7mm-300wsm reloading

Discussion in 'Reloading' started by mw185, Jun 17, 2010.

  1. mw185

    mw185 Member

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    Could some of you with experience discuss your technique,die's, etc for necking down the 300wsm case and loading for this chambering. Thankyou.
     
  2. 21buck

    21buck Well-Known Member

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    MW185,
    You will need a fl die set, proper case holder, set the die according to specs, lube the case with Imperial wax, my suggestion, make sure that the first case is lubed and the neck has a little lube. Slowly resize the case. The 308 cal will become a .284. Next measure the thickness of the neck and the fit of the empty case in your rifle. Measure the length of the case according to specs., trim as required. Make sure that you lube every case

    I would recommend that you learn how to anneal properly the neck and shoulders of the case. There are many locations to get this information to do it properly. The case life will greatly increase and even more so if you neck size only.

    There are various powders. I use RL 19 and will be testing RL17 soon. Be investigative look around and ask questions on various forums. It's a fun hobby.

    Need more assistance?

    21buck
     
    Last edited: Jun 18, 2010

  3. mw185

    mw185 Member

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    Thankyou for the response. Any recommendation on brand of fl die and what brand of necksizing only die are you using?
     
  4. 21buck

    21buck Well-Known Member

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    When the WSM came out I ordered a custom set of dies . I believe that they are Redding and the case holder is a RCBS. check with the various die companies for availablility and price. Also check this : a 7mm wsm is not the same as a 7mm x 300 wsm. One is a factory load and the other a wildcat. with different case measurements.
     
  5. dirtball

    dirtball Well-Known Member

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    mw185
    The link below has a lot of information regarding the 7mm/300 WSM vs the standard 7mm WSM. It also talks about the pros and cons a little. There is info there regarding dies for the 7mm/300 WSM. I opted for the standard 7mm WSM and have been very happy with it as an F-Class rifle.
    Dave


    7mm Cartridge Guide
     
  6. 21buck

    21buck Well-Known Member

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    mw185, Do you have the rifle in hand or you thinking about buying one? In the first case it is already decided for you. in the second you have to weigh the advantages and disadvantages. I was shooting my rifle long before they came out with the factory load.

    Good Luck,
    21 buck
     
  7. mw185

    mw185 Member

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    Thanks again for info, the 7mm link is agreat reference I have visited before but still does not go into much detail reguarding reloading process. I,m assuming he is using 7mm bushings in a 300wsm die(hornady). I would have to call hornady to confirm this works? Also,may be a stupid question but is a 7mm wsm seating die used? The rifle is already built(Nathan SSG) metal work looks awsome and I am finishing stock work now. I have an email out to him on reloading but wanted to hear what others are doing. Thanks
     
  8. 21buck

    21buck Well-Known Member

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    mw185, Use the full length die to resize the 300 wsm to a 7mm. Lube it properly and run it thru the die. There are no other items necessary.

    You could anneal the neck and shoulders before you load them. Make sure that the length is correct. and you are good to go for the first firing.

    Second loading, I extend the expander and primer pin a bit farther down. What you want is the die to engage enough to pop the primer out and resize the top of the neck , not the entire body of the case. Take your time and it will work out easily. You do not want to extend the expander and primer remover too far. Be careful in your adjustment . Check case length.

    When do you resize full length? Normally after 4-6 reloads and always with brass to be used on hunting trips. This is important that the cartridges feed smoothly and effectively.
     
  9. dirtball

    dirtball Well-Known Member

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    If it were me I would buy a Redding Type S full length sizing die and a couple of bushings to neck the 300 WSM case down to 7mm and a Redding 7mm WSM seating die.
    Once you work out what bushing gives you the proper neck tension and you start shooting the rifle, adjust the full length sizing die so that it sizes the case and bumps the shoulder just enough to allow the bolt to close easily.
    Dave
     
  10. 21buck

    21buck Well-Known Member

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    Why do you feel that you need a 7 mm necking die. I use RCBS dies. They are good and last . I.e. 7mm/300 wsm full length resizing die. You have a 300 wsm case and want to make a 7mm x 300wsm case. follow previous instructions and you have a 7mm x 300 wsm case , length to check, primed, powdered, and bullet seated.
    I don't understand the problem of going from a 300 to a 7mm. Another example , 30-06 to a 25-06 . Use a 25-06 full length die on a 30-06 case and you have a 25-06 case.

    21 buck
     
  11. dirtball

    dirtball Well-Known Member

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    The 7mm WSM and the 300WSM do not have the same body length or neck length and dies are either "Custom Dies" or adapted from 300 WSM.
    Read the link I provided in the post above and you will see a drawing of the two side by side.
    Dave
     
  12. 21buck

    21buck Well-Known Member

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    I would strongly suggest that you look at RCBS dies. Once you have a 7mm/300wsm full length sizing die , you can form your 300 wsm into the 7mm x 300 wsm cases. Be sure to lube them adequately. There are no other dies or inserts to contend with. Measure , trim as necessary, prime, powder, bullet to the correct length and you are good to go.
     
  13. mw185

    mw185 Member

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    Sorry, still need some clarification.Dave-when you say redding fl type s is this die stamped 300wsm?. 21-when you say 7mm/300wsm full length die is this die actually stamped 7mm wsm?
     
  14. dirtball

    dirtball Well-Known Member

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    RCBS makes a set of dies for 7mm/300 WSM. It is a Special Order and has a price of $143.00, and according to Midway will take 90+ days to get.
    RCBS 2-Die Set 7mm-300 Winchester Short Magnum (WSM) - MidwayUSA

    You could call RCBS to see if you ordered it direct from them if it would be faster.
    BUT any set of dies that has a "standard" neck diameter that sizes the neck down much more than necessary and then expands the neck back out with an expander ball/mandrel usually results in a case that is not concentric at all.
    I still think the 300 WSM Type S FL die with the appropriate bushings is the way to go.
    JMHO

    Dave