Seating depth test

[KsKevin]

I agree with ShootMo. Also looks like you have a 2nd node between 0.038 - 0.041" as well as the groups are coming back up and topping out again at the top of the sine wave just like 0.023-0.026". There is a great article by Short Action Customs where they did a TON of testing and data analytics where the 2nd/deeper nodes also tend to be less sensitive to throat erosion (ie…the node is wider). You may find that 0.040" depth to be nearly as accurate but more stable over the next several hundreds of rounds.

 

[DWier]

Well, my input is:
If it were me and my rifle, I would load 15 rounds @ .024" and only test them on a day with favorable conditions. I'd be looking for any inconsistencies.

I choose .024" because your group size AND placement are identical. And since that went from .023" to .026" that's worthy of further investigation. I feel it's much more worthy than any other two groups that you shot.

When I'm doing seating depth testing, I want as many groups in a row to be equidistant from the aim point as possible and mainly in height from the aimpoint. If you'll look at all those groups in the order they were shot, they look like a very low frequency wave form. And to me, there are only four groups that seemed flatter than the others. The tighter pair of groups lies between .023" and .026".

*My opinion is worth exactly what I charged you for it.

OMG, you jumped on the 'overpriced band wagon'.
BTW I agree with your analysis.

 

[Ucsdryder]

I agree with ShootMo. Also looks like you have a 2nd node between 0.038 - 0.041" as well as the groups are coming back up and topping out again at the top of the sine wave just like 0.023-0.026". There is a great article by Short Action Customs where they did a TON of testing and data analytics where the 2nd/deeper nodes also tend to be less sensitive to throat erosion (ie…the node is wider). You may find that 0.040" depth to be nearly as accurate but more stable over the next several hundreds of rounds.

Yeah it was starting to come back. I saw the same and would have liked to see one more depth test a .044". The 6.5cm running at a mild load should be pretty easy on the throat I would think.

 

[Ljtimber72]

Try shooting through a chronograph to see where you are with ES/SD.

 

[Ucsdryder]

Try shooting through a chronograph to see where you are with ES/SD.

I did that on the ladder test. I'll chrono next time out. That's the downside of the magneto. The change of POI and impact on groups make it hard to use during seating depth. I found a very good velocity node over .6grains already but haven't done a group to see spreads.

 

[Stan Malinky]

It appears that you may have 2 nodes to work with. The 0.023 and 0.026 require further investigation. If this length fits and chambers properly from your clip or magazine I would not worry about the 0.030.

 

[Willys]

Slight wind, prone off rear bag with those groups doesnt tell me enough. Maybe .026 is good or maybe the 3rd shot got lucky. Shoot 4 more at .026 . If you are a 600 yd shooter you keep testing til you see touching at 100.

 

[QuietTexan]

Pretty much. .020 or .040 seem to be a decent place to start for powder development. I don't know that it really matters.

I don't think it matters a whit where you start, ultimately any starting point is arbitrary. I unintentionally started at 0.050" jammed one time because I couldn't read a caliper that day apparently Turns out it shot a one hole group with my starting powder load.

The questions start with how in-depth do you go on moving away from that starting point, then you're into opinions and the wheels come off

 

[Rflshootr]

I'd shoot the .o2o, .o23 & .o26 again, but in reverse order to see if it stays consistent. If it does, go with the longest to keep in tune longer.
The 1st group has a touch of vertical which typically means seat the bullet deeper. As you see the next 2 groups, the vertical went away. Might even try .o21 & .o22.
Don't worry about the throat currently, it just got broken in for you and it will whisper in your ear and tell you when it's time to make a change.

 

[kellyc33]

Curious how others would decipher this. I indicated distance off the lands on each picture, that's not group size. I felt like I was shooting pretty well today. The only shot that felt off was in target 2 and I noted "pull". I shot my 4th shot at .026" into the .029" target but the poi was in the same group as the .026, which was my best group of the day. I also noted 1st of the day. From these results I think my seating depth should be .023" which gives me some room as the throat erodes? I wouldn't be scared of .020" either, especially with that first shot of the day being high, then 3 shots in a small group.

100 yards, 3" spot targets, prone of a bipod and rear bag. Very slight wind right to left. 6.5 creedmoor shooting 147 eldms. Gun is new to me but has 600 rounds through the barrel. Not sure if I worry about throat erosion at this point seeing it's a 6.5cm and already has 600 rounds down the barrel.View attachment 365047

 

[kgunz11]

Components are too expensive for testing in .003" increments. If my load opened up by moving the seating depth by .003" in either direction I wouldn't use it. The smallest delta I ever test is .010" increments. My load needs to shoot for .030" or I'm not using it. I shot a rifle a LOT, go through at least 2 barrels a year. I have no desire to chase seating depth in one of my rifles.

 

[Rflshootr]

Components are too expensive for testing in .003" increments. If my load opened up by moving the seating depth by .003" in either direction I wouldn't use it. The smallest delta I ever test is .010" increments. My load needs to shoot for .030" or I'm not using it. I shot a rifle a LOT, go through at least 2 barrels a year. I have no desire to chase seating depth in one of my rifles.

Have any used barrels for sale?

 

[kgunz11]

Have any used barrels for sale?

I may have a couple laying around. Some were still shooting good when I pulled them. They're going to be 6Creedmoor, 6XC, or 6BRA barrels. I go through a pair of 6BRA barrels a year with about 2200 rounds on each one.

 

[Rflshootr]

I may have a couple laying around. Some were still shooting good when I pulled them. They're going to be 6Creedmoor, 6XC, or 6BRA barrels. I go through a pair of 6BRA barrels a year with about 2200 rounds on each one.

When you get chance, PM me and let me know what you have. I need something for a varmint gun for the granddaughter.