RPK Headspacing Service: Customer Supplied Kit *READ INSTRUCTIONS IN DESCRIPTION*

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For headspacing RPK or other heavy/long barrel kits.

Parts required for headspacing:
✔️Front Sight/gas block
✔️Gas tube
✔️Lower HG retainer
✔️Rear Sight
✔️Front Trunnion
✔️Barrel pin, 4mm pin, 3mm pins
✔️RPK cleaning rod retainer & Bipod (depending on build needs)

❌Bolt carrier is not neccessary for headspacing, you do not need to send it.

Headspacing lead time will apply. SEE FAQ FOR CURRENT LEAD TIMES.

Simply add this service to your cart. Print your invoice after placing your order, and put it in the box with your parts when you ship them to us. Once work is complete, we will ship your headspaced kit back, and you will get an email with the tracking number. If you need us to supply any parts that we have in stock, including a barrel, feel free to include them with this order.

Our shipping address is: 

Arms of America
1210 Industrial Dr
Royce City, TX 75189

If you have any questions or want to know about non-standard or custom work, please contact us and let us know.

*Please package your parts individually so they do not get dented or dinged in shipping. Please do not send more parts than you paid for.


  • All kits that we headspace will ship with a drilled gas port.

  • During assembly, it is normal for tools and machines to cause minor cosmetic scratches to the original parts finish.
    Most commonly, drilling any holes will cause metal shavings to scratch paint around the hole, and hammering any pins in with a punch will remove finish from the pin.
  • In order to complete your build, you will need to remove your barrel from the trunnion, rivet the trunnion into your receiver, then press the barrel back in.
    We pre-drill the barrel pin hole so you are able to use that as a guide when pressing your barrel back in.

    Go/No-Go gauges must then be used to verify headspace before fully installing your barrel pin.
  • Your kit is 100% head-spaced correct out of the box. We perform a series of checks across several team members prior to every order shipping out.
    If you have concerns, you must check headspace BEFORE changing anything about the headspaced assembly using GO/NO-GO GAUGE!!!

    If you have questions, please take pictures, and/or video, and reach out to us.
  • Once the barrel is removed, or any alteration has been made to the populated barrel, at that point the customer or builder becomes responsible for the build. AOA cannot take responsibility for a headspaced assembly once alterations have been made to our gunsmith's work.
    Removing the barrel and reinstalling it may result in head-space loosening or tightening of your pre-head spaced kit if you are only eyeballing the barrel pin hole. It can look lined up, but still be off by a few thousandths of an inch.
  • Recheck head-space after you are done riveting your trunnion into your receiver and reinstall the barrel, and ensure it is correct BEFORE pressing the barrel pin.

    **If you need to send an assembly back, we will charge another headspacing fee. We also cannot accept receivers, so if it needs to be sent back in, you must remove the receiver if it has already been riveted.
  • Once all built, please clean your firearm before firing to make sure your new firearm is clear of assembly or shipping debris. If your assembled firearm is failing to cycle, sometimes metal burrs may get lodged in the gas port and need to be cleared out.
    Thank you again.


  • 5
    Very happy with results

    Posted by Kort Laupp on Nov 13th 2021

    I am very happy with the results with my kit, they were very informative and helping me with my oversized tronium and sugestion solutions, I was able to keep my original trinion and use the barrel i sent , I would highly recommend anybody else who would like to head space and care