308 COAL W Cannelure

[Donny1]

I have 147gn M80 type bullets with the cannelure.

I've done a lot of 223 but this is my first time loading 308. Most (all) the load data calls for 2.800 COAL. If I seat these in the middle of the cannelure they with be right at 2.700 COAL. Should I seat in the cannelure at 2.700 and reduce the charge to start, or ignore the cannelure and go to 2.800? At 2.800 they wont be seated as far as I'd think they should.

I have some Fiocchi 150gn and they are right at 2.715. I have a chrono and the plan was to chrono the Fiocchi and aim to get close to that target ammo but I'm just looking for a starting point.

[Cowboy T]

Go ahead and seat the bullet to the cannelure. As long as you're not past the SAAMI max length for the cartridge, you should be just fine. You don't necessarily *have* to seat at 2.800"; that's the *max* overall length.

[tabascoz28]

Gun that you will be shooting this out of?

[fx1974]

You mentioned "most of the load data" so maybe you were looking at load data for a variety of bullets? The Hornady FMJBT that I use specifies the COAL to 2.700 and it is spot on at the cannelure, whereas other bullets of same weight but different profile are spec'd to as much as 2.800". From the few loads I developed, the OAL will always vary with the bullet profile.

Saying that, I think you should be fine seating to the cannelure and of course start at a safe starting load.

[jsanch03]

[Donny1]

Gun that you will be shooting this out of?

Savage Axis II

[nedro]

For a bolt gun, I wouldn't concern myself with the cannelure.
I would be more concerned about the bullet jump to the lands and work from there.
But that's me.

Cannelures are for semi autos so that the bullet doesn't get pushed farther into the case as the bolt slams shut.
Not needed on a bolt gun.

[Donny1]

I would be more concerned about the bullet jump to the lands and work from there.

I've been following Erik Cortina and some other precision shooters on YouTube. After many hours of videos I'm getting a much better understanding of the importance of all this.

I have a Hornady headspace gauge set, OAL gauge coming with the dies this week. Not that it's that important for an AR but after having the knowledge now I want to keep things in spec, for the .308 I see more potential for problems if something isn't right.

I know a couple of people that have been reloading rifle cartridges for years that are giving me a blank stare when I start asking questions. They just load and shoot and I guess that's fine, but I don't want to be that guy. Trying to teach and old dog (myself) new tricks. I actually find it easier now that I'm older because I have some patience now.

[nedro]

One thing to keep in mind is that you are not loading for others. Only yourself.
So keeping everything at factory spec. OAL is not necessarily where you and your rifle want to be.
Again, if using semi auto is your goal, by all means, use the factory specs and crimp in the cannelure.
My point was that tying yourself to the bullet cannelure is not optimal in a bolt gun. And not necessary.

[Donny1]

Until I get my tools/dies in this week I won't know how the chamber is cut but I'll work from there. With these bullets I don't think I'll be able to do too much as they are light, short but it will be good to learn and make some target ammo that's not $30 a box (of 20).

I've read seating depth should be at least the dia of the bullet but many say they load far more shallow without issue. The cannelure starts almost exactly at .308 on these bullets so I imagine that is their reasoning for the location.

[tabascoz28]

Really the major low hanging fruit as far as accuracy is going to be consistency.

powder and consistency or measurement of.
bullet type and seating depth consistency to ogive is better.
same group of brass helps, if you full size, watch out for shoulder bump.

Different guns like different things, the rule of thumb is .02 away from the lands, give or take some when you find your best powder group.

[smoothy8500]

I have 147gn M80 type bullets with the cannelure.

...and make some target ammo that's not $30 a box (of 20)..

If its just to "learn reloading" and easily assemble blasting ammo for your Savage, those M80 fmj are at best a 2 MOA projectile.

Get some better projectiles.

[G-forceJunkie]

Came to say that . If your loading for accuracy, thats not the bullet you want. Thats for making blasting ammo for a semi auto. Get some 175 Sierra match Kings, set at the longest length that will work in your guns magazine over 43.5 grains of Varget in non -military brass and you will have a copy of Federal Gold metal match.

If its just to "learn reloading" and easily assemble blasting ammo for your Savage, those M80 fmj are at best a 2 MOA projectile.

Get some better projectiles.

[Divernhunter]

No need to crimp and just seat them where you want within specs that do not push the bullet into the rifling

[tyler_sti]

Case overall length is irrelevant in a bolt gun if you are hand loading. That is only used for magazine size(the largest size(length) round that you can reliably feed from your magazine). The most relevant measurement is from case head to ogive of the bullet. That is the actual space from your bolt to the lands of the barrel(actual maximum room available for a round with a closed bolt) . As you mentioned once you measure to the lands on your rifle you will know maximum length to ogive.

Now remember all bullets have slightly different ogive so making sure your overall length is within sammi spec might make you jam the lands with specific bullets. Its all a balancing act of finding a sweet spot. some rifles like more jump off the lands than others especially with solid copper bullets.

My best advice is buy the cheaper bullets in the grain that you want. Get your measurements/consistency down low ES/SD/AVG VEL etc. Then start buying the pricey .60c-90c bullets for the actual final load development.