Are there available rifling buttons for these platforms? I can’t find them anywhere. Even hammerbutton does not have them. Or is there some rifling button with specific characteristics that work, but they are not specifically labelled as AR15/M4?
Are there available rifling buttons for these platforms? I can’t find them anywhere. Even hammerbutton does not have them. Or is there some rifling button with specific characteristics that work, but they are not specifically labelled as AR15/M4?
There’s no difference in the rifling. The differences between 5.56 NATO and .223 Remington are all in the chamber dimensions.
Thank you. Does this mean that you need a different chamber reamer for these two?
The roughing reamers can be the same but the finish reamers are different.
Once again, thank you! I do not know the difference between these two. But that website sells “chamber reamers”. So if I buy the one equivalent for this rifling button, will I be ok?
Bottleneck cartridges usually need two reamers. Unlike straight-wall pistol cartridges, rifle cartridges require opening up the chamber to a much larger diameter than the bore. A rough reamer is used to aggressively remove material to get the chamber near the correct size and then a finish reamer is used lightly cut the chamber to the final dimensions. The same rough reamer is often used for both .223 Rem and 5.56 NATO (and .223 Wylde). The finish reamer will be specific to which chamber dimensions you want. Either way you will need two reamers.
Thanks a lot for the detailed answer. Hammerbutton only sells rifling buttons. So what can I do in this situation? Is it possible to find the reamers elsewhere? Or is it possible to machine them on my own?
Several places sell reamers online. For example mansonreamers.com. You’re looking at about $400 for a set.
This is extremely expensive… Are there DIY alternatives?
Not currently, and that’s why you don’t see any fully DIY .223/5.56 rifle designs. Making a safe and accurate barrel for a cartridge with a CIP maximum chamber pressure of 430 MPa requires extremely precise tooling that is capable of working very strong steel alloys. Keep in mind that you’re also going to need a set of headspace gauges (that’s another $100) in order to ensure you have the chamber cut to the correct depth for your bolt. There’s a reason why this kind of work is typically only done by professional gunsmiths – one needs to produce several barrels to amortize the cost of training, tooling, and testing (expect to ruin 2 - 3 barrels while you are getting your process perfected).
I don’t know what you’re trying to build, but if you’re in a place where you can purchase chamber reamers and rifling buttons, I would think just buying a barrel for a fraction of the cost would be a better solution. If you must go the DIY route for some reason, I really think pistol calibers rather than rifle would be a better fit for your knowledge and budget. Pistol calibers open the door to barrel manufacture by electro-chemical machining which is dramatically cheaper than mechanical methods.