Goverment Chamber

markmcj · August 15, 2001, 09:30 PM

I recently traded for a Rem 700 with a Douglas Heavy Barrel. The Rifle is chambered in .223 Goverment. Says that right next to the air guage markings on the Douglas barrel. The rifle also has a Leuplod fixed 16x 50mm AO scope. The guy who had it before me, I figured really likes to shoot varmits. My reason for the trade also.
So I want to reload for this rifle, but I figured that the previous owner wanted to have the Nato chamber to allow for expansion
of commercial brass, neck size only an add another grain or so of powder to the capacity of the case.
So I head to the shop were I traded for this rifle and pick up my dies and the owner of the shop tells me he has some ammo for my rifle that the previous owner had reloaded. I check out the reloads and the brass has Nato head stamps(cross in a circle), thicker brass less powder capacity, right? So now I'm wondering why the Nato chamber?
The only thing I can figure is that the Nato brass will allow for more reloads, thicker brass equals more reloads per case, right?
Also if I use commercial brass in a Nato spec. chamber, will I run the risk of premature case head seperation ? Markmcj

Art Eatman · August 16, 2001, 10:04 AM

Overall, I wouldn't worry about a thing. Just shoot and enjoy. That rifle will happily digest anything you feed it, whether military or commercial.

When reloading, you'll get the best results if you neck-size only, since the brass is fire-formed to your chamber. Doing this means no possibility of case-head separation, since you're not working the brass in that part of the case.

Eventually there will be splitting of the case neck, but that's trivial; .223 brass is just way too cheap. Generally, free for the salvage...

, Art

markmcj · August 16, 2001, 05:51 PM

Thank you for your input Art.

I really like the idea of forming the commercial case to the Gov. chamber, if my thoughts are correct. First the Goverment (ie. Nato) chamber will be larger than the standard factory chamber (SAAMI) to allow for the chambering of less than ideal ammo, dirty,dented cases. Then to allow for well used firearms the cases used by the military are usually somewhat thicker.

Maybe I'm putting to much into it.

But,
If I take a commercial case, which is thinner, fire form it to a slightly larger chamber, I might be able to cram a little something extra in the case.

One thing I left out of my first post, the barrel really likes the lighter bullets. I'm thinking a 1:12, 1:14 twist, I tried to find the twist rate but to get a rod to twist in the barrel required to much force.
I'm kinda thinking a 50 or 52 gr. BTHP around 3600 fps might require alittle extra powder, maybe not.

markmcj

Chris McDermott · August 16, 2001, 07:41 PM

I think that it isn't that the chamber is bigger overall, you just have a little more clearence around the neck area so that the bullet is released normally from that thick govt brass. Without this extra clearence in the neck (a tight 223 "match" type chamber doesn't have it), you sometimes can't even chamber Nato brass, and if you can chamber it, pressures can go through the roof because the bullet can't get out of the neck of the case if there isn't any room for the brass to expand and release the bullet.

August 15, 2001, 09:30 PM	#1
markmcj Senior Member Join Date: June 14, 2000 Posts: 136	Goverment Chamber I recently traded for a Rem 700 with a Douglas Heavy Barrel. The Rifle is chambered in .223 Goverment. Says that right next to the air guage markings on the Douglas barrel. The rifle also has a Leuplod fixed 16x 50mm AO scope. The guy who had it before me, I figured really likes to shoot varmits. My reason for the trade also. So I want to reload for this rifle, but I figured that the previous owner wanted to have the Nato chamber to allow for expansion of commercial brass, neck size only an add another grain or so of powder to the capacity of the case. So I head to the shop were I traded for this rifle and pick up my dies and the owner of the shop tells me he has some ammo for my rifle that the previous owner had reloaded. I check out the reloads and the brass has Nato head stamps(cross in a circle), thicker brass less powder capacity, right? So now I'm wondering why the Nato chamber? The only thing I can figure is that the Nato brass will allow for more reloads, thicker brass equals more reloads per case, right? Also if I use commercial brass in a Nato spec. chamber, will I run the risk of premature case head seperation ? Markmcj

August 16, 2001, 05:51 PM	#3
markmcj Senior Member Join Date: June 14, 2000 Posts: 136	Thanks Thank you for your input Art. I really like the idea of forming the commercial case to the Gov. chamber, if my thoughts are correct. First the Goverment (ie. Nato) chamber will be larger than the standard factory chamber (SAAMI) to allow for the chambering of less than ideal ammo, dirty,dented cases. Then to allow for well used firearms the cases used by the military are usually somewhat thicker. Maybe I'm putting to much into it. But, If I take a commercial case, which is thinner, fire form it to a slightly larger chamber, I might be able to cram a little something extra in the case. One thing I left out of my first post, the barrel really likes the lighter bullets. I'm thinking a 1:12, 1:14 twist, I tried to find the twist rate but to get a rod to twist in the barrel required to much force. I'm kinda thinking a 50 or 52 gr. BTHP around 3600 fps might require alittle extra powder, maybe not. markmcj

August 16, 2001, 10:04 AM	#2
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	Overall, I wouldn't worry about a thing. Just shoot and enjoy. That rifle will happily digest anything you feed it, whether military or commercial. When reloading, you'll get the best results if you neck-size only, since the brass is fire-formed to your chamber. Doing this means no possibility of case-head separation, since you're not working the brass in that part of the case. Eventually there will be splitting of the case neck, but that's trivial; .223 brass is just way too cheap. Generally, free for the salvage... , Art

August 16, 2001, 07:41 PM	#4
Chris McDermott Senior Member Join Date: March 30, 2000 Posts: 245	I think that it isn't that the chamber is bigger overall, you just have a little more clearence around the neck area so that the bullet is released normally from that thick govt brass. Without this extra clearence in the neck (a tight 223 "match" type chamber doesn't have it), you sometimes can't even chamber Nato brass, and if you can chamber it, pressures can go through the roof because the bullet can't get out of the neck of the case if there isn't any room for the brass to expand and release the bullet.