This thread is a result of a conversation in the Big Bore Forum’s Ruger basic to 458 Accrel thread.
http://forums.accuratereloadin...131085302#9131085302

Here are the pertinent excerpts from that thread:

quote:

quote:

Originally posted by RIP: posted 24 August 2014 03:37
The cartridge on the far right below is a .458, then .423, .416, .395 and .375:

quote:

Originally posted by capoward: posted 24 August 2014 04:35
….
I have previously commented on the .458 caliber being the largest to "upsize" the .375/.416 Ruger case to - with a huge caveat - that being if the shoulder diameter is increased then it can be "upsized" to .475 caliber. At that point it would be much easier to use the Hornady .375 Ruger Basic Brass than "upsizing either the .375 or .416 Ruger formed brass.

But I will say, once one arrives at the .475 caliber without using a belt then you're better served to use either the RUM case or the 404 Jeffery case for the derivative cartridge to assure sufficient.

quote:

Originally posted by RIP: posted 24 August 2014 04:41
Jim,
Have you made a drawing of the .475 Ruger-Ward?
CAD it!
That would take almost no case taper on the Ruger basic case to make a .475/.375 Ruger with a tiny shoulder.
Hey you could end up headspacing on the case mouth or extractor like some people claim to do.

Originally posed by capoward: posted 24 August 2014 05:10

quote:

That would take almost no case taper on the Ruger basic case to make a .475/.375 Ruger with a tiny shoulder. Hey you could end up headspacing on the case mouth or extractor like some people claim to do.

Ron,

Yep way back in 2009.

Better yet, I already have a PT&G finish chamber reamer and C-H reloading dies for a .500 caliber 2.65" cartridge using the Ruger Basic brass. Yes it does headspace on the case mouth (2.650") or extractor like the 50 B&M (2.670"). It has very little case taper and has an actual 0.5225" 0.522" (Edit: found my actual measurement notes) case mouth diameter using the basic brass. The finish reamer and dies are labeled "50 MDM".

I designed 2.65" shortened RUM case, LOL... also named "50 MDM" earlier but after many back n forth discussions with Michael I settled upon using the 375 Ruger Basic brass.

While having the finish reamer and reloading dies manufactured I procured a Wiebe 5MX bottom metal, 5-down drop box for the .375/.416 Ruger cartridge, to use for the 50 MDM in one of my FN commercial M98 Mauser actions. You waylaid that with the 12.7x68 Magnum (338 Lapua Magnum) based wildcat as I just couldn't resist going bigger..

How 'bout a photo you ask?

Here ya go. 550gr SST/Lehigh Copper FN Solid seated to fit within a standard length magazine...

quote:

Originally posted by RIP: posted 24 August 2014 06:07


.475 Ruger .500 Ruger

quote:

Originally posted by capoward: posted 24 August 2014 07:28

quote:

Originally posted by RIP:


.475 Ruger .500 Ruger

Yep, I designed the .500 caliber 1st and then the .475 caliber while .500 caliber finish reamer and dies were being manufactured.

The freebore is a bit long at 0.490", but it was designed before the BBW#13 nose style and meplat was designed and finalized. So the freebore was set so that the cartridge could be chambered in standard magazine with the upper band out, or in a 3.6" magazine with the two upper bands out using either the 550gr or the 510gr FN Solids to maximize powder capacity and performance.

Chamber is set with a straight taper from bolt face to freebore, 90% chamber mouth, while the reloading dies are tapered to 2.300" length and cylindrical from there to freebore commencing.

Kinda funny, based on the QD drawings and computations the .375 Ruger Basic based 50 MDM cartridge has perhaps a couple grains greater powder capacity than the RUM based 500 B&M cartridge.

Kinda funny also, I had two finish reamers manufactured, one with 1º30' throat angle and one with 0º30' throat angle. Probably ought to have the second reamer re-cut for use with the CEB, GSC, and NF Solids and perhaps tighten up the chamber diameter at the chamber/freebore junction; only need to assure the gauges set works with the modified reamer...

For the .475 caliber using Ruger Basic, have drawing only which very likely needs to be updated from what we learned with the 500 AR Nyati - no need for a lot of freebore to accommodate all currently manufactured .475 caliber bullets. Guess on a also need to settle on an exact case length; match the commercial .375/.416 Ruger or go with the longer 2.65" case length. Guess I'll have to check to see if I have an appropriate die sleeve for the Ruger's neck and a .475 caliber bullet. Will have to wait until Monday to dig everything out 'cause we're busy tomorrow...

quote:

Originally posted by RIP: posted 24 August 2014 09:33
Jim,

Hope you can post some of those immaculate CAD drawings of a Rugercat or two, cartridge and reamer.
Should be very enlightening for us masses.

quote:

Originally posted by capoward: posted 24 August 2014 10:03

quote:

Originally posted by RIP:
Jim,

Hope you can post some of those immaculate CAD drawings of a Rugercat or two, cartridge and reamer.
Should be very enlightening for us masses.

