Cannelure vs precision

Discussion in 'Handloading and Reloading' started by Laphroaig, Nov 23, 2021.

  1. Laphroaig

    Laphroaig Member

    Joined:
    Feb 24, 2013
    Messages:
    1,940
    Location:
    W. PA
    I've had a long standing suspicion that a cannelured bullet isn't as precise (group size) as the same smooth bullet. The two bullets I'm questioning are .224 55 gr. VMax and 68 gr. Hornady HPBT but wonder if the HR group has experience with others as well.

    I've shot quite a few 55 VMax through both AR's and my Savage M10 Precision Carbine with great results. Quite a few years ago I bought 500 55 VMax's with cannelure, must have had a bad day with them, and stashed them in the back of my cabinet. Last summer I became involved with an informal bench rest league at my club which I shot with the M10PC. With the component shortage I eventually had to dig out the box of 55's I had stashed that had at least 400 bullets left in it. I gave them a try and the following is my test target.

    IMG_20211123_113906863.jpg

    I'm going to give the bullet the benefit of the doubt and assume the 8 o'clock "flyer" was my fault. My conclusion is that it didn't matter as much as I had thought, and maybe not at all. Now I can't wait until next year's competition starts.

    As for the Hornady 68's, that's my go to bullet for 200 yd. Service Rifle. About 10 to 15 years ago I bought a box of 500 from Pat's Reloading. Pat buys bullets from Hornady in bulk and repackages them to sell a little bit cheaper than the factory packs. The box was labeled 68 gr. HPBT w/c. The only 68 HPBT Match bullet I know of is Hornady. When I opened the box I immediately noticed the ogive was significantly different than the bare 68 Hornady's that I was used to and figured they were an off brand. When I finally shot some I wasn't pleased with the results and chalked it up to a bad decision on my part. I've been loading a few of them recently in every batch I do to shoot in the standing phase of matches to stretch my supplies. Top is the bullet from Pat's, and the bottom is a Hornady 68 HPBT.

    thumbnail_IMG_20211007_211807695 (1).jpg

    That box got stashed in my cabinet too. Recently, when I was surfing Midway for bullets, I came upon this:

    https://www.midwayusa.com/bullets/br?cid=19785&Brand=Hornady&Diameter=0.224+Inches&Grain+Weight=68+Grains

    The image shows the the ogives aren't the same for the bare and cannelured versions and looks very similar to the bullets I have. Is anybody else aware of this difference ?

    I'd better shoot some off of the bench to see if they too are decent bullets. Maybe I just had another bad day when I shot them in the past?
     
    .308 Norma likes this.
  2. westernrover

    westernrover Member

    Joined:
    May 4, 2018
    Messages:
    333
    That's a crimp groove, not a cannalure. The cannalure dates from prior to metallic cartridges and is used to alter the center of gravity of the bullet, hold lubricant, and/or to reduce the bearing surface. A crimp groove is to roll the brass case mouth into for the purpose of preventing bullet setback or crimp-jump.
     
  3. Soonerpesek

    Soonerpesek Member

    Joined:
    Sep 1, 2019
    Messages:
    579
    Location:
    Omaha, NE
    Hornady Match Bullets 22 Caliber (224 Diameter) 68 Grain Hollow Point Boat Tail with Cannelure
    • Product #: 921444
    • Manufacturer #: 2278C (500)





    16 ReviewsWrite a ReviewAsk a Question

    614955.jpg


    Looks like HORNADY ( the manufacturer ).........calls it a cannelure........:thumbdown:
     
    .308 Norma, Skgreen, TimRB and 2 others like this.
  4. The Glockodile

    The Glockodile Member

    Joined:
    May 6, 2020
    Messages:
    659
    Haven't tried firing these without a crimp.

    Did you crimp yours?

    I think it's really the crimp which alters things...
     
    Bottom Gun, AJC1 and Laphroaig like this.
  5. Laphroaig

    Laphroaig Member

    Joined:
    Feb 24, 2013
    Messages:
    1,940
    Location:
    W. PA
    No.
     
