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Reloading the .308
civiliansoldier
Member Posts: 430 ✭✭✭
Okay folks, I am going to start reloading for my .308. I want them to be "match grade" for long ranges. I am looking for advice on powderbrand and type, primers brand and type(Is .308 large rifle or small rifle?), etc. I think I am going to try the Sierra Matchking 168gr. bthp and the 175gr. bthp,(my barrel has a twist rate to accomodate 175 grain balls) to start with. I have reloaded before, although it was exclusively .45ACP. I have a Lee starter kit with the challenger press, a scale, a powder measure, primer loader, and deburring tool. To get me started with the .308, will this gear suffice? I will of course have to buy dies. I will not be cranking a bunch of rounds out at one time, so I am content with measuring each powder charge on a scale instead of investing in a good powder measure from the start. Thanks in advance for the advice folks!
Comments
Step two, look at the data Sierra provides, esp the accuracy load specified (you may need to tweak the powder charge slightly for your rifle)
If you don't already have one, buy a 6" caliper
A powder trickler will be of great benifit to your efforts.
Consider upgrading your LEE scale in the near future (either with a all metal balance beam or a decent digital)
At some point you'll need to trim your brass (your calipers will tell you when), so unless your brass supply is quite large, consider adding a case trimmer in the next year or so.
ern98 asked what kind of rifle I will be reloading for. It is a Remington 700 5R Mil-spec with a 24 inch barrel with an 11.25 twist rate.
Very nice gun. So what's the definition of longe range?
The Sierra 168 MKHP is a great bullet. IMR 4064 and 4895 along with their "H" counterparts work well. RL15 works fine too.
I guess neck size or full length is a decision to be made. I neck size only for my bolt guns. Be consistent with your case and OAL and you should be fine.
I'm right there with you.... received my mil-spec 5R in .308 only a week ago. and, this too is my first attempt at loading a "quality" rifle round to test the limitations of the weapon (and myself). Let's keep in touch with the results so we don't make the same errors, or if the "pet round" is found for our 308. I currently have my first loads completed & should get to try them in the next week or so. Here is my first starting load...will let you know how it shoots.. Lake City Match brass, sized--CCI large rifle primers--Hodgdon Benchmark powder (Varget on the way)--Nosler 168gr Custom Comp HPBTs. First loads are at the low end of the scale at 38.0gr and I started at .020" UNDER the max OAL of 2.80"... I've tried to research what length would work best in the 5R, but haven't had much sucess. Was just planing on experimenting with the lengths.
Any idea specifically where the lands are (length)... or a good/dependable way to measure it accurately. Are you planning on any break-in routine for your barrel; if so, what.????
Keep in touch..CG
This is a concise description of the high points used for reloading accurately:
Accuracy Variables for Reloading
Which of the variables within a reloader's control have the greatest impact on rifle accuracy?
There are several at least and it's usually the combination of all of the elements that accomplishes the best accuracy. The shooter/reloader needs to determine for themselves, the degree of accuracy required and then apply the techniques to gain that control over their ammunition.
However, and I can't emphasize this enough, the greatest accuracy is achieved when the chamber is exactly straight and concentric in relationship to the bore of the barrel. This includes all of the parts of the chamber: the chamber body, neck, leade and throat. The other techniques are just tuning.
With regard to the tuning aspects of accuracy, primer uniformity is probably at the top of the list. Non-uniform primers mean a greater velocity spread, which means the vertical stringing at the target will be greater. In some situations, simply changing a primer manufacturer will make a noticeable improvement in your accuracy. It's easy to get good cases, bullets, powder and the tools to assemble them. The hardest part is getting good, uniform primers. Primers not only vary quite a bit across lots but by manufacturer as well. testing new lots of primers is required.
Case length isn't quite as important as some might think. As long as the mouth is square with the case axis, case length can vary 10 to 15 thousandths of an inch and accuracy can still be maintained. The greatest importance is that the case does not get crushed into the end of the chamber, thereby raising pressure and creating poor accuracy. Your trim to length measurement will keep you out of trouble.
Neck wall thickness should be reasonably uniform with no more than a .0005-in. variance. This helps keep the necks straight when the cases are resized. They should not be sized too small. If they are, the increased neck tension will cause an increase in pressure and potentially a greater velocity spread resulting in inconsistencies. If neck tension is consistent and minimum, the velocity spread remains lower resulting in improved accuracy.
Increasing neck tension can sometimes contribute to an improvement in powder burning efficiency. It's a technique that comes into use when a particular combination of bullet and powder isn't producing enough pressure to burn the powder efficiently. The slight increase in resistance for the bullet to leave the neck allows the powder a tiny bit more time to build pressure and burn more of the charge. Many times it's a better choice to simply switch powders. The reloader has to determine by testing when an increase in neck tension or a change in powder is necessary.
Case weight variance plays a somewhat important part. Heavier cases have less volume because of the case wall thickness, hence slightly higher pressures and velocities for the same set of components. A 1% spread in case weight is typically good enough for best accuracy. Anything better (closer) is great but doesn't seem to make any significant difference.
Primer pockets and flash holes should be uniform. Pocket depth needs to be consistent so each primer has more uniform ignition. Flash holes need to be the same diameter so the same flame properties are transferred to the powder. But these two things only make a tiny MOA difference in the group size. The greatest improvements occur when all of the techniques are added into the total system.
Powder charge weight variance can also cause more velocity spread. But just as important is powder type and charge weight. It's been my experience that for a given powder and bullet combination, there's more than one charge weight that tends to produce the best accuracy. These are commonly referred to as accuracy nodes. A chronograph and some graph paper for plotting are needed to correlate this information. Charges with no more than a tenth grain variance are usually considered to be adequate. Primers typically can cause a greater difference in the velocity spread than a tenth of a grain of powder unless the load is already at maximum pressure. Careful record keeping will be a benefit in the long run.
Bullet seating depth also has an effect on accuracy. Best accuracy can be achieved when the bullet contacts the lands. A lot of folks are reluctant to do this as the max pressures will be higher. They're right but cutting the powder charge a few tenths of a grain will reduce that pressure. Bear in mind the statement I emphasized at the beginning. The chamber must be straight and concentric with the bore. With this condition met, seating off the lands can be accurate as well.
Bullet concentricity in the case is important, too. The greater the bullet runout, the more the groups will open up. The more distance a bullet has to jump to the lands, the straighter it needs to be. Those of us acutely aware of accuracy will use case preparation, bullet seating and even jamming some bullet styles into the lands to get the best end results. Square and chamfered case mouths allow us to get bullets started straight when seating.
Here's a link to another set of thoughts:
http://www.mamut.com/homepages/Norway/3/15/MarkBrooks/newsdet24.htm
And another link with reloading data:
http://www.gunsandammomag.com/reloads/match_0620/
Best.
I've used all the powders the others have stated with good success.
I settled on a load with 165 Sirra HPBT mostly because it was also rated for hunting bu=y Sierra and it shoots as well out of several 308s as the 168gr.
I use W748, chrono'd it gives good velocity with modest presure. functions in M1A's and of course bolt guns and is easy to use in powwder measures.