Well, you have the .500 caliber posted above - it's actually the only one created though I reckon I could crank out another one or two with current CEB bullets. But it'll be Monday before that happens...

The .475 depends upon whether I have the correct die insert 'cause I've nothing in .475 caliber.

I can do a .475 Ruger chamber print and electronic dummy cartridge though; do you want the .375/.416 Ruger case length or 2.65" to match the .500?

quote:

Originally posted by capoward: posted 24 August 2014 11:03
Ok Ron. I've copied the pertinent posts from this thread. Monday I'll dig my dies, reamers, and 375 Ruger Basic brass out of my storage boxes and see what I can put together for you - including photographs.

Cartridge and reamer drawings will be updated in QD to reflect our gathered knowledge since the summer of 2009; I'll post those as well.

quote:

Originally posted by capoward: posted 24 August 2014 11:03
Ok Ron. I've copied the pertinent posts from this thread. Monday I'll dig my dies, reamers, and 375 Ruger Basic brass out of my storage boxes and see what I can put together for you - including photographs.

Cartridge and reamer drawings will be updated in QD to reflect our gathered knowledge since the summer of 2009; I'll post those as well.

quote:

Originally posted by RIP: posted 24 August 2014 22:52
Jim,

Don't want you to go to any trouble with creating dummies, just drawings.

The .458 Ruger dummy I made has a mid-neck diameter of .488".
If the Standard shoulder of the cartridge for .375 Ruger is .515" (correct me if I am wrong off the top of my head) then the shoulder minus neck-one is .515 - .488 = .027".

That is better than a 400 Whelen.
Even with my improved 400 Whelen-Berry, that difference is only 0.021" for cartridge brass maximum spec, apples to apples.
One might have to specify a brass maximum for the .458 Ruger neck-one of about .492" for apples to apples, tolerances.
That is .515 - .492 = .023" which is still better than the 400 Whelen-Berry by .002".

Hey, maybe just running a .375 Ruger reamer into a .458 WinMag chamber with a .458 pilot would work.

Only thing is that the .458 WinMag throat is a long and sloppy-wide funnel.
It is over an inch long before the leade-only throat gets down to bore diameter.

It would be better to start with a virgin .458 barrel and a .458-piloted .375 Ruger reamer, then use a .458 Lott reamer to make the neck and throat.
Voila.

I would be very interested in how your max brass specs compare to your minimum chamber specs for headspacing a .500 Ruger.
.475 Ruger too.
.458 Ruger three???
I am a real beggar, eh?

quote:

Originally posted by RIP:
Jim,

Don't want you to go to any trouble with creating dummies, just drawings.

The .458 Ruger dummy I made has a mid-neck diameter of .488".
If the Standard shoulder of the cartridge for .375 Ruger is .515" (correct me if I am wrong off the top of my head) then the shoulder minus neck-one is .515 - .488 = .027".

That is better than a 400 Whelen.
Even with my improved 400 Whelen-Berry, that difference is only 0.021" for cartridge brass maximum spec, apples to apples.
One might have to specify a brass maximum for the .458 Ruger neck-one of about .492" for apples to apples, tolerances.
That is .515 - .492 = .023" which is still better than the 400 Whelen-Berry by .002".

Hey, maybe just running a .375 Ruger reamer into a .458 WinMag chamber with a .458 pilot would work.

Only thing is that the .458 WinMag throat is a long and sloppy-wide funnel.
It is over an inch long before the leade-only throat gets down to bore diameter.

It would be better to start with a virgin .458 barrel and a .458-piloted .375 Ruger reamer, then use a .458 Lott reamer to make the neck and throat.
Voila.

I would be very interested in how your max brass specs compare to your minimum chamber specs for headspacing a .500 Ruger.
.475 Ruger too.
.458 Ruger three???
I am a real beggar, eh?

Ron,

I don’t know that I’d get quite as “wrapped up” about the need for 0.020”, or 0.022”, minimum shoulder for your cartridge.

