New to the .308 Winchester round ?

[sean eady]

I have been reloading for about a year or so now and am very comfortable with the .223 .45acp .40S&W 9mm and 5.7x28mm. I just orderd a rifle chambered in 7.62NATO/.308Winchester and want to reload for it as well.

I just got in all my dies , primers and bullets. I am planning on loading up 150grain Hornady fmj-bt with new Winchester brass and Winchester magnum primers using 46grains of W748. My question is in the OAL of the completed round. All of the data I have found showes the bullet seated to a 2.800 coal with a max of 2.810 . My confusion is with the canneluer. If i seat to the center of the groove I am at 2.715 . If I were to seat to the recommended 2.800 the canneluer would not be in the case mouth. I purchased some Winchester super-x power points that are also 150 grain and when set side by side my completed round they look very close. Am I correct to seat to the middle to top range of the canneluer using the components I have ? Thanks for any and all input.

 

[rcmodel]

Yep.

FWIW: Hornady#6 manual says 2.780" for that bullet.

They also say W-748 =
40.3 start load.
46.7 MAX.

Anyway, if you seat to the cannulure with any bullet, you can't go too far wrong.

rc

 

[mtrmn]

RC answered before I could sign in. And he is absolutely correct.

 

[Ridgerunner665]

If the rifle is a bolt action...you don't really need to worry about the cannelure...just seat them where they shoot the best (and will fit in the mag).

If the rifle is a semi-auto.....seat them to the cannelure.

 

[rsrocket1]

The canneluer location is not important unless you intend to crimp the case into the bullet. If the bullets seated to 2.80" feed and chamber properly in your gun and magazine and you find they shoot more accurately than 2.715", then work up the loads to a 2.8" length. If you have feed issues or insist on crimping, then seat to 2.715" and work up your loads to find the most accurate charge with that length.

The recommended charges published for 2.800" is for that bullet seated to that length. Seating deeper will result in higher peak pressures and slightly higher muzzle velocities.

As always, start lower and work up. Don't start with 46.0 grains unless it is the minimum recommended charge (which I strongly doubt).

 

[Ky Larry]

The purpose of the cannelure is for a roll crimp on the finished round. If you're not crimping, the location of the cannelure isn't important. The deeper you seat the bullet, the more pressure is created on firing. When you get your new rifle, find the location of the throat,or leade, and start loading the bullet .010 shorter than that measurement. You can play with the C.O.L. and find the sweet spot.

 

[rcmodel]

BTW:
If ultimate accuracy is of any concern to you?

You bought the wrong bullets.

FMJ with the jacket opening in the base will never be as accurate as bullets like SP, HP, or ballistic-tip plastic nose with the jacket opening in the nose.

rc

 

[sean eady]

Glad I asked. I have loaded up 10 rounds @ the 2.715 coal with 46 grains of W-748. I will load more starting at 40.3 and work up. Should I pull the 10 I have loaded or since they are still .7 under max feel safe to shoot them ?

The rifle is a semi-auto , so I am crimping with a Lee FCD. I know some do and some dont and so far I am on the "I do" side of the fence. Thank you all for the help.

 

[sean eady]

Just shooting paper @100yds. Was just looking for a low cost pliker round.

 

[rcmodel]

I wouldn't pull them.

I would start lower and work back up.
If you get back up to there?

Choot'm Lizabeth! Choot'm!

rc

 

[Ditchtiger]

If the rifle is a semi the OL needs to fit into the mag.
I have found a few with the cannulure farther back and had to seat the bullet below the cannulure to fit the mag

 

[rcmodel]

Shorter then the mag is perfectly fine.

Longer then the mag is not perfectly fine.

rc

 

[ArchAngelCD]

The Max OAL for the .308 Win is 2.800" but that's not the OAL you have to use, you can go shorter. But like mentioned above if the load data was developed at that OAL seating the bullet deeper will raise the pressures so be careful.

 

[No4Mk1*]

All of my hornady data is for standard primers. Expect higher pressure with magnum primers.

 

[sean eady]

I am going to be safe not sorry . I pulled them down and reloaded them with 41 grains. Thank you again everyone for all your info.

 

[Cougar71]

Is your brass trimmed to 2.015. New brass or fired?

 

[rsrocket1]

By the way, crimping will wear out the case mouth faster, but so do hot loads. Crimp is not used to hold a loose bullet in or help build up case pressure. In revolvers, it is used to keep bullets from walking out and jamming the gun. In military rounds, it is because of all the jarring during potentially years of being transported back and forth. In tube fed guns, it keeps the bullets from being pushed in while sitting in a shooting gun.

Try loading some without a crimp and shooting a magazine full -1 and measure the last one to see if the bullet moved in or out. I doubt you'll see any movement. You could also load 2 dummy rounds, one with a crimp, one without. Then chamber each one from the magazine to see if a crimp makes a difference.

 

[helotaxi]

The deeper you seat the bullet, the more pressure is created on firing.

Not accurate with a rifle until you get to an extreme. Because rifle powder burns more slowly and the volume reduction caused by seating the bullet deeper is a very small percentage of the total case volume and the pressure spike on the typical rifle round comes when the bullet is an inch or so down the barrel and the principal increase in the pressure occurs when the bullet engraves on the rifling, seating a bullet deeper into a rifle case will actually reduce pressure. This is because the pressure increase from the very slight reduction in case volume (which is largely irrelevant because of the slow powder burn rate) is more than offset by the decrease in engraving force because the bullet has a "running start" at the rifling.