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Flat base vs boattail bullets

So, I have another question about loading for my win 70 in 25-06. Looking over all my load data that I recorded for this rifle, an interesting anomaly popped out at me. On virtually every load I've tried, my most consistent loads have all come from boat tail bullets. Whether 100 grain, 115 or 117 grain, it really didn't seem to matter, boattails were always more consistently accurate than flat base, and for what it's worth, the nosler partitions, whether the 115 or the older 117 grain, were always the least accurate, and the hornady 117 boattails always the most consistent. Just wondering if this is weird or unusual, or if it's just me. Can't quite figure it out.

Comments

  • Butchdog2Butchdog2 Member Posts: 697 ✭✭✭
    On the average a boat tail bullet will be more accurate, longer and better ballistic coefficient.
    Hunting bullets are usually less accurate, just the nature of the beast.
    Sometimes accuracy is more involved than just bullets. Brass, primer, powder, operator, and firearm all play a big part in the final result.


  • Okie743Okie743 Member Posts: 1,971 ✭✭✭
    You say you can't quite figure it out.
    Speaking from experience working up loads for consistent accuracy for hunting rifles
    You have done a good job of figuring it out. You have determined WHAT THE GUY LIKES instead of what you would like for the gun to like. You might test another same type rifle, same caliber and it not like your existing recipe. It's mainly barrel harmonics.
    and Yes about Nosler Partition bullets or most any bullet designed as a hunting bullet for large game will usually be little less accurate, because they are not  silhouette  or target bullets. 
    Listen to the gun when you are testing. It's trying to tell you something about what it likes for accuracy AND
    have fun testing reloads for max accuracy.
  • nononsensenononsense Member, Moderator Posts: 10,296 ******
    Looking over all my load data that I recorded for this rifle, an interesting anomaly popped out at me. On virtually every load I've tried, my most consistent loads have all come from boat tail bullets.

    I think the word 'anomaly' if a good choice. There are generalities we can observe and record but as a point of fact, every rifle is an individual unto itself. There are no absolutes which apply to every rifle rifle and every load. So it's likes and dislikes are dependent on the testing you run to find the sweet spot and balanced load for your rifle.

    I test dozens of rifles and cartridges a year and I have found some generalities to remain true but there are always the variables found in the process of reloading. In your situation, you probably have a 1:10 twist which can affect the type and style of bullets which respond best to your loads.

    In general, those flat base bullets respond best to the slowest twist rate which stabilizes the bullet length. Check the benchrest shooters and that's nearly all they shoot is short jacket flat base bullets.

    and Yes about Nosler Partition bullets or most any bullet designed as a hunting bullet for large game will usually be little less accurate, because they are not  silhouette  or target bullets.
    There are always exceptions and the Berger Hunting bullets will usually outperform most other bullets even though they are labeled as 'hunting' bullets. You have to pay attention to the jump though. Also, I've had exceptional accuracy from Nosler Partitions even though their BCs are lower than the hunting VLDs. I've had them shoot one-hole groups at 100 yards up to a little over 1/2" from other rifles.

    These observations are from rifles built with custom barrels, not factory barrels, so your mileage may vary. :)

    Best.



  • OkieOkie Member Posts: 177

    hadjii:

    Just curious


    Awhile back you had a post on hefre about a hunting rifle you were flogging and had accuracy issues and nonsense and I were giving you tips about how to check the bedding, etc and you just all at once evaporated and quit replying.  Just wondering what happened. Thought maybe the gun may have blowed up in your face or ????

    Is this the same rifle from your previous post??


    Good to se ya back at the bench and reloading. 

  • kidthatsirishkidthatsirish Member Posts: 6,866 ✭✭✭

    It's always good when you find the load your rifle likes! Turns out my hunting rifle prefers flatbase bullets my self.


    If you don't mind me ask what kind of powder are you using?

  • OkieOkie Member Posts: 177

    It's always good when you find the load your rifle likes! Turns out my hunting rifle prefers flatbase bullets my self.


    If you don't mind me ask what kind of powder are you using?


    Most of my hunting rifles prefer the flat base bullets. I have a couple of custom barrel 243's that have just a slight preference for boat tail bullets. The bearing surface on a boat tail bullet is little longer than a flat base bullet of the same weight. I normally start testing a rifles accuracy at first when working up a load with a flat base bullet and then when I get the rifle to shooting consistently accurate I then test  the same weight more expensive hunting bullets and usually a hunting bullet, such as Nosler, Hornady, Speer will not average as good of a group, probably due to maybe rotational balance. I prefer a hunting rifle to consistently shoot less than a 1 1/2 inch group at 100 yards from a cold barrel shooting one shot at least 8 hours apart and comparing the group over several days. If a hunting rifle does not consistently shoot the first shot from a cold barrel on target it's not really a hunting rifle. I've seen several rifles that would shoot a good group after the first shot, but the first shot from a cold barrel would be a flyer. (outside of 1 1/2 inches)

    I've also seen rifles that would not shoot a good group from a cold clean bore, but preferred a fouled bore. This is a reject for a hunting rifle. I do pay attention to the weight of hulls and keep them matched. Mismatched weight hulls can sometimes really make a normally accurate rifle produce bad groups, especially when testing non-magnum calibers. 