This is partially the rational I used when I drafted the .500 Ruger 2.65” cartridge/chamber specification back in August 2009.
I looked at headspacing off belts – specifically the 470 Capstick - - -
Why? Because it has to headspace off the belt due its straight body and as it turned out it’s odd chamber chamfer angle; I figured it’d be a good place to start…
The following data is drawn from the SAAMI Cartridge and Chamber Specifications…
Cartridge Specifications:
Belt Diameter: 0.532” -0.005” – Average = 0.5295”
Body Diameter (Belt/Body Junction: 0.5126” -0.008” – Average = 0.5046”
Bolt Face through Belt Length: 0.220” -0.008” – Average = 0.216”
Mouth Diameter: 0.499” -0.008” – Average = 0.495”
Cartridge Length: 2.850”
Chamber Specifications:
Belt Diameter: 0.534” +0.012” – Average = 0.540”
Body Diameter (Belt/Body Junction: 0.5146” +0.002” – Average = 0.5156”
Bolt Face through Belt Length: 0.220” (Min) to 0.227” (Max) – Average = 0.2235”
Mouth/Chamber Intersection: 0.501” +0.002” – Average = 0.502”
Chamfer Angle: 67º22’
Chamber Length: 2.860” +0.008” – Average = 2.864”
So here we end up with…
Cartridge (Max) to Chamber (Min) Difference:
Belt Diameter: -0.002”
Body Diameter (Belt/Body Junction: -0.002”
Bolt Face through Belt Length: -0.0075”
Mouth Diameter: -0.002”
Cartridge Length: -0.010”
and
Cartridge (Avg) to Chamber (Avg) Difference:
Belt Diameter: -0.0105”
Body Diameter (Belt/Body Junction: -0.011”
Rim through Belt Length: -0.0075”
Mouth Diameter: -0.007”
Cartridge Length: -0.014”
and
Cartridge (Min) to Chamber (Max) Difference:
Belt Diameter: -0.019”
Body Diameter (Belt/Body Junction: -0.012”
Rim through Belt Length: -0.015”
Mouth Diameter: -0.012”
Cartridge Length: -0.018”

Anyway what all this stuff relates to is that the cartridge belt diameter at the chamber belt/body intersection provides the following headspace:
Headspace:
Max Cartridge Spec/Min Chamber Spec = 0.0194” total or 0.0097” per side
Avg Cartridge Spec/Avg Chamber Spec = 0.0139” total or 0.00695” per side
Min Cartridge Spec/Max Chamber Spec = 0.0104” total or 0.0052” per side

So based upon the above, a 0.017” Headspace, or 0.0085” per side ought to be good… Which is why I came up with the following (just remember this is the second finish reamer print, the first chamber finish reamer had a 0º30’ throat angle).


The .500 Ruger-2.65” cartridge:
.375 Ruger rim and body (at head) specification.
Cartridge Length: 2.65”
N1/N2 Actuals: 0.522”

Comments Added:
Originally the finish reamer print had a straighter body with a shoulder, 0.529” diameter at 2.300”, but it was impossible to keep when sharpening the reamer cutting edge. The unfired dummy cases created using the 500 MDM LN (Long Neck) dies created a 0.5265” shoulder at approximately 2.300” on the .375 Ruger Basic Brass – yep a very small shoulder but also very cute! Anyway the original assumption was the combination of the CRF extractor and the almost straight case with the dinky shoulder would secure the case sufficiently to not require using the case mouth as secondary to the primary CRF extractor (the proven concept with the 50 B&M cartridges.

And, by using a +0.020” chamber length to the cartridge length, a 45º chamfer angle, plus a 0.490” lead (freebore) gave sufficient overall freebore to allow seating the 550gr and 510gr .500 SST/Lehigh Copper FN Solid bullets (two wide upper bands and a very wide base band) with two upper bands exposed when used in 3.6” magazines – at least that was the rational for the 0.490” lead (or freebore).

Unfortunately when redrawing the chamber specifications without the shoulder and changing the chamber angle from 45º to 90º two things were forgotten:
1) change the 0.005” chamber to cartridge clearance specification at the case mouth to a tighter 0.003” clearance specification.
2) change the lead (freebore) from the 0.490” specification to a tighter 0.350” (50 B&M specification) specification.
I’ll so both the corrected (updated) chamber specifications with the actual dummy cartridge specifications tomorrow.

I’ll post the revised chamber drawing with relating cartridge drawing in a bit…

Great!
Very interesting!
Wildcatting is its own reward.
Highjack off on the other thread.
Got your own thread now to dispay your brilliance.
I am following you, not baffled yet ...

Edit added to the 2nd post... In blue at bottom.

Jim,

Got it. Thanks.

Please don't get loose with the terminology.
Parallel-sided free-bore is not leade, and especially not "lead."

I am sure you know this but please allow me to clarify in case anyone might happen to read this besides you and I, to prevent confusion.

