Need help with a load for .308 target 1' Barrel 30" long 1in8 twist .

[james lambert]

Hi everyone my name is James and i'm new here . I'm looking for help for my .308 bolt action rifle . I'm going into the F-Class midrange NRA competition . been in it a few times already not with a good rifle yet .. just had a new barrel put on my rifle 1 inch target 30" long 1 in 8 twist .. trying to find what I've been told is that 1 bullet my barrel will like with the powder n grain amount that will give me a 5 shot group @ 100 yards that I can cover with a dime . I've been testing have not found that load yet . All help is greatly appreciated . a friend has a 1in12 twist with a 155 Hornady A-Max in his .308 and he did what i'm after , he covered his 5 shot group at 100 yards with a dime . thanks for listening James

 

[nastynatesfish]

Why did you do a 1-8tw? I'd think you'll want a heavy bullet as you can find. Your not gonna be told the best load for your rifle. Your going to have to put some leg work in

 

[Keith Glasscock]

Let's start simple - What bullet are you using right now?

I know you will get some "too much twist" replies. Let's ignore that issue for now - I'm running 155's in a 10 twist and shooting HM scores. Fast twist can work well.

 

[DRNewcomb]

Well, I'm not going to be the one who says, "Too much twist" but I will say that with that twist you want to be sure to use a very high quality bullet. Every two feet the bullet will make three revolutions. At 2800 fps that's about <mumble> 4200 RPS or 252K RPM (?) about 25% higher than 1:10. At that rate, small errors in jacket concentricity show up as big errors on the target.

 

[Marksman63]

Please, tell me, why a 1/8 TR???

 

[james lambert]

Let's start simple - What bullet are you using right now?

I know you will get some "too much twist" replies. Let's ignore that issue for now - I'm running 155's in a 10 twist and shooting HM scores. Fast twist can work well.

I tested some 155 a-max with a 5 shot group a covered with a quarter it was the best so far . and 168 in hornady & berger . 175 in berger vld , 178 hornady . a 180 nosler 3 rd best results .. and a 185 berger .

 

[james lambert]

Well, I'm not going to be the one who says, "Too much twist" but I will say that with that twist you want to be sure to use a very high quality bullet. Every two feet the bullet will make three revolutions. At 2800 fps that's about <mumble> 4200 RPS or 252K RPM (?) about 25% higher than 1:10. At that rate, small errors in jacket concentricity show up as big errors on the target.

thanks sir , I've got a few good bullets i'm testing but powder I use is mr 2000 , varget . bullets hornady a-max , n match hpbt , berger , nosler .

 

[james lambert]

If you don't mind spending a little more $$$ than you might for something else, these would be just about perfect with that fast twist rate and jacket failure shouldn't be an issue:

http://www.warner-tool.com/#!product-page/c1u5r/bdce101d-0eae-e733-4df3-30051598e486

Having said that, the first thing you really need to determine is the distance to the lands using a Hornady OAL gauge or similar device with whatever bullets you already have on hand. That will tell you how long/short a bullet you can expect to seat optimally in the case for your specific rifle. Once you have some idea of how long a freebore you have, you'll also have a much better idea of which bullets you might want to think about using. As a general rule of thumb, I'd go with the highest BC bullet that you can seat optimally in your rifle. That comes with the caveat that if you have a really long freebore and can load very long heavy bullets (i.e. 215 Hybrids, for example), you'll also want to consider whether you can effectively manage the recoil using that heavy of a bullet. Some folks have found recoil management to be a struggle when using 30 cal bullets in a .308 that are > ~200 gr or so. For others they work just fine. In any event, knowing how much room you have to seat bullets will probably net you better responses and information here.

As far as powders go, there are lots of choices in .308. Varget is really the go-to powder for many. It is fairly temperature-insensitive, meters reasonably well, and will give decent velocity. H4895 is another choice that will usually give you a tick more velocity than Varget, but at the expense of slightly higher pressure. If you haven't started assembling reloading components as yet, I would strongly suggest using Lapua Palma brass, which takes small rifle primers rather than large rifle primers. The Palma brass has just a bit more case capacity than standard Lapua brass. Even better, the primer pockets are noticeably more resistant to higher pressure loads because there is more metal in the webbing. There are really many other choices of powders for .308, such as IMR4064, IMR4320, H4350 (for the very heaviest 30 cal bullets), IMR8208XBR, PowerPro2000MR, the list goes on. One thing to consider in making your choice would obviously be availability.

Thanks , I will check on this , I have IMR & HODGDON 4350 .. and IMR 4064 along with Varget , Aliant MR 2000 . good powders to start with. jim

 

[james lambert]

Please, tell me, why a 1/8 TR???

when I said I was new at this I wasn't kidding .. I tried the savage palma rifle with a 1 in 13 . the barrel was to think I was told . .. everything I tried was ok at best .. I asked around on what to replace it with and was told a 1 in 8 .. maybe they were trying to though me off the trail. reloading is easy , but the right bullet and powder is hard .. I only get a few days a mouth to work on all my non skills . and in short even at the NRA shoot the masters n high masters don't like to give you any of their secrets ! I don't think they like competition ? wish I could do this 24-7 .. maybe I would have learned over time the knowledge that I need . but i'm a over the road truck driver .. I love this sport .. hoping to improve . 1 in 8 is another mistake I guess .. but i'l work on it the best I can till the money is right for a better twist .. maybe a 1 in 10 or 1 in 11 or 1 in 12 .. what do you think I should get next sir ? jim

 

[DanSavage]

Try some 190 grain Sierra MatchKing's and start at a few 10ths of a grain under load data Min. charge weight and slowly work up. The 1/8 twist isn't ideal but I think you can work with it for the time being.

