Newbie reloader here - COAL verification question

J

janssen

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Apologize for what is probably a simple questions to you gurus, prefer not to have my first round be my last round - appreciate your insight!

Just getting ready to load my first rounds, seems to be alot of different ways of find COAL for your rifle.

I did the following

-Set head in case
-Ran marker over head
-Seated head until marker ink showed no lands
-called it done

Reloading data from Sierra 5th. 3.340 COAL Mine currently measures out at 3.304 ? Doing it this way shouldn't I be longer?

Questions:
Am I sitting too close to the lands?
Am on on the right track or am I going to cause Problems?


Plan on doing ladder test then seating head further down to tweak for accuracy.
Using 180 grn HPBT, RL-19 starting at 65.4 grains and working up to 71.1
 
People are going to need to know what caliber you're working on to make heads or tails of your OAL.

Personally, as a fellow noob, I'm seating strictly to the OAL specified in my book's load data and not worrying about how far off the lands I am. I'm also doing a ladder test, but varying powder only-- I don't want to be modifying two variables at once with my level of (in)experience.

Varying OAL can have drastic effects on pressure, particularly if you are seating close to the lands. I'm personally not yet experienced enough to feel 100% confident with my ability to reliably read pressure signs. So I stick to published load specs, including OAL.

Generally though, yes: when you seat close to the lands your OAL will be longer than what's specified in the book. So something's not right there. How are you measuring OAL?
 
I don't shoot 300 WM, but the SAAMI spec does specify 3.340" for the COAL. Personally, I would just stick with whatever the Sierra book says and vary your powder. It sounds like you are seating those bullets way deep. Depending on what kind of rifle you have, when you seat to the lands you generally wind up with COAL that's so long that you have to single feed, so something seems to be off.

In fact, if this is your first batch, I personally would forget about the ladder test and maybe load the minimum specified powder charge and one step above that in two batches. That's what I did the first couple of times until I got the hang of the process.
 
I do it the same, only different.

Remove extractor and ejector.
Wooden dowel down the barrel.
Seat bullet long in neck sized case.
I rough in by hand, no bolt, chamber with finger. You'll get a feel for it.
- if I can move the case up n down in the chamber, it's still touching the lands.
I dial in with bolt, by measuring to the marks on the ogive, seat the next a couple thou long to confirm.
Done.
The dowel is to tap the bullet out through the process.

If I've made it sound difficult, it really only takes minutes to do.

edit to add:
This is to measure chamber length, not coal
Going off chamber length, each bullet has it's own coal
 
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OK Figured out why it was so screwed up.

Since I was going nice and slow - many iterations the ink was building up on the head significantly, causing the ogive to move, making me screw up.

Redid it using smoke and came out much closer.

Am just going to use spec coal for this time, get fancy later :) Waiting for my primers to come in so playing on the bench.

Looking forward to taking my new Ron Smith Barrel for a walk.

JJ
 
Since the rifle used to develop the data in the manual wasn't your rifle, the COL listed in the manual, is pretty much meaningless. The throats of different barrels can vary considerably, so base the COL of your cartridge, on your rifle, including taking into account, the COL that will function in the magazine.
 
stubblejumper said:
Since the rifle used to develop the data in the manual wasn't your rifle, the COL listed in the manual, is pretty much meaningless. The throats of different barrels can vary considerably, so base the COL of your cartridge, on your rifle, including taking into account, the COL that will function in the magazine.
Click to expand...

Like he said. Each manufacturer uses their own version of a throat, plus the throat moves forward with erosion from shooting.

When I start loading for a new rifle, I seat the bullet long. (By the way, that pointy thing is called a "bullet", not a "head". The head is actually the correct name for the base of the case.) I then chamber the long round and note how much rifling mark I see on the bullet ogive. I put that round aside, screw in the seater a bit, and seat another bullet, and repeat. I keep doing this until I don't see a mark. Then I turn the seater stem another quarter turn and note that OAL. Then I take all the longer rounds, with the rifling marks, and seat them to the final setting. I assume that setting is off the rifling a bit and carry on with testing, and then come back to that distance later, when I have a good powder charge, and then experiment with the bullet 10 thou deeper and longer.
 
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When segregating brass by weight, the heaviest or lightest make great dummy rounds.
Those dummy rounds are then full length resized and the expander is run through the neck a couple or three time to remove some of the tension.
These dummy rounds are then identified by seating a spent primer backwards.
Three bullets are then seated to the lands and the shortest becomes the standard and the COAL is marked on the case.
The seating rod is backed out and the standard inserted. The seating rod is screwed down to make contact, backed off a bit so the cam of the press does not seat the standard deeper.
The seating rod is then turned in a quarter turn and locked.
When the first rounds are seated, they are checked to find the difference from the standard and at this time may be seated deeper in the interest of safety.
Once safety in firing has been established, the OAL may be experimented with.
This process probably saved a lot of grief with my 280 Remington as it seated deeper than SAMMI Specs.
 
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