If you look on various gun forums, you will find a lot of different opinions regarding the quality of AR-type rifle components. One hotly debated component is the bolt.

There are many manufacturers of AR parts and the quality ranges from excellent to average and perhaps less. For the purpose of this discussion, we will look at bolts manufactured by Noveske, Daniel Defense, Spikes Tactical and Bushmaster. This is not to say that other manufacturers are not equally good or better than what we tested. This is just a small sample and many companies large and small are capable of producing a great product.  It’s just that we had to draw the line somewhere and really don’t have any way, short of destructive testing on a statistically significant sample size, to compare bolt ‘A’ to bolt ‘B’, other than by specifications and markings.

A lot of companies claim their parts to be MilSpec. The reality is, only military issued AR parts or weapons are actually MilSpec. Parts can be made to a standard that might be equivalent or even better than MilSpec, but that doesn't make them MilSpec since they were not accepted for use by the military.

Millions of guns on the civilian market are not MilSpec and yet they still work reliably. We've got some Winchester 94s from the early 1900s that work as well today as when they were made, 100 years ago. It will be interesting to see if, 100 years from now, some of these MilSpec guns made today are still in one piece.

This is not to say that there are not processes and tests that should be done to various parts to ensure quality. Making a quality part requires quality materials, precise manufacturing methods and extensive testing. Testing is important because even the best materials and manufacturing processes sometimes create bad parts.

While nobody really knows what makes a MilSpec part, except for the manufacturers of military riles (Colt and FN), there are parts of the standard that are public knowledge and have been used by manufacturers to compare things.

With regards to AR-type bolts, the typical requirements for a high quality piece are:


               1 – Made with Carpenter No. 158 steel
               2 – High pressure proof test
               3 - Magnetic particle inspection
               4 - Shot peening
               5 – Heat treatment

We pulled the bolts from several rifles that we borrowed to compare them. Some shown below are clearly marked as to what tests they have passed.  Others have no markings at all. All of these bolts come from mainstream manufacturers and are used in rifles every day. Is a bolt that is fully tested and machined from the correct steel a superior product? Probably so. If you can afford the high end products, it’s probably wise to get the best you can afford. On the other hand, the bolts in the every day utility rifles that are not marked as tested, are not failing constantly. A search of the internet doesn't turn up reports of untested bolts blowing up.  In over thirty years, we've never seen an AR bolt break, regardless of manufacturer. We know it happens at times but it happens to all brands and not just the lower tier ones. It's certainly probable that a high end product that was machined out of the best materials and tested to high standards will outlast the consumer grade product in high use and stress situations. However most people who buy these rifles don't shoot them very often and will likely never see the difference.

Our best advice is to buy what you can afford and don’t worry about the difference between the Ferrari manufacturers and the Chevrolet manufacturers.  Unless you want to constantly drive 100 miles an hour (shoot tens of thousands of rounds a year), both the Chevy and the Ferrari are going to get you home.