I am loading some Hornady 123 gr SST bullets, Hornady manual calls for a COL of 2.710, at this depth I am not even close to the cannalure.
Do I ignore the cannalure and seat to the published COL?

The cannalure is there to hold the bullet together during expansion, not to be used as a point to crimp the brass into the bullet.

Yes, but I’ve had a bullet manufacturer tech tell me to crimp into a cannelure if it was close in terms of COAL. (Barnes in that case)

I’m gonna break out my broken record: call the bullet manufacturer.

Do you know how (or even if!) that load fits your rifle?
Does it fit the magazine and reliably chamber? Where is the bullet ogive in relation to your chamber throat?

If you’re loading for accuracy, the rule of thumb is to seat the bullet so the ogive is touching, or just shy of touching, the rifling in the chamber throat. (That’s one reason why match grade bullets generally don’t have a cannelure, besides the fact that they distort the bullet.)

Depending on your application, such as feeding, or loading in the magazine, you may need to adjust. If your rifle is properly designed and built, hopefully all these factors will work together.

Reloading manuals stipulate specific COL because seating depth relates to case capacity and therefore chamber pressure.
All of this needs to be juggled by the individual handloader to safely obtain the optimal results in one given rifle.

So, ultimately it’s an individual’s informed and intelligent decision. Nobody, not even the bullet manufacturer, can tell you what’s ideal for your rifle.

That’s the beauty of handloading.

Bullets are held in bottleneck cartridges by neck tension. No crimping necessary. Your dies may not even do crimping.

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I've still got it made.

I spent a lot of time developing my 6.5 reload. First what type of gun are you shooting this round out of...bolt or semi? What is your intended application...precision target, hunting round, or plinking?

As 6string mentioned above you must first measure your chamber so you know where the ogive touches the rifling of said bullet. Hornady sells a tool for this. Then once you know that you have to figure out the "jump" distance of the ogive to rifling (trial and error and testing rounds). This is what matters, not so much OAL and cannelure.

And of course that's after you have decided on your powder, primer, and brass you want to use. Then sizing, trimming, neck tension, and runout.

But I digress, it really depends on your usage for the round and how much you want to get into the weeds. I have an extensive development notebook to include bullet jump and powder variation in weight. Faster was not always better too.

When I was done testing I ended up with .250" MOA and was quite pleased and considered done. Keep in mind that for the benchrest shooters out there this ain't good enough lol. I target shoot at distance out to and including 1000y for fun not competition. It's stupid accurate too, golfballs at 300y is easy. I really enjoyed the development phase.

My cartridge specifics: Hornady brass, Hornady 140g ELD Match bullet, H4350 powder, Federal GM primer, 1.910 trim length, .002 neck tension, .015" bullet jump, .001" or less runout, and 2661 FPS.

Good luck and have fun with this!

Some pics

Attached Images

	Jump Testing Final.jpg (62.6 KB, 19 views)
	CM Runout.jpg (129.1 KB, 17 views)
	RPR 6.5.jpg (77.1 KB, 16 views)

2.800 is the max OAL for 6.5CM, so you can go that far or less. If you're trying to get accurate loads, size a case, seat and then remove a bullet (so a bullet will move easily in the neck like a fired case). Reinsert a bullet without neck sizing to greater than the max OAL, and chamber it (no powder or primer). Remove it carefully so as not to disturb the location of the bullet, and then measure the OAL of that round. That will give you the max OAL of your chamber, because when you chamber the too long round, the bullet will get pushed back by the leade of the rifling. Back off a couple of thousandths and start from there with your loads.

Of course, if your rifle is magazine fed, your max OAL will be what will fit in the magazine, if shorter than 2.800".

My thoughts are the 123 gr 6.5 was produced for the Grendel and why the cannelure does not match close to a factory OAL. If you go to the 140 gr like the interlock then the cannelure will match. On another note, most / many 6.5 bullets don't even have a cannelure since they were not designed specifically for an auto. If you have an 8 twist barrel you can likely get sub half inch to sub quarter inch groups with the 140’s and my best with the 143 grain Hornady.

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S&W factory revolver armorer

If you're loading for a bolt action rifle and plan on using more than one bullet weight or brand. And especially if you load for several rifles I'd suggest getting one of these.

Access Denied

Hornady lock n load overall length gauge. Then you can see exactly what to set the depth at for different bullets/different guns.

But man you can get so deep in all the gadgets with rifle loading it's not even funny.

I use a Stoney Point tool (also made by Hornady now, I think) to determine maximum overall length with a particular bullet in my rifles, then (providing magazine length will allow, seat bullets to .010 to .020 short of the lands. If I really get picky with a particular load, I may experiment with different seating lengths off the lands. Sometimes it matters, sometimes it doesn't seem to have much effect. I ignore the cannelure if it doesn't happen to be where I want the bullet seated.

Here's a card like I make for each of my rifles showing max OAL for various bullets. This one happens to be for my 6.5 Creed, a Kimber 84M. Like I said, sometimes it seems to matter (with a particular rifle and/or bullet), sometimes I get the same results if I just seat them to loading manual specs. It's a place to start, at least.

I was initially thinking the same thing, and why was OP using 123 grain when terminal performance in the 6.5 CM is better with the heavier bullet. The BC of the 140 is better than the 123, and although the MV of the 123 is significantly faster it won't sustain the extra energy as long as the heavier bullet. 123 grain in the Grendel is optimum because the 140 has to be seated deeply enough that it robs case capacity and therefore falls short of enough powder to launch the heavier bullet to equivalent velocity or range as the 123. I load and shoot for the 6.5 Grendel, and I don't use bullets with a cannelure. As for OP, ignore the cannelure and load the rounds to the advertised OAL for that cartridge and bullet combo.

Yup

Of all the rifle bullets I've loaded in my closing in on 40 years of it I've only used bullets with a cannelure a small handful of times. 308 for a CETME many years ago, stuff like that.

In general I agree with you. However, like so many questions in life the answer is “it depends”. For bolt action rifles, no crimp. For lever action rifles with a tubular magazine always crimp (yes 30-30 is peculiar as a rimmed, bottleneck cartridge). For a violent semiauto rifle like the Garrand or M14/M1A, crimping might be a careful man’s choice if, and only if, there’s a cannelure or crimp groove in about the right place.

I also reload for a M1A, and have never had any issues with setback, and have never used cannelured bullets; I prefer match bullets. Properly sized cases have sufficient neck tension to hold the bullet securely. It does help to anneal the case mouth and shoulder area to extend the life of the case, but I test my cases for case base thinning every time I reload and dispose of them once I detect any thinning in that area, as case head separation is a worse problem to deal with. I use Lake City 7.62x51 once-fired brass exclusively and get 4-5 reloads per case before I feel the need to trash them.

My school of thought, if the cannelure is where I want my OAL to be, I use it, if not I don't worry about it. Problem is, any given bullet may be used in multiple cartridges that have multiple different seating depths/OALs, there is no way the manufacturer could make a bullet to have the cannelure in the "proper" place for all cartridges in that caliber.

I do make it a point to crimp in the cannelure in semi-auto and lever rifles if possible, in bolt guns/single shots, etc, I don't worry about. Adjust to OAL that gives best accuracy.

Rosewood

I partially agree with this. If you chamber and magazine will accept longer than 2.800", then you can go longer. The shorter of the 2 is what you have to go with. Chamber and mag are the restrictions and 2.800" is the assumed max by manufacturers that provide load data likely based on SAAMI.

Rosewood

All true. I was basing my comment on how sometimes a bolt action single shot will allow a longer OAL than a magazine fed semiauto.