What's the best way to specify dimensions for a custom chamber reamer? I've got a drawing of the maximum dimensions of the formed case I'd like to use, and I can certainly dimension that. Is that all the reamer maker will need? Will they add necessary size to the appropriate areas of the chamber? If not, are there 'standard' allowances to use - like add .003" to the diameter of the base of the chamber, and add .0005" or .001" to the neck area? Where do I specify other reamer dimensions, like throat length, etc?

I'm going ahead with the 416-375RUM x 2.5 (more catchy name pending...) concept I had some time ago, unless there is some EXCEPTIONALLY compelling reason that the 416 Taylor is a better fit for a M98 action. I've gone through that sort of argument hundreds of times in my head, but still can't get away from this creation. I've never ordered a custom reamer. Are there any pitfalls or other things to be aware of? I'd like to get it right the first time. thanks, maxman

Have you figured out a way to make a dummy case of your wildcat? if so make a couple and send them along with your drawings. The reamer maker will look at your drawing and measure your cases and then contact you with the information. If you can't make the cases send him a copy of the drawing and then arrange for a time to call and discuss the case and design after he has examined the drawing. The reamer maker will/should give you an idea of the feasability of your design and if there will be any potential problems.


www.duanesguns.com

I am not 100% sure I can answer your question, but I can tell you of my personal experiences.

My first experience was with a 300 ICL Tornado < !--color--> , I got the information for the round from PO Ackley's book, I am not going to go into my reason for chosing this round, here is a link to info on that if you want it [ 300 ICL Tornado ]

So as my wildcat already existed I was able to call a ream maker, which in this case was Clymer [ Clymer Tool ] They were very helpful in making the ream and the gages, but I did not have to provide the drawing or any of those things.

My next experience is more like what you are doing now, I designed a Pistol Round I am calling it 45/50 Kodiak < !--color--> I am re-chamber a 45 Winchester Magnum barrel in a LAR Grizzly Mark V Pistol to my new round which will be a 50AE Brass Case necked down to 45 caliber, the goal is to try to get 454 Casull or near that from an auto-loading pistol.

I designed my case using a program called QuickDESIGN, here is a link to it: Neco.

But this time I did not use Clymer as I had heard about another company that was cheaper and came highly rated: Pacific Tool

They have a page that you can use to fill out and submit for your Ream Drawing. They will also help you design the Ream (both rougher & finisher) and Gages. I ordered the 2 Reams & Go and No-Go Gages.

Thier pricing is about 1/2 what everyone else charges.

For the Dies, I will have Hornady make those once I have the barrel chambered and have fire-formed some brass, most of the die makers will make custom dies, but the prices vary quite a bit. They will all ask for 3 or so fired cases to take messurements from.

It is my understanding that you can make a Re-Sizing Die from the Rougher Die, but I do not know much about that.

I hope this all helps you some, and feel free to post any questions you come up with, and I will be happy to try and answer them. Please post the questions here though as others may benefit from our experience.

I wish you good luck on your project and I look forward to hearing how it goes, and ultimately how it shoots and works out!

Z < !--color--> e < !--color--> R < !--color--> 0 < !--color-->

SOUNDS LIKE A 375 DAKOTA TO ME.
LYLE

Actually, it's pretty close to a 416 Howell, except I'm starting with RUM brass rather than the 404 Jeff. It is intended to provide all the performance of the 416 Rem in a standard length action using a case with no belt. 400 grs @ 2400 is all I'm asking. No real hotrod. Something that will do the same thing as the 416 Taylor without having to run at peak pressure all the time. RUM brass is a lot cheaper than 404 brass - price difference in brass alone will cover the price of a custom reamer!!

Thanks for the tips. This sort of info really helps. maxman

Maxman, right on. Excellent project. If I may offer my 2 cents, the Howell could use some "improving," [no offense, DR!] Make the shoulder .535" and give it a .35" neck and it'll scream with the 350 grainers.

