How do you you determine bullet seating depth?

[Howa]

Do you measure from base of the case to the tip of the bullet using a digital calliper, basically deciding on a AOL and not worrying about differences in bullet lengths, especially encountered in lower grade makes and ballistic tips?
Or do you use a Hornady type bullet comparator kit, and thus measuring from the ogive for each round.

For members who do use a comparator, how much improvement do you notice?

 

[User00044]

Overall Length Gauge will give more consistency by far and is easier too . I've measured bullets to the meplat/ tip and seen variations of 0.007"+ compared to variations of 0.002" at the ogive on the same bullets . That was enough to convince me .
I'm assuming your determining distance to the lands ?

 

[NullMac]

Load it to mag length/COAL. Check it will cycle. Shoot it. See if the precision is good enough. It will be. Don't mess about with it. Go shoot.

I loaded a 308 like that with everything from 110 to 208gr and they were all sub 0.5moa some quite substantially. If you want to chase <0.25moa for some reason then you need to get into measuring to the ogive.

On many stalking rifles though your tuning efforts may be in vain as the manufactures often cut the lands longer than mag length to hamper idiots reloading efforts. So to load close to the lands the length is often longer than the mag which defeats the point

 

[Reloader708]

Watch what Eric Cortina has to say on bullet seating depth, he's a good youtube channel that's worth a watch.
Never heard of him? He's the holder of the world's smallest 1000yd group.
Makes me smile when I hear of folks altering seating depth by a thou and claiming its halfed group sizes.

 

[Bowland blades]

Mostly all hunting bullets are built to be very jump tolerant! Why? Because they are built to sell to folks with factory hunting rifles that are generously cut in the chamber .
To answer your question though while i assure you unless you get it wrong or have a close tolerance chamber, here is how its done
Trial and error under ideal shooting conditions shooting groups ! Oh and very accurate measuring off the bullet sides using a gauge for your Vernier calliper. once you get close to the sweet spot ( talking Benchrest here with custom rifles ) You mess around with high quality hand dies and shims cut from a coke can to change the length .
My advice is forget it ! load safely , stay away from contact and spend more time on making a totally concentric bullet / case alignment sub 2 tho , use the best components and run them all on a fixture with a Dail test indicator "DTI" . really straight bullet to case will usually improve accuraccy when the shooter reaches the required skill to outshoot their kit ( that is likely 5% of deerstalkers )

 

[Bowland blades]

Overall Length Gauge will give more consistency by far and is easier too . I've measured bullets to the meplat/ tip and seen variations of 0.007"+ compared to variations of 0.002" at the ogive on the same bullets . That was enough to convince me .
I'm assuming your determining distance to the lands ?

Thats why the very best BR bullets are expensive . Hunting bullets on the other hand have far more put into them expending well than being very alike in the box

 

[safer]

I measure to ogive because that is the part of the bullet that is going to hit the lands and not the tip of the bullet.

 

[Night òwl]

Measure on the ogive if the round will fit the magazine

 

[DVS1]

Vid 1

Vid 2

watch and enjoy

 

[Reloader708]

Vid 1

Vid 2

watch and enjoy

I've been using the method described in vid 2 and it's completely simplified the process!
Incidentally Eric measures from the ogive, I'd say the bullet tip is an inconsistent point.

 

[User00044]

Thats why the very best BR bullets are expensive . Hunting bullets on the other hand have far more put into them expending well than being very alike in the box

Not a br bullet, but weirdly the worst offender that I've encountered is the Nosler CC . Highly inconsistent at the meplat, hardly any variation at the ogive . Similarly, Sierra GameKings.. They shoot well , so I'll forgive them.

 

[sikadog]

Seat bullet to base of neck SHOOT

 

[HandB]

The GunBlue method is close the bolt on an empty chamber, slide a cleaning rod down the barrel until it touches the bolt face. Mark that with tape on the mod flush with the muzzle. Put a bullet into the throat, hold in place gently with some dowel. Slide cleaning rod down barrel until it touches the tip of the bullet. Mark with tape. The distance between the two bits of tape shows the length of the cartridge when bullet is seated on the lands. Then you can play around with different loadings with different seating distances from the lands. For example, my .222 and .243 shoot small groups when seated 15 thou off the lands. My larger cartridges prefer bigger jumps, of 75thou.

 

[paul o']

Adjust it is all I do until its as good as I need it to be for a 4" target.

 

[timbrayford]

I just use the manufacturers reload data as a starting point, the do a few loads + /- a thou and work from there. Variations in powder burn rates & loads appear to have greater influence.

 

[pete evans]

I’ve always got a factory round put it into the seating die then wound the die down until it touches bullet. This will seat your reloads to same depth. I’ve always had acceptable results using this method. What constitutes acceptable for me is approximately .5 moa

 

[Heym SR20]

I just stick with manufacturers overall length - ie the distance from base of cartridge to tip of bullet. With soft lead tips these are easily deformed so use one that is not.

Some bullets have an obvious canelure or crimping groove for the case neck so use that as a guide as well.

I make up a dummy - ie empty cartridge with no primer, but with bullet seated to length. Colour the bullet with a black sharpie pen, or marking blue. Put straight into chamber, close bolt and make sure there are no marks on the bullet from the lands.

Then use this dummy to check cartridge feeds from magazine.

Then if all good, use it not set up dies in the future.

 

[BigFrank]

Thank You Reloader78…just watched the Erik Cortina video on YouTube!….Amazing.

 

[Stalker62]

I'd say the bullet tip is an inconsistent point.

Beautiful...

 

[Howa]

My thanks to all members who responded to my post, they have provided me with many hours to come watching and reading on this aspect of reloading.