A little 308 help please

[TommyD11730]

Hey Guys I want to thank you all for your comments and suggestions.

So after a range day today I got to thinking, "what do I really want". Basically what I would like is for this rifle (currently 223) to shoot smaller groups but in 308. So forget the stockpile of current projectiles.

To do that it's got to shoot .400" MOA or better. The 223 avgs mid .4s.

I'm thinking for 200Y the Berger 115FB would be a good choice. As far as a barrel Shilen makes a Prefit for my Origin. @ 28" (truck 1.25" straight axle) 1-17T , 4 groove ratchet rifled. Not sure about the throat, in a perfect world it would be no turn.

Being in uncharted territory I would welcome comments. Thanks guys!

 

[Bob3700]

It is best to figure out what u want to do first. U sound like ur aiming at a Varmint for score rifle. U want a 30 BR to achieve ur goals of small groups with a 30 cal.
They say “ If u don’t know where u are going, any Road will take u there”!

 

[C.E.Smith043]

Don't rule out Benchmark powder. And also the 4064 u have may really please you.

 

[SVT_Tactical]

With the new outlook go 30BR and dont look back. You can't beat the accuracy, ease of tuning, and barrel life. I haven't found a bullet mine won't fire into 1/4 moa groups with little work up. 100pc of brass will last a long, long time. Speer tnts will shock you as well for a economical option that still shoots itty bitty.

My 30br is out the norm just as a side note. 1-14 twist .330 neck. It's been getting 125 clines lately and it loves them but I've put the berger 115s and Speer tnts through it to with great results.

 

[Infrequent Shooter]

I shot the 308 Win for years, 10" twist. For my rifles, Varget and IMR 4064 were outstandingly excellent powders for 125, 150 and 165 grain bullets. Sierra bullets were my top performers but good luck finding them today.

If, as you stated, the rifle is intended for recreational range shooting, I would opt for a 24 to 26" semi-varmint contour barrel with 10" twist for shooting 125 or 150 grain bullets. Personally, I prefer the lighter bullets in in this caliper to keep the recoil tolerable for sustained shooting. The heavier barrel will also help for recoil reduction and control of the rifle.

The stock selection is also extremely important. I would select one that is very stable (stiff) with a bedding block system and designed to free float the barrel.

100% agree on bullet weight. 168 gr Federal GM will put a whoppin on your shoulder.

 

[boltfluter]

Hey Guys I want to thank you all for your comments and suggestions.

So after a range day today I got to thinking, "what do I really want". Basically what I would like is for this rifle (currently 223) to shoot smaller groups but in 308. So forget the stockpile of current projectiles.

To do that it's got to shoot .400" MOA or better. The 223 avgs mid .4s.

I'm thinking for 200Y the Berger 115FB would be a good choice. As far as a barrel Shilen makes a Prefit for my Origin. @ 28" (truck 1.25" straight axle) 1-17T , 4 groove ratchet rifled. Not sure about the throat, in a perfect world it would be no turn.

Being in uncharted territory I would welcome comments. Thanks guys!

Sounds like you have gone from plinking to one hole accuracy. So, shooting a .308 to these new accuracy requirements is going to take some serious effort on your part. Recoil, and how to control it, will be first and foremost to my way of thinking after owning several. 308 rifles. Since we have gone from 150 - 175 grain bullets to 115 - 130 grain bullets everything has changed. Do yourself a favor and read up on the .30BR if you have not done so already. Sounds like a perfect match to my way of thinking. I need to stop thinking out loud myself, as I may need a .30BR in my arsenal as well! Lol. Good luck with whatever you choose. Having fun is the name of the game.
Paul

 

[TommyD11730]

Boy have you guys got my number

Seems like every 308 conversation I have eventually turns to "sounds like you need a 30BR". After watching a 6BR (friends project) come together I probably do.

The only thing holding me back was the brass. Or the necking up of the 6mm case to 30cal. While I have some experience neck turning & expander mandrals this is a whole' nother ballgame.
I mean is the PMA neck mandral do that much better job to justify the cost vs K & M ect...

