To crimp or not ?

Discussion in 'Hand loading your Sako' started by Bucktote, Mar 31, 2021.

  1. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Reloading various calibers it came to my attention that in 308 cartridges crimping the necks is recommended. Does crimping cause higher pressures ? as the projectile seems to have to overcome the neck wall resistance in microsecond time before starting travel up the barrel.
    All my rifles have not had any problems without having shot reloads not crimped. The only crimped loads were factory loads and I see no advantage to the crimping , am I missing an important step ? Also I have experienced full sizing with small base dies having 6 out of 20 casings not chambering prior to priming & charging. I removed the decapping pin & ran them thru a neck resizer 2 or 3 cycles with success in chambering the cases. Is this a common problem while reloading ? I always dedicate brands of casings to different rifles of the same caliber to prevent chambering issues ( 30/06 = Sako Federal cartridge , Weatherby = Win/ west) etc.

     

  2. icebear

    icebear Sako-addicted

    Messages:
    1,877
    Likes Received:
    1,015
    Country Flag:
    USA
    State/Region:
    US Arizona
    If a reloaded round is not crimped, there is a danger that the combination of recoil and inertia could push the rounds in the magazine forward, in turn shoving the bullet a ways back into the case, thereby reducing the volume and increasing the pressure. If the bullet fits tightly into the neck and the round does not have a lot of recoil, this is unlikely. It is, however, a known and documented issue with Magnum rounds and I have seen it happen even with lower-powered rounds if the bullet didn't fit tightly enough in the case.
     
  3. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

    Messages:
    7,814
    Likes Received:
    1,722
    Country Flag:
    USA
    State/Region:
    US Texas
    With proper neck tension there are very few instances in which a modern, bottlenose round for a bolt action rifle requires crimping the bullet in. It is useful in some semi-autos and in rifles which use tubular magazines where the bullet rests against the round in front of it. As far as heavy recoiling magnum rounds, I have Sakos in .375 H&H and .416 Remington and I DO NOT crimp either of them. Never had a problem.

    Regarding pressure, crimping can make a small difference in handgun cartridges which use relatively fast-burning powder. It makes no measurable difference in the typical centerfire rifle cartridge.

    As far as accuracy, ask any benchrest shooter if he has ever used crimped-in bullets. He'll laugh himself off of his chair.
     
    Tomball likes this.
  4. icebear

    icebear Sako-addicted

    Messages:
    1,877
    Likes Received:
    1,015
    Country Flag:
    USA
    State/Region:
    US Arizona
    I agree.

    This may be why crimping was recommended in the instructions for reloading .308, which is almost the same thing as 7.62 NATO, a widely used military caliber. And military ammo is ALWAYS crimped.

    There's no point in crimping any cartridge that is going to be used in a single-shot rifle. The only real need to crimp reloads is to prevent the bullets in the rounds in the magazine from creeping under recoil, and that obviously isn't an issue in a bench gun. In the old black powder days, shooters with Ballard rifles and the like would sometimes come to the line with a primed cartridge case, pour in the powder, push in the bullet by hand or with a hand press, and then take their shot.
     
  5. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

    Messages:
    7,814
    Likes Received:
    1,722
    Country Flag:
    USA
    State/Region:
    US Texas
    Many bench shooters still do much the same thing today. They will have a tight necked chamber, turn the neck of their brass to perfectly fit the chamber, then never resize the brass at all.
     
  6. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Thanks Icebear & Stonecreek,
    I do not have a .308 but my friend an X Army Ranger, and my son do & I was researching for them. one has a semi auto & the other has a bolt action rifle. I guess the semi auto rounds need to be crimped and the bolt action not. Neither shooters are bench rest shooters, so I guess sub moa are not critical. I think however getting the most out of a cartridge is still desirable as we owe a quick kill if we are going to hunt any game animal. Delayed kills are what I dislike about bow & arrow hunting. I feel that it gives too much negitive fodder to talk about by the anti hunting crowd.
     
