seating depth or charge weight first?

[31incher]

Hey all I'm new to the forum. I have been a long time reader. I have gained tons of knowledge through this site by just searching through old threads. Anyway here is my question I have been searching an answer for to no clear avail. I'm working up a load for my rem 700 7mm rm. I'm loading the 168 bergers over some h1000. So my question is... where do you start? Do you start the seating depth first by using berger seating depth test? If you do... what weight charge do you start with? Or do you start with charge weight and then once you find most accurate charge do you start messing with seating depth? I'm sure this question has been answered before but like I said before I haven't been able to find clear cut instructions. Thanks

 

[sourdough44]

I start by looking over powder charge weights from several reputable sources, net or manual. Then I start in the lower/midlin area. I may adjust the charge weight some if the bullet has some differences from most listed in the data.

For COL, seating depth, I measure to what point that particular bullet touches the lands in the rifle bore. There are different types of tools to do that with. I compare that COL, to book numbers, and magazine limitations. I then want just a bit of leeway to the shorter side for normal variances.


For most of my shooting and hunting I don't need the ragged edge of max, midlin/upper is enough for me.

 

[31incher]

I start by looking over powder charge weights from several reputable sources, net or manual. Then I start in the lower/midlin area. I may adjust the charge weight some if the bullet has some differences from most listed in the data.

For COL, seating depth, I measure to what point that particular bullet touches the lands in the rifle bore. There are different types of tools to do that with. I compare that COL, to book numbers, and magazine limitations. I then want just a bit of leeway to the shorter side for normal variances.


For most of my shooting and hunting I don't need the ragged edge of max, midlin/upper is enough for me.

I appreciated the quick reply. I have done all of what your talking about. I'm not a complete newbie when it comes to reloading. My question was more geared toward.... When you go to the range the first time with a new load... what are you testing first? Seating depth or charge? Do you start with a middle of the road charge weight and play with seating depth the first time? Another question I forgot to ask is... say I find a seating depth that works with powder x.... will the same seating depth work with a different powder? Maybe I'm over thinking this a little but I just don't want to waste powder because that shizz is hard to come by! Lol

 

[Bill Johnson]

This is for loads for hunting:
If magazine length permits, I set initial seating to 0.010 off the lands. Do charge weight work-up to best accuracy. From there you are fairly safe increasing seating depth as pressure increases due to reduced case volume are offset by pressure decreases due to increased distance ogive-to-lands. I've always worked in 0.025 increments. You can also decrease seating depth until you touch the lands, but I consider that a bit risky unless you have an ogive comparator (which I do not).

This is the method I've used long before the internet and works for me but may not be the best advice. It's just how I do it.

 

[Firearrow]

I start of with powder charges to see what I will get for Accurecy and Velocity. Then I adjust seating depth to "fine tune" to see if I can get any improvement in accurecy.

 

[FearNoWind]

I start of with powder charges to see what I will get for Accurecy and Velocity. Then I adjust seating depth to "fine tune" to see if I can get any improvement in accurecy.

That's also my technique. My initial loads start at about .020 +/- off the lands and work up in half grain increments. When I find a node I load to either side of it by .3 grains and that's usually enough to put me in the ball park. From there I work on seating depth. As an example, today I work on a load for my .284 that worked well with 57 grains of H4831 behind a 150 grain Barnes LRX.
My chamber measures 2.633 ..... Keep in mind that this isn't an accuracy test, but a consistency test. Next I'll adjust for the 200 yard zero and it's all done.
Here's the progression:

 

[Mikecr]

Seating depth is the coarse adjustment. Powder is fine.

I test seating during brass fire-forming with a mid press load(any).
Like Berger's recommended:
1. .010 into lands (jam) 6 rounds
2. .005 off the lands (jump) 6 rounds
3. .010 off the lands (jump) 6 rounds
4. .050 off the lands (jump) 6 rounds
5. .090 off the lands (jump) 6 rounds
6. .130 off the lands (jump) 6 rounds

With best of what I got here, I move into ladder & incremental load development using powder, and then tweak seating a smidge(1-3thou) both directions to shape grouping.

