Seating depth with cannelure - Hornady OAL Gauge

G

Gawp

New member
Hey,

I started handloading my .30-30 Win cartridges for my Marlin 336 XLR and so I bought the Hornady OAL Gauge to seat my bullet at the right depth for my rifle (https://www.hornady.com/reloading/p...tools-and-gauges/oal-gauges-modified-cases#!/).

I did the measurement for my Marlin, but here is what I found:
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As you can see, the "correct" seating depth (minus 0,020 to 0,050 in) is way off the cannelure. I measured with the Hornady Bullet Comparator: 56,75 mm (2,234 in). If I seat the bullet so the case mouth is on the cannelure, it is about 52,45 mm (2,065 in).

What should I do in this case?
 

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#1 Crop the picture.
#2 Cannelures are rarely where you want them to be. The position can be ignored. Your ability to crimp may be limited to taper crimp. Lee factory crimp dies are very good for that. You DO NOT want and WILL NOT get a rolled crimp on that bullet at that seating depth. Go with published Over All Length.
Since we talking about 30-30 here, something looks wrong. There are a wide variety of bullets SPECIFICALLY intended for this long popular cartridge with flat or soft points, and softer lead to expand at lower velocity. If this is not one of those, that is your problem. 30-30 is an old chambering, originally using black powder. It is VERY different than 308 or 30-06. You cannot expect the bullets to interchange, even with the exact same diameter.
From Hodgdon Reloading datacenter:
WEIGHT170 GR. SIE FP
ManufacturerWinchester
Powder760
Bullet Diameter.308"
C.O.L.2.550"
Another idea forget the Hornady gadget (for a moment) and just measurethe COAL with a caliper or even a ruler.
Then compare to the published OAL.
You loaded cartridge looks way too long. Double check your measurement units (metric versus inches and conversion). That photo looks roughly like 3" OAL.
 
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Gawp,

The image was so big it didn't fit most screens. Try something like this (there are lots of other free image resizers online as well). As a rule of thumb, try to keep the largest dimension down to 1024 pixels. In this case, I have resized if for you and hosted it here.

I will point out that you have no way to know what the "correct" seating depth is until you test a number of them in your rifle. If you seat the bullet out so far that it is touching the throat of the chamber, the pressure will be about 20% higher than is given in load data that publishes such pressures. Usually, you want to be at least 0.030" shorter than that to avoid raising pressure. Nonetheless. you will find that 0.030" is not what all rifles like for accuracy. That has to be determined.

Also, in a lever gun, you will find the carrier in the action can't work to feed a round from the magazine if it is too long, and also that you need to crimp to be sure recoil doesn't bounce the bullets into deeper seating. Certainly, you can crimp anywhere on the bullet with a Lee Factory Crimp Die, but, again, you don't want to have the bullet out so far it disables the rifle's feeding ability.

Read this article for some background information on seating. You may find your gun likes bullets seated to match the mouth and cannelure just fine. Also, lever guns are not configured for benchrest accuracy, so you want to temper your expectations a little. Figure your first move toward improvement is to see if it will still feed if you resize cases to headspace on the shoulder rather than the rim by sizing them down just a couple of thousandths at the shoulder. Work on your loading method to maximum the concentricity of the finished cartridges. Those two things will go a long way toward getting your rifle as accurate as it can be. There are also accurizing steps that can be taken on the rifle itself if you want to try that. M.L. McPherson has written a good deal on the subject.
 
Since we talking about 30-30 here, something looks wrong. There are a wide variety of bullets SPECIFICALLY intended for this long popular cartridge with flat or soft points, and softer lead to expand at lower velocity.
Click to expand...
The cartridge in the picture is a modified cartridge for the Hornady OAL gauge and not a real/loaded cartridge. The "seating depth" shown in my picture is the result of the measuring method as shown in this video: https://www.youtube.com/watch?v=fW6H9HJzsvQ

The bullet is a Hornady FP #3060, which I think is ok for .30-30 Win because here in France there is a manufacturer which sells .30-30 Win cartridges with that bullet specifically (that's why I picked this bullet for handloading).

You loaded cartridge looks way too long. Double check your measurement units (metric versus inches and conversion). That photo looks roughly like 3" OAL.
Click to expand...
The OAL is 68.25 mm (2.677 in), which indeed exceeds the max OAL (64.77 mm or 2.520 in).

The image was so big it didn't fit most screens.
Click to expand...
Sorry, I will pay attention next time! Thanks for cropping it.

Usually, you want to be at least 0.030" shorter than that to avoid raising pressure.
Click to expand...
That's basically what I wanted to do: find the depth at which the bullet touches the throat and then substract 0.030". But it turns out it will exceed the max OAL of .30-30 Win.

