Powder fouling

[Harnic]

I recently finished my 6mm BR using a Ruger #1 action & a 27" Hart Undersized HV contoured barrel with a 9 inch twist. I loaded 50 of my new Lapua cases with 30 grains of Varget behind some Hornady 75 gr HPs I had left over from my 6mm CHeetah to fire-form the brass. The groups were very good for fire form loads, all between ¼"&½" at 100 meters, but the powder fouling was awful! You'd think I was shooting black powder! I cleaned after every 3 shots & the first patch always came out BLACK. I'm going back to play with loads tomorrow, but I think the Varget will stay home in the magazine. I'm going to play with H4895. What do the rest of you use & have you noticed bad fouling with any specific powders?

 

[Preacher]

That is usually caused by low pressure, and a increase in powder weight for that bullet weight is called for.
Lots of rifles are shooting 30 plus grains of Varget with the 105's.......

 

[Harnic]

Thanks for your reply Preacher. I noticed the pressure was very low because the primers had not shown any change at all other than the dent in the center. Some powders burn very clean even at low pressure,for example 2400 in reduced cast bullet loads in my 45 Sharps) but Varget does not! I think in my chamber, with the throat length I cut I will reach a compressed load of Varget long before any pressure signs occur which is why I'm going to try the H4895. It's slightly faster burning & a denser powder, so there's more room the work with. I'll save the Varget for when I start shooting that box of Hornady 105 gr A-Max I bought at a recent gun show. The local gun club only has a 100 yard rifle range & I have to drive almost an hour to get the a 300 meter range & over 2 hours to get to a 500 meter range, so a lot of my shooting will be close range with either 75 or 87 grain bullets, which ever shows the best groups.

 

[Harnic]

I got out today,cold blustery day, about 50°F) & fired several test loads, all using a Hornady 75 gr HP. I tried 32 gr of Varget & there was definitely less fouling, but no pressure signs so Preacher's assessment of low pressure seems correct. The max load I tried of 31 gr H4895 also showed no pressure, but burned very cleanly. Similar groups & poi with both, the rifle obviously shoots much better than the guy hanging onto it is able. I've built 9 6mm BRs over the years for customers, now that I've retired from professional gunsmithing I wanted to play with one myself. I am starting to see what everyone raves about. It's accurate, very low recoil & easy to feed, so far. It sure is nice to have my hobby back!

 

[Preacher]

Just for the fun of it try either the 80 grain Fowler flat base, or the Berger 80 in your rifle and watch the eyes open bigger...
My old 6mm AI shoots the 80 Fowlers like little lasers in a 10 twist, and is hell on Coyotes...

 

[Harnic]

Thanks for the tip Preacher, a friend suggested the Fowler bullet a couple nights ago. I just Googled Fowler & his prices are certainly reasonable for a good bullet. I will give them a try. For an inexpensive bullet, the Hornadys have worked well to get started with, but the groups could be better.

 

[Preacher]

You might want to give RL-15 a try, and also try the Russian SRM primers if your looking for better accuracy than Varget is giving....

 

[tjj]

I just got my first 6BR put together and have been working on some loads lately. It's a 700 Rem with 26" Hart Lt var taper in 9 twist also.
Some promising results with these so far:

80 Berg, 31.2gr H4895, seated at rifling, 3060 mv
95 Berg VLD, 29.5gr RL15, seated 0.010 into rifling, 2864 mv
70 SMK, 31.0gr H335, seated 0.010 off rifling, 3260 mv

Still fine tuning but it's been a "blast" so far.

 

[Travelor]

There is some mislabeled Varget floating around that is really 4350. Might check the granules against another lot of VARGET as it sounds as if you have one of the affected lots.

Hogdon will replace the powder free if that is the problem.

George

 

[AckleymanII]

Years ago, I shot a cartridge called the 6 BR long which was suggested to me by Jim Williams in the middle 80's. It was the 6 BR with a 243 AI reamer ran in .100 long in a Hart 12 twist barrel. The 6 BR long has the exact case capacity as the 6 Dasher.

I shot H335 with the 60,65, and 70g Bullets. After 100 rounds down the barrel, you could remove the bolt and while looking down the barrel, the bore would look unfired.

I used the following loads in my 6 BR long:

38.5g of H335 with the 60's at 3850
37.5g of H335 with the 65's at 3700+
36.5g of H335 with the 70's at 3650

The 60g load was competitive with any of the many 6 PPC's that I had at the time, shooting more zero's with that gun and load than anything that I have ever had, too bad that I had quit shooting Registered Benchrest Competition.

These accuracy loads were all in 1/4" area and less, how much less depended on my attention span of watching the wind that day and the quality of the prevailing conditions.

Good luck!

 

[Harnic]

Haven't had a lot of time for shooting lately, but I managed to get out yesterday. Finally got 100 cases fire-formed a week ago so was playing with some loads. This target shows some definite potential!

I checked my can of Varget against some 4350, it's not the same but thanks for the suggestion. I suspect it was just low pressure loads causing the early fouling.



Preacher, I can't imagine groups better than this, I think I can safely stick with the cheaper, easily available Hornady bullets. I know Fowler makes good bullets, but it seems so does Hornady. I have always had very good performance with them, both for target & field use.

 

[Harnic]

Well, after several more trips getting exceptional accuracy with Varget, I'm still finding it dirtier than I'd like. H4895 is MUCH cleaner burning & just as accurate using a Hornady 87 gr hpbt. I can't fault Varget in the accuracy dept., but I need to clean a lot more frequently when shooting it. Anyone else experiencing this?

Keith, thanks for the loads you suggested, but I'm finding with my twist,1-9") anything lighter than 80 grains, groups start to open up slightly. Still shoots well, but not as tight as what I'm getting consistently with the Hornady 87 gr. When I chambered my 6mmBR last winter I was undecided on what configuration to use & almost chambered it with my CHeetah mk1 reamer. I finally decided to use the 6mm BR Rem reamer I had in stock & have not been disappointed. The extra capacity I would have gained isn't needed for my casual plinking. Next test will be the box of Hornady 105 gr A-Max I bought in the spring. My local range only has a 100 yard rifle range, so I haven't wanted to waste them there. I belong to another club up the valley with a 250 yard range, so I'll wring a few out there. I bet Varget will burn a bit cleaner with the heavier bullets.