20x47 Lapua..

[desilva]

Hi All

Im awaiting my overdue custom 20x47 rifle and im having trouble with sizing my brass. I am getting a small bulge at the neck/shoulder junction and want to get rid of it but dont know how. Can anyone tell me what their sizing method is and perhaps i can see if im going wrong. Below is how i do it and pics to show the results.

Take std Lapua 6.5x47 brass and run it through the 6x47 FL die
Then run it through a 22x47 neck sizing die
Then run it through a .260 bushing
Then through a .246 bushing
Then through a .238 bushing
and finally through a .230 bushing
After this i neck turn to 14.25 thou which will give me 20 thou neck tension.
Bullets seat nice (berger 50 grn & 55 grn @ .2035" dia) but there is still a slight bulge at the said junction.




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Any help would be really appreciated as im losing too much hair now.

Many thnx in advance

[bucksnbears]

i don't dare look at those pics. yesterday a newbie came on here and posted pics and my computer got infested with some kind of virus.

[desilva]

The pics are safe i always scan anything before i post.

[Tim Anderson]

The pic.'s seem ok.

I think you are useing the wrong bushings or missing a size. I'll have to go look at mine and see what I have..

[desilva]

Many thnx Tim cant wait to see wots going wrong

[Tim Anderson]

I coat all the case necks with imperial sizeing wax and will touch up as I go.
I use a Redding FL bushing die used for the 6mmx47 lapua.
Bushings used ; .275, .260, .253, .245, .233, .231 being the finish bushing and is also used for reloading from then on..
Most 20x47 chamberings are cut so you don't have to turn the necks but still tite enough so you can true up the necks if you desire. As for the donut at base of neck this canbe removed by neck turning.
What I do is take a very lite cut just enough to true up the necks and then remove the donut at same time.
I will fireform this brass and then check to make sure neck is openning up far enough to release the bullet.You can check this by trying to drop a bullet through the case mouth after it has been fired or resizeing a case and seat a bullet and take measurement of the O.D.. I have noticed I still have a little bit of the donut still there so I will neck turn one more time, but don't make any adjustment to the cutter, leave on same setting that you used the first time and just cut once more..

I will also caution you on the 50 gr. and 55 gr. Berger, both bullets are semi vld. and can only be pushed so fast . With my rifle I fired 225 rounds through it and the throat got rough enough to cause the bullets to go puff. Not the gun or gunsmiths fault but the bullet manufacture fault. To soft or to thin of a jacket...
Both bullets seem to hold together if you keep the vel around 3800 fps. I have pushed the 50 gr. bullets to a little over 4000 fps but as the barrel wore or got rough then they started to puff so I backed off on the vel..
As a back-up you can go to the 40 gr. V-max and shoot them a little faster. Have'nt tested them enough to see how fast I can go yet... Good luck...

[desilva]

Hi Tim

Thanks very much for the info at least im not doing anything wrong as such. Your bushings are not too different from mine. I will try the extra neck turning to try and get rid of that bulge. What is your OAL? What powder are you using? (ive just got the first batch of IMR 8208 XBR in the UK) and what neck tension are you running?

Once again many thanks

[Tim Anderson]

Case trim length: 1.844

Powder: N-540, Ramshot Big-game, Hybrid 100, N-550 ( caution; sensative powder)

Neck dia. fired case .235
resized neck dia. .231

[desilva]

Thnx buddy all the best

[desilva]

Hi Tim

Can you tell me please what pistol powder you use and how much you use to fireform your cases?

Many thnx in advance

[Tim Anderson]

I use a 40 gr. V-max and 36.0 gr. of big-game which gives me a vel. of 3750 fps.....


The 20x47 Lapua holds about 1 gr. of wather less than a 22-250..

You can use the same loads from a manual for the 22-250 but keep in mind you have to start 1 gr. less than the starting load listed for the 22-250 and same bullet weight.. Use powders that are in the slow burning range from N-140 on down..... It helps if you have a Chronograph to check youre vel. and keep in mind the 55 gr. will max out somewhere around 3800 or a little more.. The 50 gr. should max out at 4150 or a hair more depend on how slow of a powder you use....

[desilva]

So you put a bullet down the barrel when fireforming brass? Isnt that going to accelerate barrel wear over time?

[Tim Anderson]

Use youre fireform loads for break in and hunting..