 

[TommyD11730]

“ If u don’t know where u are going, any Road will take u there”!

I LOVE that!!!

 

[TommyD11730]

100pc of brass will last a long, long time.

Can I ask which tools your using to expand and turn the necks?

My only experience is with K and M brand.

 

[FrankG]

A 12 twist will handle up to conventional 190gr bullets but not new ones like the 169SMK. According to my numbers those need a min of 1-11 twist.

I'd go 10 twist. It will cover you for any bullet you want to shoot.

Barrel length? 20" is what I run on most in 308w. Why? With a good bullet/decent load you can still make it out to a 1k yards most of the time and keep the bullet above the speed of sound.

You get a 169smk coming out at 2600fps its still traveling about 1200fps at a 1k.

I had box Hornady 168AMAX ammo out of a 18" barrel making just shy of 2600fps. It was like 2595fps avg.

A longer barrel will help muzzle velocity some but a 20" vs a 22" or 24" or 26" isn't going to make that big off a difference. The 308win round is a very efficient round.

Or go 24" to start with. If you don't like the length you can always have a smith cut an inch or two off of it etc...

Later, Frank
Bartlein Barrels

 

[Tangent]

I didn't know how everyone gets the velocity out of .308. I have a 20" Tikka barrel and 44gr N140 with 155gr is only getting me 2550fps in Lapua Palma brass. I may have to have a play with the N550 I've got...

 

[TommyD11730]

I didn't know how everyone gets the velocity out of .308. I have a 20" Tikka barrel and 44gr N140 with 155gr is only getting me 2550fps in Lapua Palma brass. I may have to have a play with the N550 I've got...

In 223 I got consistently lower (100FPS or more) speeds on N140 vs Varget. The N140 showed pressure signs much quicker.

That's just my observation though.

 

[Tangent]

In 223 I got consistently lower (100FPS or more) speeds on N140 vs Varget. The N140 showed pressure signs much quicker.

That's just my observation though.

Thanks, of course the better option is banned here, typical bureaucracy! Seems I'm stuck with a slow barrel and slower powder. I'm planning a rebarrel so I may just see what the double base powder can do for the velocity.

 

[FrankG]

I didn't know how everyone gets the velocity out of .308. I have a 20" Tikka barrel and 44gr N140 with 155gr is only getting me 2550fps in Lapua Palma brass. I may have to have a play with the N550 I've got...

what you don't know is and I tell everyone this.... your not comparing apples to apples when you say this gun or that gun or this custom barrel to this custom barrel that brand A is faster than brand Z.

Unless you know what chamber reamer spec the chamber was made to (don't forget there are chambers that are called production chambers...typically bigger/looser on the dimensions) and unless you know to the 4th decimal place what the bore and groove size the barrel is made to... you won't know why this one or that one is faster or slower etc... and that's just a couple of variables in the equation!

Now throw in bullets, bullet diameters, powder, lot of powder blah blah blah...

 

[Tangent]

what you don't know is and I tell everyone this.... your not comparing apples to apples when you say this gun or that gun or this custom barrel to this custom barrel that brand A is faster than brand Z.

Unless you know what chamber reamer spec the chamber was made to (don't forget there are chambers that are called production chambers...typically bigger/looser on the dimensions) and unless you know to the 4th decimal place what the bore and groove size the barrel is made to... you won't know why this one or that one is faster or slower etc... and that's just a couple of variables in the equation!

Now throw in bullets, bullet diameters, powder, lot of powder blah blah blah...

Very true, you need to have all the variables. Well the next barrel is planned to be a Bartlein chambered for 6GT, that'll definitely be faster

 

[dryhumor]

Accuracy trumps speed, is what a pretty smart fellow told me once….

 

[TommyD11730]

Accuracy trumps speed, is what a pretty smart fellow told me once….

Amen brother! Long live the low node.