Yes, Worth a try. - I do enjoy experimenting. 
I spoke with a representative at Pro Plastics 
who said I should be able to see it well enough and as uscra112 suggested, and it works for him.

hepburnman wrote on Feb 16^th, 2023 at 10:59am:

westerner wrote on Feb 16^th, 2023 at 2:39pm:


Once the O.P. establishes a dimension for case length, he can make a gage.  Where he's at right now is trying to determine what that dimension should be, in the absence of any published data.

Westerner,

I have several chamber length gauges made by Wilson for various cartridges. And for those they are helpful if the chamber is a SAMMI spec.

But as uscra112 aptly pointed out my application is for a non standard chamber.

As someone else discussed I could do a chamber cast, then check each case with calibers, but that would not provide the visual (satisfaction) I'm looking to achieve..!  

And as SSDave pointed out, as long as I drill the bore  exactly at my barrels diameter I can play with seating depth.

When I first provided Dave Kiff at Pacific Tool and gauge the drawing for my chamber, it was based on Dan Theodore's tight neck (min tolerance) design concepts. 

I then designed a bullet (.350)X(.357)(NASA) profile to match my chamber where the front driving band matched the dimensions of my freebore and the first 1/2 of my leade, both in diameter and angle to match the leade. 

In front of the forward most driving band, in the nose riding section there is a very slight centering band which is intended to give the bullet the very best start on it's path down the barrel.   

I had Gail at CPA use the custom reamer and Steve Brooks cut the mould to my 345gr. design.

Naturally this little experiment is in search of the holy grail. 

For those of you who had not had the pleasure of reading about Dan Theodore's design and shooting experiments and successes over the years you missed out.
Sadly I hear Dan passed away about 7 years ago?

I always admired his attention to detail about all things BPCR and numerous other subjects, as I have since read about his journey it appears he was also accomplished in many other endeavors as well. 

I was fortunate to have been tutored as far back as 2002 with input from Dan and Dr. Richard f. Gunn., noted bullet designer.
Dr. Richard analyzed my design for me and provided a interesting synopsis of it's ballistic coefficient, bottom line was that he thought it only had a BC of .4 or to put it bluntly, not that great (my words)

So if anyone is interested once I return from the current road trip I am on, I can post pictures of the bullet, the chamber design and Dr. Gunn's critique of the design with his rationale. 

bob

[quote author=3E2C3A3D2C3B272C3B490 link=1676147394/16#16 date=1676576397]Is a case length gauge an advantage over a set of calipers? 

When I was a kid my dad had hardened case gauges we used to trim cases to length with.  I've been reading this thread but finally had to ask.

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Link to Dr. Gunn's work

No lathe, but when I get home I'm going to get a bolt with a shank
that will fit in the top of the chamber and with my drill press file the threads down to the case mouth suspected diameter to test case length. 

uscra112 wrote on Feb 16^th, 2023 at 11:04pm:

RJ-35-40 wrote on Feb 16^th, 2023 at 11:30pm:


Use a long enough bolt, and you can run a nut onto it flush with the breech face of the barrel.  Measure from face of nut to the head of the bolt, and there's your case length.