• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Seating Depth adjustments.

This is a new aspect for me as when I was shooting a target 223 with 69gr class bullets the seating depth didn't really seem to make much of a difference.

I am believing this is going to be a bit different with the 6mm bullets.

Currently I am using the Lapua Scenar 105 and am about .005" off touch. Next bullet I have on hand to test with is the Barnes Match Burner 105gr, which I have not loaded any of these yet.

I understand some bullets are more conducive to jump or jam but I have no clue which ones are which. I have also come to understand that .003" movement is the most used.

Would like to hear everyone's thoughts or advice!
 
It has more to due with the level of equipment and skill of the shooter than the bullet. It is determined somewhat by your chamber/ throat. Same cartridge done with the same reamer by the same smith usually results in similar load characteristics.I usually start at a square mark from the lands then back up .003 at a time until I find what I want. Then refine it to .001. Only had one barrel out of the last roughly 20 or 25 that wanted to jump. I have quite a few 6PPC barrels I shot at the square mark . If first 2 shots don't go in the same hole move on, it won't get better. If they do, shot 2 more. If they are in one hole you might be done. My goal is to find a repeatable competitive load, not wear it out shooting groups for no purpose.
 
Have you fireformed your brass? After fireforming I'd recommend doing a powder ladder with 2 or 3 different powders at .005" back of your "touch measurement. Then select a load and then start work on seating depth.
 
It has more to due with the level of equipment and skill of the shooter than the bullet. It is determined somewhat by your chamber/ throat. Same cartridge done with the same reamer by the same smith usually results in similar load characteristics.I usually start at a square mark from the lands then back up .003 at a time until I find what I want. Then refine it to .001. Only had one barrel out of the last roughly 20 or 25 that wanted to jump. I have quite a few 6PPC barrels I shot at the square mark . If first 2 shots don't go in the same hole move on, it won't get better. If they do, shot 2 more. If they are in one hole you might be done. My goal is to find a repeatable competitive load, not wear it out shooting groups for no purpose.
Agree with Jeff. With the level of equipment and skill of the shooter seating depth will matter even @ .001 variations.
 
Some background to this point.

Not new to reloading or reloading for accuracy. Been shooting a 223 in a local league for 3 years already. As stated the 223 didn't seem to be much effected by seating depth.

This year and right now, this 6mm is all new to me so I am still in the learning curve. Learning bullets and powders. At this point I have already ladder tested 6 powders. 3 of which was just because I had them and wanted to witness for myself what they would do. I have narrowed it to two powders and have identified an accuracy node with each. Now I want to try and tighten these up.

So again it is seeming that .003" increments is the way to go?
 
Some background to this point.

Not new to reloading or reloading for accuracy. Been shooting a 223 in a local league for 3 years already. As stated the 223 didn't seem to be much effected by seating depth.

This year and right now, this 6mm is all new to me so I am still in the learning curve. Learning bullets and powders. At this point I have already ladder tested 6 powders. 3 of which was just because I had them and wanted to witness for myself what they would do. I have narrowed it to two powders and have identified an accuracy node with each. Now I want to try and tighten these up.

So again it is seeming that .003" increments is the way to go?
I prefer .002 intervals but to each their own.
 
You might want to try some Berger 105 hybrids, I’ve had great results with them under varget in a 6 dasher. I also do .003 increments in seating depths when testing.
 
Tune a load. Shoot and see what happens. Sometimes you may have to adjust seating depth. Other times the erosion or wear of the throat does not seem to matter.
I think this reenforces something I've thought about for quite a while - we refer to tuning by how far the ogive is from the lands ("jump"). But I wonder if in reality we aren't looking at the wrong end of the bullet and what we are really doing is varying the case volume by moving the base of the bullet in or out of the neck?
 
I think this reenforces something I've thought about for quite a while - we refer to tuning by how far the ogive is from the lands ("jump"). But I wonder if in reality we aren't looking at the wrong end of the bullet and what we are really doing is varying the case volume by moving the base of the bullet in or out of the neck?
I have also thought the same thing. Though I do believe the amount of jump plays a part.

On the 223 I use to shoot with a factory Savage Model 12 barrel I could load 55gr bullets out so far they would hardly stay in the neck. It also liked a soft jam with 69gr bullets.
 
I think this reenforces something I've thought about for quite a while - we refer to tuning by how far the ogive is from the lands ("jump"). But I wonder if in reality we aren't looking at the wrong end of the bullet and what we are really doing is varying the case volume by moving the base of the bullet in or out of the neck?
It’s BOTH…J M O
 
Last night I reviewed all the targets with the different powders and found what I think is the best. It was a ladder that was only loaded a little past mid point so I loaded up another 3 rounds of 5 charges that brings me to just under max by the Hornady Bolt data and seated these .003" deeper. See if some of the Horizontal stringing disappears. Won't get to shoot these until tomorrow.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
166,254
Messages
2,215,067
Members
79,496
Latest member
Bie
Back
Top