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Fieldcraft 18-20 inch .308 performance?

JOct1

Private
Minuteman
May 4, 2010
9
0
44
Northeast US
Hey, I'm new to the forum and would like to say hi. Been around shooting for some time but was always interested in the art of precision shooting and science involved. While I've seen vids of shooters (i.e. Galli) hitting 1000 meter shots with the GAP Gladius, I was told by Mike Lau that using 168-175 gr. 308 out of an 18-20 inch barrel would make it go subsonic really quickly and obviously that would lead to problems. Is this accomplished using lighter projectiles, higher yield propellant, Nightforce optics or does one compensate for the transsonic disturbance? Thanks for any help in advance.
 
Re: 18-20 inch .308 performance?

I just ran a load of IMR8208 w/ a 155 Lapua at an easy 2885fps. My bullet will not be going sub or trans-sonic for well past 1K yards.

I shoot a Badger M2008 w/ a 20" barrel, others will chime in and attest to similar results.

If you run a search on short barrel or 16-20" bolt rifles you find hours of informative reading.

In addition you would be best served to fill out your profile completely before you get your ass handed to you by less tolerant members.

KT
 
Re: 18-20 inch .308 performance?

18-20 is enough to get the job done, no changes to gear required. Velocity gain for longer barrels isn't very significant.

If you search here i'm sure someone has posted the data before.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: REM700MAN</div><div class="ubbcode-body">I don't know why everyone is worried about bbl length. As long as you have a Nightforce your bullet will be fine to 1000 </div></div>

Damn, why am I just know hearing this????? I'll take two please
 
Re: 18-20 inch .308 performance?

Interesting. I read an article by Dick Metcalf last year that indicated the increased rigidity of shorter barrels and how that furnished solid accuracy. Figure the 155 gr. Lapua seems to be a popular long range .308 load as both SingleShot 85 and Galli (and probably others) use it. Guess it has a high BC. Now to affording a Nightforce ... thanks for the info.
 
Re: 18-20 inch .308 performance?

JOct1...the video you saw of Frank shooting the Gladius to 1K im almost 100% certain he was using Corbon or BlackHills 175 loads. You dont want to shoot the 168 SMK for anything Long range.
 
Re: 18-20 inch .308 performance?

On the youtube video where he's shooting the GAP Gladius, the info that scrolls across the screen said 800+ and then 1000+ yards, 18.5 inch barrel, Nightforce scope, 155 gr. Lapua.
 
Re: 18-20 inch .308 performance?

I have an 18". It's neat but if I were shooting long range I would want a 24". Velocity is the name of the game when you are shooting long range.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: REM700MAN</div><div class="ubbcode-body">I don't know why everyone is worried about bbl length. As long as you have a Nightforce your bullet will be fine to 1000 </div></div>

lol wrong it's the Super Sniper scopes that make your bullets go to 1k yards, says so on the box.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: REM700MAN</div><div class="ubbcode-body">As long as you have a Nightforce your bullet will be fine to 1000</div></div>

I really can't wait for the Nightforce now!
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JOct1</div><div class="ubbcode-body">On the youtube video where he's shooting the GAP Gladius, the info that scrolls across the screen said 800+ and then 1000+ yards, 18.5 inch barrel, Nightforce scope, 155 gr. Lapua. </div></div>

Yeah that's ONE of the videos. He has a couple and I do remember in one of them he was running 175 CORBONS. It's been done and proven time and again that the short barrels shoot just as well if not better then some the longer barreled guns. Granted it all comes down to what you will be doing with it. I'm building a 18.5" because I'm LE and I have enough shit in the trunk of my patrol, let along a 26" cannon, plus 95% of the time I will probably be shooting 600 yards and in when I do shoot it. 99% of the time if I would have to shoot it at work it will probably be from 25-100 yards. It doesn't help I'm 5'11" and only 165 pounds, granted I'm only 4% body fat but I really don't want to lug a 15-16 lbs rifle around when I'm training. At least I know if I want to I can shoot it to 1000.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">I have an 18". It's neat but if I were shooting long range I would want a 24". Velocity is the name of the game when you are shooting long range.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: REM700MAN</div><div class="ubbcode-body">I don't know why everyone is worried about bbl length. As long as you have a Nightforce your bullet will be fine to 1000 </div></div>

lol wrong it's the Super Sniper scopes that make your bullets go to 1k yards, says so on the box. </div></div>

Very true my friend, but with all the new powders and bullets available these days the "need" for a long barrel in not a necessity any longer.

Nothing wrong with a longer barrel and application will dictate.

I guess my point is; if you need the portability of a SBR you can have it and still retain exceptional levels of accuracy. If maneuverability is less of an issue and you are trying to obtain the fastest possible velocity then the long barrel is the ticket.
 