Also, in a lever gun, you will find the carrier in the action can't work to feed a round from the magazine if it is too long, and also that you need to crimp to be sure recoil doesn't bounce the bullets into deeper seating. Certainly, you can crimp anywhere on the bullet with a Lee Factory Crimp Die, but, again, you don't want to have the bullet out so far it disables the rifle's feeding ability.
Click to expand...
Thank you for the info!

Also, lever guns are not configured for benchrest accuracy, so you want to temper your expectations a little
Click to expand...
I didn't want to do it to improve accuracy, but more as an experiment to see how all this worked. But it turns out this kind of rifle is perhaps not made for this kind of "optimization", right?

Let's say I want to do long range shooting with a bolt action rifle and I want my bullet to be anywhere between 0.020" to 0.050" from the throat. Would any bolt action rifle be able to meet this requirement or should I consider this when buying the rifle? Because clearly with my lever gun, I couldn't do it (but again as you said, lever guns are not configured for benchrest accuracy).
 
didn't want to do it to improve accuracy, but more as an experiment to see how all this worked. But it turns out this kind of rifle is perhaps not made for this kind of "optimization", right?
Click to expand...

Right.

As you can see, the "correct" seating depth (minus 0,020 to 0,050 in) is way off the cannelure.
Click to expand...

Its way off the cannelure because its not the "correct" seating depth. The measurement generated by the Hornady tool is NOT "the correct" length, its a possible seating depth, the longest possible before hitting the rifling. That's all.

The "correct" seating for the .30-30 with the bullet shown is seat to the cannelure, and below the max listed length for the round (2.550") which, if you seat to the cannelure, it will be.

There are rifles where you can use that tool and seat bullets to be just short of the lands, repeatibly, and which will shoot somewhat more accurately, if you do so.

There are a lot of rifles where you cannot do this, or, even if you can, its essentially wasted effort.

With the typical .30-30 lever action, seating to just short of the lands is essentially turning the rifle into a single shot, and may not show any significant accuracy gain, even going that route.

There may be room in the BARREL to seat the bullets long, but that room normally doesn't exist in the action's feed system. You can make rounds too long to feed from the tube magazine into the chamber. You can single load them into the chamber and shoot them, but you 've lost the rifle's ability to function as a repeater.

Additionally, lever guns, with their relatively coarse sights, and trigger pulls, and the large number of parts involved are rarely capable of being shot as accurately as other guns. Minute of deer, yes. A bit better, often, minute of angle? rarely...

My advice, concerning a .30-30 and the lever gun it's in, is take that Hornady tool, put it back in the box, and sell it to someone who might actually find it a useful thing.
 
I think you are trying to determine where your loaded round is in relation to the lands and grooves. You can do this by making a sized dummy round: no primer, no powder. Take a sized case and start the bullet. Try to close the action. Take it out and size a little deeper. Try to chamber it again. Continue until the action closes on the round. You want to find the point where the closing action pushes the bullet to the rifling. Write that COAL down. It will be different for each gun AND each nose profile. On a bolt gun I do this with a downward pressure on the bolt handle. I do not if it will work in a lever gun.
Once you know that point, you can vary your COAL TO find best accuracy. Some guns have a longer throat or leade. I vary COAL to fit the known chamber specs.
 
Once you know that point, you can vary your COAL TO find best accuracy. Some guns have a longer throat or leade. I vary COAL to fit the known chamber specs.
Click to expand...

While this works in some guns you are much more restricted in others.

If you have a single shot, or you are single loading a repeater, you can load bullets out to the edge of the lands, "for best accuracy" (which may or may not be the case), but are you prepared to turn a repeater into a single shot for better accuracy?

If you aren't, then you must load rounds that will fit in the magazine and feed into the chamber. These rounds WILL be below max listed COL length, and WILL be well short of the rifling.

The tips and tricks used for target shooting don't apply across the board for all guns and shooting situations.
 
I think you should seat to the crimp grove and crimp there . As stated above and you appear to understand . That cartridge in a lever gun ??? is not set up for this type of advanced reloading method . I have a 30-30 bolt action ( JC Penny I believe ) that I still wouldn't try that level of reloading with . Although I did find my max COAL , that length would never fit in the mag so it doesn't really matter what my max COAL "could" be . I'm stuck with loading to max mag length . Some day since it is a bolt gun I do plan to load some pointy match bullets in it just to see how it does .
 
Gee, yet another seating depth thread with "Hornady OAL gauge" in the title. :rolleyes:

I'll agree with Metalgod here.
The factory 30-30 cartridges seem to have a slight roll crimp.
Best done at the cannalure.

And the long freebore is to help reduce pressures for a lever action it was originally designed for.
 
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