then you will have clear signs of too much pressure.
    *****************************************
    Driepootx, I will speak collectively and I will speak loud, so >>>>>>>>>>>> NO ONE DOUBTS YOU - NO ONE TAKES YOU LIGHTLY, trust me on this, you are respected and there is "f'all chance that AR was dis-respecting you.
    PS - side note, got Cody 303 to under 1 inch today - thank you.

  6. #46
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    Quote Originally Posted by driepootx View Post
    You make it sound as though I do not take safety seriously. Rifles only blow when pressures reach 100K psi+. They are tested to 80K psi. An overload of 2 grains should not get you there and even then you will have clear signs of too much pressure.
    Dear Oom Driepoot. Nothing could be further from the truth. I have tremendous respect for you and your wisdom, even though we have never met.

    Usually, when posting here on GS, I try to take into account who may be reading the info here. (I have been rapped over the nuckles about this before.) Not everyone capable of reading here will have the background knowledge and experience that you do. So I do tend to be extra cautious with any reloading advice. I have seen a few mishaps in my life and I have seen some mishaps posted on the interwebs. Most of these were the direct result of some reloader happily disregarding a safety precaution (or more) while reloading.

    So here are a few notes on reloading safety for general consumption. Not specifically aimed at YOU, but you are definitely not exempt from these either:
    1. Never assume. Assumption is the mother of all ....... (You get my drift.)
    2. Safety is no accident. It is a planned event.
    3. When the pressure signs become visible, you have ALREADY PASSED the safe limit. You are in dangerous territory now. Stop shooting and back down your loads immediately.
    4. There are a few more...



    The following IS aimed at you:

    "I witnessed a friend shooting a starting load through his brand new custom built 7x64 rifle, built on a .284 barrel and shot with .284" bullets. The Somchem load data is for .283" bullets in a .285" barrel. Guess what? The start load blew the case and damaged the rifle. Guess what? He had to back down by 5 grains below the recommended start load, after repairs to the rifle, to get a safe load. That points to a serious gunsmith error"

    Please re-read the whole paragraph. The error stems from the load data that was developed with mismatched components, giving uncharacteristically low pressures. Nothing wrong with the gunsmith's work, although he could have warned the owner of the issue, if he was aware of it. Very few people seem to notice it. And the reloader should not have changed the components from those used in load data developent, without taking precautions.

    And please note that I did not say that it "blew the rifle". I specifically said "case". The damage to the rifle was a bent extractor and mag floor plate. Miraculously the stock held.



    "The 303 is a poor example to reference, as the barrel groove diameters can vary wildly between .312" and .318". Actual .311" barrels are quite rare. Additionally, the max pressure spec is significantly lower than that of a modern 7mm, so the margin of error is quite a bit wider. New barrels have been fitted to many old 303's and I would presume that they have been built to the correct diameter."

    I would not presume anything. The new military spec barrels could very well have been built on the same machinery and to the same sloppy specs as the originals. New Musgrave made commercial barrels excluded off course, but they are somewhat rare.

    The thing is, we can not just hold other people responsible for our own safety while shooting reloaded ammo. We have to make double sure that our loads will be safe in our guns under all possible conditions. Sometimes this may involve a little more than just following a published recipe.

    One of the variables that we should not just change without further thought is the bullet diameter. Some calibers do have different sized bullets available and some manufacturers make off-spec bullets. These relatively small differences can have a significant effect on pressure, especially if we are already near max peak pressures. The hardness and compressibility of the bullet core is also important here.

    Again, the 7-08 Rem calibre is one of those that has less chances of causing unexpected dangerous situations, as long as the reloader sticks to the bullets made on the same side of the pond that the rifle came from.

  7. #47
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    We are messing up Treeman's post. Let us agree on safety first and leave it there.

  8. #48
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    Default Re: the 7mm -08, yesterdays 6.5 Creedmore ?

    I certainly gained some valuable knowledge in any event, even if it was incidental.

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