First handloads for 6mm BR

[Pareto]

Now that I've started playing with 6BR, I'd like to ask how much below recommended loads should I start when reloading 6Br. I have some Lapua brass, Euber and Barnes 68 grain bullets and Varget, Benchmark, and LT32 powder to start with as well as a half pound of H335. I plan to start with Varget and I see many recommended loads. Should I start 2 grains below a recommended load? (For example, I often see 34 grain of V mentioned as an optimal load +/- a little bit for 65-70 grain loads in a 1:14 twist. Should I start at 32 grains or lower to be safe?)

Thanks.

 

[Webster]

I shoot below 34.0 gr with any powder (55-68 gr bullets). Starting to get ejector swipes above that. You may get a little above 34 gr with some powders but your starting to push the limits hard. My favorite load is 60gr sierra Varminter with 33.3 gr of 8208 3580 fps. Decent accuracy with Varget and RE-15 but lower speed. When I got a new computer I lost a lot of data. I recreated a spread sheet from saved targets with loads printed on them. H322 has good speed. never tried H335. A2230 gave very low speed.

 

[Barossa_222]

Personally I will look through the manuals I have on hand or go to manufacturers data. I'll look for the powder that has the highest case density and highest velocity with the least pressure at max load and start with that powder. I will usually start 1gr under max powder load and work up.
The data printed in American manuals, I have found to be well under max, but having said that you must consider different brands of brass and quality of the rifle being used. A Borden action that has been long throated will take a lot more powder than a factory Remington with a SAAMI chamber.
10% under maximum is the general rule of thumb. I suspect in your BR you'll be up 33.5gr and higher of varget with a bullet of that weight depending on the batch of powder and throat in the rifle. In my Dasher, which is slightly bigger, I'm running 65gr VMAXs with 36.5gt of varget. In my Savage LRPV 6BR 32gr of the same with a 75gr VMAX jammed 10 thou.

 

[OMW57]

I have been running 31.0 grains of H4895 behind a 70 grain NBT in my cooper montana varminter 14 twist, good for right at 3200 fps
very accurate load for MY rifle!

 

[Walt Krafft]

With the large number of 6BR chambers, it is impossible to give you any advice other than start LOW. You may shoot some extra rounds, but you may shoot only one that is too hot.

 

[Pareto]

Thanks then. I'll start at 31 grains, 3x groups till I figure out what's safe. Good advice. I'm using data from Berger as I don't have load data for Euber or Barnes. Barnes doesn't even list 6Br as one of their load options. And anyway, I prefer the lighter accuracy nodes over the hotter ones.

 

[ssv1761982]

Look on the H335 can, that works great for me with light bullets. You may want to start just a little lower since every gun is different.

 

[22BRGUY]

Do you know how to look for high pressure signs?

 

[Pareto]

Yes. I have some limited experience but I'm a little fuzzy on cratering. Also this is for 100 yard ranges so I don't worry about hitting a certain speed.

 

[Mark W]

Yes. I have some limited experience but I'm a little fuzzy on cratering. Also this is for 100 yard ranges so I don't worry about hitting a certain speed.

Cratered primers are quite possibly the worst indicator of pressure since they are usually caused by a sloppy firing pin fit. Flattened primers, ejector marks, and heavy bolt lift are better indicators.

 

[Pareto]

Cratered primers are quite possibly the worst indicator of pressure since they are usually caused by a sloppy firing pin fit. Flattened primers, ejector marks, and heavy bolt lift are better indicators.

Yes. I've looked at all the pics online and have never gotten these, so I have to rely on my understanding of the pics. Twice I got a pierced primer so I backed off the charge. In both cases, it was just under the listed max when I shot a ladder, so I just avoided that load. This was with 223.

 

[Pareto]

First loads with Varget went well. Followed the Murdica advice to shoot 2x then 3x groups on the better ones. It seems my good groups were all in the lower 31 to 31.5 grain range with V and 68 Eubers. Will load about 20 or so to followup in this range the next time I go out. Shot at 100 yards indoors off a front rest and rear bag.

 

[Pareto]

The biggest issue were the loads with TAC. I got hard bolt lift and in three cases I couldn't extract the case without a rod and hammer to help me yank the bolt back, so I stopped shooting those. I figure I perhaps loaded the bullets too far out and should seat them deeper?

 

[K redden]

Sound like they were loaded hotter than just needing a seating depth change. more likely start over completely at a way lower charge. I mean cmon man , if you have to beat a cartridge out, it’s beyond Hot

 

[Pareto]

Sound like they were loaded hotter than just needing a seating depth change. more likely start over completely at a way lower charge. I mean cmon man , if you have to beat a cartridge out, it’s beyond Hot

Ok. I already started at the recommended minimum, but I'll come down more.