Sorry
I misunderstood, I thought it was going to be a .375 ca.
You might run into feeding and mag problems with that
fat case in a mauser. the 416 Taylor would be a snap.
I have a 375 Taylor. it goes thru the mag without
lengthing. Any bullet I use seated to 3.250 does not
infringe on powder space. It feeds like a champ.
Lyle

Here's the specs I came up with. Retaining the same body taper of the RUM and simply pushing the shoulder back gives me a shoulder diam of .529" A full one caliber neck length of .416", followed by a 30 deg shoulder angle and a body length of 2.014". Overall case length is 2.500"

I think that's about as improved as I want to make it. I don't have quickload, so I can't estimate the capacity of such an animal, but COAL should be within the magazine length for the Mauser with any 350-400 gr bullet I care to load. With the long neck, I should have plenty of neck tension, plus the bullet base should not intrude into the powder space. I like the 30 deg shoulder to help feeding, and I don't want to reduce body taper for the same reason. I suppose I could look at a shorter neck length. I think there was another post recently that dealt with .416 bullets: total length, distance from base to channelure, etc. I'll see if I can look up some more facts. I do like the way it looks with the longer neck, though.

And the plan is: rechamber a 416 Taylor barrel using this new reamer (so just a finish ream is necessary), open up the bolt face, and adjust the follower (as the first step). There will most likely be some rail work as well, but I think I'll try to work on feeding starting with the follower so that cartridges in the magazine are held at a better angle. It should be a fairly straightforward project and I anticipate good results. maxman

Just out of curiosity, would the neck and throat of the Taylor barrel fall into the right place for your finished round?
How about useing a 375 Dakota reamer, rent one?, use it to cut the body and the neck and throat are already there. This will cut your cost down to a reamer rental and new dies.

Look up Pacific Precisiong Grinding, for the life of me I can never find them on google, but they do have a website. You'll probably get a near consensus from gunsmiths that PPG makes the best reamers, and they also have a pretty good turnaround. Give them your specs, and they should have no problem making the right reamer for you. They'll probably provide some suggestions as well.

A couple comments, don't go over 30 degrees on the shoulder of a round you have to set back the shoulder when forming brass. I've dealt with a 40 degree shoulder on an ackley round, and a 45 degree on my 350 rigby, and very sharp shoulders are a bitch to set back, often resulting in case loss when you don't get the shoulder set back enough. 30 degrees is stated as the maximum angle that is easily formed.

I wouldn't shorten the neck or straighten the body. You'll have plenty of case capacity, and body taper does help feeding/extracion, and one caliber neck provides good tention, and is more friendly to cast bullets.

Just confirm that your shoulder isn't further back then on a 416 Taylor, so you don't have a problem cleaning up the chamber.

Here is a link for PPG http://pacifictoolandgauge.com/

They are 1st class in my book.. Have only had 1 reamer cut buy them but turn around time was exactly what they said and the reamer is excellent!!!!!!!!!!

Well, I've taken stock of all the typical reamers in .416 out there, and the closest winner is the 416 Rem, with a neck length of .419" So, there is a possibility of using the 416 Rem reamer run in to a specific stop depth to cut the neck and throat. Then use the 375 Dakota reamer with a 416 pilot to cut the body and shoulder. Does anyone have complete dimensions for the 375 Dakota handy? I can only find basic sizes for rim and shoulder diam, etc.

The neck of the Taylor is only .345" long, so cleaning up a completed chamber would require setting back the bbl a turn. If I were to buy a short-chambered barrel, these are supposed to be cut .050" short of full depth. And, .345" + .050" = .395", which leaves .021" hanging that will not be cleaned up (please check my math...). So, a new short-chambered bbl will still have to be set back 1 thread (.083") in order to give me a full cleanup of the chamber. Hmm...not as easy as I thought...

Unless, I specify a neck length of say, .390" on my cartridge. Then the 416 Rem and 375 Taylor reamer combo will completely clean up a short-chambered 416 Taylor bbl. Just as a sanity check, does anyone care to verify my numbers??? I don't think losing .025" or so of neck will amount to anything, and it would certainly simplify getting this completed with just a couple rented reamers.

I'm still working on what sort of dies I'll need to get the initial cases ready for firing to be sent out for custom dies. Basically, I just need to lop off the RUM case and neck it down to proper neck size, trim and fireform. Maybe a real simple necking bushing I can fabricate will be enough. Pondering on... maxman