Some .458 SOCOM Tips


  1. If you recently purchased a new rifle, please remember, you must clean the rifle before you use it. Pay special attention to the head space to make sure you have no dirt, grit or manufacturing residue left in the chamber. The .458 SOCOM is VERY TIGHT and any debris in the head space can cause it to jam and or not cycle. Always clean your rifle before using it, especially if it is a new rifle.
  2. Always feed the rifle by way of the magazine. NEVER drop a round into the action and close it; this is VERY dangerous and could cause a slam fire. We always recommend a GI MAG as a starter mag to get used to your new .458 SOCOM, unless you purchased a CMMG Anvil, which comes with a modified magazine.
  3. If you have a new rifle, we highly recommend “breaking in” your rifle prior to testing out various rounds — the CTX Migration is a great round for this. Shoot anywhere from 20-40 rounds, then deep clean the rifle before moving on to other specialty rounds. This “breaking in” period will help to clear the barrel of any remaining burrs that might exist due to the manufacturing process and polish the head space.
  4. Never use your head space as a case gauge to test ammo or finger push a round into the chamber. This rifle was made to be fed by way of your magazine and a bolt slamming shut, not gravity or your finger tip. Spend the $45 dollars and purchase gauges to assist you instead.We highly recommend either a SBR or Tromix case gauge.


We use these in the manufacturing of our ammunition, and they will instantly tell you if your head space is too tight or good to go. If the round fits the gauge but not your rifle, the head space is the issue.