6BR Powder Choice and Barrel Life

[Sheldon N]

For metering, I'd look at alliant MR-2000. It's cheap, available, made in the USA and flows like water.

If someone could send me the latest QL powder file, I could update the barrel life spreadsheet. Would greatly appreciate it.

I'm curious about the heat of explosion numbers for 2000MR. Is it in the latest release of Quickload? Does anyone have that #?

 

[kountryboy2]

I'm happy with 64 gr Berger's column bullets. Barrel is 12 twist and it loves Lt 32 powder.

 

[Shynloco]

FWIW,
I do believe heat in the load is what does the most damage to a barrel as heat causes throat erosion and then goes after the rest of the barrel. Carbon is removed with a thorough cleaning and should not be permitted to build up. And I'm talking consistent best accuracy and NOT that a barrel can't be used for general shooting. In my experiences, I used VNN133 in my 6mmbr and first noted the barrel loosing it's repeatable consistency right around 3700 rds. At 4000 rds, she still shot, but not to the standards I demand for a 6br. Changed barrels to a new Kreiger and she regained her consistant accuracy.

Alex

 

[Sheldon N]

Thanks Alex, your reports of barrel life seem to line up with the heat numbers and Viht N133 being very cool burning. My only concern with that powder is that it seems the higher cost of the powder negates most of the projected increased barrel life/cost savings.

Seems I'm hunting for something in the Varget burn rate zone, that burns cool like the Viht powders, that meters well from a Dillon thrower, and that is cheap.

 

[BradY]

Barrels are consumable items. I would suggest choosing a powder that produces accurate ammo. If your using 105 class bullets the best known are going to be h4895, rl15 and varget. I'm running on varget now for the 107 sierras and it just works.

 

[Sheldon N]

Oh I've got Varget and will be shooting it for match loads at full power with 105 Hybrids or maybe the new Nosler RDF's. What I want to load secondarily is "practice" ammo to get trigger time working barricades, odd position shooting, shooting under time pressure... all the things that make or break success in PRS style competitions.

I'd prefer it to be quick and easy to reload (ie thrown from a Dillon) rather than weighed to the kernel like my match loads, with a powder that meters well so it can still maintain some semblance of powder weight consistency. I'm also going to load reduced pressure/velocity with the goal of stretching barrel life, and shoot cheaper bullets.

In a perfect world I'd just build a 223 trainer to mirror my match rifle, but for now shooting practice ammo side by side with my match ammo out of the 6 Dasher seems a reasonable compromise. Just trying to maximize barrel life in how I choose to build the practice ammo.

Right now IMR XBR 8208 seems like the best choice. Just wish it was a little slower burning so I could get a fuller case at lower pressure. All the slower burning powders have big kernels though and meter poorly through a Dillon.

 

[rimfiremac]

I will echo what BradY and others have alluded to- you save nothing trying to save a dime per round in practice. All this effort to 'save money' with a 'trainer' would be better used just practicing with your current barrel, or reaming out the br barrel to dasher also and practicing with that. If you truly want to save money, shoot a heavy rimfire for positional training.

 

[Sheldon N]

I will echo what BradY and others have alluded to- you save nothing trying to save a dime per round in practice. All this effort to 'save money' with a 'trainer' would be better used just practicing with your current barrel, or reaming out the br barrel to dasher also and practicing with that. If you truly want to save money, shoot a heavy rimfire for positional training.

I've already come to that conclusion about not a adding second caliber for a trainer rifle. I'm going to just stick with the 6 Dasher for training and matches, same rifle for both. Being able to share dies/brass etc just makes things cheaper and simpler, and adding a second rifle as a trainer is expensive regardless of what you choose. I may run two Dasher barrels (same reamer) simultaneously so I can keep a match barrel in good shape throughout the season, or I may just shoot one and then rebarrel later when it starts to get close to the end of its life.

The main thing I'm doing now is choosing components for the Dasher practice ammo that are less expensive (ie Nosler CC or Hornady BTHP rather than Hybrids), and a powder that meters well with a Dillon press for easy loading and that may help extend barrel life (ie XBR 8208 rather than Varget)

And while cost is important, it's more about the "easy to load" factor with the Dillon that I'm concerned about. Going to a progressive press with thrown charges will save me a large amount of time. On the cost front I'm penciling the numbers out at about $0.20 per round cheaper for the practice ammo, all costs considered.

I'm going to buy a pound of XBR 8208 and test how accurately it meters vs Varget, then will eventually do some testing to see if it shoots well or not.

 

[rimfiremac]

Great decision. I've had good luck with Hornady 105 HPBT's in the 6BR. They are 'consistent enough', and usually cost competitive with the NCC's, but either achieves the task.

 

[Sheldon N]

Picked up a pound of XBR8208, did some tests in the Dillon 550 to see how well it metered vs Varget. Ran 20 cases of each at 6BR/6 Dasher loads (~30gr) then weighed them on a precision scale. Here's the resulting weight deviation numbers as well as velocity and vertical dispersion numbers from Quickload/JBM modeling.

Varget
0.124 grains Standard Deviation
0.46 grains Extreme Spread
38 fps ES per Quickload
10.2" vertical @ 950 yards per JBM

IMR XBR 8208
0.079 grains Standard Deviation
0.26 grains Extreme Spread
21 fps ES per Quickload
5" vertical @ 950 yards per JBM

Not BR territory, but if I'm going to throw charges on the Dillon XBR 8208 looks to be a much better choice than Varget.

 

[Barrel Nut]

....... snip............

Not BR territory, but if I'm going to throw charges on the Dillon XBR 8208 looks to be a much better choice than Varget.

I don't know exactly what causes a powder to meter well, but I do know that my intuition is not a good indicator. I would think that a fine spherical powder like CFE-223 would meter well; however, it does poorly both in my Hornady Lock-N-Load mechanical dispenser and my RCBS Chargemaster. A short stick powder, like IMR 8208 XBR does MUCH better for reasons I don't fully understand. My careful tests show that IMR 8208 XBR does the best of the 10 different powders I've tested, both with the mechanical dispenser and the RCBS trickler/scale. Varget is middle of the pack when it comes to metering accuracy.

 

[Sheldon N]

My careful tests show that IMR 8208 XBR does the best of the 10 different powders I've tested, both with the mechanical dispenser and the RCBS trickler/scale.

That's good to know. I'm hoping to get some rounds downrange and see how it does before too long.

 

[JEFFPPC]

Br go to powder....VV135

 

[Dgd6mm]

I know this is an old thread, but my PRS 6br rifle gets fed IMR4895 with 105 Amax.

 

[Bigdaddy405]

I have been shooting a relatively mild load of H4895 using Fed 205M primers in my 28" 6BR at a few NRL matches & occasional 200 BR varmint matches and have at least 2500 rounds in my barrel. 2804 fps with 28.4 gr H4895. 105 Hybrids, Lapua brass. slowed down about 10fps over a year ago but I'm thinking it's just new lot of powder.

 

[mikecr]

I have been shooting a relatively mild load of H4895 using Fed 205M primers in my 28" 6BR at a few NRL matches & occasional 200 BR varmint matches and have at least 2500 rounds in my barrel. 2804 fps with 28.4 gr H4895.

I'm thinking you'll soon see a step change in results.

 

[mikecr]

No, it isn't. That one is very old.
This is the latest, and it still needs updated with newest powders.
I dropped the moly specific adjustment, and modified the math to account for extreme underbores (like 30BR).

 

[expiper]

I think you are wasting money and the most valuable thing of "your time" ,,,you should practice with what ever you compete with,,,the trajectory will be different ,,the wind drift will be different ,,,the way the ctgs feed from the mag will be different,,,just to name a few,,,,,,do the fuel dragster/funny car guys do a pass with a Vega to practice ??? NOT HARDLY!!,,,,Practice time is a good time to test various powder and bullet combos....what you learn in practice should be directly aplicable to your competetion rifle,,,,the cost of barrels,bullets,components is nothing compared to your time and effort,,,,,,,Roger

 

[dbduff]

Well, there's really only one way to find out. I think I may end up keeping it simple and doing Dasher for both barrels. Thanks for the suggestion!

True that!

 

[Sheldon N]

Since my original question from 5 years ago keeps getting brought back to life, I suppose I should close the loop on where I ended up.

Never did do a Dasher or 6BR trainer. Ended up building a 223 trainer instead, which was a much better fit my PRS style shooting practice. Shoot heavier 75gr bullets, load with XBR8208 because it meters awesome from a Dillon. Brass prep is easier because it's not doing double-duty with my primary match brass, overall costs are lower compared to a 6mm, simpler all around. Currently on my third barrel for the 223 trainer.

Match rifle has migrated to 6BRA with H4895. Run them slow at around 2880 fps with a 105gr bullet, 27-28" barrel length. Currently on barrel #4 for that caliber, seems to get 2500-3000 rounds if I treat them nice (PRS accuracy standard). Also have gone through 3-4 Dasher barrels, Varget and 105's, probably 2000-2500 rounds on average per barrel.

It's been a long 5 years since I started the thread, probably 30k rounds fired in practice and matches, have managed to win a couple dozen trophies, traveled to national finales, still shooting matches at least once a month. If I was to give my "5 years ago" self advice it would be this.

Caliber choice > Powder choice if you care about cost/barrel life for a trainer. Can't make a 6mm last as long or be as cheap as a 223.

Running slower velocities helps barrel life, no need for speed in the game of PRS.

Simplifying ammo loading/logistics is very important, if you're going to be loading tons and tons of ammo. XBR8208 meters great and is a perfect choice.

Buy more primers, you won't regret it.