Heaviest bullet for a 1in12", 26", .308Win


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hadmanysons
April 9, 2010, 11:30 AM
I'm looking into working up a load for my 700 SPS-V with a 1 in 12" twist, 26" long that's chambered in .308. It's shoots 168gr SMK's really well but I want something heavier in the 180gr range to keep it stabilized out to 1000yds but everything I've read says that my barrel my not stabilize something that long/heavy cause my twist rate isn't fast enough. Is this a real concern or should I just buy a box of 185gr Berger VLD's and if it works it works?

Thanks

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918v
April 9, 2010, 11:37 AM
What does Berger recommend for their 185gr VLD?

Jim Watson
April 9, 2010, 11:50 AM
Berger thinks a 12 twist will stabilize their 185 gr VLD.

Ought to do great with a 175 gr SMK.

I have been fooling with 155 gr Scenars and will likely try the 155.5 gr Berger. Less recoil and the higher velocity makes up for the lighter weight and slightly lower BC.

Zak Smith
April 9, 2010, 01:25 PM
The 155 Lapuas (or 155.5 Bergers) at over 2900 fps is the best long-range .308 load. At the '08 and '09 Steel Safari match, the high 308 shooter for the last two years has used this load (and come in "only" 7th place overall).

However, I have shot as heavy as the 210gr Berger in my 1:12 24" .308 barrel. At my altitude, it flew fine, however, slow. (At lower altitudes you might need more twist.)

hadmanysons
April 9, 2010, 02:50 PM
Thanks for the tips guys, i'll try some of 175's first and go from there.

USSR
April 9, 2010, 05:44 PM
Myself and a lot of guys shoot 190SMK's out of our 1-12" twist .308's. Don't believe everything you read about .30 caliber twist rates.

Don

responsiblehunter
November 5, 2010, 12:19 PM
I have a weatherby vanguard .308 win with a 24 inch barrel, with a 1:12 twist. Whats going to be the difference considering my barrel has 2 inches less than the 26 as far as pushing heavier loads like a 180gr?

Where can I go to figure out the heaviest bullets I can push? There are a lot of factors to consider but where have you guys noticed a huge drop off in velocity and foot pounds performance with heavy gr bullets in .308?

Glad to hear what you said about twist rates-- I need to learn which twist rates work with which gr bullets in my .308, but if you think it isn't written in stone thats excellent.

Zak Smith
November 5, 2010, 12:43 PM
Where can I go to figure out the heaviest bullets I can push?
There is no limit other than twist rate. Different bullet types of the same mass may stabilize differently. If you are interested in a particular bullet, you have to test it. Alternatively, you can use the required twist rate suggested by the bullet manufacturer.

Heavy is a matter of perspective. There are .30 caliber bullets up to 240gr, while .308's sweet spot is more like 150-180 grains.

rbernie
November 5, 2010, 12:55 PM
Glad to hear what you said about twist rates-- I need to learn which twist rates work with which gr bullets in my .308, but if you think it isn't written in stone thats excellent.Bullet stabilization is a function of twist rate, velocity, and bullet length (not weight) as well as temperature and altitude.

As Zak stated, the sweet spot for 308 tends to be in the 150gr-180gr region. I would expect the Vanguard to be oriented towards using commonly-available hunting bullets in the 150gr-165gr range. If you're looking for VLD designs, then you may get better results in the lighter ranges (altho USSR's experiences suggest the possibly of getting heavier bullets to work well).

rcmodel
November 5, 2010, 12:57 PM
It's interesting to note the military M14 rifle also has a 1/12 twist, 22" barrel.

The new standard GI M118 Long Range Match & Sniper ammo uses a 175 grain boat-tail Sierra matchking.

So I think your 26" 1/12 would handle those or 180's just peachy keen!

rc

Zak Smith
November 5, 2010, 12:57 PM
Here is a bunch of math about twist rates. It's pretty interesting
http://yarchive.net/gun/barrel/rifling_twist_angle.html

responsiblehunter
November 5, 2010, 01:05 PM
It's interesting to note the military M14 rifle also has a 1/12 twist, 22" barrel.

