how do you guys choose your seating depth

matt_3479

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Jan 31, 2010
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I finally have my first custom rifle and I'm having a hard time getting it to shoot just right. It shoots really well but i know it can do better and i haven't done anything with seating depth yet. I was going to try and load up 5, 3 shot groups of seating depths of 10 thou off the lands, 20 thou, 30 thou, 40 thou and 50 thou off the lands and see which one shoots best. if one stands out more then the other i will load 3, 3 shot groups of 5 thou up and down from that particular seating depth. once i figure that out, i will then go back and work on powder charge.

For the mean time i will use to powder charge that worked best 43grs of H-4350.

What do you guys do to tune a load.
 

g0rd0

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Mar 9, 2012
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New germany, NS
I go with sug. start load at the lands X5, then back off 10 tho X5, ect until I see a good group I then increase load 1.0 grn to max (of course looking for high preasure signs). Once I have a winner I might try to fine tune the depth or charge. But, sometimes you get lucky out of the box.
Lets say that the 3rd time I find 3/4 inch at 30 tho + sug start, I call that good to duplicate another day. If it still gets 3/4inch then I will try 5 thou +/- X5 and see if I can improve, if not I then start to increase the charge by 1grn X5 to see if I can get that down to 1/2 inch
 

bruce_ventura

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Ventura CA
I run a string of increasing charges (.5 gr increments) from a starting charge that is about half-way between book min and max, looking for nodes in impact location, and pressure signs. I start with .020" off lands. If no joy, I repeat with bullets touching lands. Then .040", .060", etc.

Usually the results of those strings suggest a good load to start exploring group size. I change the load in increments of .3 gr charge and .010" COAL. If the load is for long range (>500 yds), then I measure MV ES at the same time as I measure group size. I'm looking for the charge and COAL that minimizes both.

Also, I fire 5 shot groups for each charge/COAL. It's too easy to get misled by 3-shot spreads that are way below or above average.
 
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Whitesheep

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Phoneix
Read Len's reprint of Berger's recommendation that is the first thread in this reloading sub forum. I use this for all bullets, not just Berger's and it works fine.

I have not worked between the 0.040" points as I have always found a setting that gets me at or below 1 MOA which is my goal for hunting rifles.

You may be surprised that a load that is printing terrible groups will suddenly jump down in size with just a 0.040 shorter load. This just happened to me a couple of weeks ago.

Good luck and have fun.
 

jonthomps

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Dec 2, 2005
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Missouri
Get a modified case in your caliber and a Hornady COAL case gauge. Best thing you'll ever buy for reloading.
 

woods

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Jun 4, 2006
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Run a seating depth test. Not only looking for best group but also lowest standard deviation and extreme spread

1211-1.jpg
 

Whitesheep

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Aug 22, 2010
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Phoneix
Looks like 0.060" off the lands is the load for you Woods. Nice shooting. Now for a powder ladder?

My rifles usually like it closer to the lands than this. Once I started out too far and had to go back and start over. This was on a .308 FNAR and it likes them close.
 

matt_3479

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Southern Ontario
I always start 15-20 thou in the lands and do powder tests.

After finding what I want, I work on seating tests.

Okay thanks, I ran a powder test a few times already at 100, and 300 yards. I'm shooting 260.rem 140 hybrids and looks like 43 and 43.3 did the best. With 43grs being a little better on average. I just know this thing can shoot better and wanted to figure out the best seating depth test and I like the way WOODS ran his. Is that the way most of you boys do it, start .10-.15 off and move back in .15thou increments
 

rcoody

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Jul 1, 2015
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When you start in the lands there's no place to go but off.

I don't frog around trying random depths......


been playing with the berger VLD for some time now. I know if I jam it .02 into the lands it will be a one holer.

problem is I don't want my deer rifle a single shot. I tried the berger recommendations on finding the jump it liked and found some col's that shot some decent groups but nothing to write home about.

I know I can load sierra MK at mag length and shoot one holers all day long.

I have ordered some Berger hybrid hunting bullets that I should get this week. Going to try them. anyone have any experience with them.
 

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