    Last edited: Apr 14, 2021
    sakojim likes this.
  7. dgeesaman

    dgeesaman Well-Known Member

    Messages:
    98
    Likes Received:
    15
    Country Flag:
    USA
    State/Region:
    US Pennsylvania
    Benchrest shooters might use a variety of neck thicknesses, but the overwhelming majority full length size the brass each time and maintain .002-.004 of clearance between the loaded round neck and chamber neck diameter. If there are any shooters who still only neck size their brass, they’re not competitive. Competitive benchrest shooters take impeccable care of their brass and reuse the same cases many times if the primer pockets support it.

    The reasons why I would not crimp in a competition rifle are simple: 1) it’s completely unnecessary in a single shot bolt action rifle 2) it’s an added variable to manage. For the best possible tune and accuracy, reduce the variables as much as possible.

    Another data point: I do not see PRS shooters crimping their loads and they load from magazines. As long as the neck tension is not too light, and the loaded magazines are not handled roughly, the lack of a crimp has not caused issues.

    Semi auto and roughly handled bolt actions are where I’d start crimping.
     
    Last edited: Sep 15, 2021
    icebear and ricksengines like this.
  8. ricksengines

    ricksengines Sako-addicted

    Messages:
    1,512
    Likes Received:
    319
    Country Flag:
    USA
    State/Region:
    US Florida
    After over 55 years of handloading I can only say that I crimp when the cartridges are being used in tubular feed rifles. This prevents the bullets from being pushed back into cases that are stacked one on top of the other. This occurs from recoil and in rare instances can cause detonation in the tube feed magazine. Otherwise crimping is not necessary and con only be done when bullets have a crimping ring on them.

    rick
     
    paulsonconstruction likes this.
  9. paulsonconstruction

    paulsonconstruction Sako-addicted

    Messages:
    3,686
    Likes Received:
    744
    Country Flag:
    USA
    State/Region:
    US Iowa
    If your firearm type or situation gives you a need to crimp, the bullet you use MUST have a crimping cannelure as rick mentioned.
     
    dgeesaman likes this.
  10. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Thanks for the info. gentlemen, I'll pass it on to the 308 guys. by the way I am seeing much rifle casings for sale on GB, some prices are reasonable if any one is interested.
     
    dgeesaman likes this.
  11. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

    Messages:
    7,814
    Likes Received:
    1,722
    Country Flag:
    USA
    State/Region:
    US Texas
    As you can tell from my previous post, I have very limited use of crimping.

    But when crimping must be done most people do it the wrong way -- by simply setting the seating die low enough that the crimping ring engages the case neck at the end of the bullet seating stroke. This is so wrong: When set up this way the bullet is simultaneously pushed deeper and the neck of the case crimped against it. This cannot help but scar and/or deform the bullet. It also increases the bullet's resistance to seating, thus the pressure applied by the seating stem has to be greater and may deform the ogive of the bullet.

    The proper way to do it (with a seating die with a built-in crimp ring) is to back the die off so that it does not engage the brass. The seating stem is then set at the right depth and the bullets seated.

    In a separate operation the seating stem is backed off (or removed entirely) and the die is re-set lower to provide the amount of desired crimp. In this manner the bullets are not moved as the crimp is applied and therefore no damage to the bullet occurs (provided you've seated it in the right place to begin with.)
     
    dgeesaman likes this.
  12. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Good Info. Stonecreek, Thanks,
    While we are in the reloading section I ordered & received .243 casings from
    Rockwell Workshop advertising on GB. (TEXAS VENDOR) The casings were cleaned, sized and in great condition. I deprimed them, trimmed to length, champhered necks, cleaned primer pockets, and every one of them chambered in my Forester. I cannot be happier with this vendor and can give them my sincerest thanks!!
     
