Best weight 308 projectile for long range from a 20" barrel ?

M

Metal god

New member
So I've worked up only one load for my RPR in 308 and that's duplicating-ish the 168gr GMM load at 43gr of IMR-4064 . It's a good load and shoots pretty well .

I normally would just start buying bullets and testing all kinds of combo's but with this rifle I want to limit the load development round count to no more then really needed .

Now I've read the heavier ( 190gr to 200gr ) bullets are better in the short barreled 308's at long range - 600+yds ??? I have been thinking about the 155gr Palma bullets though for having the higher BC but the lighter weight to push a little faster .

So I'm looking for one or two weights to try and more less looking at Hornady or Sierra as the manufacturer . I know Berger likely has the bullet I want but I'd rather not have to pay the extra cost if I don't need to . Bergers locally at that weight are in the $.50 to $.60 a bullet range and that's high dollar to me . Although at that price I'm sure that would help keep the round count low :p

I had a great load awhile back using 190gr smk and N-540 that may have been the best load I've ever produced but the powder was never available locally so that load pretty much just got pushed to the back of the binder . Maybe I try to bring that back now that the components seem to be a little more available these days .

What say you ? :)
 
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I would look seriously at the Hornady ELD Match bullets.
Weights available are 168, 178, 495, 208 and 225.
I only shoot the 168's currently but the ELD Series get rave reviews and are reasonably priced.
 
Difficult or impossible to get decent velocities out of such a short barrel with those heavy bullets. If you don't care about trajectory, maybe not a problem.
I don't see a problem using 155 or 168 grain bullets @ 400-500 yards although others might find the heavier bullets resist wind drift better.
 
Everybody brags about their short barrels at long range, so it can be done.
When I was shooting FTR, even though with a longer barrel, I was pretty happy with the 175 SMK. The 155 Scenar and Palma bullets did not do anything special.
 
I have some Hornady 178gr BTHP on hand . I'll likely give those a try

As for heavies in a short barrel . It's been awhile but I remember the guys saying IMR-4350 , N-550 and other slower powders are what you need . Maybe Varget would be good with a 190gr smk . The above is my issue really . I've been doing this long enough to know what to do . The problem is I don't want to send 500+ rounds down the pipe testing 3 or 4 bullets and 3 or 4 powders . That can be 16 different loads to test with a minimum of 40 rounds each to there final results .

Right now the 178's are the heaviest I have on hand and I don't have any slower powders in quantities enough to run the tests . This is why I'm here asking you all . To narrow the list of components I buy next .
 
Out of my 20" 308 win I haveca hunting load of a 180gr Hornady SST over 42grs of RELOADER 15. Havent run it out to great ddistances but it is an accurate load. Conversely I can't get them to group well in my 300WM.
 
Its not weight that is the important variable, its BC and velocity.

Extreme is a round nose 200 grain vs a sharp nose boat tail 150 grain.

The shape and higher velocity will get you further out above sonic than will the 200.

Now you can lob that 200 a long way, but then you subject it to more wind and erratic ops when it falls through sonic.

And a 150 is going to go a LOT faster. The 308 is capacity limited, its oriented around the 150.

Twist in some rifles is 1-12.

For what its worth, I finally found a bullet my XCB barrel seems to like, H168ELD. Everything else has been inconsistent and or mediocre.

The Hornady Amax in that caliber is a good one as well. Its a target bullet, Hornady is not consitant with the AMAX thing as lower down its a varmint bullet. Cabella use to carry the same bullet with a green tip called the ZMAX (zombie of course)

XCB is poor finish compared to Shilen and Lothar Wather and an outfit called Apache is NOT the place to go for a finished barrel (guy thinks 1 inch MOA is a good result from a custom made barrel)

Agreed on Berger. I got some Jugernauts on sale, was getting great results in the 7.5 Swiss, can't afford them.

No real answer but spending time on load development is part of what its about.

You probably have 8,000 rounds before you replace the barrel.

Once you do, get a 32 inch and shoot the heavies if you want (but go with 1-10!)
 
Its not weight that is the important variable, its BC and velocity.

Extreme is a round nose 200 grain vs a sharp nose boat tail 150 grain.

