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.308 Win bullet seating

ccjkingccjking Member Posts: 3 ✭✭
I am trying to reload for a new Rem 700 SPS Varmint in .308 Winchester caliber. A lot has been written about seating the bullet to precise distances from the lands (e.g. 0.020" typ). Using a Hornaday OAL gauge, and Hornaday bullet comparitor I am finding that a normal 150gr spire pt factory round is seated about 0.200" away from the lands in this gun. If I try to get closer I am getting bullets that are way over the recommended max overall length and in fact they won't fit in the magazine. Seems like 0.100" is about as close as i can get with this bullet. I saw a recipe for a 110gr bullet calling for 0.010" into the lands. If I tried this the bullet wouldn't even be in the case neck. I've never run into this with other rifles. Anyone know what's up?

Comments

  • shooteroneshooterone Member Posts: 139 ✭✭✭
    edited November -1
    I just bought a new Rem. 798 with plastic stock. I too tried to seat the bullet close to the lands. Forget it, to get close the bullet practilly will fall out of the case. The distance was very, very long. So I seated the bullet in a "normal" depth with a loooong space between bullet and lands. At my first session in sighting in the rifle it put five rounds in the same hole at 50yds. I will put the finel sighting in at 200yds. I cant wait to see what it will do at 200yds.
  • shooteroneshooterone Member Posts: 139 ✭✭✭
    edited November -1
    By the way, the caliber of my rifle is also a 308win.
  • Rocky RaabRocky Raab Member Posts: 12,872 ✭✭✭✭
    edited November -1
    That's why I always start at the max length that will fit the magazine and move the bullet deeper from there. Once I find a seating depth that is accurate, I load all loads to that depth, measuring from cartridge base to the bore diameter (not groove diameter) datum line on the bullet.

    If one bullet is accurate at that head to datum length, most bullets will be, IME.

    If you ask me how far off the lands that is, I neither know nor care. I can easily duplicate the correct seating depth without ever knowing the off-lands distance. Here's a bullet marked with the bore-diameter datum line:
    offland.jpg

    Here's how to measure it for seating depth:

    Junk0308005.jpg
    I may be a bit crazy - but I didn't drive myself.
  • ccjkingccjking Member Posts: 3 ✭✭
    edited November -1
    OK, so it sounds like this experience is not uncommon. Rem 700's are well known for great out-of-the-box accuracy so it's kind of starting to sound like the need to have close bullet/land spacing is a bit of a myth or I would imagine that Remington would chamber their rifles differently. It's just a matter of finding the sweet spot for a given rifle?

    By the way Rocky, I can't get your website to open in Internet Explorer.
  • nononsensenononsense Member Posts: 10,934 ✭✭✭✭
    edited November -1
    ccjking,

    Welcome to the Gunbroker Forums!

    "OK, so it sounds like this experience is not uncommon."

    No, your experience is not uncommon with factory rifles like Remington but also Weatherby which has a longer leade by design. Factory riflemakers use this longer leade and throat to reduce high pressure excursions that inexperienced and stupid reloaders like to create by their inexperience or ego. Look at it like a safety factor for the accidental high pressure problems that sometimes occur. We thought that Remington was coming around from this practice but evidently the new honcho has relegated them back to the past again. It's unfortunate.

    "Rem 700's are well known for great out-of-the-box accuracy..."

    Still are even with the longer leade and throat.

    "...so it's kind of starting to sound like the need to have close bullet/land spacing is a bit of a myth..."

    No, it's not a myth. You need to determine what level of accuracy you and those folks writing the articles are talking about. You also need to figure out if they are writing about factory rifles and barrels or have they set the barrel back and cut a shorter leade and throat or have they replaced the barrel altogether.

    For general hunting rifles such as your M700 SPS Varmint, you might be able to achieve that proverbial 1/2 MOA with some load development, a great scope, shooting practice, a good rest and some additional work done on the rifle. But chances are good that the best you'll accomplish is something under 1 MOA. You need to concentrate on making consistently good ammunition that is concentric. If the leade and throat are concentric to the bore, you rifle should exhibit good accuracy. If the chamber is off then your accuracy will suffer.

    Those of us who have experience with barrels that are chambered properly for a range of bullet lengths, often find that accuracy is improved by 'jamming' a bullet into the lands. If for some reason you doubt this then you might want to chat with some of the thousands of point blank benchrest shooter and long range accuracy fanatics to get a better idea that it does work. On the other hand, I find that Barnes bullets perform nicely when seated off of the lands just as they recommend.

    What you can count on is the fact that every rifle and barrel is an individual and will behave differently under different circumstances. That's why we always suggest working up loads for your rifle instead of just using someone's accuracy load right off the bat. Rarely will two rifles perform to the same level with the same load. Changes in components alone will see to that.

    "...or I would imagine that Remington would chamber their rifles differently."

    Remington is doing what it takes to keep them out of court while still providing a decent, acceptably accurate rifle for the masses.

    "It's just a matter of finding the sweet spot for a given rifle?"

    Most barrels have more than one 'sweet spot' which are normally referred to as nodes. There is some interesting reading on the subject of barrel harmonics that will help with this. You might also want to look at the information regarding the use of a technique for load development named the Audette Reloading Ladder.

    Good Luck!

    Best.
  • Rocky RaabRocky Raab Member Posts: 12,872 ✭✭✭✭
    edited November -1
    You'd think that a website developed with a program from Microsoft would work with the Microsoft browser, wouldn't you? Nope.

    I'm sorry for that. You can either download Firefox or Google Chrome. Both work perfectly with my website.
    I may be a bit crazy - but I didn't drive myself.
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