35 Whelen Chamber vs Die Dimensions

[Double Dropper]

Custom 35 Whelen Barrel on a Remington 700 action, working up loads with CFE 223 and noticed the primers were very flat on starting charges. I played with the calipers a bit and noticed the following dimensions, new brass sized case neck size is .377, with a loaded 225 grain Sierra .379, fired case was .388 at the neck. Dies are RCBS. I backed off the die a bit only sizing as minimal as possible but notice a bit of neck "bulge" below the sized portion. It looks odd, however, where there was high pressure signs and primer flattening, it is now gone and they look normal (average pressure) not a max load. I get it, do not oversize brass, and headspace on the shoulder, but those neck dimensions seem large??? Thoughts or just tight dies?? 1:12 gain twist and shoots very well with a top load of Varget with multiple bullets. (out of Varget in Canada) Sammy chamber dimensions attached and Using factory Remington 35 Whelen brass.

 

[Edd]

Is that new 35 Whelen brass or something necked up? .379" with a seated bullet seems a little small to me.

 

[Double Dropper]

New brass, factory Remington 35 Whelen brass.

 

[Will Henry]

The 35 whelen SAAMI chamber dimensions are a little on the generous side. Indeed, 35 whelen chambers have always been a little large in the neck. The neck is based on a nominal neck thickness of .013" with .003 clearance. Generally speaking, one never sees a neck thickness over .011" on 35 Whelen brass or on necked up 30/06 brass. The die dimensions reflect this fact so there is likely to be a significant bulge.
The very flat primers on the first loading are an indicator of head clearance between the brass and bolt face. Not unusual with new factory brass; especially in the Whelen. A chamber neck of .382 would look a little nicer but would not function any better. WH

 

[Double Dropper]

I discussed this with a gunsmith as well, I have ordered a neck sizing die. this should leave the shoulder alone, allow for the slightest tension on the shoulder when chambering new loads, (very slight)

 

[Edd]

New brass, factory Remington 35 Whelen brass.

When I decided to build a 35 Whelen, I bought 300 pieces of Norma brass. The neck thickness of the brass averages .012”. That should make my loaded ammo measure .382”. I ordered my reamer with a tapered neck, .386” in the front and .387” in the rear.

 

[Double Dropper]

Edd, fantastic idea...but too late for me. Norma brass? 30-06 resized?

 

[Edd]

Norma brass? 30-06 resized?

No, it's Norma 35 Whelen headstamp.

 

[Double Dropper]

Damn thats is a good find.