Pressures and such...??

Discussion in 'Reloading' started by StoneCold, Oct 5, 2006.

  1. StoneCold

    StoneCold Member

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    Jun 24, 2006
    Hey all. I have a question regarding pressures and loading. First let me say I am not totally new to this. I have been loading and learning since about 1982. However I have a question...When loading is it safe to go over the max powder charge in the "Books" if you are not getting the same velocities (assuming using the same components). Example: I loaded some 180 ballistic tips for my .300 win mag , 76 grains of RL22, Fed 215, 3.35 OAL - max load from Nosler #5. I was getting 2950 over my Chrono from a 24" barrel. So I loaded some more at 79 grains of RL22, Fed 215, 3.35 OAL (a full 3 grains over listed max). Now velocity is 3050 +/- . Still 100 fps below noslers data. I have in the past assumed this would be safe in that rifle. My question is..is it really??

    I would not sweat the extra 100 fps and normally would tune the load via OAL before trying a new powder or whatever. One of the reasons I'm asking is my friends rifle blew up next to me yesterday. Shooting handloads - same recipe he has used for years. It is under max powder charge and at the velocity of the Book he was using. Being right next to it and seeing him get fragged and me too was not cool.

    Details: Win Mod 70 stainless classic long action, trued, lapped, bedded, laminate aftermarket stock, 26" stainless Shilen barrel, 7mm magnum.

    Load: 69.5 grains of RL 22, Fed 215, Lapua brass I think and 140XXX. Velocity about 3350fps. Barnes shows that as a max load in standard data and under for coated. So we thought ballpark for the XXX. Brass has always lasted numerous reloadings and shows no signs of pressure I could detect.

    Basically a detonation. Right side of the stock blew off, left side cracked - both sides cracked through the pistol grip. Extractor - missing and unable to locate any part of it. Bolt locked shut. Magazine box, follower, and floor plate all bent to hell. Overall I think the action performed well. Most all of the gases went out the vents in the bottom of the bolt. I could see brass along the extractor cut. Glad he was shooting over a pack and not holding it.

    So are my thoughts on line or do I need to rethink what I am doing?
     
  2. steve4102

    steve4102 Well-Known Member

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    Mar 13, 2005
    Sorry, but I think your friend may have made some kind of mistake. 69.5gr of R-22/140gr bullet is not enough to blow up that rifle. That load is within safe limits. Something else(Wrong Power) must have been the cause of the distruction. JMHO.
     

  3. big wally

    big wally Member

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    Nov 23, 2012
    Any load data you get from a book or a friend even if they have an identicle rifle/powder/primer bullet/coal is a bomb waiting to blow your gun and yourself to bits IT IS ONLY SAFE IN THE GUN IT WAS WORKED UP IN AND NO OTHER. YOU MUST start as low as you can and work up slowly watching for any signes of pressure and act accordingly.
    No gun made can have the identicle chamber size /throat dimentions/ freebore and who knows what the powder scales are doing for you most are accurate when new but unless you have weights for the charge you are using its guesswork .
    I use Viht 120 for a 17A/Hornet and run at 3,650ft/sec w ith a 20gr pill.
    My first batch/lot of powder used 10.8gr for that velocity but my second batch/lot needed 11.4gr for the same velocity my current batch/lot uses11.0 gr for same velocity.
    If i had started with the second batch(11.4gr )and loaded that ammount of the first batch into the case it would have scrapped the gun and me but i used my head and start at least 10% down on any componant change.
    That ammount of charge difference is nothing in the larger cases that most of you seem to use and i dare say that some of you go up in 0.5gr incruments or more but believe me in 17A/H case you need to go up in 0.1gr and no more

    A good tip for safty is next time you see that same chap on the line pack up and go home.
    YOU KNOW IT MAKES SENSE
    Big (safe )wally
     
  4. Canadian Bushman

    Canadian Bushman Well-Known Member

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    just my two 2 cents, but i dont typically increase a load by more than .5 grain when working up a load because the results can become unpredictable. I also dont ever load a round to the max load because velocities will vary to greatly and its hard on the brass. Sometimes i also have trouble producing factory results and this can be credited to many variables to which i dont entirely understand. Like i said this is just my practice and its yeilded some good results. Happy hunting and good luck.
     
  5. Joe King

    Joe King Well-Known Member

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    Apr 29, 2012
    I'm assuming you know how to, and what pressure signs to read, so you'll know what is safe in your rifle, 30 years is a lot of experience reloading usually.

    Your friends rifle, who knows! Primer jumped the bullet into the lands causing a pressure spike, maybe a piece of something some how made it's way into the barrel, jacket flaked, inside of a case flaked off. with as much pressure these cartridges generate it doesn't take much of anything for things to go south with a sound rifle.

    Glad you both came away with little more than ruined underwear
     
  6. justgoto

    justgoto Well-Known Member

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    Apr 11, 2009
    Indeed.