New Brass first firings do i.....

[6.5x300 WBY]

6mm creedmoor new alpha brass and was wondering if I need to pay attention to things like CBTO?. I AM just back into reloading but 95% was handgun and rifle I haven't done in >10 years maybe 15. I am treating myself as a beginner and reading a ton here. So

My first load is
ALPHA. BRASS. NEW
CCI 41
H4350. 39 GR.
Sierra 107gr HPBT
Now do I worry that the first two loads had a varying cbto of .025 difference.
Should I not worry about measuring till it's formed to my chamber??

Just feel very confused if I should be doing anything special or just load them up and shoot.

Any help appreciated.

Oh I am loving my new. Reloading bench

 

[BW64]

What make press & die?

 

[DoneNOut]

Now do I worry that the first two loads had a varying cbto of .025 difference.

That is beyond acceptable variance. I'd measure the bullets themselves, bullet base to ogive with the comparator and see if it's a bad run of bullets, or there is a loading procedure inconsistency.

Should I not worry about measuring till it's formed to my chamber??

Find the distance to lands and back off .020 for the first firings. The brass will likely stretch .010. Then you can fire next time with ogive .010" off the lands and get serious with load development.

Just feel very confused if I should be doing anything special or just load them up and shoot.

Consistency is key

Any help appreciated.

Oh I am loving my new. Reloading bench

 

[6.5x300 WBY]

Forster ultra micrometer. T7 turret but creedmoor sports upgraded head.

 

[6.5x300 WBY]

That is beyond acceptable variance. I'd measure the bullets themselves, bullet base to ogive with the comparator and see if it's a bad run of bullets, or there is a loading procedure inconsistency.

Find the distance to lands and back off .020 for the first firings. The brass will likely stretch .010. Then you can fire next time with ogive .010" off the lands and get serious with load development.

Consistency is key

Finding the lands is driving my wonky. Seriously wonky.
I tried to methods.
Method 1. Made a dummy round seated it long and closed the bolt to push back the bullet. Used ram rod to gently tap round out. Did this two times with exact same numbers. 2.832
Method 2. Hornady oal guage.

Very consistent numbers x6 attempts.
2.8165
2.816
2.816
2.8165
2.816
2.8165
So I'm lost. And bald now

 

[Rick Richard]

Finding the lands is driving my wonky. Seriously wonky.
I tried to methods.
Method 1. Made a dummy round seated it long and closed the bolt to push back the bullet. Used ram rod to gently tap round out. Did this two times with exact same numbers. 2.832
Method 2. Hornady oal guage.

Very consistent numbers x6 attempts.
2.8165
2.816
2.816
2.8165
2.816
2.8165
So I'm lost. And bald now

Using method 1 normally requires removing the firing pin.

 

[BillLarson]

Using method 1 normally requires removing the firing pin.

And the ejector...

 

[6.5x300 WBY]

Using method 1 normally requires removing the firing pin.

Well I didn't do that for sure so maybe the hornady guage could be right then

 

[Rick Richard]

Well I didn't do that for sure so maybe the hornady guage could be right then

I use the Hornady method and is plenty accurate enough to get me in the ball park for fine tuning.

 

[DoneNOut]

Finding the lands is driving my wonky. Seriously wonky.
I tried to methods.
Method 1. Made a dummy round seated it long and closed the bolt to push back the bullet. Used ram rod to gently tap round out. Did this two times with exact same numbers. 2.832
Method 2. Hornady oal guage.

Very consistent numbers x6 attempts.
2.8165
2.816
2.816
2.8165
2.816
2.8165
So I'm lost. And bald now

I'd trust the Hornady gadget over the bolt closure. You could be stuffed into the lands that additional .016" on the bolt closure method. You could sharpie the ogive area on the bullet to see if there are land marks.

My favorite, and what I think is most accurate, is to let gravity show you.

1. Clean chamber.
2. Muzzle up with buttstock on bench. Take a new piece of brass and load it into the chamber with your pinky finger. You should be able to press hard on the back of the case head and it should fall out no problem as you let your finger loose. (Now, this is a test to make sure the brass is clearing the chamber with no false reads)
3. Same piece of brass, load a bullet in it a bit long, like 2.840. Slowly insert the round into the chamber as before and see if it will fall free when you push on it hard with your pinky. If it doesn't fall free, but sticks in the rifling, then seat the bullet deeper a little as a time, like .003" until you can push hard on the back of the brass and it falls back out freely with gravity. A bullet will stay in the rifling with even .001" into them. SO, when it falls free you are extremely close to the lands. (Punch stuck round out with a cleaning rod from muzzle or small dowel rod)
4. Record that length, and then go .020 deeper to ensure the new brass stretch won't put you into jam. That shoulder of the new brass will move forward with the bullet maybe .010ish. Second and subsequent firings you size shoulders back just .002" from fired length so they don't get worn out so fast from stretching from factory length.

On another note. H4350 is gonna be accurate, but slower than H100V and RL17. I'd nod to the H100V since it has less burn temp. RL17 is a velocity champ, but burns hotter. Me, I don't care, barrels are consumables.

 

[6.5x300 WBY]

I'd trust the Hornady gadget over the bolt closure. You could be stuffed into the lands that additional .016" on the bolt closure method. You could sharpie the ogive area on the bullet to see if there are land marks.

My favorite, and what I think is most accurate, is to let gravity show you.

1. Clean chamber.
2. Muzzle up with buttstock on bench. Take a new piece of brass and load it into the chamber with your pinky finger. You should be able to press hard on the back of the case head and it should fall out no problem as you let your finger loose. (Now, this is a test to make sure the brass is clearing the chamber with no false reads)
3. Same piece of brass, load a bullet in it a bit long, like 2.840. Slowly insert the round into the chamber as before and see if it will fall free when you push on it hard with your pinky. If it doesn't fall free, but sticks in the rifling, then seat the bullet deeper a little as a time, like .003" until you can push hard on the back of the brass and it falls back out freely with gravity. A bullet will stay in the rifling with even .001" into them. SO, when it falls free you are extremely close to the lands. (Punch stuck round out with a cleaning rod from muzzle or small dowel rod)
4. Record that length, and then go .020 deeper to ensure the new brass stretch won't put you into jam. That shoulder of the new brass will move forward with the bullet maybe .010ish. Second and subsequent firings you size shoulders back just .002" from fired length so they don't get worn out so fast from stretching from factory length.

On another note. H4350 is gonna be accurate, but slower than H100V and RL17. I'd nod to the H100V since it has less burn temp. RL17 is a velocity champ, but burns hotter. Me, I don't care, barrels are consumables.

Thank you for those tips and tricks. I don't have H100v or RL16. So h4350 or staball6.5

 

[victor3ranger]

Keep posting your tips and tricks fellas very good information

 

[6.5x300 WBY]

Keep posting your tips and tricks fellas very good information

Absolutely I have so much to learn.

 

[Kmccord]

To truly find the lands, the Alex Wheeler method works the best, it will require removing the firing pin and ejector and use a dummy round to locate the lands. If you do a search on this website you should be able to find his procedure. It takes a long while, but once you find it then it will become easy for loading.