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View Full Version : Gonna pull the trigger on a OBR but which length 18" or 20"?



mstennes
04-04-11, 11:34
I decided over the weekend I'm getting a OBR! I just can't decided on the 18" or 20" barrel, it's going to be used on our range that can go out over a mile, but for all intents and purposes it's going to be used at 500 yards out to 1200 yards or so. It won't be used for kicking in doors or snap shooting, but for longer range target and varmiting. What does the 18" give up to the 20" at longer ranges?
Thanks

Spiffums
04-04-11, 12:00
I'd vote 20 if your going to try to go to 1200 with a 308.

aveisone
04-04-11, 12:08
You dont lose any accuracy with the shorter barrel, but you do lose velocity. Velocity will stabilize your bullet at longer ranges and take less interference from wind. I would go 20" or longer for 1200yd. Just one mans opinion.

DTHN2LGS
04-04-11, 15:38
With your intended purposes, definitely 20".

RyanB
04-04-11, 15:55
From 16 to 18 to 20 in the OBR the difference is 50 fps and a half mil of drop at 1000 for each imcrement.

m1ajunkie
04-04-11, 17:36
I had a similar decision recently and chose 20" and haven't looked back. My thinking was a dedicated precision rifle should be set up to make shooting long range as efficient as possible. For me, that meant the 20" because it would get me a little more velocity to help fight wind and make it to 1k without any trouble. I run my rifle solely precision as it sounds you may do with your obr so I see no reason not to go 20", especially if you are planning to get to 1200yds.

FWIW, I have also debated swapping my rifle to 260 or 6.5 creedmore, but I am limited to 700yds and it seems a .308 will hold its own at that range.

308smk
04-06-11, 22:02
If you dont have space confinements, like vehicles or buildings, definitely go with the 20" barrel. As mentioned the extra few inches will get you a bit more accuracy past 800m, where the limitations of the cartridge start to come into play.

1stIDvet
04-07-11, 00:25
You wont lose much accuracy, if any, with an 18" barrel. I vote for the 18", It'll be more handier if your going to be moving and carrying it. I wouldn't want 2 inches of extra barrel + flash hider.

mstennes
04-07-11, 08:36
You wont lose much accuracy, if any, with an 18" barrel. I vote for the 18", It'll be more handier if your going to be moving and carrying it. I wouldn't want 2 inches of extra barrel + flash hider.

I was just about to order the 20, and read this, it will be getting a can eventually this summer also. Damn back to square one.

1stIDvet
04-07-11, 11:10
This should help with your decision. An 18" barrel will do you just fine, though in the video the rifle is a bolt action, it gives you an idea of what an 18" can do..

http://youtu.be/15qj032UJ1I

mstennes
04-13-11, 09:28
This should help with your decision. An 18" barrel will do you just fine, though in the video the rifle is a bolt action, it gives you an idea of what an 18" can do..

http://youtu.be/15qj032UJ1I

I always thought that you can get away a little shorter on bolt guns vs gas guns, due to gass loss to cycle the acton?

1stIDvet
04-13-11, 11:26
With reputable company's such as POF, LWRC, GAP, and even larue I guess, you will not have any issues with an 18" barrel.

Gutshot John
04-13-11, 18:14
1200 with .308?

Damn, that's no joke the longest recorded kill was at 1350 yards using an M24 (24" barrel). That's going to be tough to pull off with a semi-auto with a 20" barrel.

You won't lose much accuracy with an 18" barrel, but you'll definitely lose some muzzle velocity/range.

20" is the only choice if you intend on hitting a 1200 yard target.

mstennes
04-14-11, 09:01
1200 with .308?

Damn, that's no joke the longest recorded kill was at 1350 yards using an M24 (24" barrel). That's going to be tough to pull off with a semi-auto with a 20" barrel.

You won't lose much accuracy with an 18" barrel, but you'll definitely lose some muzzle velocity/range.

