COAL question

[matt_14_85]

I am brand new to reloading and loaded up my first batch today.

I used 55 gr bullets and did up 18 rounds. 3 at 34gr 3 at 34.5gr etc...

Problem I am having is with cartridge overall length. It is varying about plus or minus .003".

I trimed all my cases.

From what I read that the bullet tip can be deformed so to really compare COAL you need to measure from the ogive. (special tool required, which I don't have)

Is .006" variance bad at all? Any one have any experience with this?

Thanks,

Matt

 

[joe-nwt]

I
From what I read that the bullet tip can be deformed so to really compare COAL you need to measure from the ogive. (special tool required, which I don't have)

Is .006" variance bad at all? Any one have any experience with this?

Thanks,

Matt

What you have read about measuring bullet tips is true. The good news is your seating die does not push on that tip to seat the bullet. So likely, your variance is not .006.

 

[matt_14_85]

So even though the tip of the bullet varies in distance to the rifling of the barrel, this should not matter since the ogive of the bullet is consistently the same distance?

Or at least more consistent than the .006" variance I thought I had measuring the COAL.

This make sense? Am I on the right track?

Thanks again,

Matt

 

[sunray]

"...3 at..." Five of each is better. Easier to keep track of 'em. Depending on what rifle you have one mag load works best.
I've always just measured from the point. The point won't be damaged by the die and 2 like weight bullets can have different shapes. 6 thou doesn't make much difference either. Having 'em all the same is the important part anyway.

 

[joe-nwt]

So even though the tip of the bullet varies in distance to the rifling of the barrel, this should not matter since the ogive of the bullet is consistently the same distance?

Or at least more consistent than the .006" variance I thought I had measuring the COAL.

This make sense? Am I on the right track?

Thanks again,

Matt

Yes, you are! If you want to prove this to yourself, buy a bullet comparator. They don't measure from the tip.

It is certainly refreshing to see someone who is researching before posting questions. Enjoy your new hobby!

 

[stubblejumper]

Don't worry about the different in bullet tips, your bullet seater doesn't seat on the tips anyways.

 

[varmintboy]

What you can do is get a small piece of mild steel rod, 3/8 or 1/2 diameter (doesn't matter which) by about an inch long. File the ends flat, or face them flat in a lathe. Drill a 7/32 hole about 3/4 of an inch deep. Debur the hole. The 7/32 hole is as close to the bore diameter of 22 centerfire as you're going to get. Less than half a thou smaller. I assume you're loading for 22 w/ 55 gr bullet.
Measure your chamber for length (bullet touching the rifling). Take a new brass and slit the neck on one side with a dremel or hacksaw. Debur the slit. This will make the case hold the bullet, yet let it slide back into the case without too much effort. Start a 55 gr bullet in the brass, put it in your gun and close the bolt. Remove cartridge.
Put the mild steel sleeve on the cartridge used for measuring the chamber and use calipers to get an overall length of cartridge and sleeve.You are now measuring the ogive where the bore diameter is instead of the end of the soft point bullet. Write it down. That is your reference number. That is the maximum length you can use to touch the rifling in that particular gun. Now you can load any bullet weight or bullet length. As long as the new cartridge (with sleeve) measures the same or less than your reference number (chamber length) it will fit your gun and not jam into the rifling. It's good for playing with lengths for moving the bullet back from the rifling. If you want to try seating .030 from the rifling, subtract .030 from the overall reference number and you're there.
I likely explained this as clear as mud, but it works

 

[Ron AKA]

The method I use requires no special tools other than a vernier.

Split Case Method

1. Take a neck sized only fired case, and use a Dremel to cut a single narrow slot in the neck and shoulder.

2. Select a bullet from the box you plan to load and fit it in the split case. Pick a bullet with a consistent flat tip, or file it a touch to square it up. Adjust case by squeezing the neck to increase tension as required. It does not need a lot of tension and just enough hold the bullet.

3. Carefully chamber it, and remove it slowly. If the ejector is pushing the case sideways, use your finger to keep the bullet from dragging on the side of the chamber or receiver.

4. Measure the overall length of the cartridge to the tip of the bullet, and record it.

5. Repeat step 4 until you get consistent numbers within .001". When you think you are close, then just pull the bullet a slight touch out from the self seated position and confirm it consistently returns to that same spot, and record the final length of the cartridge, and record in you loading book. Mark this bullet so you don't mix it up with the rest.

6. This length represents what overall length you need for that specific bullet to touch the lands. In my opinion just touching the lands is a poor position to seat too. I go either 0.010" longer to jam the bullet, or increments of 0.010" shorter to create a jump to the lands. Calculate your desired OAL to give the jam or jump you want, and record that number.

7. Use this marked bullet to load a live round long in the case, and by seating it deeper and deeper by trial and measure match the OAL you have calculated in step 6.

8. At this point methods may differ. Some save this load and use it to set up your die for the next loading session. I have a micrometer style seating die, so I just record the seating position in my loading book and use the test round at the range.

9. This test load, or recorded seating depth in theory is good for that specific batch of bullets, if it were not for throat burning. Especially when new the throat burns so is a moving target. So, especially with a new barrel you may want to repeat this exercise more often, or if you bought a large batch of the same bullets.

 

[matt_14_85]

Thanks for the help guys. It's nice to be able to back things up you read on the internet with actual people with real experience.

Also thanks for sharing the "split case method".

 

[Cameron SS]

When measuring off the tip .005" variance is not uncommon. I've seen as much as .010" Some bullet manufacturers are better than others, but ultimately, as others have mentioned, the bullet seater in your die seats off of the ogive where that variance would be greatly reduced.

A comparator would be the best way to be able to check for that remaining variance, as well as a hundred other important measurements. They may seem expensive, with good ones going for over 200$, but you will discover many uses for them on your way to becoming an expert yourself.