Reloading Problems

[6.5 JUNKIE]

I hope someone has ran across this. I reloaded 50 rounds for my 6.5-284, 25 were with never fired Nosler brass and 25 with never fired Lapua brass. All the loads were in the medium powder charge range with the same powder. When I fired these loads at the range about 85 % of the cartridges that were loaded using the Lapua brass came out with a sooty-burnt film on them but the ones using the Nosler brass did not. I have inspected the cases and have not found any signs of excessive pressure.
Am I right in believing that the Lapua brass did not seal to the chamber properly and let some gases escape rearward, if so is this a one time thing now that these cases have been fire-formed ?

[Pathfinder76]

Your right, but the cause is lack of pressure more than excessive pressure. The Nosler brass is obviously softer (not suprised). Fireforming will not cure the problem. Loading them like they were meant to be loaded will.

[catnthehat]

This can be caused by several things, normally a lack of neck tension is the cause, but sometimes if a case has a slightly larger case capacity this will also cause sooting. The result in both instances is a lack of pressure .

Nosler brass is made by Norma IIRC, and Lapua is made in their factory, so you are dealing with different neck diameters likely, and slight differences in case capacities.

Cat

[6.5 JUNKIE]

so would you recommend some higher charged loads ????

[foothillsman]

As stated by Cat

normally a lack of neck tension is the cause,

Go to a hotter primer. This didn't work for me, but it's worth a try.

Increase your neck tension. This can be done by putting your expander ball and stem into a drill and reduce it's diameter by carefully sanding it with first 280 grit then polish it with 400, then 600 grit.

If you're seated up close to the rifling, and your rifle is freebored, your bullets may not have enough tension because there is not enough bullet for the case neck to grab. The pressure doesn't build enough, so your bullet leaves before the brass can seal properly. You should seat the bullet in at least 1 full caliber's length into the neck but can get away with less. If your gun likes to have the bullets close to the lands to shoot tight groups, try a heavier bullet, there is more bullet for the neck to grasp.

[Sigma]

If you have access to a chronograph, it may give you more data to solve your problem.

[switchsl]

I have seen soot trouble, with low end starting loads in an '06, a 303 and a 35 whelen, the 303 was the worst, i have my suspicion as to why. I agree with chuck and cat. I am having trouble of my own now, so Im reluctant to say any more.

[Dean2]

The sooting is definitely cuased by insufficient pressure reulting in the case not expanding enough to completely seal the chamber.

Assuming the cases are the correct length and that all of your loading equipment is in spec; neck size the once fired brass, then load groups of three, starting .5 grains higher than the load that caused the sooting, and add progressively .3 grains moe powder till you reach max published load. You will reach a point where the sooting stops. This should be your minimum load with that batch of brass. You can now work higher till you start to see pressure problems.

Lapua is great brass, but becuase it is so often used by Benchrest and competitive shooters it is designed to be shot on the hot side of loads. Very often Lapua brass will not show pressure signs till you are quite a ways over some published max laods.