  • kidthatsirishkidthatsirish Member Posts: 6,866 ✭✭✭

    Why is it a reject to you for a rifle to shoot better from a fouled bore? I know lots of folks who will check zero one last time prior to start of season, then, at seasons end, clean the rifle.

    Is it that you just prefer to start each hint with a clean bore or do you hunt with a rifle that fouls quickly (i.e. muzzleloader or purely cast bullets?)


    Or is it just a personal preference?

  • OkieOkie Member Posts: 177
    edited February 18

    Why is it a reject to you for a rifle to shoot better from a fouled bore? I know lots of folks who will check zero one last time prior to start of season, then, at seasons end, clean the rifle.

    Is it that you just prefer to start each hint with a clean bore or do you hunt with a rifle that fouls quickly (i.e. muzzleloader or purely cast bullets?)


    Or is it just a personal preference?


    To clarify: When testing a center fire smokeless powder HUNTING rifle I do not consider it a reliable hunting rifle unless it will consistently shoot a good group from a cold clean non-oily bore. If at the start of season if the bore is oily I get the bore de-oiled using a snug fitting swab, then to the shooting bench and watch the first shot print. The hunting gun has been previously tested to shoot a group from the cold bore. The bore then is usually not cleaned or oiled until after season usually, but if may get a dry swab run through the bore with no oil or cleaning until after it's no longer used during season. When working up a load testing and I see a good group I then thourghly clean the bore, then de-oil and let the gun set day or two and I shoot one or two shots each day from a cold bore and compare the group, especially watch the print of the first shot. You also have to be a good shot to compare cold bore shot groups over a long period of time, I've seen lots of guns that would shoot a warmed up barrel good group, but the first shot from a cold barrel would be out or maybe even the first few shots would not group. I've also seen quite a few center fire rifles that would not shoot a good group until the about 6 or more bullets were sent through a non-clean bore and these guns would not group the first shots with a clean bore. These are reject guns. Animals in my neck of the woods do not stand around and wait for practice shots/ fouling the bore and warming the barrel for the bullet to be on target .I glass bed and float all my center fire rifle hunting guns and the stock can be completely removed and re-installed and the Point of Impact of the shot group does not shift on paper at 100 yards more than 1/2 inch and usually not any shift at all. Kroil barrel lube usually does not shift the POI but I do not purposely shoot through a oily bore gun.

    Most of our Black Powder guns, shooting saboted bullets/209 primers and Pyrodex triple 7 like for a fouling shot to be fired first (burn out the oil from previous lubing from storage) then no major cleaning or oiling of the bore until after season, just a damp swab or tight fitting bristle brush about every 3 shots. We have some scoped black powder rifles that produce consistent 1 1/2 inch or less groups at 100 yards from shooting bench. Green Mountain black powder barrels usually are very consistent black powder barrels.






  • Canmiss.Canmiss. Member Posts: 1
    I would think that a flat based hunting bullet, like the Nosler Partition bullet could not be as precision formed, cast or lathed as it was meant to drop the game not win a accuracy contest. They have dropped almost everything I have shot with a single shot, 2 on one barren ground caribou. Trophy black bear, caribou, fat Kansas whitetails. The bear was on Vancouver Island and we weren't allowed into the carcass to take anything except its' outsides, the bullet was just under the thick fat on the opposite side. Right rear rib cage entry, almost exiting behind the left foreleg, the bullet was mushroomed out well, but intact. A front leg came up and the critter just rolled over and quit. 19 5/16" on the skull, and about 8'6" on the square. Shokkey was the OF.  
  • Hawk CarseHawk Carse Member Posts: 4,289 ✭✭✭
    I figure game bullets in a hunting rifle are a crapshoot, you have to try enough to see what works.
    Benchrest shooters at 100-300 yards use flat base bullets, they are generally more accurate.
    Target shooters firing at mid- and long range use boattail bullets because they have a higher ballistic coefficient and will shoot "closer to the wind" and carry supersonic velocity to greater ranges.
  • bpostbpost Member Posts: 30,645 ✭✭✭
    In my 22BR Encore the 52gr Berger FB bullets performs best.  When testing AR type rifles I find that same bullet to be the best bet for accuracy at 100 yards.
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