Question to RCBS and reply about neck expander dies

[Ford SD]

Question to RCBS and reply about neck expander dies

this is to let every one know who might be buying RCBS neck expander dies
what size you order is not what you will get
I am very happy with the neck expander I bough so many years ago it is a hair bigger than what is marked even after expanding thousands of cases

and Im posting this for other people who might be buying RCBS neck expanders

My next order from midsouth will be a 0.311 die so it will be app .310 dia and a .228 expander that i will polish down to a size i need for 223
and fyi midsouth is my go to place to buy stuff that will ship stuff across the border

there is no place near me that has casting stuff in stock, so everthing is special order




From: Wayne
Sent: Thursday, March 26, 2015 11:22 AM
To: rcbs tech
Subject: Problems with recent order from Midsouth shooter supply



Recent problems with my orders from Midsouth shooter supply.

I am writing to inform you that the RCBS parts I purchased from Midsouth shooter supply are not machined correctly.
Upon careful measuring parts are Undersize. Due to being in Canada it is very inconvenient to return parts to the USA and there is no guarantee that replacement parts if replaced will be the correct size. I ordered as many parts as i could that were in stock on two different orders and some of your product was still out of stock.

My Back ground casting and reloading from some time around 1980,
I have been using your RCBS neck expander die.309 dia, part # 39819, for may years and have been very happy with it.
It measures .3091-.3092 (mirror polish from usage) and have been using it to reload all my cast rifle 30 cal loads.

Recently I picked up some new molds and some new rifles that required a different neck expander die.
So I purchased a new neck expander plugs and was disappointed by what I received.

part # 39869 a .310 dia. --0.001 larger than my old die (so i thought when i ordered it)
When I went to reload some rifle cases with the new die. I checked new plug with my micrometer it only measures 0.3093-0.3095 plug is marked .310, so plug is UNDERSIZED, especial if you conciser that it has not been used and has not been polished to a mirror finish.( mic checked for zero) New plug is only 0.0001-0.0003 larger than my old well used plug, So a loss of hard earned Money.

So I measured the other plug I had purchased

part # 39803 .224 dia. measures .2232- .2236 in different locations and is not a super smooth finish UNDERSIZED (bullet i am using is .226 sized)

part # 39879 .358 dia. measures .3575- .3576 in different locations and is not a super smooth finish it is UNDERSIZED I am using it for 38/357 using a .359- .360 dia lead bullet.
(the expander plugs that come with some die sets are undersized for shooting cast lead.)

So of the 3 neck expander plug I bought 3 were machined undersize, I thought you should know

PS
Your Cast bullet manual number 1 is in need of a update (Hint)

there reply
-----------------------------

THE NECK EXPANDER PLUG WILL BE .001 THOUSAND UNDER YOUR BULLET DIAMETER FOR NECK TENSION. LOOKS LIKE ALL THESE NECK EXPANDER ARE IN SPEC.

BACKORDER ITEM TRHOUGH OUR DISCTRIBUTOR IS DEPENDING WHEN THEY THE ORDERS AND CARRY THE ITEMS. I WOULD CHECK THROUGH A FEW DISTRIBUTOR IF THEY GOT ANY IN STOCK.


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[EDG]

When Jay Postman was still alive I called him at RCBS and he pulled up engineering drawings of die components and gave the dimensions right off the drawing. I am sure if they have a new Jay Postman type expert he can tell you if they make exactly what you want. Turned parts are doing really well to be within a total tolerance range of .0015. If you expect parts that withing plus or minus .0002 they have to be ground. So far as I know the Lyman M plugs are the only ground plugs.
You might be better off making your own or buying .001 to .002 oversize and polishing it to size.

[Ford SD]

You might be better off making your own or buying .001 to .002 oversize and polishing it to size.

That's what I plan on doing

But I have worked in CNC Shops checking parts--
I was the go to guy when a part came off the CNC machine and the part needed to be checked
or there was a problem on the assembly line and parts would not go togeather

Im not a machinist but I have checked lots of machined parts to 4 decimal places

my 30 year old expander plug tolerance is what i expected with the new plugs

Rcbs sells a .308 -.309 -.310 and a .311 plug in the 30 cal size, and what was marked was what i expected (or close to) get

the new .310 plug should have been marked and sold as a .309 not as 310