Range Report 16" or 18 " 308. SA58 ?

[carryhold]

Can any one give some info on the pros and cons of a 16" compared to an 18 " 308. barrel SA58 rifle shooting standard ball 147 grn. - 155 grn. ammo ? Im kind of leaning towards the 18" because of over all better velocity and accuracy and powder burn. I plan on shooting 100yd to 200yds on average. Or should I chop it to 17 inches instead to meat half way ?

Some info please

thanks guys

 

[J.Boyette]

Re: 16" or 18 " 308. SA58 ?

My 16" Ar-10 goes to 700yds shooting 155 Noslers just fine.

John

 

[kraigWY]

Re: 16" or 18 " 308. SA58 ?

I dont know what you are using your gun for, but here is an ideal of what will happen.

My Grandaughter and her little friend are working on a science project. The main theme is. Assuming: the normal max range for hunting would be 300 yards; Assuming: 1800-2000 ft lbs of energy is needed for a safe, humane killing of elk. Goal what would be the shortest barrel lenght for a 308 Rifle yet develope the required energy at 300 yards. Using Rem. Factory 180 ammo.

I donated the rifle and they cut, from 26 -16 inches, 2 inches at a time, getting the velocity, then energy. Here is the results for their testing. Remember they were using normal factory hunting ammo.
Length Vel KE Vel KE
Muzzle 300 yards

26 2826 fps 3,192 2240 2,005
24 2722 fps 2,961 2149 1,846
22 2713 fps 2,942 2141 1,832
20 2677 fps 2,864 2109 1,778
18 2654 fps 2,815 2089 1,744
16 2552 fps 2,603 2000 1,599

 

[sobrbiker883]

Re: 16" or 18 " 308. SA58 ?

Accuracy is a relative term when one is speaking of SA58's and 147gr ball ammo.....
Get whatever length floats your boat. If you want accuracy there are much better platforms for the money.

 

[carryhold]

Re: 16" or 18 " 308. SA58 ?

Hi

yeah Im not really trying to refine the accuracy rather trying to get an idea of general performance. But what would you suggest for a semi auto clip fead in 308 as far as accuracy goes ?

Thanks

 

[carryhold]

Re: 16" or 18 " 308. SA58 ?

thanks for the info, interesting project

 

[akxx]

Re: 16" or 18 " 308. SA58 ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">
My Grandaughter and her little friend are working on a science project.

I donated the rifle and they cut, from 26 -16 inches, 2 inches at a time, getting the velocity, then energy.
</div></div>

You, sir, are a fine grandparent!

Your grand daughter's findings are similar to what I have heard: that the jump from 18" down to 16" is a bigger hit velocity-wise.

 

[Switchblade]

Re: 16" or 18 " 308. SA58 ?

HA! I have a R1A1 that has a 17" barrel. The standard 147fmjbt's work fine. If you reload them a little hotter they will go up to 2700fps. You do lose about 50fps per inch from 18" to 16".
Shoot me an e-mail and I will send you an XFL document that has some load data that I have done so far with a few rounds. It's a better place to start than from scratch. I am still in the process of developing the best load for this one so I am willing to share what I have so far. Go to 18". Anything shorter is just loud and a pita to get faster rounds and gas operation working good(you need to drill the gas hole to .0811 for it to work better if you go 16"

 

[Superswamp]

Re: 16" or 18 " 308. SA58 ?

I wish I had a science project like that in hi school. The info is very helpful I am deciding on a .308 project with a <20 inch barrel. What is the KE for Whitetail deer, needed for a clean kill? Thanks

 

[Switchblade]

Re: 16" or 18 " 308. SA58 ?

You want 2600fps to 2700fps without upping chamber pressures. In a shorter barrel making a heavier bullet go faster will require more powder. A new option is also the new Hornady rounds as well. You can get their bullets, and match cases and primers, but their powder is a in house thing for now.