Re: 18-20 inch .308 performance?

Ranger1183: tried the link but was not loading for some reason. If there's a correction needed, resend b/c def. interested to learn more.
K9222: I agree with you on the topic of capability; where I am they consider it generous zoning to give you 300 yards, much less 5-6, even less for 7-1000. I prefer a short rifle that has quality 'smithing in it and yet, should I decide to take a course in NC or TX, would like to know I don't have to switch sticks to engage longer distance targets.
 
Re: 18-20 inch .308 performance?

Def. learned a lot, gents, and now eager to learn more. If Lau was right, and 168-175gr. go sub-sonic before 1k, wonder how that is factored. My situation is that I'm training on a Rem 700 SPS Tac w/ Trij. 5-20x50. Would like to get a well-built stick with some custom attention, and though not sure I'd spring for a Gladius since suppressors are sadly out where I am ($3,850 ain't chump change either), I'd like to go for a rifle of similar specs. This is for when I improve, and so first I feel it's wiser to learn more, hence my questions on shooting when bullets may likely hit the trans-sonic region. So far, though, it appears that modern manufacturing and loading has done away with the short-barrel, short range paradigm. I always appreciate more info, but also understand the moderators don't want topics going on forever. Any info on .308 performance appreciated (I've got Blitz's book and software so should use that), but thanks a great deal for clearing up that 18-20 inchers can actually perform at 1k with 155 Lap. Scen. AND 175 grainers, too. I'll be asking for opinions on manufacturers down the road!
 
Re: 18-20 inch .308 performance?

and yes, REM700man, I'll start saving for my Nightforce immediately. Deadly0311, quick ques: though from what I've learned states heavier projectiles have better BC's at reducing velocities, does the 168 gr. SMK have a lower powder charge than the 155 Lap. Scenar (yeah, I know guys, answer one ques and get another. Sorry, will post a diff. thread if that's more appropriate)? I know the 175 has ousted the 168 for longer range performance, and actually just learned of the 155 today, but just curious since the latter is the lightest of the three. Thanks again, everyone.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JOct1</div><div class="ubbcode-body">Ranger1183: tried the link but was not loading for some reason. If there's a correction needed, resend b/c def. interested to learn more.</div></div>

That link is loading fine for me. Anyone else having a problem connecting to this article?

http://www.tacticaloperations.com/SWATbarrel/
 
Re: 18-20 inch .308 performance?

Frank has explored and understands the physics behind his choices very well. His employment of Lapua 155 in a shorter barrel tends to finish off the 'how to' argument nicely.

My thinking runs to longer barrels, and that belies my own approach, which is neither tactical nor adapted to deal with CQB situations. Simply put, I think shorter distances favor shorter barrels and longer distances favor longer ones.

There is also the matter of our height disparity, with me being rather well over a foot taller than Frank. This is not a dig at Frank, it simply means that a longer barrel could well be more wieldy in my hands than some others.

I do own short barrel long arms, and I do allocate them to shorter distances. But I take advantage of the shorter distance and the limited tendency for drop, and employ chamberings which deliver more mass.

Basically; I favor chamberings like .44Mag and 20ga to lob slugs across shorter intervening distances, where their (nearly identical, I might add) ballistics and terminal effects are well suited. IMHO, lighter projectiles at faster velocities pack a lot of accuracy, but the heavier, slower ones tend to have favorable terminal performance, and at shorter distance I think it's reasonable to sacrifice some of the former to gain some more of the latter.

CQB and LR precision are not two sides of any coin. They are separate coins. That's an opinion.

Greg
 
Re: 18-20 inch .308 performance?

I'm running 175gr SMK's at 2650fps out of my 20in .308 SPS Tactical, with 45grs of varget. My question is would there be any difference in downrange ballistics if it was a 24in barrel loaded to 2650? After it leaves the muzzle I can't see how anything would be different, maybe more muzzle flash but that's what suppressors are for.
 
Re: 18-20 inch .308 performance?

Why is it always 1000 yards?
Any old 308, with any barrel length >/= 16" will do 900 yards nicely.
Shorter barrels pair up nicely with the 155 grain palma style bullets.
Longer barrels do better with any weight.
A lot of fretting takes place to extend the range of the 308 from an easy 900, to 1000 yards and beyond.

A 30" barrel shooting long loaded 155 (and greater) grain bullets will make 1200 yards with little extra effort.

It takes a lot to pick up those last few hundred yards.

Embrace the cartridge for what it is.

Or boost performance with a genuine Nightforce scope.
My .22 LR used to be a dog at 400 yards.
Now I shoot it in "any sight" OTC matches.

