6mm BR - Back to the Future?

[Henryrifle]

That is great shooting! And, great hand loading too. I am jealous. Using the results from a few posts up, I was hoping to see groups like yours at .011 in the lands and maybe something good around .010 or .011 off the lands. Instead, I got groups in the .7s with the 107s.

I did reduce the powder charge for the round loaded into the lands and I got a lot less velocity than I expected. I am a little lost in the testing at this point and am tempted to give the Berger 105 Hybrids a try but really wanted to make the 107s work.



Open to suggestions...

Thank you for the update. I am inspired to keep trying. Those are great results!

Henryrifle

 

[mjl650]

Very typically I see the same seating depth numbers with the burger 108. They will shoot very small between 20 and 30 jump they also shoot very small between about 4 and 8 in. I think you're seeing the same thing and there are a lot of similarities between the 107 Sierra and the Berger108 as far as seating depth goes. In all actuality the Berger 108 is kind of a copy of the Sierra 107.

I'm not going to say that the into the lands seating depth shoots better but I would say it's one of the good seating depth. I have found that very little neck tension is needed

Good to know as I also have a bunch of the Berger 108 and going to do load development for those. Also @WSMNUT gave me a sample pack of Barts 105 to try out. Sure am having a lot of fun on load development for this rifle.

 

[urbanrifleman]

Good to know as I also have a bunch of the Berger 108 and going to do load development for those. Also @WSMNUT gave me a sample pack of Barts 105 to try out. Sure am having a lot of fun on load development for this rifle.

I shoot 25 jump because 20 and 30 shoot great. 25 puts me in the middle of the node. .I know that's probably heresy to say it shoots the same in that range.

 

[Tokay444]

I shoot 25 jump because 20 and 30 shoot great. 25 puts me in the middle of the node. .I know that's probably heresy to say it shoots the same in that range.

I can believe it, but I generally load in the middle of my powder node, but on the long side of my jump node, since the lands are only ever going to get further away, not closer.

 

[urbanrifleman]

I can believe it, but I generally load in the middle of my powder node, but on the long side of my jump node, since the lands are only ever going to get further away, not closer.

Correct. Apparently, This is what Erik Cortina has been preaching also as of late.

 

[JFrank]

I did make it to the range today but I think the only thing I learned was that my rifle doesn't like .02 off the lands. I shot these at 100 in zero wind using the Seb Neo and Bigfoot rear bag. I am seeing the kind of velocity I expected to see from my 29" barrel but was surprised by the poor and erratic SDs. Brass was prepped and seating was grossly normal. There were a handful of cartridges that required a second run through the seater but were only off by .001.

Next steps are to pick a charge and run seating depth tests to see what that can tell me.

The UGLY:

View attachment 1226059
View attachment 1226061
Henryrifle

Well sir
Im just a dumb ass but I can tell you what I see.
When you exceed 30.gr your groups start getting erratic some are trying to break out then under 29.9 they are a bit loose but not crazy. If this were mine I would be 29.9 - 30. max

 

[JFrank]

One more trip to the range today to see if there was more to learn by testing seating depth. You'll notice that several of the tests were in the lands which means I am getting desperate as I am not a fan of those kinds of loads. I don't like three-shot groups either, but, also, don't want to waste components. All of the below were shot with 29.9 grains of Varget. Muzzle velocities, especially those in the lands, were faster than I wanted.

What I think I see in the groups below is that somewhere between .008 and .014 off the lands should be a good starting point for more powder charge tests.

Do you see anything I am missing?
View attachment 1226272
View attachment 1226273
Henryrifle

I like .011 off
at 29.9 -30. Gr depending on weather.
Do you sort bullets?

 

[Henryrifle]

Nobody around here is dumb -- that's for sure. Crazy? Well, probably. I have not sorted any of these bullets--yet as I have been shooting relatively small samples looking for a reasonable starting point. I will be sure and do that before the next round of testing.

Thank you for your help!

Henryrifle

 

[Ccrider]

Don’t be afraid to try further off the lands.