  6. Walkalong

    Walkalong Moderator Staff Member

    Joined:
    Nov 20, 2006
    Messages:
    69,673
    Location:
    Alabama
    Since evenly walled jackets are so key to accuracy (balanced bullets), I can't imagine that putting that hideous lines of indentions in the jacket is good for accuracy, and it's easy to believe it's bad for it.
     
    cfullgraf, AJC1, Demi-human and 2 others like this.
  7. vongh

    vongh Member

    Joined:
    Jan 16, 2013
    Messages:
    262
    Location:
    NM
    I use a Lee factory crimp die right on cannelure. I load for multiple rifles and I like to make sure the oals stay right where I put them. I've always loaded in this caliber like this even if the projectile didn't have a cannelure. I always worked up loads with it and accuracy was always acceptable.
     
    Edcnh likes this.
  8. EricBu

    EricBu Member

    Joined:
    Apr 2, 2021
    Messages:
    343
    Meh. Maybe? IDK. I ***generally*** buy rifle bullets without a cannelure, because I rarely want to load to the COL the cannelure is set too. This is especially true with .308 bullets for me....I load the same bullets (in some cases) in 4 calibers....30-30, .30-06, .308, and 300 BLK. So the .308 is a bolt gun, I stretch them waaaayyyyy out, because that guns likes a longer COAL. I have several .30-06's. One is a garand...the garand I generally load straight book loads specific for the garand. My 300 BLK's will eat anything, any profile, and within a wide variance.....but they are sensitive to OAL. I like the round nose soft point 200 gr bullets for suppressed coyote hunting, but I load them to a much different length than I load the same bullet in my .30-30.

    For .223, I no longer have any bolt guns in that caliber, only AR platforms........I load them all to magazine length, always. That doesn't line up with the cannelure on any bullet I've ever bought in that caliber. If I end up with bullets that have a cannelure, and it happens when resources are scarce, I seat them where I want and ignore it.

    In every case above, the only impact to accuracy that I've ever noticed......is my shakey ass old man hands, and crappy old deteriorating eyes.
     
    AJC1 and ballman6711 like this.
  9. IALoder

    IALoder Member

    Joined:
    Oct 23, 2020
    Messages:
    595
    I've used 77smk's and Hornady 75 bthps, both with and without cannelure. Can't tell an accuracy difference between em. I do like a cannelure in blammo ammo though, gives a nice spot for the Lee FCD to roll in a crimp!
     
    Last edited: Nov 24, 2021
    Chuck R. likes this.
  10. AJC1

    AJC1 Member

    Joined:
    Jan 14, 2020
    Messages:
    4,890
    Location:
    Memphis
    I believe it may have a small impact on bc but very minimal impact on accuracy. I cant immagine a well done factory process would create a bad rotational imbalance. If competing I would choose without as it's just another thing to worry about.
     
    Skgreen and South Prairie Jim like this.
  11. Chuck R.

    Chuck R. Member

    Joined:
    Jan 23, 2005
    Messages:
    3,750
    Location:
    Leavenworth, KS
    I honestly don't know, but all cannelures aren't created equally. This is 5rds of Sierra 77 OTM with cannelure

    JvnTcb5l.jpg

    It's basically a MK262 clone load I put together with PMC brass and a thrown charge of TAC.
     
  12. Walkalong

    Walkalong Moderator Staff Member

    Joined:
    Nov 20, 2006
    Messages:
    69,673
    Location:
    Alabama
    No one shoots bullets with a cannelure in any serious rifle competition.

    The difference in average jackets vs match jackets is measured by ten thousandths.

    Zero doubt in my mind a bullet with a cannelure won’t be as accurate.

    That said, it can still be plenty accurate for a lot of applications, but you won’t win any registered Benchrest matches against top notch competition.

    So, it depends. :)
     
  13. Walkalong

    Walkalong Moderator Staff Member

    Joined:
    Nov 20, 2006
    Messages:
    69,673
    Location:
    Alabama
    Absolutely true
     
    Chuck R. likes this.
  14. AJC1

    AJC1 Member

    Joined:
    Jan 14, 2020
    Messages:
    4,890
    Location:
    Memphis
    No canalure on your custom barts ;)
     
    GoldieMI, Demi-human and Walkalong like this.
  15. Walkalong

    Walkalong Moderator Staff Member

    Joined:
    Nov 20, 2006
    Messages:
    69,673
    Location:
    Alabama
    Nope, and I have some. :)
     
    GoldieMI, Demi-human and AJC1 like this.
  16. unwashed

    unwashed Member

    Joined:
    Mar 31, 2021
    Messages:
    181
    One of the reason I like the Barnes 62gr TTSX, they give a decent range for crimp and COAL.
    Barnes_Bullet_Tipped-TSX_30188_Component.png
     
  17. CoalTrain49

    CoalTrain49 Member

    Joined:
    Jan 10, 2014
    Messages:
    4,493
    Location:
    Somewhere in WA.
    Now that we are discussing .224 bullets, I'll ask this question. Are boat tail bullets as accurate as non-boat tail bullets? I really like BT bullets because I hand seat each one and I don't want to bell my brass.

