I have a 375 Whelen AI in the works and am wondering what I'll need to form brass. I would like to use Win 06 brass rather than the Rem 35 Whelen brass if it possible to neck up that far. Also I'd like to neck over 375 and then back down to form the false shoulder for fireforming. I have 358, 375, and 416 tapered expanders--can I go all the way to 416 with 06 brass and then back down to 375? I hear of guys expanding to "400" and then back down but have been unable to locate a .405 tapered expander. Any help with this would be greatly appreciated!!

Just after I posted this question here in Wildcats, someone replied to a similar question I posted in Reloading a couple of weeks ago--I assumed that he was responding to this post and I replied:

"Ramrod, thanks for the link. Some quick calculations--
If the brass is the same thickness at the shoulder as at the mouth (I know it tends to be thicker at the shoulder), 06 brass whould have an inside diameter of around .4101 at the shoulder. A 416 expander (.414 nominal) would expand the shoulder about .01. I assume that running the straightened case into the 375 whelen ai die would resize this portion of the case as the false shoulder should be formed very near the original case shoulder, right??

Can anyone avise me as to how a case should be annealed when doing a fairly radical neck up? Would a slow cooling rather than the standard water quench make for softer brass--then re-anneal following the neck up in the standatd fasion to return the brass to a more standatd hardness? I'm just thinking out loud here.

I have heard that the Rem brass is thicker and I want to preserve case capacity for this round---the differecne may not be enough to matter though.

Thanks!"

Sorry for the double posts. I'd like to hear what those with experience in case forming have to say about this process...

Snowcat,
I just finished a 375 Whelen Imp 40 for a customer. I furnished a set of RCBS loading dies with the long tapered expander. In testing the rifle I made cases from new LC-54 military 06 cases in one pass. Since I chambered this the normal .004 short and used a PT&G headspace gage and a o6 GO gage as NO-GO I had a crush fit on the case. The forming loads from the "Handloader" article on the 375AI produced beautiful finished cases. Have Fun Jerry

Taking an 06 to 375 is not that big of a deal if you have a tapered expander. If the chamber is cut correctly you should have a crush fit on the 06 case I wouldn't worry about a false shoulder. I would stick the bullet into the lands if the necked up 06 isn't tight. I have taken 280Rem cases up to 416 for use in my own wildcat. My shoulder is moved forward and the case improved.

I have always found the norma 280 brass to give me the most capacity. But, you are talking small differences.

As to the annealing. My method is to hold the case head and stick the neck in a small torch flame. When it get Warm to hold I drop it in water.

Thanks for the great information. I called Redding and got a .416 tapered expander delivered yesterday. I took Win 06 brass to 358, annealed, and then went to 416 with no loss. Those redding expanders are fantastic (used a bit of wax in the necks to ease things up.) I am thinking of asking my smith to cut the chamber long, leaving a shorter neck like the Hawk/Scovill (I will crimp most bullets anyway) and necking the basically 06 basic brass to headspace and form. Any reason not to? Its not as if you were going to enjoy the option of also firing factore 375/06 loads in this rifle anyway. Why not maximize capacity? The only potential problem is that the case head may not be able to be resized completely but I don't expect significant expansion anyway. Just thinking out loud. I have Redding dies on the way from Grafs, maybe I'll smoke some cases and look at die contact....

The problem I see with cutting the chamber long with a standard AI reamer is that the reamer is tapered. If you run the reamer in far enough to move the shoulder forward like on the Hawk the head would be larger than normal.

Does the reamer continue to taper beyond the diameter of the case head? If so, you're right,of course...bad idea. The convenience of a simple 375 neck up operation is likely reason enough not to dink with chamber dimensions. Thanks!

I can't speak for all AI reamers. The ones I have had did. Even if the reamer squared off at the base if you move the shoulder forward you would be moving the base demension forward. So instead of having a taper case from shoulder to base you would have a taper and then an area that was flat with no taper. Since you are having this rifle built anyway and like you said you can't shoot factory 357-06 then if you want a larger 06 based case go with Hawk or the 380Howell.

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