Best way to determine COAL?

Tazzy

Tazzy

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I'm totally new to reloading and I'm trying to figure out the length of my cartridges. I'm shooting a single shot T/C Encore. What I think is the best way is to seat the bullet further out than needed then drop the bullet in the chamber (barrel not on the gun).
Keep adjusting the die down until the rim of the case is flush with the end of the barrel.

Any suggestions are welcome.
 
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I take it that you are trying to determine COAL with the bullet just touching the rifling.

If so, then there are a couple of other ways.

1. Load a round without propellant or primer. 'Paint' the bullet with a black magic marker, let it dry and chamber it. If it touches the rifling, you'll see it. Adjust as necessary. My preference.

2. Load a round without propellant or primer; do not resize (assuming you are using brass from the same firearm). Coat the bottom half of the bullet with beeswax or some other stiff but pliable goo before inserting into the case. You should be able to do this by hand; if the goo is right, it will stay in place and require a little force to move it. Make sure it sticks out further than normal. Chamber the round, take it out and measure it. I would verify length with method #1 before firing live loads.
 
I load the round with the bullet you want to use in an unfilled case with a slightly loose neck so the bullet can slide in and out, and with the primer hole drilled out. Mount the fake round into the gun with the bullet as far in as possible (with the bolt out ) with the round in the chamber use a rod that will fit in the drilled out primer hole and gently push the bullet till it just touches the lands and then carefully remove and measure total length and then subtract .010 to .015 off and that puts you at max length with a slight bullet jump for that bullet. Make sure this measurement with fit your mag and if it does you are good to go. Important thing to remember is that every bullets ogive is different so you must do this for every bullet you are going to use. I used this in over 12 rifles with great success, it's easy quick and clean. Goodluck and have fun with it.
 
When using a dummy round for set-up it's handy to have a hammer-type bullet puller so that when you adjust down too far you can just tap the loose bullet out a bit and readjust.
 
HIGHRPM said:
I load the round with the bullet you want to use in an unfilled case with a slightly loose neck so the bullet can slide in and out, and with the primer hole drilled out. Mount the fake round into the gun with the bullet as far in as possible (with the bolt out ) with the round in the chamber use a rod that will fit in the drilled out primer hole and gently push the bullet till it just touches the lands and then carefully remove and measure total length and then subtract .010 to .015 off and that puts you at max length with a slight bullet jump for that bullet. Make sure this measurement with fit your mag and if it does you are good to go. Important thing to remember is that every bullets ogive is different so you must do this for every bullet you are going to use. I used this in over 12 rifles with great success, it's easy quick and clean. Goodluck and have fun with it.
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Very good point!

I like the method, too. Bad day when you cannot learn something.
 
ATOM said:
Very good point!

I like the method, too. Bad day when you cannot learn something.
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Sorry I didn't provide more info in my post. This was the reason I was asking, I was comparing Winchester white box ammunition with COAL of the Vmax bullets I had bought and noticed that if I seated the bullets to the same length that the ogive was very different.
 
308BAR said:
Buy A Comparator It Is Worth The Money.
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Stupid question. Will the comparator be able to help me find the COAL of my rifle or is it just used after I know the seating depth of my bullets according to the ogive of the bullet?

If it sound like I don't know the jargon of reloading it's because I don't. :redface:
 
A bullet comparator allows you to measure to the ogive of a bullet (very start of major diameter). With a Sinclair, or hornady OAL gauge you can measure the max. COAL with your action closed. Use the comparator with a calliper to seat to this length minus .01-.02 and voila! As a side note: make sure to check hornady's recommended min. COAL for those vmax. I noticed .05 difference between hornady data vs. hodgon and lee when loading for my .223.
 
One idea I picked up on here: take a Dremel with a cutoff disc, and cut 3 slots in the neck, spaced equally:

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Now your bullet will stay in place well enough until it hits the lands, where it will be pushed further into the brass until the bolt is closed. It should hold in that spot when you withdraw the unprimed/unpowdered case.
 
To the OP, the method shown by Steve BC is pretty good. Just measure a few times to make sure you get an accurate measurement.

Next, when you are setting up your die, use the exact same bullet you used in the dremeled case... this is very important.

Start load development at 20 thou into the rifling and then move back in 5 thou increments. 5 thou can the difference between 1 MOA and .1MOA groups with some bullets. Seriously. (Particulalrly VLD bullets)

As to a comparator, absolutely. Bullet tips vary a huge amount... HUGE. Ogives are what engage the rifling.

If you set your die up with the exact bullet you used for the test, the seating stem acts like a comparator. Try measuring loaded rounds. They are all over the place in tip to base measurement, but ogive measurements stay consistent. Have fun
 
As I said- I got the idea from someone else here- wish I could remember who. I thought it was pretty slick too.
 
stevebc said:
As I said- I got the idea from someone else here- wish I could remember who. I thought it was pretty slick too.
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Me too.

Another thing I do:

Take a projectile and drop it into the chamber and give it just enough of a tap to keep it there. Put something in the end of your cleaning rod to cover the jag hole. Slip the rod down the muzzle until it touches the bullet. Make a mark on the rod. Remove the bullet and replace the rod. Slip it down until it touches the bolt face. Make another mark. Measure the distance between the 2 marks on the rod. Make sure that the rod is not resting on the plunger/ejector when taking your second measurement.
 
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