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Thread: 6mm PPC small base case vs normal base, measurements plz....

  1. #31
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    The upside to the lower case neck being unsized is that you now know what your chamber neck diameter is.....at least withing a few .0001's (ten thousandths).

    The general feeling is that the unsized portion, since it's basically a 'gauge fit', helps align the bullet with the throat. -Al

  2. #32
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    Reply to your notes

    Quote Originally Posted by herbeapuce View Post
    @ centerfire.
    I already send the 3 brass to someone in Alberta. He is in the business and will get the brass to Harrell’s I’m also getting the Harrell arbor press, a shoulder gage, the .257 and .258 bushings and a good seating die….

    Were the cases fired 3 times each?????? Try the Wilson seating die.
    The Shoulder Gage (Gizzy) will come with the Harrell die. No need to buy another.

    First, I did not notice the Manufacturer of the brass you are using. The rifle came with no history records, came with 50 loaded Norma handloaded round, unknown power and primer. I was also given 50 once fired Sako brass that I intend to use later
    Second, I did not read how many times each piece of brass had been shot/fired/sized. I do not have this info, but they don’t show obvious signs of early retirement. I suspect the previous owner only neck sized those brass, as they are now getting long and the bolt is hard to close on them.

    Before getting into the notes below it is imperative that you know the Chamber Neck Diameter.
    Cerro Safe would be a good choice. It is written NCK 262 on the barrel. But I have cerrosafe and I will check soon.
    This is good to know.

    If not one can carefully expand the neck of the case and keep expanding till you FEEL the case neck coming in contact with the chamber, or it rubs off the Dykem or Prussian Blue you applied. This is available at any industrial supply house. I used to use candle smoke for this, now I use whiteboard marker black ink.
    Please remove the firing pin from the bolt for all this type of feel stuff.

    Third. Have you checked www.accurateshooter.com and gone to the 6PPC cartridge listed on the left side of the web site? Yes, there is a drawing there but it might not match your chamber.not yet. I will eventually read it I’m sure…

    Fourth: I would purchase, Your choice,NEW Brass. I suggest Lapua .220 Russian. Yes I am aware of those being the best choice, but right now I will work with what I have, but yes those are the ones I will buy
    Check the OAL length (write it down and save this information) did you mean shoulder to head?

    No I meant OAL ( overall length of case) Head (no primer) to case mouth,

    Take three .220R Lapua cases, load, and measure the loaded neck at the pressure ring of the neck after neck expanding to the 6mm size of you bullet. What bullet are you using? 68g Berger Match #24411. The gun also came with 2 brand new box of those bullets.
    Very good bullet to stay with.

    For instance if your loaded case measurement is .271" diameter and your chamber neck is less DO NOT PROCEED. The loaded round that came with the rifle seems to be neck turned for 2 different thickness:
    The last section of the neck is thinner that the section closer to the shoulder.
    The section near the mouth is on average 0.2607 thick, (around 0.168 long)
    The one closer to the shoulder is 0.2628 thick . not the safest maybe….

    You will have to get into neck turning before you proceed. (IE about 0.002" less than the chamber you are working with.) yes I will buy the outside neck turning attachment for my Forster case trimmer and turn the neck to be safe.

    Remember that if you purchase the Forster outside neck turning attachment that when you put
    the Pilot in the cutter shaft the set screw is going to offset the pilot and you will be turning an
    ellipitical. Don't ask how I know this.

    If your chamber neck is reamed 0.262" should be at least that.you will have to turn your necks about 0.0086" to arrive at a safe .2602" diameter. Or 0.0018" safe clearance.

    The 3 New Lapua cases need to be reloaded correctly and fired 3x each total to be sent to Harrells.
    Harrells will send you a die and a Gizzy but you will need a dial caliper to understand the measurement you receive.
    This measurement will be the shoulder/datum to the head (primer removed before measuring).
    Once you have this measurement (write it down) you can adjust the Harrell die for the 0.001"-0.0015"-0.002" size you wish to use.
    Oh, the three cases you send will be returned to you. Put them in a container (medicine bottle) and mark the bottle.
    Keep them forever with the barrel you are using now. OK
    New barrel, new reamer, new chamber, yes, probably new Harrell die with 3 cases fired 3x as stated above.

    Also I am unsure of what measuring tools you have and therefore what you might need to purchase to measure accurately. I have an old but nice Peacock dial Caliper and a just as old and good Starrett 0.0001 micrometer. I hope this helps you in your new journey. It does thank you ! Go slow, be careful.
    Now we are going to enjoy advanced reloading.
    Good shooting,
    Centerfire
    Hope this helps.

  3. #33
    Join Date
    Oct 2018
    Posts
    20
    Hi.

    thanks for your help.

