Results 1 to 10 of 10

Thread: A Question of pressure.

  1. #1

    A Question of pressure.

    A friend of my dad offered to load some rounds for my 7Rmag, when i gave him the cases he told me that the primers were all flat. this is a sign of pressure? what are the others? i have been told about a hard to lift bolt but i cycle my round quite hard and would not notice a problem unless it was really bad. the rounds were fedral factory i have put just under 300 through the rifle would this have caused any damage?

  2. #2
    Quote Originally Posted by Andy7mm View Post
    A friend of my dad offered to load some rounds for my 7Rmag, when i gave him the cases he told me that the primers were all flat. this is a sign of pressure? what are the others? i have been told about a hard to lift bolt but i cycle my round quite hard and would not notice a problem unless it was really bad. the rounds were fedral factory i have put just under 300 through the rifle would this have caused any damage?
    Two things about factory ammo: First is that it's usually loaded to just under max for the performance. Second is that its dimensions must be such that it will function in any rifle it's put in. The combination of a cartridge that is a bit "loose" in the chamber combined with a full power loading can deliver flat primers.

    No problem.

    Now. Engaging someone to reload for you is usually a poor practice. If they are alarmed at the flat primers from a factory round, they might not be as experienced as you might like them to be.~Muir

  3. #3
    Hi Muir,

    He has been doing for my dad since i was knee high to a grass hopper but i agree with you i wouldn't trust 99% of people to reload for me.

    Andy7mm

  4. #4
    Quote Originally Posted by Andy7mm View Post
    A friend of my dad offered to load some rounds for my 7Rmag, when i gave him the cases he told me that the primers were all flat. this is a sign of pressure? what are the others? i have been told about a hard to lift bolt but i cycle my round quite hard and would not notice a problem unless it was really bad. the rounds were fedral factory i have put just under 300 through the rifle would this have caused any damage?
    I've seen this before with factory loads in 7mm RM. The cartridge spaces on the belt, and there are minor variations in the depth and location of the belt make by make - so the case goes back, forth, and back a teeny bit on firing to reseat the primer and flatten its' shoulder radius. Every brand of reloading die also differs in this belt area cut-out. It's minor, but a feature of reloading traditional magnums.

    You can alter the fit on 1st reload to adjust the cases to headspace on the shoulder/datum by neck-sizing only. That's a trial and error job with dies and rifle to hand.

    The cases will stretch less for a while, but will need full-length sizing about 3rd/4th firing. Some die brands still won't size the area of the case which grows just above the belt enough, so the fit becomes even closer & harder to chamber.
    If I'm going to be accused of it then it's just as well I did it.

  5. #5
    IMHO all who reload metallic rifle cartridges should get a good reference book, the one I use is modern reloading by Richard lee it has proved invaluable, very well written by a man who really knows what he's talking about, in fact I'd go as far to say it's the most important tool I have packed full of all you need to know to reload cartridges safely.
    Last edited by dlz90; 14-03-2013 at 22:12.

  6. #6
    Quote Originally Posted by Sinistral View Post
    Some die brands still won't size the area of the case which grows just above the belt enough, so the fit becomes even closer & harder to chamber.
    This chap makes a "Belted Magnum Collet Resizing Die" for just this problem.

    Agree with previous, flat primers on factory ammo not unusual or in itself worrying.

    However if there is also a small circular ridge around the firing pin dimple, that would be a concern.
    Last edited by Sharpie; 14-03-2013 at 15:14.

  7. #7
    Quote Originally Posted by Sharpie View Post
    This chap makes a "Belted Magnum Collet Resizing Die" for just this problem.
    Innovative Technologies - Reloading Equipment ?

  8. #8
    Quote Originally Posted by baconbuttie View Post
    Thats the fellow. Finger fumble

  9. #9
    Thanks very much. just ran out and checked its as you said the the primers are flat but as you said the mark from the fireing pin is normal so thanks for the advice

    Andy7mm

  10. #10
    Trying to judge pressure by peering at primers is like trying to carry water in a paper bag. Futile.

    Primer batches vary slightly and different makes have different thickness/strength cups etc.

    Also just because someone has been doing something a long time does not always mean they know what they are doing many start off wrong and just keep going until an accident occurs.

    I was given a fairly large quantity of 7.62x51 boxer primed cases many years back that came from a top lady competition "County" shot. I had to go through and de-prime every single one and prep the cases properly. It seems this highly respected and to some knowledgeable reloader had never heard about crimped primer pockets and just forced the new primers in on a press. Most were all mangled up some in sideways even. I suspect a progressive reloading machine was being used . Some were in totally back wards. Several detonated when the slightest pressure was put on them .

    Once deprimed I checked the cases over and I doubt any had been trimmed, none of the primer pockets had been cleaned and when I showed this to the chap who got the cases for me he would not believe me. All he kept saying was that she had bee reloading her competition ammunition for many years and KNEW what she was doing. The facts spoke differently though.

    I suppose it was this and the way I was ridiculed for telling what I had found that began my suspicion and mistrust of these "competition target rifle shooters". Sadly this was later reinforced by experiences on the ranges as a RCO where most of the dangerous actions were done by the very same types.

Similar Threads

  1. Pressure shot
    By www.yorkshireroestalking. in forum Other Shooting & Keepering
    Replies: 16
    Last Post: 10-09-2011, 09:17
  2. no pressure then
    By Scots_stalker in forum Training and Qualifications
    Replies: 13
    Last Post: 30-08-2011, 11:52
  3. Reloading: Pressure By Any Other Name...
    By jcampbellsmith in forum Ammunition, Reloading & Ballistics
    Replies: 2
    Last Post: 25-08-2011, 16:13
  4. Possible pressure sign
    By chickenman in forum Ammunition, Reloading & Ballistics
    Replies: 54
    Last Post: 14-12-2010, 00:37
  5. pressure problems
    By heathrobinson in forum Ammunition, Reloading & Ballistics
    Replies: 23
    Last Post: 05-10-2008, 18:54

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •