CBTO measurement

[Boozer]

Hi all-

Still very new to reloading. I was starting to reload for my 30-06, but after I discovered it had a jump in excess of 1", it has been sent to the gunsmith for a new barrel. While I'm waiting for it to return, I'm working up loads for my AR, and am wondering something. Shouldn't the CBTO measurement be (basically) the same even between bullets of very different nose profile? I have a bunch of 55 gr. hornady bullets that I got free with my kit:

Hornady Manufacturing Company :: Bullets :: Rifle :: Choose by Caliber :: .224 22 CAL :: 22 Cal .224 55gr SP with cannelure

And I bought a box of 100 of these:

https://www.sierrabullets.com/store/product.cfm/sn/1375/224-dia-60-gr-HP

Initial CBTO measurements are coming back very different, but I thought CBTO was supposed to be consistent?

 

[Mikecr]

CBTO is where you set & verify it.
Should be where your gun shoots best -with any particular bullet -as determined by testing.

 

[FEENIX]

Hi all-

Still very new to reloading. I was starting to reload for my 30-06, but after I discovered it had a jump in excess of 1", it has been sent to the gunsmith for a new barrel. While I'm waiting for it to return, I'm working up loads for my AR, and am wondering something. Shouldn't the CBTO measurement be (basically) the same even between bullets of very different nose profile? I have a bunch of 55 gr. hornady bullets that I got free with my kit:

Hornady Manufacturing Company :: Bullets :: Rifle :: Choose by Caliber :: .224 22 CAL :: 22 Cal .224 55gr SP with cannelure

And I bought a box of 100 of these:

https://www.sierrabullets.com/store/product.cfm/sn/1375/224-dia-60-gr-HP

Initial CBTO measurements are coming back very different, but I thought CBTO was supposed to be consistent?

Find the best COAL and CBTO combination that cycles safely out of your rifle. When done accordingly, your CBTO measurements should be fairly consistent ~+1/- .001" or so. Although not a must but highly recommended by most that have far more experience than I do in reloading AR type platform, I use a SB dies ...

Here's a nice thread on a different site >>> http://ar15armory.com/forums/topic/55192-reloading-223556/