16" vs 18" 308?

[Queen Bee]

Just looked

Yeh spending 400-500 dollars on the scar25 replacement lower is not my idea of a good investment. Looks like the scar is out if the running on this buy.. Till i hit the lotto

 

[mac1911]

I've got a lot to add here.

re build vs buy - I built an AR10 in .308. Its about as good as you are going to get for accuracy. I've got a Lilja barrel on it with a matched bolt. Mega upper and lower. Its only an 18" barrel, but the longest I get to shoot is typically 300 yards.
It is very accurate. I have not chrono'd my 175 SMK reloads out of it.
It has less recoil than any .308 I've ever shot. I've got a JP adjustable gas block on it that is set for my reloads and a SJC Lund muzzle brake. The difference in recoil between this and what would typicallly be found on a rifle like this is beyond belief. It recoils more like a .223 with a flash hider than a .308.

re scar for 1000 yards - Its definitely not an ideal 1000 yard rifle. But it does very well at 300 and there seems to be no reason to believe it won't do well at much more. The SCAR 17 has a strange ability to transcend the fact that its a piston driven gun with a skinny barrel. I'm not saying the shots won't walk if you shoot it fast. But it is surprisingly accurate.

If you must have a semi-auto a better (buy vs build) choice might be one of the RRA or DPMS varmint or predator rifles in .308. They come with heavy, accurate, stainless barrels and are reasonably priced. I know everyone here hates DPMS, but they are very accurate. You can also get the DPMS in 6.5 creedmoor, which is a better long range cartridge than the .308. It recoils less and has much better external ballistics. The RRA uses proprietary (modified FAL) mags and the DPMS uses the same ones that everyone else other than Armalite uses.

DRB - remember, the effective range is based on the speed at which standard military ball ammo either goes transonic or its KE drops below a certain threshold. Something like my handloads or Superformance match will push a heavier, higher ballistic coefficient bullet faster. So the effective range could be much more. I'm not saying its much good for more than that. Just that you should reserve judgement until some better info on the external ballistics of a fairly hot round like a Hornady Superformance Match 175gr are shot from its 16" barrel.

Mac1911 - the longest I've been able to load that will fit in an AR10 mag is 2.015". At that length, the bullet is well off the lands. (I can't remember how much) One of the things I'd like to do (someday) is check the accuracy of my lilja barreled AR with magazine length cartridges vs something loaded with the bullet just .003" off the lands. (or some otehr relelatively short jump) I guess my point here is that if you are willing to single load, you may be able to get more accuracy out of an ar platform.

Where I get a little hung up when looking into a 30cal AR type platform is the rifle and ammo have to have at least the ability to reach out and preform @ mag length maybe not @ 1000 yards. I know I will not see 1000 yards often....
If I am going to have a AR platform for target shooting to 600 yards and have to single load.........I'm sticking with the 223. As mentioned above.
Set aside mag preference or issues........ for the money I have a hard time not looking back to the RRA A4 style 308 rifle. My current RRA rifles shoot better than I can deliver. Flawless function also.......hmmm. I'm still banking on buying the larue my friend has.....he is on the verge of buying something "new " he tends to dump guns cheap when he has his sights fixed on the next best thing.

 

[fbirdquik6]

Didnt you post about being so broke that you were going to be homeless not long ago in this thread: http://www.northeastshooters.com/vbulletin/threads/228931-Storing-guns-when-you-become-homeless?

and not being able to handle the recoil of a 5.45x39 or 5.56 in this thread: http://www.northeastshooters.com/vb...ly-frustrated-with-being-a-wuss-with-a-rifle?

Not to be a dick but this thread doesnt make a whole lot of sense to me....

 

[Queen Bee]

Got a job and hired for 3 days a week 8 hour shifts and im good now

 

[Queen Bee]

No problem yeh it took alot of experimentation with limbsavers and pads to reach my comfort level with larger calibers

Got hired for a good permanent position which gives me enough to have a small apartment that i share with my brother so thats all set too.

 

[soloman02]

I thought the main point of contention between a 16" 308 and an 18" 308 was the the 18" burns all the powder and the 16" does not...

 

[bsalie]

I saw a test that cut a barrel down from 28 to 10 in 1 inch increments. they did not see a reduction in vel or accuracy, till they went shorted than 13 in with a .308. When done with a .300 win mag the barrel needed to be longer( Like 22 in) to get the most out of a load.

 

[ChevyGuy91]

I saw a test that cut a barrel down from 28 to 10 in 1 inch increments. they did not see a reduction in vel or accuracy, till they went shorted than 13 in with a .308. When done with a .300 win mag the barrel needed to be longer( Like 22 in) to get the most out of a load.

No reduction in velocity from 28 inches to 13 inches? I'd like to see that video.

 

[92G]

cutting the barrel by 1" increments and then testing accuracy is retarded.....every time the barrel gets cut it massively affects barrel harmonics, vibration and node location, so it just isn't so easy. as i was taught, any given barrel/rifle setup will have specific ideal lengths where the antinodes are in optimal locations.

the length vs. velocity relationship is much easier to comprehend but length vs. accuracy is not so simple.

 

[bsalie]

here is the article, i just found it
http://www.thetruthaboutguns.com/20...t-barrel-length-muzzle-velocity-and-accuracy/