General Discussion

425 readers

94 users here now

Discuss anything GunCAD related. If you need help, see /c/help. If you think you're discussing a thing a lot of the time, consider making your own separate community.

Abide by the global rules or be smitten.

Shitty stock image may be changed at moderator discretion.

founded 2 months ago

MODERATORS

TheShittinator

ItsBildo

Alyosha

AR15 and M4 rifling buttons (self.general)

submitted 1 month ago* (last edited 1 month ago) by majorbull to c/general

17 comments fedilink hide all child comments

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?

you are viewing a single comment's thread
view the rest of the comments

[–] Kopsis 2 points 1 month ago (1 children)

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.

[–] majorbull 1 points 3 weeks ago (1 children)

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?

[–] Kopsis 2 points 3 weeks ago (1 children)

Several places sell reamers online. For example mansonreamers.com. You're looking at about $400 for a set.

[–] majorbull 1 points 3 weeks ago (1 children)

This is extremely expensive.. Are there DIY alternatives?

[–] Kopsis 2 points 2 weeks ago (1 children)

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.

[–] majorbull 1 points 2 weeks ago (1 children)

Not even china, or sites like AliExpress, are to the rescue, for tools like chamber reamers and heaspace gauges?

[–] Kopsis 1 points 2 weeks ago

Tell me you shouldn't be making rifle barrels without telling me you shouldn't be making rifle barrels.

Seriously, give up this project. You don't appreciate the quality and precision that's required, and trying to make a rifle barrel on the cheap is going to get you seriously injured or killed. Buy a barrel for $100 or make a 9mm.