Hammerhead

CA-Legal AR-15 Stock Adapter

Frequently Asked Questions

Please note, photos may not necessarily represent a legal configuration in your state.

  1. Is it comfortable?

    While no grip or stock will be comfortable for everyone, many of our customers have remarked how comfortable it is. One shooter said it was "all-day comfortable." So don't judge it strictly by appearance. Try one risk-free for 90 days. If you don't love it, return to place of purchase for a refund.

  2. Does the recoil throw the weapon up and over your shoulder since the stock is not on-axis with the barrel?

    We've sold tens of thousands of units since our company's founding in 2009. The only complaints we've heard about muzzle rise and recoil have come from people who have looked at a photo of the Type I configuration on the internet and declared that muzzle rise would be a problem. We've never had a complaint about this from customers who've actually shouldered and fired it. Laws requiring a muzzle brake rather than a flash hider are likely also a factor in mitigating muzzle rise.

  3. Is it hard to reach the safety / selector switch?

    People have differing capabilities with their hands. Some customers report no trouble actuating the safety. Most customers prefer to use an ambidextrous ("ambi") safety.

  4. Is it hard to reach the magazine release?

    Most customers have no difficulties. If you have very small hands you may need to rock the trigger hand forward to hit the mag release. Some customers with very small hands report success using the Arredondo mag release or other similar extended magaine release button.

  5. Can you post a photo with a [Brand X] Stock?

    We have a bunch of stocks on hand but there are probably thousands of stocks on the market. It's just not practical for us to try every stock. Have a look at our customer photos page to see if your desired stock is pictured there.

  6. Will you produce a grip-only version without the bulge at the tail section and without provision to mount a stock?

    It is easy to modify the product by cutting off the threaded tail section entirely using a hacksaw, then filing, sanding and painting. Of course such modification voids the warranty, and depending on how far you cut and what jurisdiction you live in, you may negatively impact the legality of the product.

  7. Will it fit my (non-AR-15) rifle?

    Hammerhead™ was designed to fit mil-spec AR-15 lower receivers. If your pistol grip mount point is identical or very close to that of the AR-15, it may fit. Customers using the AK may have to modify the product to get it to fit, and the use of the ACE/Doublestar AR/AK grip adapter can be of great help.

  8. Will it fit on my .308 AR?

    This product should fit to the pistol grip mount of your .308 AR, but you may have to grasp the grip with your thumb back a bit further than with the AR-15 due to the .308 lower extending more to the rear.  This photo shows a Hammerhead™ stock adapter mounted to a .308 AR receiver:

  9. Can I attach [Brand X] stock upside-down?

    Generally you can attach a stock upside down if it won't interfere with the pistol buffer (receiver extension) tube. The best stock we've found for this purpose is the ACE ARUL-E stock.

  10. Will it work with an A2 stock?

    Hammerhead™ does not fit with the standard A1/A2 stock attached to the back of the receiver. We recommend choosing an alternate stock. The ACE stocks work well, and we carry these and other compatible stocks on our secure online store.

    A good way to get something of the A2 look and still have the ability to wrap your hand around the rifle is by use of the Rock River Arms Entry Stock, again in Type I configuration:

    It is also possible to dremel or otherwise cut down the rear of the Hammerhead™ so that it will fit under the A2 stock and in that case you would have an underhand hold instead of being able to wrap your hand around the product.

  11. Will it work with the Magpul PRS / UBR / other fixed stock?

    Just about any AR-15 stock will work in Type I configuration, but customers asking this question are usually trying to get one of these stocks to work in Type III configuration. The way to tell if your existing fixed stock will work in Type III is to look at the clearance for your thumb.

    Pinned collapsible stock allows space for thumb to wrap around Hammerhead™.


    No space for your thumb with this stock.