The leade is the angle of taper from P-S free-bore diameter down to bore diameter,
or the angle of taper from end of chamber mouth chamfer diameter to the bore diameter in a leade-only throat.

The throat's overall effective free-bore is a function of the summation of effects of

case maximum length versus chamber minimum length,
+
chamfer from neck-2 of the chamber to start of P-S free-bore diameter (or start of the leade in a leade-only throat),
+
length of P-S free-bore,
and finally,
+
the leade
+
the bullet nose shape/ogive figures into how much jump the bullet has to engagement.

Whew!


You know that!

"Leade": Get the "lead" out.

Sorry, couldn't resist.

Ron,

I’m not arguing over terminologies – But please re-look at the reamer print.

I did not generate it from my QD program, or any other program. It is a standard PT&G reamer print annotated with the terminology that they use with dimensional data annotated by Dave Kiff of PT&G relating to my chamber finish reamer. It was emailed to me by PT&G in a pdf format at my request. All I did was use pdf program to generate a jpg copy for inclusion in the thread.

Succinctly, it’s their labels, not mine… PT&G labeled “LEAD” as identification of the “Parallel-Sided Freebore” section and “THROAT” as the angled section from the “LEAD/PS-Freebore” to the “Bore” dimension.

I simply utilized the labeled terminologies for clarity of anyone reading my comments compared to the PT&G reamer print.

And yes a number of us agreed some time back that:
“Effective Freebore” = (Chamber Length – Trimmed Case Length) + Chamfer Length/Height + PS-Freebore + (the Length of the Leade from the PS-Freebore Diameter to the Barrel’s Groove Diameter)

That said, we must acknowledge that obviously at least one company in the reamer manufacturing business utilizes different terminologies than we’ve settled upon…

Jim,

Confusing usage of terms by Dave Kiff or
any reamer maker does not make it right.
Dave Manson calls them properly.
What are we, barbarians?
Leade is proper Olde English terminology.
It is the end of the throat, leading from free-bore into the full-bearing rifling.
Let us not humor the sloppy.

Ron,

Not sure that Dave Kiff initiated the terminology; only thing that can be said is that it's PT&G labeled terminology.

But I'll certainly make an effort to use the proper words...

quote:

Don't want you to go to any trouble with creating dummies, just drawings.

The .458 Ruger dummy I made has a mid-neck diameter of .488".
If the Standard shoulder of the cartridge for .375 Ruger is .515" (correct me if I am wrong off the top of my head) then the shoulder minus neck-one is .515 - .488 = .027".

Hey Ron,

Finally had a chance to work on your .458 and .475 caliber Rugers using QuickDESIGN and ran into the first interesting issue and it relates to your .458 Ruger dummy case with its mid-neck .488” diameter. Interesting issue arose in that QD indicates an N1/N2 of .4865”/.4855” respectively…

Still looking for where I squirreled away my case forming bushing die with multiple size bushings. Sure miss my old storage cabinet…

Jim,

Use N1/N2 of .4865"/.4855".
That becomes N1/N2 = .487"/.486" when you round up to nearest .001" which is customary.

I was just doing a quick measurement off of one crudely imperfect dummy, no check for concentricity.

Reamer N1/N2 minimum then becomes .491"/.490"
with the usual +.004" tolerance for chamber minimum.

Close enough for preliminaries.

Ron,

Yes pretty close.

If I recollect correctly your 500 Bateleur neck dimensions using the Captech/Jamison basic brass were about 0.004" less at N1/N2 than your 338 LM brass fireformed for your 12.7x68 LM - adjusted for the difference in caliber. Just can't find my notes for the specifics.

I want to find my case forming bushing die set so that I can determine whether the basic brass gives the same or slightly thinner neck wall thickness rather than to just rely on the QL algorithm.

Upsizing the .416 Ruger to a .458 Ruger is fine but I figure using the basic brass for a .475 Ruger would be better; perhaps even going down to .458 Ruger. Unfortunately I only have .375 Ruger formed brass and .375 Ruger Basic brass, no .416 Ruger formed brass except for a few factory loaded ones.

Hum... Just noodling here...
Perhaps I'll expand a few of the .375 Ruger formed brass up to .423 caliber and crunch a few of the .375 Ruger Basic brass down to .423 caliber and see how the N1/N2 data matches between the two. That'd be +0.048" and -0.77", definitely ought to show some difference...

Anyway back to the reason for this thread...
Preliminarily QD gives the .458 Ruger a 108.5grs water overflow capacity and the .475 Ruger a 111.7grs water overflow capacity - both at 3.40" COAL.