Bullet wobble/handloading problem?

[Korhil78]

I just picked up the newest issue of Handloader Magazine. Took a look and the author of one of the articles was saying that about 20% of all of winchester and remington case necks are not concentric which makes the bullet sit slightly crooked in the case mouth when seated. He stated that this will make the bullet "wobble" into the rifling which in turn makes shots less accurate. He said that Lapua and Norma brass are the most concentric and tends to eliminate that problem. He said also that if you want to seat the bullet properly and ensure a nice straight fit into the case that one should use the competition seating dies because of the tight tolerances of these dies. There were some other options that he threw in there but these are the ones that stuck out to me. Anyone buy this? Im not saying that it isnt true but does it really make a big difference or is it just a few things that add up to make better accuracy?

Thoughts?

 

[Coyboy]

He felt obligated to say that since Lapua and Norma advertise there brass in the rag!!

Well may-be...

I have used rem and win brass in many rifles. More often than not the hand loaded brass will hold 1/4 to 1/2 moa out to 600 yards.

I neck turned 400 pcs of rem 7saum brass a month ago, taking about .002" off the total neck dia.. I had about 15 cases that were not cleaned up completly on one side, indicating that the neck thickness varied by at least .0015 on those 15 cases. Not even close to 20%. Those 7 saum loads hold 1/3moa at 600 in my hunting/tac rifle.

My 260 has shot 2 consecutive 5 shot groups at 600 with perfect conditions under 2" using weight sorted rem brass.

My 6br using lapua brass holds better than .25 moa verticle at 600 once the barrel warms up with 8-9 shots, but that gun is scary accurate, repeatadly shooting 1.5" 600 yard groups.

every thing adds up, but it could be all for nothing if an uncorrected variable other than the brass is still present.

Now if your talking about shooting in a factory rifle, I would go with the cheap stuff.

 

[GNERGY]

Jim, when you weight sort brass how close do you keep them? Let's say .308 win and then 338 Ultra mag cases. I was thinking of trying some weight sorting.
Thanks
Tarey

 

[WildRose]

Bench rest guys get fanatical about the most minute details.

Once the bullet leaves the case however it is traveling 20-28" or more down the bore in contact with the riflings so I fail to see how such a wobble at the other end is going to have any real impact on overall accuracy.

With case necks the thing I'm more concerned with is thickness as it can affect chamber pressures if some are significantly larger in a tight chamber.

 

[Korhil78]

Bench rest guys get fanatical about the most minute details.

Once the bullet leaves the case however it is traveling 20-28" or more down the bore in contact with the riflings so I fail to see how such a wobble at the other end is going to have any real impact on overall accuracy.

With case necks the thing I'm more concerned with is thickness as it can affect chamber pressures if some are significantly larger in a tight chamber.

I agree..I don't think that it is going to matter as much as he was making it out to be. If you get a chance, take a look at the article. Its on page 60 of the magazine. He makes it out like all of the case prep variables and the placement of the bullet into the case is super important. Only thing that I did totally agree with is that the bullets that are made today are very accurate because of the precise methods used to make them.

I am sure that it is super important to a benchrest shooter because they are competing with their preciseness and all the little things add up for them to make a difference. But as for the hunter, I don't think that is going to matter too much.

 

[Coyboy]

Tarey, the small cases 308 based I measure into a range of 2 grains. usually end up with 2 piles and a handful of culls that are below or above the 4 grain spread.

With the big cases I go to a 3 grain spread, (wsm, rsaum and UM)
I have seen variables of up to 12 grains, high to low, in 500 count boxes.

I made the mistake one time of mixing 2 lots of lapua brass in my 6.5x284 f-class rifle, that had about 4 firings on them. Couldn't understand all the verticle I was getting at 1000 yards during a match. When I got home I weight the remaining loaded rounds and sorted them, the fired brass revealed a weight difference of 3.5 grains on average. Shot the sorted brass during the next match and the verticle went away. That is somthing you would never notice at 300 yards but it shows at 1000.