 

[BCP]

Re: 16" or 18 " 308. SA58 ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: carryhold</div><div class="ubbcode-body">Hi

yeah Im not really trying to refine the accuracy rather trying to get an idea of general performance. But what would you suggest for a semi auto clip fed in 308 as far as accuracy goes ?

Thanks </div></div>

AR-10. Mine shoots 1.5" or better with every kind of ammo I put into it. Handloads are .75". I shoot off a bipod, bagged it would probably be a little better.

 

[marduk185]

Re: 16" or 18 " 308. SA58 ?

not to hijack but seemed kinda relevant to the conversation here, is it possible to cut back a standard length r1a1 to near the gas system and re-crown without any further mods to the gas system and have it run well/not malfunction with standard factory ammo?

 

[BCP]

Re: 16" or 18 " 308. SA58 ?

Yes, I see plenty of FAL's that have been cut down from the regular 21 to ~18 and they function fine. I believe 18" barrel with standard gas system is "Carbine" size.

 

[BCP]

Re: 16" or 18 " 308. SA58 ?

I would also have it threaded and add a flash hider.

 

[sobrbiker883]

Re: 16" or 18 " 308. SA58 ?

BCP huh? AZ?

Switchblade's well dialed in on the system and gives solid advice. 18" is as short as any 308 needs to be.

As I said, accuracy is a relative term with the FAL design. Good as a minute of bad guy battle rifle, but if you want precision an AR or M1A can be made to shoot better, just my oprinion. FAL's are fun though, I miss the R1A1 I sold lsat year......

 

[BCP]

Re: 16" or 18 " 308. SA58 ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">BCP huh? AZ?
</div></div>

Juggling between CA and AZ at the moment, was fixing up foreclosures in Maricopa and Casa Grande. I'm in Cali right now, wish I was in AZ though it's raining and cold here.

That and the houses are stupid cheap, a friend just bought one 2600ft, pool w/waterfall and boat-deep garage for 112k at auction. It's in Maricopa on the north side of the railroad tracks, and has a park behind it so he's not surrounded by his neighbors on all sides.

 

[sobrbiker883]

Re: 16" or 18 " 308. SA58 ?

I was asking in regards to the screen name, if it had anything to do with jesuits?

 

[BCP]

Re: 16" or 18 " 308. SA58 ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">I was asking in regards to the screen name, if it had anything to do with jesuits? </div></div>

Nope, sorry.

 

[Winny]

Re: 16" or 18 " 308. SA58 ?

I'm running a 16 inch barrel on .308 and I have no issues reaching 700 with 175 SMK's...

 

[Switchblade]

Re: 16" or 18 " 308. SA58 ?

FAL types get right particular on their gas systems when you go below 18". 17.5" does not make a big difference nor does 17", however, 16" on a FAL type requires accurate work on the gas tube bleed off.
Yes they will shoot 175's just fine, but the amount of powder you need to push them burns out the end of the barral as BIG FLASH. 147/155 is the way to go in a FAL type with a shorter barrel. You can bump them up to 2700fps before you start getting a lot of flash. I have Varget, and am going to look hard at some others that are made for military style auto rifles for mine to see if I can find a balance between velocity and accuracy(I am looking for no more than 2MOA. If I can get 1.5MOA, cool

 

[Lowlight]

Re: 16" or 18 " 308. SA58 ?

I was hitting at 1000 yards this week with a 16" AR10, it took 39 MOA or 11.6 Mils for me to do so in less than desirable conditions.

But it wasn't easy, however at 800 the rifle is an extreme hammer and will hit a 1 MOA plate at that distance with no problems.

 

[Cologgi]

Re: 16" or 18 " 308. SA58 ?

I had the 16 and it was just fine, it looks better to. In real life there difference will be so small you wont notice the difference. Plus if you add a can it will be more manageable for tactical shooting. You can turn down the gas to quit it up with a can which is pretty cool.

 

[Tyler Kemp]

Re: 16" or 18 " 308. SA58 ?

The difference in FPS sure will be noticeable.