    Any thoughts?
     
  18. EricBu

    EricBu Member

    Joined:
    Apr 2, 2021
    Messages:
    343
    I believe those are actually drive bands, not necessarily intended for using to crimp.
     
  19. The Glockodile

    The Glockodile Member

    Joined:
    May 6, 2020
    Messages:
    659
    Anectdobubbatactically, as far as the .223 Remington is concerned - flat based bullets seem to be more accurate up to 300m and fall off after that.

    That's how it seems with the lighter bullets, where flat bases are more common...
     
  20. unwashed

    unwashed Member

    Joined:
    Mar 31, 2021
    Messages:
    181
    Hmm, didn't know that, learn something new everyday but they still make crimping with COAL more easy and diverse. They also work well on boars :)
     
  21. edwardware

    edwardware Member

    Joined:
    Feb 23, 2010
    Messages:
    3,782
    The cannelure, itself, likely has a vanishingly small negative effect on precision, for the disruption to air flow. . .

    but I'll bet the effect of variation in the process used to form the cannelure is much, much greater. For starters, it appears to be a non-axial tool (die and opposing rollers).
     
    .308 Norma likes this.
  22. edwardware

    edwardware Member

    Joined:
    Feb 23, 2010
    Messages:
    3,782
    Nothing anecdotal or caliber specific about it, a flat base projectile IS more precise. . .

    but it's BC is lower, therefore it slows faster, therefore any source of on-target variation that scales as a power of range has more effect, and more as distance grows.

    So:
    -sports where linear-to-range variation rules, like aiming error, use flat base bullets;
    -sports where power function variations rule, like ranging error, wind reading error, wind direction error, or muzzle velocity variation, use boat tail bullets.
     
    .308 Norma and The Glockodile like this.
  23. jmr40

    jmr40 Member

    Joined:
    May 26, 2007
    Messages:
    15,371
    Location:
    Georgia
    The research I've seen says flat base bullets are SLIGHTLY more accurate if everything else is the same. Most of us won't be able to tell the difference. At least at close to moderate ranges. At moderate to longer ranges the better aerodynamics of the boat tail bullets more than offsets the slightly better accuracy possible with flat base bullets.

    Also, boat tail bullets have more effect on BC with larger caliber bullets than smaller caliber bullets. A boat tail 22 caliber bullet improves BC only slightly over a flat based bullet. But as caliber increases, the more advantage you get with boat tail bullets.
     
    .308 Norma likes this.
  24. runner3264

    runner3264 Member

    Joined:
    Jun 9, 2021
    Messages:
    90
    They are drive bands and not meant to be crimped into. Actually with a boat tail bullet no crimp is needed
     
    unwashed likes this.
  25. Random 8

    Random 8 Member

    Joined:
    Jun 19, 2018
    Messages:
    2,074
    Location:
    Central MN
    The Hornady 68 and 75 OTMs are loaded in their LE ammunition, and designed for certain terminal performance specifications. They may or may not be made with the same jacket as the non-cannelured versions. I would be especially suspicious of the 68, given the apparently different nose profile. I have fired both of the 75 gr versions, and visually inspected versions of both. I cannot tell the difference there through my rifle, but in my case it's a RRA NM AR-15 and "good enough for government" work is my accuracy standard for 2-300 yard high power targets.

    ETA It appears they have dropped the 68 gr LE loading. They now also differentiate the T2 LE bullet from the 75HPBT Match bullet, although they call both of them an OTM. It is listed with a slightly different BC, but still called a secant ogive match bullet. The difference in BC may be due to testing protocols or the presence of cannelure, or may be due to a different jacket being used. They didn't used to differentiate between the 2, you just had to know, which meant being privy to some inside information as one would get if they frequently shoot with individuals who test ammunition for a major manufacturer such as Vista/FC/ATK. Here is a listing for the 75 T2OTM LE loading. https://www.hornadyle.com/rifle-ammunition/75-gr-bthp-t2-tap#!/
     
    Last edited: Nov 24, 2021
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice