Rock River LAR-8 and Gemtech Looming....need 308 tech advice.

[Rastus]

OK...happy call from Rock River to my FFL dealer this week.  The one year wait for the production line is actually...6-8 weeks.  I figured that was coming.

Anyway, I've got the LAR-8 Varmint with the 26" SS barrel coming down the skids and I'm waiting on paper from the ATF so I can possess what I own from GemTech.

Now...I need to thread the barrel, but I am thinking about cutting it down to make it lighter and more manageable....which I'll certainly do...and here is the question...how much velocity will I sacrifice going from 26" to 22"?  I've read and heard that 308 ammo is optimized for 22 inch barrels, if that's the case it's a no brainer for me....I might even go to 20".

I know it depends on the load, but let's assume match bullets 168 or 175 grain, boat tail only...maybe with a polymer tip if not match.  No hollow points.  I really don't want to lose over about 75 fps by shortening the barrel, since the 308 is a little anemic in the speed category.

I'd appreciate guidance from someone who is a 308 guru.

Thanks,
Ken

Late Addition--I'm also wanting good quality scope rings for it.  Any suggestions on good and stable rings (easily removable not a requirement, this thing will never have iron sights on it) for a 30mm tube and 50+mm objective is appreciated too.  As soon as I settle on a scope, I'll need to get those rings in a height that will allow about 1/8" clearance.  Also for a bipod, drag bag, etc.....

[Overload]

Won't that be kinda long with a supressor at the end of a 26" barrel?

[Rastus]

Won't that be kinda long with a supressor at the end of a 26" barrel?

Yeah that's why I wanna chop it off...

Wanna sell that FS 2000?  I might be interested.

[fightingquaker13]

Rastus
Like always, the question is what do you want use it for and how long is the can? How does it effect velocity? Range gun, varmint gun, tactical? What ranges etc.? The load detail is helpful, but in mho (which needs education) is that the difference between 20" and 26", plus x inches of can, will probably not matter under 300 if we're talking about 4" groups. Beyond that, what is it for?
FQ13

[PegLeg45]

I was just talking about this with my friend (long range competitor) last week. He directed me to a couple of links with articles on barrel length vs. velocity.

It may not help. but it might.

http://www.shootingtimes.co.uk/features/136776/Barrel_length.html

Last section is on velocity:
http://www.chuckhawks.com/rifle_barrel.htm

[Sponsor]

[Rastus]

Thanks guys.

Overload...might be interested depending on when it was made.....

[Rastus]

Peg, those were pretty good references.  I had been leaning towards cutting the barrel from 26 to 22 inches and those articles helped.  I want to have 400 yards and closer working distances for this 308, my Remington 700 will be for a bit longer distance.   

The one thing I did not see mentioned that was contained in at least one other article I read somewhere is that the 308 round is loaded with powder optimized for shorter, "tactical" barrels....at least in the rounds I'll be using like Federal Premium and Winchester Supreme.  I'm still scratching to see if that is really true or an "urban myth" kind of a thing.

[tombogan03884]

As I understand it, 308 is optimized for 20 inch barrels. That's why that length is used on the M 40

[Rastus]

As I understand it, 308 is optimized for 20 inch barrels. That's why that length is used on the M 40

Good deal.  I might even pick up some velocity going a smidgen over up to a 22" barrel.  Cutting it back a few inches will make it stiffer and maybe improve the groups (though you never know about an individual barrel's harmonics).  That was another motive, leaving enough barrel so I could lop off a bit more if it didn't shoot well.

[tommy tornado]

I have two of Rock River's 1-inch scope mounts and really like them.  They are about $50 on their website, but I found mine at a gun show for $45 from a RRA dealer.