Discussion in '6BR, 6BR Improved & Wildcats' started by dave7mm, Dec 3, 2019.
Sure are pretty.
Long-Norma neck, short - Lapua neck?
I hope you post a couple things after you finish drooling all over the boxes! How consistently do the necks measure prior to turning and how well does the brass weight sort? Those two things often say a lot about the overall quality of a particular lot of brass.
Because you asked.
Small Rifle Primer
.080 diameter flash hole.
Weighed on my FX-120.
Out of the first box I opened.
5. 132.94 low
19. 133.96 high
The low was 132.94
The high was 133.96
The Average for 50 was 133.3912.
You now have to sell me something before the next two day at Ridgway.
The things I do for you....
Hero shot for you.
My pin mics are shot.
Give me a few days and ill get back to you on the necks.
Dave,you need to take your 6 Dasher to the GBA nationals with us next year and kick his arse!
I think I remember someone telling you they'd likely sort within about a grain. as their larger brass also does. Sure are good people to deal with too.
Someone did tell me that....
Spent some time measuring the brass.
The same 50 cases I weighed.
For over all length.
The longest was 1.541.
The shortest was 1.5385.
The average was 1.5395.
There is a very slight burr on the inside and outside of the neck.
They dont look like they were trimmed but there is a burr.
I deburred 5 cases and came up with....
The outside neck diameter is .2674 for a 5 piece average, checked with outside 0-1 mics.
The inside neck diameter is... .241 goes and 242 starts but wont go all the way in.
i used minus gage pins.That mean the pins are .0002 under the nominal number.
The .241 diameter pin went in all 100 cases. NO dents or dings on these case mouths. NONE..
For checking neck wall thickness.
I did not have tubing mics.
I have what are called pin and anvil mics.
i came up with .013 to .0135 neck wall variation ( worst case ) out at the case mouth.
This increased to .014 and .0145 as I got closer to the neck shoulder junction.
I set up a Brown & Sharpe vee block. Glued a block as a stop on the vee block end, and clamped the whole mess down on a surface plate.
Used a surface gage and a Interrapid .0001 indicator and checked the run out on the flash holes.
So im checking the concentricity of the flash hole diameter against the outside body of the case....
Simple set up, you just put the case in the vee block and slide the case head up against the stop.
Spin the case and read the indicator.
I was getting .004 to .0045 total indicator run out and I checked 20 cases.
This means that the flash holes are about .002 out of center to the case body.
I could have reset the indicator point and checked the primer pocket but I didnt think of it..
I then got a .080 minus gage pin and checked the flash hole diameters.
A .080 - pin has to be pushed in and then pulled out. The diameters are a fit to the minus pin.
I checked a pile of them and the flash hole diameters are all the same to .0001. Amazing close
I always have Randy make me a stub gage made with the chambering reamer.
We take the 1 inch off the end of the barrel and use it for finding the lands for bullet seating and checking headspace.
He uses a go headspace gage and writes the number on the gage.
I took a couple of fired Lapua cases and checked them against the new Alpha cases.
The Gage says 2.266.
Fired Lapua cases say 2.266 2.267.
Unfired Alpha cases measure 2.265 2.266.
Took a bunch of Alpha cases and put them in the gun.
Bolt handle went down on all of them...no problem..
Must have been a slow night in the shop at work last night huh buddy ? Lol. Good work
OP.,,,,sooo,,,the flash holes are .080" !!!!...what is the diameter at the .200 line,,,???,,,that will tell us if they are original Reminton specs (which we dont want ) or modern Lapua specs,,,,thank YOU,,,Roger
i had long runs....
Flash holes again..
I pulled out a minus .081 pin while I was messing around on my slow night, and tried it.
The .081 pin didnt fit in any of the 100 cases i tried it in.
I guess a person could call them and ask them ...Alpha... how there putting the flash holes in.. ie drilling ...punching...
I cant really tell by looking.
As close as they are ... it matters not...
Ill be checking head diameters tonight for you sir.
My unfired Alpha 6 Dasher lot appears to measure .4684 at the .200 line and is very much the same throughout the brass. I’m more than pleased right now. And yes it does need to be deburred and chamfered before loading.
Im getting .4682 for the most part.
@dave7mm the weights and measures you come up with mirror my own. Alpha claims as follows:
Loaded Diameter .269"
Dia. Tolerance +/- .0005
Flash Hole .08"/2.03mm
A friend who shoots PRS had some early prototype brass. In more than one ten-shot string on the chronograph his SD was in the 2-4 FPS range. I saw him shoot a 1.35" five-shot at 500 yards off a bipod with his PRS rifle in Dasher. I have no doubt the the .08 flash hole is not a deal killer on this brass. The proof will be in shooting. I want to see how well it holds up compared to what I believe is near indestructible Lapua brass.
When you guys get done measuring and start shooting let me know how it shoots fire forming.
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