Also try the Hornady 178 HPBT , you see, an 8 twist is going to cause more pressure and resistance as the bullet goes down the barrel, so you'll probably find low or mild charges of powder with a slowish burn rate to work well. Maybe a powder like reloader 17.

Regards,
Danielson

 

[Marksman63]

James, gstaylorg provided with a very good comprehensive answer about TR

 

[DennisH]

Try some 190 grain Sierra MatchKing's and start at a few 10ths of a grain under load data Min. charge weight and slowly work up. The 1/8 twist isn't ideal but I think you can work with it for the time being.

Also try the Hornady 178 HPBT , you see, an 8 twist is going to cause more pressure and resistance as the bullet goes down the barrel, so you'll probably find low or mild charges of powder with a slowish burn rate to work well. Maybe a powder like reloader 17.

Regards,
Danielson

First, I agree with the above post.

James, I have NO idea who told you a 8" twist was your best option for a 308. I have shot 308's for years, mainly with 10 twists, and I have had two 12 twists which shot 190's perfectly @ 600yards. I don't think I have ever seen anyone shoot a 8 twist 308.

With a 8" twist, your bullet should be spinning close to or exceeding 250,000rpm's.

I would start with a 168 grain bullet with a minimum charge. It should be around 40 grains (Varget/RL17 is also a choice) and check your spent brass for any pressure signs, especially around the primer area. I don't know if I would shoot any heavier bullet with an 8 twist. And I would be very careful when uping the powder charge.

I love 8 twist barrels, but only in my 6mm's and 6.5mm's. 10 twist's have always seemed to be the key for 308's.

Just for the record, I tried some 155.5 Berger's in my 10 twist 308 with a stout load of Varget. The rifle performed exceptional. Only one problem, a few of the bullets never made it to the target. They disappeared before they made it to the target. Pushing any bullet in a 8 twist 308, you will probably experience the same thing.

JMO, Dennis

 

[Lapua40X]

James, your 1:8 can work just fine so don't let the twist rate get in your way.
The 215 grain or the 168 grain Berger Hybrid Target should work very well in that rifle; but because no load works the same in every rifle you'll have to do some work to achieve your goal. Research is the key.
Take a look at this:
http://www.accurateshooter.com/cartridge-guides/308win/
and see if there is something that offers a starting point for your research.

 

[Keith Glasscock]

OK, let's start with load development!

From my perspective, 8 twist *WILL* work. It may work different from other 308's, but it will work. If nothing else, you are getting to run a grand experiment.

Do you know what chamber reamer was used? What freebore it has?

Have you determined how far each bullet is from the lands (rifling) or how long you need to make them to touch the lands?

Now, tell me the specs you used with the 155 Amax - what charge, COAL, primer, and brass. Did you chronograph it?

Then tell me what you did with the 185 Bergers.

I can type the long story, but let me put it this way: I have a friend that was having serious problems with his F/TR rifle. Come to find out, his seating depth was the problem - he didn't have any bearing surface in the freebore.

 

[manitou210]

I would try the 215 gr Bergers with Varget Lapua palma brass with a increase of 200 bc over the 155 gr you would have a great edge at 1000y on the windy days

 

[M14AMU]

So...you've got this 1-8 twist and you're in a match! For once....you've got everything working and you're shooting good shots....good score going and heavy with anticipation about maybe winning your first match! Then....on your 10th round fired....target doesn't go down! Someone says..."I was watching that round through my scope and I saw something odd when it was about half way down....looked like a 'mist' from the trace and...........????

With a .30.....1-8 ain't the way to go!!

 

[savagedasher]

Hi everyone my name is James and i'm new here . I'm looking for help for my .308 bolt action rifle . I'm going into the F-Class midrange NRA competition . been in it a few times already not with a good rifle yet .. just had a new barrel put on my rifle 1 inch target 30" long 1 in 8 twist .. trying to find what I've been told is that 1 bullet my barrel will like with the powder n grain amount that will give me a 5 shot group @ 100 yards that I can cover with a dime . I've been testing have not found that load yet . All help is greatly appreciated . a friend has a 1in12 twist with a 155 Hornady A-Max in his .308 and he did what i'm after , he covered his 5 shot group at 100 yards with a dime . thanks for listening James

Varget seem to be the powder of choice.Larry

 

[joshb]

What would a barrel manufacturer make an 8 twist 30 cal barrel for?

 

[spclark]

What would a barrel manufacturer make an 8 twist 30 cal barrel for?

Maybe the new Warner Tool Co. solids? Be the first bullets I'D try in a 1:8....

With conventional lead core copper jacketed bullets most everything produced commercially will need something between 1:10 and 1:13. Heaviest need the faster twist, lighter work in the slower... mostly.

(I know a fellow who swears by Berger 155 Hybrids in 1:15*! 'Course he's saying he's using special barrels with very shallow rifling so he can push 'em to 3,200 fps without pressure. I'm not going to try that anytime soon.)

*Velocity - more of it - can help where twist isn't quite optimal but more speed than a twist / bullet combo can stand usually results in pressures going over the top before bullets start falling apart down range.

...and in short even at the NRA shoot the masters n high masters don't like to give you any of their secrets!

In a word: nuts.

I'm a HM, I earned it shooting a 308 with 1:13 or 1:12 twists & 155's in Palma shooting. No scope, no front rest. We use a sling and match sights & do just fine thankyou.

We'll share our 'dope' with anyone we don't think will hurt themselves or others while doing so.

I admire (some) truck drivers for their skills. I abhore others for their rudeness. I've driven school busses full of kids but a 54' trailer's GOT to be a handful under any circumstances let alone in traffic. We all have things we do well.

 

[CJ6]

What would a barrel manufacturer make an 8 twist 30 cal barrel for?

300 Blackout and I'm not so sure it wouldn't due well in a 308 with 250's too.