Reamers

[chris.tyne]

Ok so we measure a .204 pill,say it measures .204 exactly to make things easy,so then we measure the neck thickness of the brass.The brass on my old gold box stuff is ....let's use round figures,its .015,the blue box is .0125,so using the first figure of 15 thou,double that for both sides of the neck is 30 thou.......still with me?.
Now add the 30 to our .204 and we have a total of .234,theoreticaly cause necking down will usually thicken the neck a bit so I will allow an other thou for that.
So our neck when measured with a projectile seated would measure .235 and we should have 1.5 to 2 thou clearance,reamers tend to cut slightly oversized ,maybe by a few tenths anyway.
If using the newer brass it would be more like 6 thou clearance,I would/will measure and SPEC my reamer to suit the newer blue box brass as that's what the majority would be using,and if I used the old brass then I would turn them to suit.

[trevort]

so the bit I missed was that you dont want to neck turn. Every case I have formed by necking down a bigger one has always shaved brass from only one side when skim turned which as caused me to hypothesize that necking down thickens the brass more on one side.

I will be turning the necks. But I will copy those other dimensions since I will be using redding dies too.

[JasonF]

What are you going to use for seating? I am guessing a Redding 22/6br type-s bushing neck sizer with an appropriate sized bushing and 22/6br body die will do the sizing work.

[trevort]

Jason, I would be surprised if Redding don't do a 20br set but the 22 br dies will work, I have a few bushings!

My Jab 20 pills are seated with a 223 seating die with the bottom of the sleeve trimmed off so the seating stem gets down far enough, seems to work!

[WARDY91]

Ptg's 20 br print has a .235 neck for the no turn chamber.

[Ol 55]

Glen nice rifle,I ain't into tacticool but I can appreciate a well built rifle,now you can do a no turn .20 BR,I don't have any .20 projectiles but maybe someone could neck a BR case down seat a projectile and measure the neck at the pressure ring.
I do know that my old Br brass gold box, of which I have 3 boxes of are around .0025 thicker in the neck wall than the newer blue box.

If no one has by the morning I will but I think I have no cases that haven't been neck turned, will check.
Ol 55

All my cases have been neck turned, chris do they only thicken by a thou or so?
Ol 55

[trevort]

Wardy, I hope you arent trying to be sensible and suggesting something as simple as asking the smith,

who might say something like "I order reamers from xxxx" and XXX might have remer print that measures just what it measures

[JasonF]

Jason, I would be surprised if Redding don't do a 20br set but the 22 br dies will work, I have a few bushings!

$260us for a type-s match neck set adds a fair bit to the cost of the project. Looks like the comp seater is $152us. Hoping my existing 6br bushing neck die will work with smaller bushing.

[trevort]

I can send you a bushing if you want to try a case or two

[WARDY91]

Sensible? No never haha. I'd much rather be sure with a dummy round just for peace of mind.

[chris.tyne]

All my cases have been neck turned, chris do they only thicken by a thou or so?Ol 55

It may vary two thou,thats why I will get couple of pieces of brass and neck them down,run them over an expand iron,size them again,seat a projectile and measure them before I spec anything.
I know one thing for certain and that is you will have a doughnut that homer couldnt eat and for me that will be a problem in as much it will near need to be turned of to chamber a case anyway,I suppose I will find out soon enough.
Wardy that sounds right and it would be for the newer brass as the neck in thinner,I dont mind turning case necks,wont say its my favorite past time but there is worse things to be doing.........................................I think ,or maybe not.
I will have to check but I am sure I specd the Beggs reamer with a .236 neck,their std turn fit neck is .228 by memory,I am going to make an inline seater die for the Beggs and use Hornady sizing dies.

Regards Chris.

[Mick]

A mate of mine may have happened to have bought every single reamer Shane Clancy owned, a couple of weeks ago. I can ask him if he has either the 20br or dasher reamer if you want?

[chris.tyne]

.............you have my attention,that fishing tackle box was likely the most expensive thing in the shop.

[trevort]

Hey Chris, this was my thread

[chris.tyne]

Its all yours