20" is the only choice if you intend on hitting a 1200 yard target.

Our range is a old wheat field, lots of distance, no I just want to be able to hit out that far if possible, a buddy does it with his Remington 700, yea I know bolt gun, but I do want to be able to be consistant at 900-1000 with the ability to hit on out, future plans are for a 300 Win Mag, but for now this is my summer pruchase. Looking for a more of a do all long range rifle, with some coyoting (lots at the range) and ground hogging.

Gutshot John
04-14-11, 11:37
Our range is a old wheat field, lots of distance, no I just want to be able to hit out that far if possible, a buddy does it with his Remington 700, yea I know bolt gun, but I do want to be able to be consistant at 900-1000 with the ability to hit on out, future plans are for a 300 Win Mag, but for now this is my summer pruchase. Looking for a more of a do all long range rifle, with some coyoting (lots at the range) and ground hogging.

Out of curiosity, what configuration is your buddy's remmy? 20" barrel? or longer?

Belmont31R
04-14-11, 20:36
If you plan on getting a 300WM later on I would get a 16" 308 gas gun, and then make the 300WM the dedicated LR gun.



I would not consider any gas gun a reliable 1200 yard shooter. Not even most 24/26" bolt guns unless the conditions were right with a top notch shooter.


Look at the trend the British and the US are going to. 308 gas guns out to 800M and magnum bolt actions up to 1300-1500M. I figure it is only a matter of time before the USMC goes to a magnum bolt action now that they are getting M110 gas guns for intermediate use.

Steve
04-14-11, 21:57
1200 with .308?

Damn, that's no joke the longest recorded kill was at 1350 yards using an M24 (24" barrel). That's going to be tough to pull off with a semi-auto with a 20" barrel.

You won't lose much accuracy with an 18" barrel, but you'll definitely lose some muzzle velocity/range.

20" is the only choice if you intend on hitting a 1200 yard target.



We took 16 and 18 barreled suppressed Obr's to a mile and did it enough that it wasn't just lucky,,

while ot my top knowledge i saw no issue and had no issue taking steel to 1200 yards with either barrel i went 18 inch

Steve
04-14-11, 21:59
If you plan on getting a 300WM later on I would get a 16" 308 gas gun, and then make the 300WM the dedicated LR gun.



I would not consider any gas gun a reliable 1200 yard shooter. Not even most 24/26" bolt guns unless the conditions were right with a top notch shooter.


Look at the trend the British and the US are going to. 308 gas guns out to 800M and magnum bolt actions up to 1300-1500M. I figure it is only a matter of time before the USMC goes to a magnum bolt action now that they are getting M110 gas guns for intermediate use.



I wouldn't tell that to the guys we saw from a MIL team doing those types of shots + in 15-20 plus winds 800 and then some

Belmont31R
04-14-11, 22:27
I wouldn't tell that to the guys we saw from a MIL team doing those types of shots + in 15-20 plus winds 800 and then some



800 is doable in that wind. My home range is a flat central TX plain where we get winds regularly to 25MPH, and when its particularly windy even more than that.


I have witnessed some really great shooters including Todd Hodnett try to shoot the 1k yard targets out there and not have enough success I would call a 308 a good 1k+ yard gun. At 1k yards the difference between a 18MPH wind and 20MPH means a miss or hit.


YMMV but I think the issue has been pretty well been ironed out by now. Of course there there one of examples of the 308 being taken further but that doesn't mean there are not much better calibers for shooting that far.

Steve
04-15-11, 04:04
I agree fully, as we spent a week + with Todd at his place learning how to do it i admit the H-58 reticle made life much easier

if i knew i had too yes i could, if i knew i would be, it be 300 and up range.... if that makes sense

mstennes
04-15-11, 08:33
Out of curiosity, what configuration is your buddy's remmy? 20" barrel? or longer?

