6x50 R Bellm

The following data was developed by Blaine Eddy, Clearfield, UT about 10 years ago.  The cartridge was promoted so long as brass was available, but when it became quite hard to obtain, the cartridge and this data for it were filed away.  Huntington's, www.huntingtons.com is now importing high quality Hirtenberger brass and offers it at $39 per hundred, which while not in the $20 per hundred bracket for more common brass offers pretty spectacular performance in Contenders for under double the price.  The RWS brass formerly used was over $1 per empty unprimed case, so the Hirtenberger brass is much more attractive.

The data was taken from two custom 1-10" twist barrels I made, a 161/2" and a 20."  Data from both is listed, but not all loads were fired in both barrels.  I view this cartridge as more suited for carbine lengths, but it would make an excellent 14 to 15" handgun barrel also.

Best bullet weights for larger game like deer and antelope are probably 80 to 90 gr. maximum.  Some 100 gr. loads are shown, but caution should be exercised to be sure these slower bullets will expand reliably.  For general use, 75 to 80 gr. bullets should be ideal.  Remember that 6mm bullets are generally  designed for rifles like .243 Win. and faster.  At somewhat reduced velocities, some bullets may not expand well.  For this reason and the fact that within normal hunting ranges the lighter bullets will deliver a flatter trajectory and higher energy, it is best to step down in bullet weight.  Roughly speaking, if you would normally use an 80 gr. bullet in a .243 Win., step down to a 70 or 75 gr. in the 6x50 R Bellm unless you expect to be taking shots on shoulders or angling shots.  For heart/lung shots, ie., low behind the shoulder, even the 55 gr. Sierra Blitz does a fantastic job on deer.  However, I have seen 100 gr. bullets from a .243 Win. blow up on the shoulder of a small spike buck and run like he wasn't even hit.  So, with the 6mm, pick your bullet well and place your shot.

For varmint use, do not overlook the newer 55 gr. Sierra Blitz and Hornady V-Max bullets.  If varmints are your main interest, I suggest a 1-12" or 1-13" twist.  In my .225 Win based 6mm, the 1-12" twist is shooting about 200 fps. faster than the identical barrels in 1-10" twist.  No data is available for bullets lighter than 65 gr., but in a carbine length barrel, it should be quite possible to push 55 gr. bullets to over 3600 fps with a 1-12 or 1-13" twist.


6x50 R Bellm Load Data

Barrels used:   Bellm Custom 16 1/2" and 20"

Twist:   1-10" in both barrels.

Brass:  RWS 5.6x50 R fireformed in the Bellm "maximized" chamber

Primer:  Federal 205

All loads should be reduced at least 10% below the maximum  loads shown and worked up carefully, especially where only the max loads are listed.

Due to variations in individual barrels and procedures used by individual reloaders, neither Blaine Eddy nor I assume any liability for the results obtained from the use of this data.  Top loads shown are absolute maximum for the barrel in which they were tested, but were safe.  

65 gr. Snow custom bullet

Powder Charge Velocity in fps, 16 1/2" Velocity in fps, 20"

IMR 4895










3204 Max












3408 Max









3214 Max












3208 Max


IMR 3031






3085 Max