6BR “Boyer Method” Help Needed

[Ccrider]

Decided to test 80gr Bergers in my 1:8tw 28” Criterion using Varget and 450cci primers. Started off at .01 jumped and made .005 increases.

Pretty much confused as to where to go next. No pressure signs with the 31.8 gr Varget. Too much info for me to process. Any help will be appreciated.

 

[Curious]

I dont get this at all.

Assuming you are following the method (which Im not familiar with) to the letter then I struggle to see what that method could hope to deliver?

What I know for sure with BR based cases is that charge weight increments of 0.2gr or less are needed to find and then tune the centre of nodes, you are missing so much jumping up in 0.6gr increments and limiting your seating depth to the 0.010" - 0.025" range.

What is the discipline that you are working this load up for and what is the level of accuracy you need?

 

[WayneShaw]

Why did you start jumped?

 

[jamesdmock]

Tony changed his method about 8-10 years ago. He starts at "touch" and only goes into the lands. He does not shoot "jumped " bullets. With the touch method he loads three loads with each seating depth....a mild, a medium and a hot load. He shoots 3-shot groups with each powder charge at touch; at .003 in; .006 in, etc.

When he finds a seating depth that will shoot (not only small) but will shoot to the same relative position on the target with all three charges. After analyzing the target he may check his "best" load with a 5-shot group. He prefers to shoot the hotter loads.

 

[BartsBullets]

Decided to test 80gr Bergers in my 1:8tw 28” Criterion using Varget and 450cci primers. Started off at .01 jumped and made .005 increases.

Pretty much confused as to where to go next. No pressure signs with the 31.8 gr Varget. Too much info for me to process. Any help will be appreciated.

View attachment 1060545

Looking at your groups I’d say .025 is your best seating depth. You have 3 good groups over a large velocity range.

Next step is to refine your powder load With .025 seating depth.

Bart

 

[Phil]

Looking at your groups I’d say .025 is your best seating depth. You have 3 good groups over a large velocity range.

Next step is to refine your powder load With .025 seating depth.

Bart

True story.......

 

[Ccrider]

Curious,
I chose .01 jump based on Erik Cortana’s recommendation to start at jam minus .020. I didn’t want to start that far away because I know this gun will shoot 105 Bergers quite well at .01 jump.

I am trying to see if it will shoot good enough for 100-300 using the lighter bullets. I know that there are better choices. Still, I want to see what this gun (and its shooter)is capable of.

I decided to use the large moves following Toby Bradshaw’s example. I figured this would get me in the general area and then I could fine tune from there.

 

[Ccrider]

Thanks Bart, Alex and Phil. Will do and post the results.

Can you explain what you are seeing that made you choose .025?

 

[Ccrider]

Thanks James. I may try this method developing my next load.

 

[Bugs]

A lot of guys tune at 100 yards with good results but I've always struggled trying to interpret targets at 100. I'm fortunate in that I have a 300 yard range on my own property and can shoot right at daylight when conditions are optimal. I can just see sizes, shapes of groups as well as vertical etc. etc. much better with 300 yard results. You might consider stretching it out a bit. Just my 2 cents.

 

[memilanuk]

Can you explain what you are seeing that made you choose .025?

Nice consistent round groups with pretty much the same POI

 

[Ccrider]

Nice consistent round groups with pretty much the same POI

Got it.

Bugs, I have to travel to shoot past 100, but will stretch things out soon.

 

[BartsBullets]

Thanks Bart, Alex and Phil. Will do and post the results.

Can you explain what you are seeing that made you choose .025?

If you look down your rows of groups, the .025 seating depth is the most consistent, of all of the seating depths. The group at 30.6 was good, 31.2 was the best and 31.8 still shot a decent group. You don’t have that with the other seating depths.

Now you can fine tune your load and seating depth to try and shoot even smaller.

Bart

 

[Ccrider]

Thanks Bart. I am trying to learn and your analysis is most helpful.

 

[powderbrake]

Your groups look pretty good, and like Bart says, the .025 seem the best. But I would expect more difference in the look of the target with seating depth changes when you are into the lands.

I suggest you try .000 to .010 in the lands from touch. This can be found with the Wheeler method or a lock & Load comparator.
I have an 8 twist 6BR that likes .007 into the lands, 31.7 gr Varget, 88gr Berger HBC FB varmint bullet.

I suggest this because all the rifles I own will shoot better if the bullet is touching the lands.

 

[BRGUY]

I have to agree with powderbrake's last statement. Every rifle that I own shoots it's best when the bullet is seated into the lands. In my case, .007 into the lands.

 

[urbanrifleman]

I would like to see you do it again with starting at touch and going longer 4 thou at a time.

 

[Ccrider]

I used the Stoney Point gauge and measured from firm into the lands. I will try jammed to .01 and see what the groups look like.

 

[Toby Bradshaw]

I decided to use the large moves following Toby Bradshaw’s example. I figured this would get me in the general area and then I could fine tune from there.

There's nothing wrong with 0.6gr spacing for a BR-sized case to get dialed in. Finer tuning with powder charge can come later. But: 1) start at jam and work out, or touch and work in. IME jumping never produces the smallest aggs; and, 2) 31.8gr Varget seems a little light to me for a 6BR with 80gr bullets.

The first thing I do is load a series of increasing powder charges (0.2gr-0.3gr increments) to see what the practical maximum load is, then do the seating depth test at max, max-0.6gr, and max-1.2gr. My seating depth "Boyer matrix" targets start at jam and work out 0.005" at a time for a 30BR, 0.003" at a time for a 6BR.

75% of the time I end up at touch+0.005" or jam-0.012" or something very close to that with typical cup and core bullets.

 

[Ccrider]

Thanks Toby. I will test jammed and work out to .010 where I started.

I stopped at 31.8 because of the recommended load here: http://www.6mmbr.com/6mmbr.html.

I am seeing no pressure signs so I will step up in two grain increments to see where the limits are.

I have thoroughly cleaned the barrel since shooting these groups so I will have to figure out what extent cleaning will have on the groups to follow.

Thanks again to everyone for your informative replies.