20" SPS Tactical

mstennes
04-15-11, 08:38
If you plan on getting a 300WM later on I would get a 16" 308 gas gun, and then make the 300WM the dedicated LR gun.



I would not consider any gas gun a reliable 1200 yard shooter. Not even most 24/26" bolt guns unless the conditions were right with a top notch shooter.


Look at the trend the British and the US are going to. 308 gas guns out to 800M and magnum bolt actions up to 1300-1500M. I figure it is only a matter of time before the USMC goes to a magnum bolt action now that they are getting M110 gas guns for intermediate use.

So 18" for the win (looks a little better than the 20"), and start on the 300 Win Mag? Not a 16" fan, no reason, the 18 just looks like the perfect balance.

RictusGrin
04-15-11, 09:08
I always thought that you can get away a little shorter on bolt guns vs gas guns, due to gass loss to cycle the acton?

It isn't significant. I've been shooting the 16" OBR and EMC along with an 18" Noveske to 1100 this week. They all do fine at that range and shoot along with the 20" guns on the line.

Gutshot John
04-15-11, 09:14
We took 16 and 18 barreled suppressed Obr's to a mile and did it enough that it wasn't just lucky,,

while ot my top knowledge i saw no issue and had no issue taking steel to 1200 yards with either barrel i went 18 inch

Like I said "tough", not necessarily impossible. The extra 50fps from a 20" can mean quite a difference at 1200 yards and would still be a better choice for more consistency at that range.

Absent knowing what kind of ammo, setup, targets you were using, you're also talking about dedicated military teams, with extensive knowledge and experience, superior ammo, a well-trained spotter you've worked with and probably lots of good dope.

If the OP is going to make that kind of time/money investment than he might be able to get out to 1200 with some kind of consistency but again it's no joke that pulling off a 1200-1600 yard shot consistently (in any kind of wind) with a .308 means you're a world-class shooter.

Steve
04-15-11, 11:31
Like I said "tough", not necessarily impossible. The extra 50fps from a 20" can mean quite a difference at 1200 yards and would still be a better choice for more consistency at that range.

Absent knowing what kind of ammo, setup, targets you were using, you're also talking about dedicated military teams, with extensive knowledge and experience, superior ammo, a well-trained spotter you've worked with and probably lots of good dope.

If the OP is going to make that kind of time/money investment than he might be able to get out to 1200 with some kind of consistency but again it's no joke that pulling off a 1200-1600 yard shot consistently (in any kind of wind) with a .308 means you're a world-class shooter.


I agree fully, we weren't shooting bull eyes, human ipsc sized steel torsos and head plates ammo was a mix of all factory blackhills and hornaday along with OBR's and nighthawks rifles leupold sb scopes and PR the h-58 made life pretty easy

Gutshot John
04-15-11, 12:10
I agree fully, we weren't shooting bull eyes, human ipsc sized steel torsos and head plates ammo was a mix of all factory blackhills and hornaday along with OBR's and nighthawks rifles leupold sb scopes and PR the h-58 made life pretty easy

Can I ask what loads you were using?

I don't handload though I should, I've always gotten the best accuracy out of Hornady 165gr. I'll have to try 175 at 1200 and see if I get any kind of better results than I have in the past.

Steve
04-15-11, 15:28
Can I ask what loads you were using?

I don't handload though I should, I've always gotten the best accuracy out of Hornady 165gr. I'll have to try 175 at 1200 and see if I get any kind of better results than I have in the past.



We had a huge variety there most was BH 308 168 and 175 loads IIRC

and in 300 we had Hornday from there hunting line up and some more BH in 338 it was all lapua ammo im sure

Gutshot John
04-15-11, 22:30
it was all lapua ammo

Mmmmmm...lapua.

http://www.mamapop.com/wp-content/uploads/2010/10/homer-simpson.jpg

Belmont31R
04-15-11, 22:37
http://i274.photobucket.com/albums/jj245/BM31R/3ea28de4.jpg