Push for more speed?

[John from MN]

Fellas,

Currently doing load work for a 6br I built. Barrel is an 8 twist .237 bore Bartlein in Remington varmint countour crowned at 26 inches.

I have a load that is showing promise at 550yds.

105 VLD
30.6 grains of Varget
Rem brass
CCI 450

According to my drop, this load is running 2810fps. 2 tenths more Varget caused serious vertical at 550. I've seen nothing to lead me to think I'm at max, but it's certainly not a mild load.

I've always used the 6br as a midrange varmint round with 55 and 70 grain bullets. This is my first go with the 105's. I'm inclined to sit at 30.6 grains instead of looking for the next node up. What say you??

Thanks,
John

 

[338 Mollett]

You answered your own question

 

[jonbearman]

It wouldn't hurt to work up to try and get the vertical to dissipate but do it in no more than 2 tenths of a grain and maybe a tenth at a time if primers start to flatten with the first move to 30.8. Just be careful and measure the expansion of the case head at the .200 thou line from the base. Let us know what your findings are and take your time and load only 1 for each step up initialy to spot over pressure and when you get to slight stiff bolt back off a 1/2 a grain. Safety first and last. Don't use any hot loads without being able to find data to substantiate what people suggest. Do you have the berger manual? If you do then great and if you don't ,buy it for a wealth of information.

 

[Erik Cortina]

Jonberman, he already tried going .2 gr. higher and it caused "serious vertical", so I would advise to stay where he is at.

 

[RDavies]

Jonberman, he already tried going .2 gr. higher and it caused "serious vertical", so I would advise to stay where he is at.

I agree. 2810 is a regular node area for most BRs and with a 26" barrel will be fairly warm. 30.6 is pretty much as hot as most people would go with a 6BR. I would say that you would have to get up to around 2920-2940 to find the next node, but short of turning it into a Dasher, you probably wont do it safely.

 

[michaelnel]

Do you have the berger manual? If you do then great and if you don't ,buy it for a wealth of information.

I agree there is some good information in it, but much of the good stuff is available on the internet at no cost.

The first 94 pages are devoted to the life of Walt Berger.

The load data tables are ridiculously conservative (for instance, they recommend 26.5 min - 29.4 max grains of Varget for a 6mm BR Norma 105 grain bullet). That is way short of what most people use very successfully (30.0-30.5 grains).

The load tables don't contain anything larger than .30 caliber (my .338 Lapua Magnum is not even mentioned).

I don't think this is a particularly good value, at least not for me.

 

[John from MN]

Thanks for the help, guys. I'll stick with 30.6.

The difference between the 30.6 and 30.8 charges was drastic. 30.6 had under an inch of vertical while 30.8 had just under 4 inches.

John

 

[Erik Cortina]

Thanks for the help, guys. I'll stick with 30.6.

The difference between the 30.6 and 30.8 charges was drastic. 30.6 had under an inch of vertical while 30.8 had just under 4 inches.

John

That indicates you are on the ragged edge. I would shoot in .1 gr increments from 30.0 to 30.7 to pinpoint your node, once you do that, load to the center of the node to give you some room on each side to compensate for temperature changes.

 

[John from MN]

I'll do that and update the thread.

 

[jonbearman]

Erik I thank you for the opportunity to learn more about going in the right direction. I never stop learning on this site. I have one question, is there any other powder more conducive to better accuracy at long range than varget. Again this is just a question as I don't know what powders are the very best for this application.

 

[Erik Cortina]

Erik I thank you for the opportunity to learn more about going in the right direction. I never stop learning on this site. I have one question, is there any other powder more conducive to better accuracy at long range than varget. Again this is just a question as I don't know what powders are the very best for this application.

Different powders will behave differently with different cartridges, barrel lengths, and even primers. I don't think there is "one" best powder, I think we should try different powders with same similar burn rates that would work in our intended application and test them all.

 

[Tim Singleton]

What seating depth are you using with the vld?

I've never been able to go above 30.5 of Varget with 105's in three different 6br's without them starting to spit shots

 

[John from MN]

I'm running .005 jam.

Keep in mind that I'm using RP brass in an RP chamber. Perhaps there is a difference in capacity between RP and Lapua?

I bought 1000 pcs of the RP for a prarie dog gun back when Midway was still carrying it. I certainly would not bother with it if I was shooting matches, but it works well enough for hunting rifles.

Also, your accuracy requirements may be significantly different from mine. I hunt and shoot steel for fun. My equipment isn't going to shoot 1/2" groups at 600yds. I'd like to see 2 inch 5 shot groups on my 550 yd plate, provided conditions are reasonable.

 

[Drop Port]

Erik I thank you for the opportunity to learn more about going in the right direction. I never stop learning on this site. I have one question, is there any other powder more conducive to better accuracy at long range than varget. Again this is just a question as I don't know what powders are the very best for this application.

Different powders will behave differently with different cartridges, barrel lengths, and even primers. I don't think there is "one" best powder, I think we should try different powders with same similar burn rates that would work in our intended application and test them all.

+1
This often overlooked due to what most believe should work. I shoot 30.6 of Varget in my 27" Broughton barrel at 2850 fps. I heard from everyone that CCI 450 were the primer to use and was advised against using anything but. Mine shot good with them but when all was said and done BR-4's got rid of the vertical and sucked the groups in even more. As stated you want to be in the middle of the sweet spot not on the edge.

 

[HTSmith]

My 6br is similar to yours--I have a 26" Hart bbl in the Rem Varmint contour. With the Berger VLD 105, I'm at an even 30.0 Gr of Varget for 2800fps. After my first 1000 yard fclass match I tried to hot it up to get less wind deflection. Tried more Varget. Tried R15--that did get me another 50 fps but not as consistent. I'm back where it seems to be comfortable 30.0 Varget.

 

[rmist]

With my BR it shoots best at 2806 fps with 30.2 gr of Varget, 105 hybrid jumped almost .020" in a 28" Krieger.

 

[Erik Cortina]

My 6br is similar to yours--I have a 26" Hart bbl in the Rem Varmint contour. With the Berger VLD 105, I'm at an even 30.0 Gr of Varget for 2800fps. After my first 1000 yard fclass match I tried to hot it up to get less wind deflection. Tried more Varget. Tried R15--that did get me another 50 fps but not as consistent. I'm back where it seems to be comfortable 30.0 Varget.

You don't need more powder, you need more bullet!

 

[HTSmith]

Well I took your advice! I'm now shooting 140 VLD's at about 2800 fps. Haven't tried it at 1000 yet but short range results look promising. I've taken a lot of notes from your posts. Thank you.

 

[Erik Cortina]

Well I took your advice! I'm now shooting 140 VLD's at about 2800 fps. Haven't tried it at 1000 yet but short range results look promising. I've taken a lot of notes from your posts. Thank you.

If they are tuned properly, you will be amazed how much easier it will be with the. 140's vs. the 105's. Problem is, you will start thinking "What if I had 180's?"

 

[John from MN]

I appreciate all the input.

Hope to get a reasonably calm day this coming weekend to do some more testing.

Those 6.5's with 140's will spoil a man rotten. I really like my 6.5 Creedmoor, it's just a bit more than I need most of the time.