Here are some of the most commonly asked questions from our customers:


What are the advantages of a roller-delayed blowback firearm in comparison to a gas-operated firearm?

Several tangible advantages are worth noting: 1) The engineering of the roller-delayed blowback system is very simple and reliable. While gas-operated systems can also be engineered to a high standard of reliability, the roller-delayed blowback system is at least their equal and arguably superior. 2) Roller-delayed firearms tend to run cleaner than direct impingement gas-operated firearms, since there is no recirculation of gas by which debris can be introduced into the chamber area during the cycle of operation. 3) Especially when firing suppressed, the far-forward position of the roller-delayed system’s charging handle will limit or eliminate the blowing of gas directly into the user’s face. 4) Due to the lack of requirement for a buffer tube, roller-delayed blowback firearms can be made more compact in pistol form than their gas-operated counterparts (e.g., a ZF-5 pistol, it’s receiver end cap, vs. an AR-15 pistol with its required pistol buffer tube).

What is the recommended break-in period for a Zenith roller-delayed firearm?

We recommend a 500-round break-in period, during which a high-quality firearm lubricant should be frequently and liberally applied to bearing surfaces of the bolt carrier assembly and receiver, and occasionally, sparingly applied to moving parts in the trigger pack assembly.

Are Zenith roller-delayed blowback firearms compatible with parts from H&K?

Our firearms are compatible with most H&K parts. However, please consult your local gunsmith before purchasing or installing any aftermarket parts or accessories.

Can I use a suppressor with my Zenith roller-delayed blowback firearm?

Provided you own a Zenith roller-delayed firearm capable of receiving a suppressor, you can use a suppressor with your firearm once you have completed the legally required paperwork and are in possession of the resulting approvals (tax stamp, trust, etc.)

Can I use +P ammunition in my Zenith roller-delayed blowback firearm?

Yes. These are military-grade firearms designed to withstand and operate with +P ammunition. However, we do not recommend the use of +P+ ammunition.

What kind of ammunition should I use in my Zenith roller-delayed blowback firearm?

The Zenith ZF-5 Series is designed to fire high-quality new production factory-loaded ammunition that meets SAAMI or NATO specifications. It is imperative that ammunition of the correct caliber is used to prevent damaging the firearm and to avoid serious injury or death. While Zenith Firearms recommends primarily using brass-cased ammunition, there are types of steel-cased ammunition that will also function reliably. Zenith highly recommends inspecting each cartridge for damage, corrosion, or other abnormalities before loading a magazine for firing.

Break-In Period Recommendations
During the 300-500 round break-in period of a brand-new firearm, Zenith recommends NATO-spec or other high-quality, high-pressure ammunition having a bullet weight of 124 grains.

Post Break-In Period Recommendations
> Factory new brass case ammunition meeting NATO or SAAMI specs from 115 grains to 147 grains
> Some types of factory new steel case ammunition meeting SAAMI specs from 115 grains to 147 grains


  • Aluminum-cased ammunition
  • Ammunition with projectiles heavier than 147gr.
  • Handloaded or remanufactured ammunition
  • Ammunition of the wrong caliber
  • Ammunition that has been damaged, corroded, or exposed to water, lubricants, grease, or other contaminants
  • Exposed lead projectile ammunition
  • Certain hollow point projectiles that impede feeding reliability
  • Low pressure ammunition intended for smaller handguns
  • Outdated surplus ammunition
  • Ammunition that has been exposed to extreme temperatures

How do I properly unload my roller-delayed blowback firearm?

Verify that your firearm is on “Safe” and pointed in a safe direction, and that your finger is not touching the trigger. Detach the magazine, and then pull the charging handle rearward and to its upright and locked position (lock the bolt in its open position). A chambered round may eject. Verify that your firearm is now empty by looking through the ejection port. Insert a chamber flag if necessary. Please consult your owner’s manual regarding proper and safe handling of a firearm.

I have a problem with my firearm. What should I do?

Please reference your owner’s manual. If your question is not answered there, e-mail [email protected] with your concern. Your ZF-5 manual can be found here. The manuals for older Zenith models can be found here.

Can I ship my firearm to Zenith Firearms for repair?

Yes. However, not without first receiving an invitation from Zenith’s warranty/technical team to do so. If you would like for Zenith to repair your firearm, please contact [email protected] to explain the problem, and then await our reply with specific instructions. Whether or not a needed repair service is covered under warranty, we do not accept unexpected shipments of firearms.

Are Zenith Firearms made in the USA?

Yes. Zenith Firearms are proudly made in Afton, Virginia, USA.

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