 

[FearNoWind]

31incher,

There are many formulas for load testing. You'll obviously select the one that works best for you. Keep in mind that some shooters reload for plinking, some for serious competition, some for hunting. The accuracy goals for competition shooting are far superior to those of the hunter who doesn't need to put every round in the same hole.
Some formulas for load development can eat up an entire box of bullets, or more, while others will give you excellent accuracy (but certainly not single hole groups on target) that will satisfy your hunting needs at far less time and expense.
I've seen a good many shooters at the range working on load development when what they truly needed to do was work on shooting skills. gun)------------------

 

[31incher]

31incher,

There are many formulas for load testing. You'll obviously select the one that works best for you. Keep in mind that some shooters reload for plinking, some for serious competition, some for hunting. The accuracy goals for competition shooting are far superior to those of the hunter who doesn't need to put every round in the same hole.
Some formulas for load development can eat up an entire box of bullets, or more, while others will give you excellent accuracy (but certainly not single hole groups on target) that will satisfy your hunting needs at far less time and expense.
I've seen a good many shooters at the range working on load development when what they truly needed to do was work on shooting skills. gun)------------------

I appreciated everyone's comments thus far. I'm not exactly looking for one hole accuracy. I wouldn't mind it but it don't think I'm capable now is my factory barrel. I went to the range yesterday working on charge loads. I set seating depth at .040 off the lands as where some previous testing showed some promise. I loaded up 30 rounds and every five I up to .5 grain increments. I started at 69.0 grains. 69.0 through 70 grains showed the best results (about .5 moa) after that they really started to open up. I didn't get to run them through the chrono and check the es(I plan on doing next time when I have more time). So my next question is where would ya go from here? Do the whole berger test? Or be happy with the .5 moa group and maybe tweak it a couple .001 each direction and see what I come up with? Thanks for the replies guys

 

[Mikecr]

Well you might have gotten lucky and it just happens that a seating depth pulled from your butt is exactly the right setting. But why would it be?
And now adjustment of seating is as likely to collapse your 1/2" performance peak from powder(changing two things at once), making seating appear to be NEEDED at 40-DTL.
I think this is where most end up, and then they assume it's best seating.

Some are relying on high starting pressure for their cartridges, and so they are going to assume ~10-ITL is best (for underbore cartridges it probably is). Mostly short range competitors here, with loads all but completely known up front.

 

[FearNoWind]

... .040 off the lands as where some previous testing showed some promise.
I started at 69.0 grains. 69.0 through 70 grains showed the best results (about .5 moa) after that they really started to open up.
I didn't get to run them through the chrono and check the es (I plan on doing next time when I have more time).

You've already demonstrated that it isn't universally true that seating a bullet on or into the lands produces good results. Some rifles, especially commercially produced standards, reveal excellent results with a jump like that .040 example you describe.
I do believe you need some chrono data to determine the ES but IMO, unless you can't hold an ES below 12 (preferably below 10) with a load between 69 and 70 grains, you're pretty much home with a .5 MOA five shot group at that seating depth.
Do the chrono workup ... let's see what the ES data reveals. Be sur to use a good quality chrono and double check conditions so you don't get false outputs.

 

[31incher]

You've already demonstrated that it isn't universally true that seating a bullet on or into the lands produces good results. Some rifles, especially commercially produced standards, reveal excellent results with a jump like that .040 example you describe.
I do believe you need some chrono data to determine the ES but IMO, unless you can't hold an ES below 12 (preferably below 10) with a load between 69 and 70 grains, you're pretty much home with a .5 MOA five shot group at that seating depth.
Do the chrono workup ... let's see what the ES data reveals. Be sur to use a good quality chrono and double check conditions so you don't get false outputs.

I bought a ced m2 chrono from the reviews it seems like a decent chrono. I plan on loading some up with 70.0 grains of h1000 with a few different primers and see which one comes up with lowest es. WRL seems to be a pretty popular choice and I have a few hundred laying around. Sound like good plan? Should I mess with seating depth at all? I'm new with the chrono so is there any suggestions you could give me about favorable conditions. I have only used it once and it worked good then the sun went over the mountain and it stopped work and I guessing it's because of poor lighting.

 

[FearNoWind]

If you're already familiar with this information please consider it as input for others who are not acquainted with the CED M2 ...
As with most chronographs of this style, setup requires careful attention to the alignment of the bore with the detectors. The instructions explain the importance of careful alignment and how to accomplish it. Distance from muzzle to chrono and ensuring that the bore and the chrono are on the same plane are probably the most important things to verify.
Actually, these alignment tasks are fairly common with this style of chrono. The only ones that I know of that doesn't present these issues are the LabRadar and the MannetoSpeed.

 

[Jaxdialation]

For me:

The first trip - do a pressure test with the bullet at .02" of the lands

Final trip - adjust bullet seating using the best load at .02" off the lands.
I use .01" increments. But I have to admit, some times I don't bother with seating depth optimization.

HTH
John

I appreciated the quick reply. I have done all of what your talking about. I'm not a complete newbie when it comes to reloading. My question was more geared toward.... When you go to the range the first time with a new load... what are you testing first? Seating depth or charge? Do you start with a middle of the road charge weight and play with seating depth the first time? Another question I forgot to ask is... say I find a seating depth that works with powder x.... will the same seating depth work with a different powder? Maybe I'm over thinking this a little but I just don't want to waste powder because that shizz is hard to come by! Lol