The shape and higher velocity will get you further out above sonic than will the 200.
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Agreed and understood , It's the very reason you want the heavy bullets . To have the higher BC at the lower velocity ( match pointed bullets was assumed ) but realize now I should have been more clear on that ;)

190 gr and above should handle the transonic zone pretty well . Right now I'm looking at the 195gr ELD . My ballistic calculator says if I can get those to 2330fps I should be gtg out to 900yds easy and 1k should be doable but they will be dropping a looong way .

You probably have 8,000 rounds before you replace the barrel.
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I have 4k rounds through another 308 and although it still shoots pretty good I no longer can get better then 1/2 moa out of it . New to about 1500rds I could get 1/4 moa often but I've not seen a group that size in a few years :( . This is the reason I don't want to waist 500rds of early barrel life doing load development . The rifle only has about 500rds down the pipe now , maybe a little less . I'd put 60 to 100rds through my Savage every range trip and I went a lot . I'm only putting 40 or so though the Ruger each outing .
 
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Barrel length has nothing to do with bullet or powder choice. The bullets and powder that give the best speeds and accuracy from a 28" barrel will still be the best option in an 18" barrel. The longer barrel will be faster, but not by nearly as much as a lot of folks believe.

Loaded to factory specs a 175-180 gr bullet is where you reach the point of diminishing returns in a 308. In fact I've been using 178 Hornady ELD bullets with a max load of Varget for just over 2600 fps in mine for a while now. I see no downsides to using them over lighter bullets. I have several 308's with 10,11 and 12 twists. Even the 12 twist barrels shoot them great.

Get much heavier and you can't get enough velocity to take advantage of the higher BC's. At least not with book loads. I've know of some guys loading 215 gr Berger bullets to a much longer OAL with over book charges that are getting hits at some extreme ranges. But I'd just load them in a 30-06 or 300 WM if I wanted to do that.
 
Metal good
It's coming to the end of my outdoor shooting season , it's my time to order a new lot of Sierra 186 gr MK's but have a box of 100 Sierra 165gr HPBT (game king ) bullets , has more BC then the MK so I'll be giving them a try in my Rem 700 308 20" 11.27 twist before I order for next year , was also thinking of the Sierra 150gr HPBT MK . IMR 4064 is the powder I only use , the GemPro 250 scale make weighting even that powder to the hundreds of a grain . My 200yard load is 40.84 on the low side but shoots well . Using the game king with the same .002 jump the bullet will be deeper in the case .
 
Barrel length has nothing to do with bullet or powder choice. The bullets and powder that give the best speeds and accuracy from a 28" barrel will still be the best option in an 18" barrel.
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I think "generally" that is true but when you're looking for more then just accuracy at 100yds the bullet weight , shape and barrel length all matter . Example : the 168gr smk is a terrible choice to shoot past 600yards regardless of the rifle or components you use . It was designed for a international 300yd competition and does poorly past 600yds . I believe it has to do with the angle of the BT . I believe it's to steep and the bullet becomes unstable as velocity drops .

This goes to my point of velocities being lower you need the longer bullets to stay stable . the 190gr + bullets not only have a longer pointier nose , the BT is longer as well keeping it more stable through the transonic zone .

So in general I'd agree with the above quote but when you start needing some very specific characteristics from your set up , all things matter and can make a difference .
 
The nice thing about Savage and Ruger (probably the other new chassis rife) is you can replace the barrel easily.

Shooting is fun so I shoot a lot. All my main target guns are Savage so I don't worry about round count. New barrel is $340 or so.

You can also extend accuracy by seating gout longer. Get a short throat barrel and you can extend that longer still (some rounds is an issue if you want max performance as you have to seat the ELDs shorter) .
 
What you have to look at is that 308 is capacity limited as it was designed around 150 gr.

30-06 is not. So for that same 190 gr bullet, you are shorting the 308 200 FPS.


A 155 gr ELD match has a BC of .439.

A 195 Match has a BC of .550. That is very close and I suspect if you run the calcs the 200 FPS more than makes up for it.

Its why the 6.5s do better than 308 in 1000 yard shooting. Lighter bullets, higher speed and a BC in the 130 gr of .549.
 
The 195 ELD has a BC of 584 but I'll be shooting it at lower velocities so it will actually be likely 560-ish . A full point better is quite a bit IMO .

When running the likely numbers the 168's will not work very well past 800yds or at least will be hitting the transonic zone shortly after and are to short to buck that destabilizing effect . The 178's will likely do well out to 900+ but the 195's appear to be going the same velocity as the 178 at the 900/1k yard mark but the extra length and weight of the 195's should handle the transonic zone better .

