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A Leupold VX-3 2.5-8x36mm scope was mounted on the Guide Gun. It is more than enough scope for this combination and not because the cartridge has limited range. I spent most of my early years hunting with fixed magnification 4x scopes, when 6x was considered a long shooting distance scope for antelope hunting. So 8x isn’t exactly a handicap and the 36mm objective is in keeping with the rifle’s compact design.

The handloading process for the 300 RCM is straight forward. Characteristically, it is reloaded like the338 RCM and other short magnum cartridges; not enough capacity for substantially slow powder, but not so small to work with relatively fast powders. Re17 and H414 seemed the best, particularly with the short barrel Ruger Guide Gun. I wanted to try for flat base bullets of the shortest possible length to preserve case capacity, however, I like the 165 grain Sierra Game King and the 200 grain Nosler AccuBond to include them in the mix. In fact, when I was near the end I added the Barnes TTSX BT because it is an effective light bullet that works well on thin skinned larger game.

Hornady dies were used, a full length sizer, with a #5 shell holder. I did check COL with all indicated bullets and used those dimensions for longer bullets and cannelure position or adequate neck engagement determined the rest. Hornady does make a modified case for use with their OAL gauge (A300R), however, I didn’t have one in the shop so we fabricated one in the shop. None of the handloads indicated exceed SAAMI maximum length. Other powders were tried, but none with good results and I was unable to attain velocity noted for these products that were indicated in several sources of data.

Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity,  pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may easily be excessive in others. All loads should be reduced by 5%,  and developed following safe handloading practices as represented in established reloading manuals produced by component manufacturers. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.

Cartridge: 300 Ruger Compact Magnum

 Rifle: Ruger Guide Gun  Max COL: 2.850″
 Bullet Diameter: 0.308″  Primer: CCI 250
 Barrel: 20″  Reloading Dies: Hornady
 Max case length: 2.494″  3 Shot Group: 100 yards



Bullet Weight

Net Water Capacity



Powder Type

Powder Charge

Muzzle Velocity

Muzzle Energy

Group Size
3 Shot “

Remington PSP 125 70.0 2.625   Re17 68.0 3297 3017 1.2
Remington PSP 125 70.0 2.625   BL-C2 66.0 3253 2983 1.2
Hornady SP 130 70.0 2.760   Re17 68.0 3270 3086 1.0
Hornady SP 130 70.0 2.760   BL-C2 66.0 3219 2983 1.1
Barnes TTSX BT 130 66.8 2.810   Re17 65.5 3311 3164 0.9
Barnes TTSX BT 130 66.8 2.810   H414 67.5 3279 3104 0.8
Winchester SP PP 150 68.6 2.800   Re17 65.0 3074 3148 1.0
Winchester SP PP 150 68.6 2.800   H414 67.0 3054 3107 1.2
Sierra SP BT 165 66.7 2.800   H414 64.0 2911 3105 0.7
Sierra SP BT 165 66.7 2.800   IMR4350 64.0 2947 3181 1.1
Sierra SP 180 65.7 2.800   Re17 60.0 2868 3287 0.7
Sierra SP 180 65.7 2.800   H414 62.0 2844 3232 0.9
Nosler Partition SP 180 65.0 2.820   H414 62.0 2835 3213 1.0
Nosler Partition SP 180 65.0 2.820   IMR4350 61.5 2818 3174 0.8
Nosler AccuBond 200 61.0 2.820   H414 57.5 2705 3249 1.0
Nosler AccuBond 200 61.0 2.820   RS BigGame 55.5 2655 3198 1.2

Funny how I get to the end, just when I run out of words…

For folks wanting more than a 30-06 Springfield, but not the long barrel and heavier weight of a full length magnum or even a WSM, and without a loss in performance, the 300 Ruger Compact Magnum and the 20″ barrel is a good solution. If there is something to consider it ,might be that there is only one supplier of ammunition and brass, Hornady. Still, the brass is top quality and there are 7 Superformance loads with bullet weights of 150, 165 and 180 grains in a number of different bullet types. For handloaders, standard powders and primers and a virtually limitless choice of 0.308″ bullets. The price of ammunition and components is very reasonable. Nice rifle, good cartridge. You’ll find further information on the Ruger site.

Ruger’s Guide Gun in 300 RCM Part 1
Ruger’s Guide Gun in 300 RCM Part 2