Tony Boyer target test - 300wsm

[antunRC]

I decided to run Tony Boyer’s target test to evaluate a brand new 300 WSM barrel.
I had only fired five rounds to zero the scope and check the group, so the barrel and brass were new and I was fire-forming during the test. I also don’t normally shoot from the bench, which made positioning a bit challenging.

Rifle: F-Class Open with a 31.50" barrel. Range: 100 m (110 yd). There was some mirage but nothing heavy.

I tested N555 at 63.0 gr, 63.5 gr and 64.0 gr.
For seating depth I found my hard jam point and loaded two rounds for each from +0.003" (in the jam) to -0.015" (away from jam).

I realize this is not perfect textbook run but any observations or helpful explanations about the group patterns would be greatly appreciated.



Also, if anyone could comment (second picture) on this observation: I noticed that in some groups (marked diagonally), it seems that when the charge is reduced, the seating depth may also need to be adjusted.


Here is also some chronograph data if you need it:


Lastly, is there still something to be learned from this, even though I know the test wasn’t done perfectly?

 

[Precisionhunter417]

Just for curiosity are theese 220 LRHT, 215 Hybrids, or 210 VLD?

 

[Jason Boersma]

6 thousands jump is what I would pick and then maybe tweak the charge again just to check but do that at distance.

 

[antunRC]

Just for curiosity are theese 220 LRHT, 215 Hybrids, or 210 VLD?

215gr Hybrid

 

[Drewel]

My experience with the 215, they like to be jumped +20 thousands. Might try a little more powder.

 

[marchx]

This thing shoots.

 

[Sandstorm]

it seems that when the charge is reduced, the seating depth may also need to be adjusted.

I have found this also with some powders, when decreasing the charge you also need to increase the
distance from the lands. Using N565 this was prevalent in my combo.

 

[Jerry Wick]

I decided to run Tony Boyer’s target test to evaluate a brand new 300 WSM barrel.
I had only fired five rounds to zero the scope and check the group, so the barrel and brass were new and I was fire-forming during the test. I also don’t normally shoot from the bench, which made positioning a bit challenging.

Rifle: F-Class Open with a 31.50" barrel. Range: 100 m (110 yd). There was some mirage but nothing heavy.

I tested N555 at 63.0 gr, 63.5 gr and 64.0 gr.
For seating depth I found my hard jam point and loaded two rounds for each from +0.003" (in the jam) to -0.015" (away from jam).

I realize this is not perfect textbook run but any observations or helpful explanations about the group patterns would be greatly appreciated.

View attachment 1694318

Also, if anyone could comment (second picture) on this observation: I noticed that in some groups (marked diagonally), it seems that when the charge is reduced, the seating depth may also need to be adjusted.
View attachment 1694319

Here is also some chronograph data if you need it:
View attachment 1694320

Lastly, is there still something to be learned from this, even though I know the test wasn’t done perfectly?

One key thing about Tony's method is that he's looking for a row that all prints at the same elevation on the target. Your -.009 seems to be the closest....maybe.

He also uses three shot groups, which I think is important.

I would shoot some 4 or 5 shot groups at -.009 with 63.3, 63.5 and 63.7 for confirmation.

 

[Jerry Wick]

Another thought, Tony was dealing with the 6PPC and around 30 grains of powder. With your 300WSM having more than twice the capacity, maybe you need to try a wider spread. Maybe 62, 63.5, 65 (I'm not familiar with the usual charges for the 300WSM). That would help you see that flat elevation between groups that he was looking for.

In a PPC, your .5 grains steps would change the velocity about 50fps. You are seeing less than 20fps. Big difference on target.

 

[antunRC]

My experience with the 215, they like to be jumped +20 thousands. Might try a little more powder.

I agree with you @Drewel yes, my final load runs at 2900 fps. Normally I do my load development at longer distances, but for fireforming new brass and the first firing on a new barrel, I tried this Tony Boyer's test. I’m wondering if using this method for the first shots on each new barrel would help reveal whether one is truly exceptional or just average.