The new standard GI M118 Long Range Match & Sniper ammo uses a 175 grain boat-tail Sierra matchking.

So I think your 26" 1/12 would handle those or 180's just peachy keen!

rc
did you mean for my 24" or did you type that for the 26"

rcmodel
November 5, 2010, 01:14 PM
Nope.
Old age brain fade I guess.

I thought it said 26" when I read it the first time.

But regardless of that, your barrel is 2" longer, giving higher velocity, then the M14 Sniper rifle being used in Iraq with 175 grain SMK's as we speak. The M40 Remington sniper rifles are 1/12 24" using the same ammo

But 175 SMK's are definately not hunting bullets.

I just responded to your other post concerning 600 yard hunting you are trying to now delete.
You might want to read that.

The .308 is limited by it's small case to bullets up to about 180 grains.
Heavier then that, and the base of the longer bullet is taking up needed power space.

A 1/12 .308 would probably max out at around 180 grains with most long range bullet designs.

Anyway, very few hunting bullets will expand as designed at the remaining velocity you would be getting at 600 yards.

Your name responsiblehunter would indicate you really don't want to be crippling big game at 600 yards, do you?

The bottom line is, 600 yards is a really long ways to place every shot in the kill zone of a big game animal. It's one thing hitting a paper target at 600 yards when you know it is exactly 600 yards.
Judging 600 yards accurately on a game animal is a whole nother ball game!

Maybe you should set your sights a little closer!

The sign of a skilled hunter is how close he can get to the game, not how far away he can attempt shots that don't always result in a clean kill

rc

Zak Smith
November 5, 2010, 01:22 PM
Barrel length has little to do with twist rate provided it's not extremely short (SBR).

Zak Smith
November 5, 2010, 01:23 PM
A student of mine whacked one or two antelope at 475 with an M1A. It's doable.

rcmodel
November 5, 2010, 01:27 PM
I would offer that 475 yards is not nearly as difficult as 600 yards!

In either estimating the range, making the shot, or getting the bullet to expand as designed.

rc

Zak Smith
November 5, 2010, 02:19 PM
I agree that difficulty is not linear with distance.

USSR
November 5, 2010, 06:24 PM
Where can I go to figure out the heaviest bullets I can push? There are a lot of factors to consider but where have you guys noticed a huge drop off in velocity and foot pounds performance with heavy gr bullets in .308?

The place you go is the range. I recommend going to a different powder with the heavy bullets than you might normally use with the lighter bullets. The hands-down best I've used with 190SMK's is VihtaVouri N550. I get 2700fps using this powder.

Don

hadmanysons
November 6, 2010, 07:45 PM
Holy resurrected thread batman!

responsiblehunter
November 8, 2010, 07:22 AM
Thanks thats some good info- off to the range, RC-my other post was almost identical to this one, i didnt mean to put it up. I did read and appreciate the response what you say about hunting those ranges and getting closer I agree with.

responsiblehunter
November 9, 2010, 11:18 AM
I could not be happier with the performance of my weatherby vanguard .308 win with the 24" barrel. Look at these results with factory ammo shown, at 100 yds using both 150 gr and 180 gr bullets. The 150 has a couple sight adjustments but my group was amazing on such an affordable rifle right out of the box (after working it up at 25yds, 50yds, then 100yds.)

Honestly I will try and push the limits up to 190 grs, but it looks like you guys are right-- the sweet spot certainly does lie in the 150gr -180 gr range on .308 win


I might post a review on the weatherby vanguard because this rifle far exceeded my expectations for the price-- no fancy features at all, quite nice results.

IMG_3729.jpg

IMG_3730.jpg

responsiblehunter
November 9, 2010, 11:30 AM
RC- What do you think about this remington core lokt soft point ammo for hunting? Expansion wise and on which game? I am so satisfied with this ammo that I would like to use the 150 gr on deer and the 180 gr for bear (and elk if I am lucky enough to see one) as i build up my .308 win brass stock pile for reloading

Would 180gr be overkill for deer? (white tail in VA) Would 150 gr be too light for bear?

Thanks!

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