Question about hornaday OAL gauge

[DsGrouse]

Up until now I've been going by the reloading manual's numbers. I picked up a Hornaday OAL gauge and a 30-30 modified case. When I follow the directions of the OAL Gauge, I end up with a max seating depth of 2.675. Which is considerably different than the books. 2.550.

So, my question is. What am I missing context wise.

[Mags]

Up until now I've been going by the reloading manual's numbers. I picked up a Hornaday OAL gauge and a 30-30 modified case. When I follow the directions of the OAL Gauge, I end up with a max seating depth of 1.675. Which is considerably different than the books. 1.550.

So, my question is. What am I missing context wise.

Seating depth of what? Bullet seating depth in a case should be about 0.400 depending on the grain of the bullet.

[DsGrouse]

170 grain sierra and hornaday. They both come to about the same oal. Like I said, I'd been seating them at 2.520, as the hodgdon manual says. But, going by the Hornaday OAL gauge instructions and the modified case I could load them to 2.635. That puts me from 0.040 from the lands.

That seems a bit long, I'm not sure they would load from the lever gate with that.

[Mags]

170 grain sierra and hornaday. They both come to about the same oal. Like I said, I'd been seating them at 1.520, as the hodgdon manual says. But, going by the Hornaday OAL gauge instructions and the modified case I could load them to 1.635. That puts me from 0.040 from the lands.

That seems a bit long, I'm not sure they would load from the lever gate with that.

I redited my earlier comment.

[Mags]

170 grain sierra and hornaday. They both come to about the same oal. Like I said, I'd been seating them at 1.520, as the hodgdon manual says. But, going by the Hornaday OAL gauge instructions and the modified case I could load them to 1.635. That puts me from 0.040 from the lands.

That seems a bit long, I'm not sure they would load from the lever gate with that.

Looking into definitions... I think you mean "internal seating depth" that's a different measure from "seating depth".
None of the books I have deal with either. Everything I see is specified at OAL.

[DsGrouse]

Whelp, Henry 30-30 with bushwacker 46 is a laser beam using factory and my super sonic loads.

So much so that I might not develop subs for it. Don't get me wrong, it's fun with subs and they are crazy accurate, but, as well as this shoots with supers, and as pleasant as it is to shoot? man, I don't know... I cleared my 'Know Your Limits' target with it. On the second time through, it fell over after the last shot.

Looking into definitions... I think you mean "internal seating depth" that's a different measure from "seating depth".
None of the books I have deal with either. Everything I see is specified at OAL.

No, I am talking about cartridge overall length.

Factory loads and what I've loaded are pretty close to 2.545 for 170 grainers.

Hornaday's modified case, and bullet combo, when you follow directions, leave me with a COAL of 2.675. They also say, for the best accuracy, you shouldn't seat the bullet further than 0.040 from the Modified case/bullet combo length. Now, the caveat there is that I'll need to do a few tests to see if bullets of that length will feed.

Previously, I didn't have any spare brass. But after my little shooting session, I can spare a couple of pieces and see if they chamber and load from the lever.

[DsGrouse]

The question is moot. The henry doesn't cycle round that are over 2.525, let alone the 2.550 max. That might improve with shooting, but I don't think it will change much.

I started by making dummy rounds and decreasing the value by 0.010 from 2.675 per dummy round. It finally cycled reliably at 2.525. So, that's my max unless I want to single feed.

[Mags]

Whelp, Henry 30-30 with bushwacker 46 is a laser beam using factory and my super sonic loads.

So much so that I might not develop subs for it. Don't get me wrong, it's fun with subs and they are crazy accurate, but, as well as this shoots with supers, and as pleasant as it is to shoot? man, I don't know... I cleared my 'Know Your Limits' target with it. On the second time through, it fell over after the last shot.

Looking into definitions... I think you mean "internal seating depth" that's a different measure from "seating depth".
None of the books I have deal with either. Everything I see is specified at OAL.

No, I am talking about cartridge overall length.

Factory loads and what I've loaded are pretty close to 1.545 for 170 grainers.

Hornaday's modified case, and bullet combo, when you follow directions, leave me with a COAL of 1.675. They also say, for the best accuracy, you shouldn't seat the bullet further than 0.040 from the Modified case/bullet combo length. Now, the caveat there is that I'll need to do a few tests to see if bullets of that length will feed.

Previously, I didn't have any spare brass. But after my little shooting session, I can spare a couple of pieces and see if they chamber and load from the lever.

Those are really short for 170gr. My Hornady Book says 2.53, Sierra shows 2.42, Speer 2.55 and Nosler 2.55. I suspect the latter are just giving SAAMI max. Even the recommended case length is 2.029 to 2.049.

I can understand why there is a difference between Hornady and Sierra. The Sierra has a flat nose shorter than the Hornady round nose. Cannelure to bullet base is the same, but cannelure to nose is the difference. Both bullets would seat the same depth from the bullet butt to case mouth, but case mouth to bullet nose length would be shorter with the Sierra bullet.

Maybe I'm still not understanding where the shorter lengths you share are coming from.

[DsGrouse]

You are right
I typed 1.5... 1.6... but meant 2.525 and 2.675

[Mags]

I don't think I would put too much into the difference between what the reloading books say for OAL vs what your rifle chamber actually measures out to. Some reload books state the 2.55 SAAMI OAL max for cartridges whereas Hornady and Sierra books state something a little less, my guess based on test results.

SAAMI doesn't specify a max for chamber length. So your rifle at 2.65 is likely where that mfgr thought best for ensuring battery lockup along with bullet acceleration and pressure buildup before engaging the barrel lands. Anyway, my thoughts.