Regarding the number of shots, I’ve read Boyer’s book a few times and agree that more shots would give better confirmation of result. I just had limited time for this test, so I went with 2 shots per group. As a side note, I’ve also seen many experienced benchrest shooters use 2 shots with a slightly adjusted test.

I would like to get some opinion from benchrest guys like @Jack Neary @Wayne Campbell or maybe @BartsBullets I apologize if I'm overstepping by asking.
Thank you all!
Antun

 

[antunRC]

Another thought, Tony was dealing with the 6PPC and around 30 grains of powder. With your 300WSM having more than twice the capacity, maybe you need to try a wider spread. Maybe 62, 63.5, 65 (I'm not familiar with the usual charges for the 300WSM). That would help you see that flat elevation between groups that he was looking for.

In a PPC, your .5 grains steps would change the velocity about 50fps. You are seeing less than 20fps. Big difference on target.

@Jerry Wick I agree with you. After seeing the velocity from the test, a wider powder charge spread would be better for the 300 WSM.
Definitely something to keep in mind for next time’s testing.

 

[CharlieNC]

Why such a narrow powder range, need 3-5% range to rough in the region for fine tuning.

 

[NDSU]

I decided to run Tony Boyer’s target test to evaluate a brand new 300 WSM barrel.
I had only fired five rounds to zero the scope and check the group, so the barrel and brass were new and I was fire-forming during the test. I also don’t normally shoot from the bench, which made positioning a bit challenging.

Rifle: F-Class Open with a 31.50" barrel. Range: 100 m (110 yd). There was some mirage but nothing heavy.

I tested N555 at 63.0 gr, 63.5 gr and 64.0 gr.
For seating depth I found my hard jam point and loaded two rounds for each from +0.003" (in the jam) to -0.015" (away from jam).

I realize this is not perfect textbook run but any observations or helpful explanations about the group patterns would be greatly appreciated.

View attachment 1694318

Also, if anyone could comment (second picture) on this observation: I noticed that in some groups (marked diagonally), it seems that when the charge is reduced, the seating depth may also need to be adjusted.
View attachment 1694319

Here is also some chronograph data if you need it:
View attachment 1694320

Lastly, is there still something to be learned from this, even though I know the test wasn’t done perfectly?

Where did you get those targets?

 

[big5ifty]

Your group centers are very consistent if you stay away from the higher pressures.

Other than that, and the fact I'm looking at good shooting, I don't know enough to draw any other conclusion.

There are two important variables changing at the same time, which complicates the interpretation. Charge and seating depth,

Other than the higher pressure group center shifts, it all looks like one big node.

An OCW with 3 shot groups over a full 4% charge variation in half percent intervals is what I use to read what the gun will do best, at a seating depth.

Once you have the charge figured out, then this test of yours will show seating depth optimisation, even with two shots per.

 

[big5ifty]

Bruce does his testing in a similar manner, this is 600 yards

I can only watch something like this, I'm not able to shoot the difference.

 

[antunRC]

Where did you get those targets?

F-class John posted long time ago

TunerDev-2.pdf

drive.google.com

LoadDev-1.pdf

drive.google.com

 

[NDSU]

Thx

 

[antunRC]

So I ran one more test with a different barrel (not the same one from my first post). Barrel is new.
I used N165 powder and changed the seating depth by 0.010".
I’m using new brass to fireform to the chamber.
The bullet was a 215gr Berger.
Just sharing this - hope someone finds it interesting.

 

[seymour fish]

So I ran one more test with a different barrel (not the same one from my first post). Barrel is new.
I used Hodgdon N165 powder and changed the seating depth by 0.010".
I’m using new brass to fireform to the chamber.
The bullet was a 215gr Berger.
Just sharing this - hope someone finds it interesting.
View attachment 1697037View attachment 1697038

Hogdon 165. Rare as hens teeth

 

[antunRC]

Hogdon 165. Rare as hens teeth

Haha. That is what happens when you think about something else and trying to write...