Reloading for the 1873 Dutch Beaumont rifle (Black Powder Cartridge)

by Frank Ambruso @, Saturday, January 18, 2014, 03:56 (2400 days ago) @ Frank Ambruso

Case expansion
After shooting the Beaumont Saturday I measures the cartridge cases fired with the anemic load of 22.5 grains of AA57544 behind 405/435 grain cast bullets

The neck measures .488" at the case mouth and .500" dia. .375" down the neck indicating a tapered chamber neck condition not uncommon in these older guns to help facilitate extraction with dirty BP ammo.

Case body has also expanded .005" med length requiring a sizing die polish to "Blend in" the die diameter closer to chamber dimension.

Cast up the Lee two cavity .457" dia. 340 grain bullet (457-340) with 25-1 lead/tin, actually cast .460" dia. 349 grains and I must say this is one of their best molds I have used with consistent quality (visual appearance/weight/release from mold). Bullet base protrudes .341" into the ..344" neck before touching lands so it appears this will be the best solution for solving excessive base protrusion into the powder area.

I also upped the charge about 2 grains to 24.3/4 grains of AA5744 and added 1/2" of polystyrene ("Popcorn") packing/filler under the bullet

On the Beaumont, I finished up forming the balance of the 47 cases (lost three in forming) this time with .035" wall brass tubing inserts vs. first 30 with .030" wall tubing inserts so will be ready for the 200-500 meter military rifle silhouette match this coming week.

The annealed inserts are swelling/forming slightly to inside of case walls under the 22.3 grain AA5744 /poly fill loads evenly around internal circumference of case, only one slightly loose one that did not fireform to case.

Recently read that someone was using up to 25.5 grains of AA5744 with unsleeved cases and 400 grain bullets, I also noted that my load was mapping a little on the light side to the sight settings( +100-150 meters) to the 200 yard target distance. Im thinking of upping the 22.3 gr. charge to 22.5 gr. with the 386 gr. spire point and watch pressure, primer, case/insert expansion signs changes with this older action.

2 MOA seems to be about the best to expect from this rifle based upon small sampling of rifles/shooters on the web so ill try to meet and maybe exceed that for the match hopefully centered on the targets, wind drift values/mapping should be the real challenge not having shot my 40-65/45-70 sharps or highwalls in a couple of years beyond 200 yards.

Complete thread:

 RSS Feed of thread

powered by my little forum