Case Preparation for Extreme Accuracy?

[Homer]

G'Day Fella's,

Around 1990, I had a short action Rem 700 completely trued to BR standards and then sleeved by the Australian Master GS, John Giles of www.pseco.com.au . The initial barrel for this rifle was made by another Australian master of his trade Neville Madden of Maddco Barrels (no use lookin, Nev still doesn't have a web site but Accuracy International made their name by initially using, Maddco barrels), in .22-250AI.
Anyways, I recently had John Giles chamber up another barrel for this switch barrel rifle, this one is in 6.5 x 47Lapua (3 groove, 1 in 8" twist).
Earlier this week, I received my latest order from Midway, which included 200x Lapua cases and a box of 500 x Sierra 142gr HPBT, 6.5mm bullets.
I have some inline dies for this chambering, flash hole deburing tools, primer pocket uniforming reamer etc etc...

So finally;
Because I'm a bit out of date on case preparation, I was just wondering;

1) Do I need to internally chamfer/debur the primer flash holes of these Lapua cases?
and
2) What about drilling the primer flash holes them selves, to a consistent diameter?
and
3) Do I need to uniform the primer pockets on these beautiful little Lapua cases
and
4) anything else I need to do, that I have completely forgotten about?

Looking forward to your replies.

Doh!
Homer

 

[FroggyOne2]

My current .223 I am turning the necks jus enough to clean up the majority at about sixty to seventy percent. Then I uniform the primer pockets, debur the inside of the flash holes and trimming to 1.750. Debur the outside of the neck and chamfer the inside of the neck at eleven degrees. This rifle is holdin two inches of elevation at six hundred yards. So yes I would say that what your asking is worth it.

 

[golfer2b2000]

On new brass I usually dont get serious till I fire the brass at least one time. I deburr the inside of the mouth of the cases. I also like the other gentleman said trim the brass till it is somewhat square. I dont mess wth the flash holes at all. After I fire the cases,(6mmBR) I then use a tool on the primer pockets that has a shoulder on the tool so I can control the depth of the cut. I then neck size. I try the cases into the rifle to ensure that they chamber all the same, and with little effort closing the bolt. I am not one of the better shooters I am sure, but even after doing all of this and shooting the brass I still cant tell that much difference in my targets.

 

[fdshuster]

Homer: Questions 1 thru 4: No. I follow the same guidelines as golfer2b2000. May do a neck sizing to straighten any small dents or irregularities in the case mouth and I do inside taper neck ream to eliminate the sharp edge that may cause some shaving of the bullet jacket when seating.

I find the primer pockets to be so close to perfect, "as is", that I do nothing to them.

 

[Shynloco]

Homer,
IMHO opinion:
1. yes
2. No
3. Yes
4. Have fun!

 

[amlevin]

The nice thing about Lapua brass is that it doesn't take a lot of work. On mine I don't do a thing until I've shot it at once. Only real work I do on mine is to neck turn like FroggyOne2 described and trim using an RCBS 3-Way Cutter that trims, deburrs, and chamfers at the same time.

Now all I need to do is start shooting as well as my equipment and ammo is capable of 8)

 

[Elkbane]

You may want to check the O/s neck diameter and the neck thickness to make sure they are consistent with the neck tension you want to run in your loaded rounds. Sometimes you might need to run them over an expander , then throug a bushing type neck sizeer to avoid too much neck tension. I just faced this with some new 260 Rem lapua cases. O/S diameter was .2095, loaded round weas .2945. Seating was pretty stiff. I ran them over a K&M expander then through a .293 redding bushing, resulting in .2925 O/s diameter. These seated much smoother for the initial firing........
Elkbane

 

[Steve Blair]

Some lots of Lapua brass have a little more case wall variation than I will tolerate. It is not a lot or a large percentage but is still worth the effort. I sort match cases to no more than .002" TIR. Those that are >.002-.003" I use for foulers/practice. Anything more than .003" TIR I do not use in competition. It is rare to find a Lapua lot with more than a few that exceed .003". Remington and Winchester cases have significant percentages that exceed .003". I just sorted 500 6mm Remington cases and only 55% met the .002" criteria. ~25% were over .003". However, the price is so low that I can discard half and still have a reasonable per case cost. If Lapua made 6mm Remington, I would use them. I sort Lapua brass in 6BR, 6.5-284 and .308.

 

[Homer]

G'Day Fella's,

Thank you ALL, for your very informative and frank replies!

Golfer2B2000, mate I know just how you feel!!!
Shynloco, in hindsight, I figure Lapua know what they are doing (re; Flash Hole diameter)!
fdshuster, I attempted to "Uniform" the Primer Pockets but gave up after 10 cases, as I wasn't removing any metal!

I expanded the case necks and then neck sized them, to a 0.001" interference fit on the bullets.
I'll fire form the cases then trim them to length. I'll then debur the case mouths and get serious about group shootin!

One more Dumb Question; Is it Best Practice to run this barrel in with Natural or Moly Coated bullets?

By the way, the thing I want to use this 6.5 for, is 500Meter Fly Shoot and 1000Yard BR, at the local ranges.

Thanks again fella's, I really do appreciate ALL your advice on this!

Doh!
Homer

 

[1066]

1) Do I need to internally chamfer/debur the primer flash holes of these Lapua cases?
and
2) What about drilling the primer flash holes them selves, to a consistent diameter?
and

All excellent advice above - One of the reasons Lapua cases perform so well is that, I think that the flash holes are drilled rather than punched giving a much more consistent ignition. I don't think I have ever found a bad Lapua flash hole but I always check and do a quick deburr inside.

Personally I would avoid the molly.

 

[Martin52]

1) Do I need to internally chamfer/debur the primer flash holes of these Lapua cases?
and
2) What about drilling the primer flash holes them selves, to a consistent diameter?
and
3) Do I need to uniform the primer pockets on these beautiful little Lapua cases
and
4) anything else I need to do, that I have completely forgotten about?

Regarding 1) Use eg K&M flash hole deburring tool but do not drill the hole (2)
regarding 3) I would recommend you do that for consistent depth.
Regarding 4) I would suggest:
Hand turn the case mouth in fine grade steel wool to remove the tiny burrs left from chamfering.

I also weigh my cases after all the prep work has been done batching these in 1 gr increments. Many shooters do not and think it's a waste of time, perhaps this is true, however much of this game is in the mind and I want to feel I could have done no more with my reloads when I am about to compete - otherwise I might tend to blame the ammo rather than the operator.

Martin

 

[amlevin]

I also weigh my cases after all the prep work has been done batching these in 1 gr increments. Many shooters do not and think it's a waste of time, perhaps this is true, however much of this game is in the mind and I want to feel I could have done no more with my reloads when I am about to compete - otherwise I might tend to blame the ammo rather than the operator.

Martin

It's all about removing "variables". Even this, equal that. Supposedly that will make every round perform exactly the same. Lately I've even seen shooters on cold days putting their ammo boxes on either heat pads (set on low temps of course) or those little "Toe Warmers" that generate their own heat. The theory being that if one heats the ammo on cold days it will perform the same as on warm days when their "heaters" aren't needed.

The largest variable and hardest one to control is the shooter. It's a proven fact that people can't even sign their name two times in a row and have it exactly the same. Same goes for shooting. Close each time but not exactly the same. (Rail Guns excepted)