Soot on Case base and Bolt face

[243winxb]

N540 HIGH ENERGY POWDER
Vihtavuori N540 is a mid-range powder in the N500 series, and an excellent choice for cartridges running from the .223/5.56mm, .308 Win. and .30-06 Springfield with appropriate bullet weights. This is also a great powder for 6,5x47 Lapua and 6.5 Creedmoor as well as the .223 when using heavy bullets from 69 to 82 grains. It is exceptionally clean-burning and delivers outstanding accuracy.

Vihtavuori premium reloading powders come in three different series:

N100 offers traditional single base propellants for rifle calibers,
N300/3N offers porous single base gun powders and precise measuring capability for pistol cartridges, rimfire ammunition and shotgun shells,
N500 series powders are special high energy rifle propellants enhanced with nitroglycerin for extra ballistic performance.

https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=69

I would try N540 with the 107 gr Sierra. A double based (NITRO) powder. The N540 is a little faster in burn rate and the nitro gets it burning faster then N150, a single base powder.
Or any faster powders. Hodgdon has 6 listed. http://www.hodgdonreloading.com




http://www.adi-powders.com.au/powder-equivalents/

 

[DLH_]

N540 HIGH ENERGY POWDER
Vihtavuori N540 is a mid-range powder in the N500 series, and an excellent choice for cartridges running from the .223/5.56mm, .308 Win. and .30-06 Springfield with appropriate bullet weights. This is also a great powder for 6,5x47 Lapua and 6.5 Creedmoor as well as the .223 when using heavy bullets from 69 to 82 grains. It is exceptionally clean-burning and delivers outstanding accuracy.

Vihtavuori premium reloading powders come in three different series:

N100 offers traditional single base propellants for rifle calibers,
N300/3N offers porous single base gun powders and precise measuring capability for pistol cartridges, rimfire ammunition and shotgun shells,
N500 series powders are special high energy rifle propellants enhanced with nitroglycerin for extra ballistic performance.

https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=69

I would try N540 with the 107 gr Sierra. A double based (NITRO) powder. The N540 is a little faster in burn rate and the nitro gets it burning faster then N150, a single base powder.
Or any faster powders. Hodgdon has 6 listed. http://www.hodgdonreloading.com

View attachment 1113667


http://www.adi-powders.com.au/powder-equivalents/

Thank you!

 

[Webster]

I understand that it’s common to get soot on the neck of a case or even down the sides with a low pressure load or too thin necks, however I’ve never experienced it on the base of the case. It almost looks similar to a pierced primer, but the soot is easily removed and no marks on either brass nor bolt face. The brass is new virgin Lapua that has been neck turned to a loaded diameter of 0.288 to fit the .290 neck of my rifle. Using 107 TMK which are sat just below the boat tail, cannot engage the lands as the barrel is throated for 123-130gr bullets. Using Vihtavuori data, I started a ladder test. Both the first shots 38.5gr and 39gr showed the same soot. No pressure signs. In the picture it’s compared to a piece of brass shot on the same day but with 38.5gr of N150 and a 123 Scenar sat to touch the lands. The barrel has fired 20 rounds. I cannot understand why this is happening, I’m not using a low charge, all the brass is sized the same, all primed with GM205M primers. Any suggestions as to what’s causing it? Will it damage my barrel?
Thanks,
Josh.

Check out the load map.
https://www.accurateshooter.com/cartridge-guides/65x47/

 

[DLH_]

Check out the load map.
https://www.accurateshooter.com/cartridge-guides/65x47/

I’ve seen it already but nearly all the powders on there are not available in the UK anymore! I was trying to avoid the N500 series’s powders with the horror stories of accelerated barrel wear and throat erosion.