Bore scoping and AR barrels

[Darkop]

Most quality, modern production AR's are plenty accurate for a fighting gun. The accuracy of these guns are generally only reduced by the accuracy potential of the ammo we feed them. Example, if we feed the rifle quality ammo such as say Hornady TAP we get better accuracy than say Wolf.

With that said, I have been looking into quality barrels and how that accuracy can be improved and still have a hard use barrel but still keep it as accurate as possible.

I found these two items below, very interesting. The first being the difference in SS barrels and how factory vs quality after market barrels differ. The second from one of our members on a S&W production AR barrel.


http://www.youtube.com/watch?v=hf9zZqn00CA

https://www.m4carbine.net/showthread.php?t=98302

I'm interested in the difference in cut, button and cold hammer forged barrels and the end product companies put out.

Does anyone have borescope pictures of these three type of barrels? I can find pictures of the rifling of cut and button rifled barrels on the web but have not been able to locate pictures of a CHF barrel.

I'm not interested in a brand argument here just facts on barrel construction and the difference in cut, button and CHF barrels and the tooling marks and chatter left in the bore (or lack)

Thanks in advance,
Darkop

[MistWolf]

Regardless of how the barrel is made, bore quality is only as good as the tooling. Use good tooling, you'll get a good barrel. With cut rifling, the final process in making a precision barrel is hand lapping to smooth out the bore and remove tight spots.

It's been thought for many decades than CHF barrels were not as accurate as other manufacturing methods because the process introduces stresses into the metal. Maybe benchrest shooters will see a difference, but as they rarely if ever use CHF barrels, I'm not sure that's been fully tested.

For all practical purposes, for a practical AR, one method of barrel manufacture is as good as another. Durability and accuracy are close enough to not really matter. Finding a barrel that is made with quality tooling and proper processes is more important to producing an accurate barrel than whether it's cut rifled, button rifled or cold hammer forged

[jmart]

I ain't no expert, so take this with a grain of salt. In addition to tooling, I've gleaned that the reason in general that SS barrels are more accurate is the material itself lends itself to producing a good barrel.

I'd defer to smiths who have hands on experience, but I've read enough times that the reason BR barrels come out as good as they do is that the smiths use a good base barrel material (i.e., 416 SS), and it's easier for them to produce a good barrel. Now when you stack this up against longevity, those may be two opposed criterion, but if accuracy is your sole metric, then good SS promises to offer better results than hammer forged just because its easier to machine and chamber.

[sinister]

The topic has been covered in detail here on this site before. https://www.m4carbine.net/showthread.php?t=756

Two excellent old fashioned paper books covering barrel manufacturing, materials, and how they wear are Page's The Accurate Rifle and Carmichel's The Modern Rifle. You should be able to get either one from your public library through inter-library loan.

[Darkop]

The topic has been covered in detail here on this site before. https://www.m4carbine.net/showthread.php?t=756

Two excellent old fashioned paper books covering barrel manufacturing, materials, and how they wear are Page's The Accurate Rifle and Carmichel's The Modern Rifle. You should be able to get either one from your public library through inter-library loan.

Sinister, Thank you for posting that link. I don't know why it did not show up in my use of the orange search button. That thread really should be stickied (and finished by K Davis)

Now, does anyone have any borescope pictures of a CHF barrel?

Until that day,
Darkop