    I am convinced the brass were fired at least 3 times each. maybe more.... but I have no die to set them back and fire them again 3 times. so it will be it....

    what neck turning tool would you recommend ? ( hopefully it's not too expensive... :cool ? )

    no need to buy another shoulder gauge , ok....

    why is it good to know and write down the OAL of the brand new 220 Russian ?

    thanks
    stef

  4. #34
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    Mar 2005
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    Reply

    Quote Originally Posted by herbeapuce View Post
    Hi.

    thanks for your help.

    I am convinced the brass were fired at least 3 times each. maybe more.... but I have no die to set them back and fire them again 3 times. so it will be it....

    what neck turning tool would you recommend ? ( hopefully it's not too expensive... :cool ? )

    Something like the Sinclair. Of course their is the Pumpkin.

    no need to buy another shoulder gauge , ok....

    why is it good to know and write down the OAL of the brand new 220 Russian ?

    Funny thing about acquiring knowledge.
    Cheap, doesn't cost much.


    thanks
    stef
    Here you go.

  5. #35
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    Jul 2005
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    Quote Originally Posted by herbeapuce View Post


    you could be right !

    ( I thought I could see very weak tooling marks at the base of the neck, but it's not obvious....)


    thanks
    Looks like the dreaded 'donut.'

  6. #36
    Join Date
    Dec 2017
    Posts
    220
    I think not
    you can see the neck turning when into the shoulder.
    more likely just the seating depth and associated wear and tear.

    Quote Originally Posted by brickeyee View Post
    Looks like the dreaded 'donut.'

  7. #37
    Join Date
    Feb 2003
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    SW Kansas
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    that case is not turned into the shoulder enough to prevent a doughnut. There is a fine line between a doughnut and having the neck seperate from the case because it's to thin.

    Richard

  8. #38
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    Jul 2005
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    Quote Originally Posted by Richard View Post
    that case is not turned into the shoulder enough to prevent a doughnut. There is a fine line between a doughnut and having the neck seperate from the case because it's to thin.

    Richard
    You have to go onto the shoulder with a cutter set to the correct angle to prevent the donut.

    That is why cutters come in different angles to match case angles.

  9. #39
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    Tennessee
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    I never knew why folks turned cases into the shoulder to prevent a donut. I just turned the neck all the way to the bottom and let it go at that. I understand that the donut becomes a problem if it contacts the bullet but never had it happen if the necks were turned to the shoulder. What's the perceived problem if you have a donut below the bullet?

  10. #40
    Join Date
    Oct 2018
    Posts
    20
    I'm getting a PMA cutter with a 30 degree angle fyi....I was told it will take care of donuts issues

    not saying the case above has one.... just saying what's on my buying list

    thanks
    stef

  11. #41
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    Feb 2003
    Location
    SW Kansas
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    there is no problem if the bullet is above the doughnut. Having your free bore to match the bullet takes care of all that.
    Where I have seen guys having problems is when the free bore is short and the bullet is way down the neck. Like I said it's a fine line between no doughnut and having a neck pop off the case because the neck is thin at the neck shoulder junction. Having a cutter at the right angle makes no difference if you cut to far.
    Just throat the bbl so the bullet is halfway down the neck and all of this is moot.
    Richard

  12. #42
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    Jul 2005
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    Quote Originally Posted by Wilbur View Post
    What's the perceived problem if you have a donut below the bullet?

    You have lost the clearance to release a long bullet that goes full diameter past the neck shoulder joint.

    I run barely 0.0020 of clearance on my varmint rifle (Panda action, Right bolt, left port, no ejector).

    It is set up very much like a longer range BR rifle.

  13. #43
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    Quote Originally Posted by Wilbur View Post
    I never knew why folks turned cases into the shoulder to prevent a donut. I just turned the neck all the way to the bottom and let it go at that. I understand that the donut becomes a problem if it contacts the bullet but never had it happen if the necks were turned to the shoulder. What's the perceived problem if you have a donut below the bullet?
    Well, one actual problem is you can't use a Jones decapper if you have the doughnut. That's also a way to find out if you have doughnuts in your brass.

  14. #44
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    Yep, I'm off base with that comment. I remember using a decapping tool and admsgt is right...and I haven't loaded anything but the PPC for a long, long time. Further, I'm not sure but I think the larger necks of todays chambers is on the money.

  15. #45
    Join Date
    Jul 2005
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    382
    I have a couple lathe projects stacked up.
    Time to buy a 1 ton foldable shop crane yo get the lathe back on its stands.

    The nearest knock down engine hoist for rent is about an 45 minutes each way away.

    Harbor Freight has on for around $100 with a coupon.

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