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Seating depth question

I'm trying to dial in the seating depth for 107gr Sierra MKs in my 6BR. It has an 8 twist McGowen barrel
and I'm using 30.0gr of Varget. Shooting two five shot groups jammed in the lands I got perfectly horizontal tight strings. Shooting two five shot groups .010 off the lands I got perfectly vertical tight strings. This may be a stupid question but if I split the difference and load .005 off the land should the horizontal and vertical stringing come together and me give one nice little hole?
 
It may and it may not. Instead, do a proper seating depth test by shooting groups in .003" increments. This will pinpoint your node as well as show you node bounds.
 
Tokimini- Here is an example of a jump test in .005" increments. you will see the group come together at the .025" jump. This was with my Dasher and 105 Hybrids. I would have refined more in .002-.003 increments but I settled on the .025". All groups here were three shot groups except for the touching "0" group. I want to mention since this test I prefer to shoot groups of 5 shots to see more of a pattern.
 

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the first thing you have to realize is that not all bullets will
do well in your rifle,no matter what you do. That is just
one of the things that happen..Like my own McGowin barrel
with the 8 twist..It will not shoot worth a darn with varget
powder.Now with a diet of H4895,it shoots good...
What I do with the 107's is,seat them at 2.200 and then
work my way out,maybe .020 at a time..I load 5 of each..
Shoot 5 in slow fire...Peterrhaps waiting a minute in between
shots..After the first 5 I let the barrel cool completely..Then
another 5 the same way..You will find the best combo..
This method works the best for me...Good luck
 
You will skip over nodes by going .020" increments between groups. Good nodes are usually .006" - .010" wide. However, most nodes are only .003"-.005" wide.
 
I don't know about good nodes,but i found you must only move .002 at a time and find the window. then different neck tension the mess around with powder and go to RL-15 and you should get your best groups…….. jim
 
I do not find that to be so..I skipped the 1 or 2 thousands game 30 years ago or so...It is a waste of your time and ammo..You will find it quicker by jumping 10 to 20 thou...It has always worked for me and I know it will for you as well....Unless you have a real skinny barrel......
 
cocopuff said:
I do not find that to be so..I skipped the 1 or 2 thousands game 30 years ago or so...It is a waste of your time and ammo..You will find it quicker by jumping 10 to 20 thou...It has always worked for me and I know it will for you as well....Unless you have a real skinny barrel......

Do you also test powder charge in 2 grain increments?

What discipline do you compete in?
 
I shoot in the f class and load my ammo as walt berger taught me years ago.

It has worked well,so I aint gonna change to make anyone happy..I change barrel every year and it works great for me..You have your way and every
has their way..It it works,then do it..
 
cocopuff said:
I shoot in the f class and load my ammo as walt berger taught me years ago.

It has worked well,so I aint gonna change to make anyone happy..I change barrel every year and it works great for me..You have your way and every
has their way..It it works,then do it..

Then why do you tell shooters doing it different than you that it's a waste of time and ammo? If you test in .003" you can test .010" and .020" and everywhere in between. When you test in .010" and .020" increments you are skipping right over good nodes and hope for the best.

I don't rely on luck to find best seating depth, that's why I test in small increments. But if luck works for you, then have at it. ;)
 
+1 on what Erik said but i prefer .002, Powder … .2 first then .1 then .05…….. looking for the window for each, seating depth and powder and try to set up in the middle. I would guess the more precise you are, would depend on the level you shoot at…….. jim
 
Berger does have a pretty good tutorial online and in the loading manual (I believe) that instructs on jumping in the large numbers of .010 or more for the VLD's. I think that works for a lot of people but misses the mark for the rest. His described methods are meant to be "short-cuts" for those not wanting to burn a lot of ammo in the ladder. You cannot dismiss what you did not try. It is nice to know after a ladder test that either you have something or there was nothing there to work with in refinement. I know lots of guys who ladder their powder in 1/2 grain increments at the minimum and change depth .015 to .020 at a time and they do come up with good loads - eventually. I used to do that a long time ago. I can't help but think of all the good loads passed right over and there aren't many nodes in the velocity range you want to be in. Sometimes there is only one - and with a certain powder there may be none. I'd want to know so I could move on. I have changed what I do in many ways, despite being told, in some cases, from those 'in the know' years ago. I doubt Walt Berger would fault your trying something new. He's a good one.
 
I agree, with Jim, Donovan, and Erik. Heres a question, do any of you ever find your seating depth before your powder charge, and does the prefered seating depth change with powder charge? ;D
 
I had always arrived at a powder charge first, then fine tune with depth - until I had a lengthy discussion with Lester Bruno several years back- whom said he did it just the oposite. With Lester being the most knowledgeable fellow I knew, I took his wisdom to heart and began starting with the powder I want to use, get a mild load going, work the depths, then increase the load to find the nodes. I have found it to work better for me in finding a good load more quickly than it took before. As for changing the depth for charge adjustments, I never change my loads by more than 3/10ths or so and never played around with the depths after getting into the node.
 
zfastmalibu said:
I agree, with Jim, Donovan, and Erik. Heres a question, do any of you ever find your seating depth before your powder charge, and does the prefered seating depth change with powder charge? ;D



Yes…… they all inter react with each other. After you work with one round long enough you have a pretty good idea what it should be. but change the reamer and you just might as well throw all that away. The reamer dictates the load not the barrel……. I have proved it as recently as this year, couldn't get the new reamer to shoot real small just average .1, so ran the old reamer in and it opened the free bore and diameter up and it went right in the zeros…….. amazing…….. jim
 
I think 1/2 the intent in Berger's procedure is to find out pretty quick that jammed is not always best for VLDs..
And then to quickly get in the same zip code as best.
Far as I know, there was never a recommendation NOT to fine tune from there.

I find ~best seating while fire-forming brass at ~2% under book max load. This, before any ladder testing.
Never made sense to shoot ladders before knowing seating is right. After all, seating is a far bigger adjustment to performance than powder.
After ladder testing & validation, I tweak seating a smidge both ways only to shape grouping.
 
If you are fine tuning your seating depth to .001 or .002 won't you have to adjust everytime you load due to throat erosion? I agree 100% with being as precise as possible but I don't test under .005 increments on seating depth and do OK. No being critical of anyone this is what works for me.
 
johnmyers said:
If you are fine tuning your seating depth to .001 or .002 won't you have to adjust everytime you load due to throat erosion? I agree 100% with being as precise as possible but I don't test under .005 increments on seating depth and do OK. No being critical of anyone this is what works for me.



At .005 increments, you can miss the window. I tested the Berger 105 H from .060 jump to zero and it shot around .2 and soon as i started in it dropped to .100 and from .008 - .012 it was in the zero's and it shot 23 - 3" groups that year at 1000 yds……. jim
 

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