  13. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Sako hand loaders,
    I have not tried annealing casings prior to resizing. Should the neck where the casing grips the bullet be heated red and not down to the taper on the casing sholder? I understand that it's best to put the casings in a cake pan filled with water covering the casings about 1/3 hight & tip them over after heating to a red color, is that correct? Please advise as I am trying to get several loadings per case without the necks splitting! Thanks in advance!! B/T
     
  14. paulsonconstruction

    paulsonconstruction Sako-addicted

    Messages:
    3,686
    Likes Received:
    744
    Country Flag:
    USA
    State/Region:
    US Iowa
    There are videos & instructions on how to properly anneal brass. There is no need for the pan of water as it just gets your brass wet for no reason. They will cool down without it. Best way is to put the brass in a socket just slightly larger than the brass diameter that you can spin with a hand held drill. Secure a propane bottle torch in the upright position & put the spinning brass neck in the flame at about the same angle as the shoulder for about 6 seconds + or -(depending on the case)until the brass just starts to glow a slight orangish color, then drop it on some kind of heat sink. I use a wet towel. It's very important not to get the brass too hot or you will destroy the alloy mix & your brass will be ruined. Best to do it in dim lighting to better see the brass turn color. If you get it too hot, which is red, the brass will take on a dull color & lose is elasticity. You don't want to get anything more than a little down from the shoulder heated, as you want the case body & web to remain hard. Look online for some detail & just practice until you get the hang of it. In all honesty, unless you are forming wildcat cases or shooting high volume varmint colonies where brass is reloaded many times annealing is a waste of time, IMHO. If your necks start to crack on a regular sporting rifle, just toss the brass and get new.
     
    Bucktote likes this.
  15. dgeesaman

    dgeesaman Well-Known Member

    Messages:
    98
    Likes Received:
    15
    Country Flag:
    USA
    State/Region:
    US Pennsylvania
    If you’re loading for competition you’ll have an annealing machine that keeps things perfectly consistent.

    If you’re not loading for competition I agree with the above: skip it and replace the brass after several firings. Hand annealing with a torch needs to be done “just right” to have meaningful results and that subject goes well beyond what’s here. Or make friends with someone who has an AMP annealer.

    if you are splitting necks after a few firings and it’s good quality brass, then maybe your die is sizing the neck too much with each firing. Try a bushing die without expander ball and use a bushing size that just pushes in the neck enough; but no more.
     
    Bucktote likes this.
  16. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    Thanks Mr. Paulson & degeesaman,
    I always get great advice from Mr. Paulson. I do not plan to shoot competion
    at my age. If I get 3-4 reloadings /case I will be happy with that. It seems a lot of work to anneal the brass,and I have been told it makes the brass last longer. How much longer? I think I will take your good advice & keep doing like I have bcen doing. Good luck during the early black powder hunting season.
    Green Mountian barrels Kill!!
     
  17. dgeesaman

    dgeesaman Well-Known Member

    Messages:
    98
    Likes Received:
    15
    Country Flag:
    USA
    State/Region:
    US Pennsylvania
    Yesterday I saw some 6BRA cases of mine labeled 17x fired. They could go much longer. But I annealed on a regular basis with them. The AMP will never pay itself off on the cost of brass alone. I bought it to improve the consistency of my neck tension.
     
  18. paulsonconstruction

    paulsonconstruction Sako-addicted

    Messages:
    3,686
    Likes Received:
    744
    Country Flag:
    USA
    State/Region:
    US Iowa
    Put a Green Mountain barrel on a Hawken style ML about a year ago & it is definitely a quality piece of steel. Too bad Sako didn't make ML's!!
     
  19. Bucktote

    Bucktote Well-Known Member

    Messages:
    206
    Likes Received:
    80
    Country Flag:
    USA
    State/Region:
    US Georgia
    MR. P,
    I shoot a .45 cal. maxi ball with 80 Gr.fff black powder, it cracks not booms & Dead Center @ 100 yds. You may try A- R.E.A.L. 50 cal, does well in slow twist barrels, it is a short bullet similar to a round ball !! best of luck. B/T
     
    Last edited: Sep 18, 2021

Share This Page