OAL for roundnose bullets

[2oakes]

I'm just beginning reloading 165-168g .308 using Rem PSPCL, Sierra MK and Hornady A-Max.

Both the SMK and A-Max state 2.800 OAL, so that seems to work out just fine, but the Rem PSPCL at 2.800 has the case mouth well behind the cannelure.
Pushing it in to 2.750 lines it up well. Commercial versions I have are also less than 2.800.

I know that I should probably use an "ogive measuring thingy" but am limited right now to a good micrometer.

How do you usually treat rounder nosed cartridges compared to the sharper pointed ones?

[John Traveler1]

The rules for bullet seating depth/cartridge overall length are simple:

1.  The COL must not be too long to fit in the magazine box or prevent action cycling (feeding/extraction of unfired rounds).

2.  The bullet must not be seated so far out that chambering forces it into the throat.  If it sticks when the cartridge is extracted, it could cause a bore obstruction for the following cartridge.

So, you see, a bullet seating/throat measuring thingy is not needed for correct bullet seating.  THAT is determined by your chamber throat, the length of the bullet, it's ogive profile, etc, etc.

Many rifles shoot better when the bullet ogive just touches the lands.  Others like it better with the bullet some distance out, so that it "jumps" into the throat.

The crimping cannelure grooves are used for heavy recoiling loads, semiauto and tubular feed actions where feeding and recoil impacts tend to move the bullet.  Crimped bullets are not needed for most bolt action rifles in most calibers.

[2oakes]

So, you see, a bullet seating/throat measuring thingy is not needed for correct bullet seating.  THAT is determined by your chamber throat, the length of the bullet, it's ogive profile, etc, etc.

Thank you

So I would be best to chamber an un-primed, no-charge, painted-tip round with the bullet left way long so it is pushed back by the lands, then measure the length from the base to the land-markings on the ogive which will give me the seating / throat measuring with that shape bullet and then work from there using range-testing to develop the best length, ignoring the cannelure?