Just like the title says, this is my first attempt at properly headspacing a Rem700 action for a home build I'm doing. However, this isn't a typical pre-threaded, short chambered barrel. I'm using an AAC .260rem barrel that I got for a steal instead. They were selling around the $400 mark, but I got one from Midway once they went on clearance. Anyways, this one is just slightly long chambered with so it will require grinding of the recoil lug to get in dimension. Here's how I did it. Tell me what you think.
Here's my pile 'o goodies so far. I'll be using a virgin Rem700 SA with a .308 bolt head for this guy. Barrel - like mentioned above - is a 24" .260rem barrel from AAC. It's got a nice straight taper and comes nitrided. Out at the end, I'll be using a JP Recoil Eliminator on the end for when the GF comes out shooting. Rings are a Nightforce 20MOA direct mount, though glass is undecided at this point. Same goes for stock (thinking Manners T4A with BDL or AICS 1.5) Finally, everything will get a nice coat of Burnt Bronze Cerakote
Anyways, the meat-n-taters of this thread. Here's my setup. I'll be using gage blocks with the headspace gages to determine my headspace butter zone.
First thing's first, I used my round stone and lightly went over the face of the action to knock off any burrs. I visually inspected the barrel shoulder, found a small nick and gently filed it off.
Install the barrel, leaving the chamber long.
In goes the NOGO...
Leave bolt open and slowly thread the barrel down until it gets just to where the NOGO won't close without using excessive force
Gage block and confirm with micrometer
Continue threading the barrel in with the GO gage to find lower limit of headspace. Repeat gaging and confirm with mic.
And that's it! Headspace dimensions require a recoil lug thickness of between .183" and .187" Worked out perfectly too, theres only a .004" difference in GO and NOGO gages. Kinda nice when things work out. First thing Monday morning, I'll run my .2007" thick recoil lug down to the local machine shop, float some guy a 20 spot to surface grind it down during lunch and bam, ready for paint and install! Below are my calculation notes. Since the action, recoil lug and barrel will be cerakoted PRIOR to barrel installation, I've factored a thickness of about .003" giver or take for the cerakote (on the action face, both sides of the recoil lug and the barrel shoulder). Factor in another ~.0015 decrease in headspace when torquing the barrel, a pre-painted lug thickness of about .184 will put me right in the middle of my headspace zone. I could go down to .183 for a slightly tighter chamber, but I think .184 will work, and going too short could prove to be troublesome (pretty hard to add thickness).
Somewhat unrelated, I'll also have to clock my JP muzzle brake after install, so I thought I'd do a little preliminary measurement to see what it'll take. Threaded down, the brake is ~75 degrees off from dead nuts. Given it's a 5/8x24 thread, and one rev on the thread is about .0412 (1"/24) and I have to go 21 percent of 1 rev (75/360 =.2083), I will have to file down the end of the brake about .0085-.009". Not too much a task for a mill file and some patience.
So stay tuned! Hopefully I'll have the my new sprayer next week and I can get this thing finished!
Let me know what you think!
Here's my pile 'o goodies so far. I'll be using a virgin Rem700 SA with a .308 bolt head for this guy. Barrel - like mentioned above - is a 24" .260rem barrel from AAC. It's got a nice straight taper and comes nitrided. Out at the end, I'll be using a JP Recoil Eliminator on the end for when the GF comes out shooting. Rings are a Nightforce 20MOA direct mount, though glass is undecided at this point. Same goes for stock (thinking Manners T4A with BDL or AICS 1.5) Finally, everything will get a nice coat of Burnt Bronze Cerakote
Anyways, the meat-n-taters of this thread. Here's my setup. I'll be using gage blocks with the headspace gages to determine my headspace butter zone.
First thing's first, I used my round stone and lightly went over the face of the action to knock off any burrs. I visually inspected the barrel shoulder, found a small nick and gently filed it off.
Install the barrel, leaving the chamber long.
In goes the NOGO...
Leave bolt open and slowly thread the barrel down until it gets just to where the NOGO won't close without using excessive force
Gage block and confirm with micrometer
Continue threading the barrel in with the GO gage to find lower limit of headspace. Repeat gaging and confirm with mic.
And that's it! Headspace dimensions require a recoil lug thickness of between .183" and .187" Worked out perfectly too, theres only a .004" difference in GO and NOGO gages. Kinda nice when things work out. First thing Monday morning, I'll run my .2007" thick recoil lug down to the local machine shop, float some guy a 20 spot to surface grind it down during lunch and bam, ready for paint and install! Below are my calculation notes. Since the action, recoil lug and barrel will be cerakoted PRIOR to barrel installation, I've factored a thickness of about .003" giver or take for the cerakote (on the action face, both sides of the recoil lug and the barrel shoulder). Factor in another ~.0015 decrease in headspace when torquing the barrel, a pre-painted lug thickness of about .184 will put me right in the middle of my headspace zone. I could go down to .183 for a slightly tighter chamber, but I think .184 will work, and going too short could prove to be troublesome (pretty hard to add thickness).
Somewhat unrelated, I'll also have to clock my JP muzzle brake after install, so I thought I'd do a little preliminary measurement to see what it'll take. Threaded down, the brake is ~75 degrees off from dead nuts. Given it's a 5/8x24 thread, and one rev on the thread is about .0412 (1"/24) and I have to go 21 percent of 1 rev (75/360 =.2083), I will have to file down the end of the brake about .0085-.009". Not too much a task for a mill file and some patience.
So stay tuned! Hopefully I'll have the my new sprayer next week and I can get this thing finished!
Let me know what you think!
Last edited:
