What’s your method for determining seating depth?

[chevytruck_83]

Looking for a more efficient way to determine seating depth. What works for you? I kinda remember Berger bullets having a write up about the vld’s Specifically. The combination I’m currently working on is 6bra and 105 hybrid.

 

[ShootDots]

Generally speaking certain bullets like to be jumped to the lands and other like to be set into the lands. My experience with Berger Hybrids is that you can start your load development right at 15 thousandths OFF the lands. EXAMPLE: Once I find a good load at 15 thousandths off , I start with seating depth tests. I will run from 5 thousandths off to 30 thousandths off. Let's say your best groups come from 15 to 25 thousandths off. Now start at 12 off, then 15 off and go to 20 off and 22 off and 24 off and finally 26 off. Somewhere in there the groups will tighten right up.

 

[varget204]

I use Bergers method,when i get close, i very BTO by.003 increments,until i find Sweet spot

 

[D-4297]

+1 on everything Ben said . I would like to add , from personal experience with Berger Hybrids , I have two different rifles that shoot low node at .005 off touch , and .020 off touch on the High node . It works , so I do it . Rule #1 . Never question something that works ....Till it doesn't .

 

[sawcarver]

I've used bergers seating depth test on lots of bullets. It works pretty good and can be very surprising where some bullets like to be shot

 

[dcali]

Start jammed and move back .010 at a time until it shoots. Then keep going until it doesn’t. Then go back to where it shoots and fine tune in .005 steps, then .002.

 

[Fotheringill]

I have used the Berger method with success.

 

[Raythemanroe]

I use stripped bolt method to get at .010 in or so and work my way off during load development. I usually always start in the lands and work out..

Edit: I like to recheck my seating depth every 200-250 rnds

Ray

 

[Arky]

I insert a flat base bullet nose first into a piece pf brass to measure the distance from bolt face to lands. I call this my X point, I do this for every new barrel, it never changes as long as the barrel has an life. I start at X+.015 with 3 shot groups, back up .005 until I reach X-.035. When I find the best group I test .002 on either side. This has worked for me for 60 years.

 

[trailrider121]

I like to start off the lands with Berger Hybrids at .015" off when testing. Once powder charge is found, then conduct seating depth test in .003" increments at 100 yards. Load from .015" - .030" OTL. You will find a node (2 to 3 groups ) in seating test that share same POI. You could then go back and adjust powder in .1grs to tighten group if you anal about it..lol

 

[Stepsjframe]

I use the Sinclair gauge.

 

[mikecr]

Are you really asking about measuring of seating depth, or determining most accurate seating depth?

 

[Texas10]

There was a thread here a little while back, and I can't seem to find it, that described a process of developing the OCW charge weight and seating depth in one outing. Basically an abbreviated OCW in .3 gr increments and seating depth changes in .005 starting at .010 in the lands, shooting 3 shot groups. Three charge wts and 4 seat depths totals 36 rounds, plus 4 sighters.

Then slap a tuner on the muzzle, load 200 rounds and send the PD's to the big prairie in the sky.

 

[JMayo]

I use hornady comparison gauges on calipers. Base to ogive.
They are aluminum and show wear around 4k rounds ...
But I am just comparing so.....

I note which end goes where when checking ogive with two on each side of calipers.

 

[chevytruck_83]

Are you really asking about measuring of seating depth, or determining most accurate seating depth?

Determining the most accurate length. I use the hornady tools to measure length.

 

[JMayo]

Wheeler method for me.
Make up a dummy round, get out the magnifying glass. Make it long and push it in till marks gone then find them again..... Dark magic marker helps.

 

[mikecr]

Determining the most accurate length.

Then Berger's recommended full seating testing.
https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/

 

[Uncle Ed]

I buy Hornady bullets and seat them to the middle of the cannelure. (honest mikecr taught me this trick)

 

[T-shooter]

The length to the tip doesn't mean much. Most important is the distance to where the bullet engages the rifling. For instance, the 2 bullets shown below are the same part number, just 2 different lots measured with this tool from both ends and a caliper for overall length. These examples are .015" different in length and .021" different where the nose inserts into the bushing.

I measure and load every round with this tool to within .001". Even with this method, the part of these two bullets inserted into the case varies by .036" which will change the case capacity and have some effect on pressure and probably velocity. If possible buy your bullets in at least 500 of the same lot number and then sort them before finalizing a load.

These are 5 shots each (shot round robin) at 100 yards using 1" diameter targets only changing the jump to the lands.

 

[dcali]

Do yourself a favor and ditch the round robin shooting. All it does is introduce position/gun handling error. Stay on target and finish a group.