Thanks Nightforce!!!!

(Real customer testimony)
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HillbillyfromAL</div><div class="ubbcode-body">I'm running 175gr SMK's at 2650fps out of my 20in .308 SPS Tactical, with 45grs of varget. My question is would there be any difference in downrange ballistics if it was a 24in barrel loaded to 2650? After it leaves the muzzle I can't see how anything would be different, maybe more muzzle flash but that's what suppressors are for. </div></div>

That's a good question. I'd really like to know the answer.

How hot is the load you mentioned? I'm trying to get into reloading for my .308.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JOct1</div><div class="ubbcode-body">On the youtube video where he's shooting the GAP Gladius, the info that scrolls across the screen said 800+ and then 1000+ yards, 18.5 inch barrel, Nightforce scope, 155 gr. Lapua. </div></div>

You are sort of mixing two different videos...

The video shot at Byers, CO at the Colorado Rifle Club is at 5300ft so the altitude is in my favor for sure. I did shoot both 155gr Lapua Scenars and the 175gr SMK... however there is another video shot at Rifles Only in South Texas, 78ft where I am shooting the 175gr Cor Bon ammo. So there is more than one video out there of me shooting at distance with an 18.5" bbl.

You have to put this stuff in context... I definitely like the 155gr Lapua loads, however I am always shooting factory ammunition whether it is from Cor Bon, Lapua or Black Hills.. (Now you can add the Hornady 178gr Superformance) so I am not reloading for any of the videos I shoot. I use factory flavors only, and definitely NOT 168gr ammo.

To answer the question above a bullet leaving at 2650fps is going at 2650fps, it doesn't matter the barrel length, if that is your MV that is your MV and that will determine where it ends up downrange, providing you do your part.

The barrel question with a 308 has been answered and beaten to death. Its been around so long, and shot by so many there is no unknown, there is truth and fiction and most fiction comes from people trying to guess what it will do and not actually going out and doing it. Most myths are passed down over and over and simply take on a life of their own, until someone actually goes out and sees for themselves...

I have even shot and have some crappy video of me shooting my 16" AR10 to 1000 yards at Rifles Only... I managed about 4 hits out of 10 shots... not very good but it hit none the less. However the same rifle will consistently smack an 8" plate at 800 yards on the same range over and over without a single hiccup. So today, in 2010, you can pretty much get away with a lot with a 308, especially when you consider it is really only an 800m cartridge, we shoot it further because we can, not because we are supposed too.
 
Re: 18-20 inch .308 performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Al Rick</div><div class="ubbcode-body">Lowlight,

"I use factory flavors only, and definitely NOT 168gr ammo."

Why not the 168gr?</div></div>

Why would you use a 168gr bullet when you have much better alternatives.

This isn't 1985, we have progressed a bit past the 168gr-ers.

Inside 600 yards they are fine, and if that is what you want to use, more power to you, but why would you even entertain a bullet that can't take you all the way to the max effective range of the rifle under all conditions. Seems foolish to work up with one bullet only to have to switch to something else to close the deal.

The 175gr bullet is a much better choice, at 2600fps will get you to 1000 yards still supersonic, a 168gr under most conditions goes transonic around 920 yards, in some cases less, so strike one. Low BC, so the wind is kicking its ass, honestly where is the sell, because its available, no thanks.

The 155gr Scenar load from Lapua is even better, so again, it completely beats the 168gr.

If you're gonna reload there are a helluva lot more better bullets available.

Just because people have been shooting it, doesn't make it the best choice, just a name most people know. Short range results not withstanding I consider it up there with most hunting ammo.
 
Re: 18-20 inch .308 performance?

Lowlight, no dispute, however I have shot 168s to 1000, with no trouble, in spite of the fact that they do go subsonic before getting there. I know it is not the best choice for that distance, but my rifles do not like the 175s, so I do better with the 168s anyway. Although, I will admit, if I really want to shoot at 1k +, I would simply use a different cartridge.
 
Re: 18-20 inch .308 performance?

Thanks, I have much too much to learn.
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Re: 18-20 inch .308 performance?

Barrel length effects can be minimized (TO AN EXTENT) with using different powder. With longer barerels, use slow burning powder to gain optimum velocity. For shorter barrels, use faster burning powder to get velocities up quicker. Also, Lighter bullets to get higher velocities. Thats mainly why Palma shooters use 30" barrels and 155 bullets. Obviously that will affect chamber pressures as well as barrel life.

+1 on the article http://www.tacticaloperations.com/SWATbarrel/ I found that to be very interesting.

Also, read the book "Rifle Accuracy Facts" by Harold Vaughn. Very insightful reading material about not only barrel length, but a variety of topics affecting your rifle's accuracy.