The longest range locally is only 960yds so I won't be able to test past that distance any time soon .
 
Palma is a critter unto itself. 155's are the only weight allowed.
Anyway, 168's are for up to 600. 175/178's past there. The 190 grain match bullets are mostly intended for .300 Win Mag match rifles.
What rifling twist you have will determine the suitability of a 20" barrel. And the weight of the barrel.
"...the Game King..." Hunting bullets are a different game too.
"...8,000 rounds before you replace the barrel..." You're doing something wrong.
 
I would consider either Sierra 175 SMKs # 2275 (BC = 0.505) or 175 TMKs #7775 (BC = 0.535) with IMR 4064 powder loaded for around 2,500 fps muzzle velocity. In a 20 inch barrel, that would let you stay around 54,700 psi, well under the .308 Pmax of 62,000 psi.

At that muzzle velocity and high BCs, the 175s should maintain supersonic velocity out to 1000 yards.
 
Well it seems the 175's and 178's are getting a lot of love in this thread . I have 200 Hornady 178gr HPBT bullets and forgot about the 500 175gr TMK I have . So I guess I'll start with what I have on hand . I also have 1k+ 168gr HPBT bullets and 400+ 168gr smk but those are my plinking bullets

I'm not sure I want to use IMR 4064 though . I'd really like to try something just a tad slower , maybe Varget or N-540 ?????? What about BLC-2
 
I tend to stick to norms . . . the 175 SMK in this case.

It's also why God created QuickLoad.

Selecting 59ksi, 90% fill to 110%(start compression) and 20" barrel:
Here are your top-10 powders . . . highest velocity first.

Vihtavuori N550
Alliant Reloder-17
Hodgdon H414
Winchester 760
Ramshot BigGame
IMR 4895
Hodgdon BL-C2
Winchester 748
Alliant Reloder-15
IMR 3031


.
 
UPDATE

So I went ahead and bought what I said I did not want to buy , Berger bullets :rolleyes:

I was at my local gun store looking for the 195gr ELD match but they were out so the owner says " these 200.20x Begers hard to keep in stock . The F-TR guys love them" http://www.bergerbullets.com/200-20x-perfect-bullet-f-tr/

So I bought some :o . $110 later I'm walking out with a hundred bullets and a pound of N-550 :eek: OMG the very thing I wanted to avoid and there I was over spending to an amount I'm now hoping this combo shoots like crap because if it's great my wallet is in big trouble .

Anyways , Now I'm looking for good data for this combo . My Sierra manual is the only one I have that at least has a 200gr bullet and N-550 . At least I have one source . I think it starts in the mid 37gr area and max outs at just over 41gr . The interesting thing here is what Berger says about these bullets .

Berger in link above said:
Another exciting feature of the new 200.20X bullet is that the shorter bearing surface means less engraving surface and barrel friction, which means more velocity at the same pressure. The shorter bearing surface also makes this bullet easy to load and shoot in standard chambers, which means you don’t need a special reamer to make it work in your rifle.
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The second I looked at the bullet the short baring surface was very noticeable to me and had me thinking I'll not have a whole lot of seating depths to play with . It will need to be seated deep enough to have good bullet hold which will leave little to play with . ( in comparison to something like a long 200gr smk ) Shouldn't be an issue but was an observation , maybe you guys know a little more about these bullets and can add your experiences .

My point to that is , with the shorter baring surface then the Sierra bullet "maybe" the low to mid 37gr start load is a tad light to start with using these bullets ???? Thinking of starting 38.4gr or so .

I may do something like this to be safe . Load one or two at the mid 37gr area then one or two more at about 38gr and use these as pressure test loads just to be sure I'm not already maxed out for what ever reason ??

Pretty much something like this to where the loads I'm expecting to be using will have 5 rounds loaded but the others just a few to check for pressure signs on my way to where I hope to end up ????

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EDIT : Update to my update , Just ordered 300 195gr ELD match bullets from Powder valley for $99 delivered . Hope they work because $.33 per bullet is a lot better then the $.56 I just paid for the Bergers . Still have bunches of 175's and 178's so I should be GTG just need another pound or so of N-550 to work with . Already have Lapua brass and Fed match primers .
 
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