PDA

View Full Version : AR bolt carrier surface hardened?


TMC
08-31-2007, 6:34 PM
Is the surface of a mil-spec AR bolt carrier hardened in any way? I want to experiment with taking weight off the bolt carrier but don't want to ruin any tooling if the surface is hardened.

Sydwaiz
09-04-2007, 8:16 PM
The whole damn thing is hardened! Use carbide.

Mud
09-17-2007, 8:32 PM
I think it is >60-68C (I forget) on the Rockwell chart. I use Cobalt Bits and End Mills to work with the Carriers, Carbide is a little too brittle. Good Luck

AJAX22
09-17-2007, 8:35 PM
just out of curiosity why would you want to lighten up your carrier? (you trying to up the cyclic rate on your FA gun?) :p

I use m16 carriers in all my guns and they seem to like the extra weight.

I believe you can get away with removing a considerable amount of material, it would probably be best to start with one of the half circle carriers that were produced during the ban.

ar15barrels
09-17-2007, 9:54 PM
just out of curiosity why would you want to lighten up your carrier?

Reduced recoil impulse due to less reciprocating mass within the rifle.
You then minimize the gas flow using a smaller gas port or adjustable gas system to de-tune the action back into a proper setup for the lower mass.

JP sells a low-mass carrier.
This is the way to go.
I run the JP.

Young also sells one, but I don't think it's as light as the JP.

randy
09-18-2007, 12:01 PM
It's not the recoil you are trying to tame as much as the return to battery.

If you watch closely you will see when your bolt returns to battery your rifle will dive down and to the right.

The lightened "proformance carrier" will reduce that and keep you on target along with keeping your double taps closer. If you are shooting a light rifle this is much more noticable than if you are shooting a heavy/varmit setup.

TMC
09-25-2007, 9:18 PM
Thanks for the info folks. I run a stainless JP in my open rifle and an aluminum one in my limited rifle (doesn't get shot very much) but since I got that dude below I was thinking I could grind up mil-spec carriers and get close to the same results on the cheap but not if its going to use up carbide or cobalt bits.

http://home.comcast.net/~tmc38s/sharpe_mill.JPG

dw1784
09-26-2007, 1:13 AM
take a spring loaded center punch and mark a spot on the rear end of the carrier, measure the depth and dia of the mark(like a brinell hardness test). Take another specimen of known hardness, say 1020 or 1040 and compare the difference.

CRTguns
10-11-2007, 11:13 PM
That thar's quite a machine for one man's garage!

I got one of those Dayton/Grainger table top jobs in my garage. Big enough for any gun job I've needed.

ar15barrels
10-12-2007, 5:02 PM
That thar's quite a machine for one man's garage!


My 1-car garage:

http://ar15barrels.com/gfx/shop2.jpg

m24armorer
10-12-2007, 10:36 PM
Guess you don't have much work......

Way too clean.

I do like the surface grinder!
But if it's a one car garage, where is the car? Get rid of it and you will have more space!

Kidding all!

Nice!

ar15barrels
10-12-2007, 10:55 PM
Guess you don't have much work......

Way too clean.

I have this habit of cleaning up every night before I close the shop up.
That makes it easier to get started again the next day.

m24armorer
10-12-2007, 11:10 PM
Ever seen pics of J M Brownings shop, I'm from the same lot.

No room and a lot of chips.......