Barrel and Caliber choice for unleaded

[ofdscooby]

With a 100% lead free CA coming down the pipes I'm gonna need to get a dedicated Cali gun built. I have a 700 with a sweet laminate stock that I just high score pillared it's a 30-06 but I'm ready to change that out I havnt been able to get it to shoot that good. I have a 7mm mag so I'm thinking of another and shoot the 139 GMX out of it.
I'm open to ideas please let me know your ideas on barrel length and brand twists and I would like to stay with hornady or Barns.

 

[MudRunner2005]

You could always build a 26" .280 AI with a 1:9 twist, that way you're covered from light to heavy. And would allow you to simply change the barrel on your 700, and you wouldn't have to change anything else. I would definitely have the action blueprinted while the smith had the barrel off, if it were mine.

 

[270Weatherby]

Agreed to stay with the 7mm. I shoot 139GMX with a 7Saum covers all things in Ca well. Easiest is the 280ai with your action.

 

[ofdscooby]

I agree a 280ai would be easiest my receiver has already been trued but the bolt was never touched but I should get the bolt done so if I'm doing that get it opened up and I wouldn't have to buy another set of dies .

 

[MudRunner2005]

I agree a 280ai would be easiest my receiver has already been trued but the bolt was never touched but I should get the bolt done so if I'm doing that get it opened up and I wouldn't have to buy another set of dies .

No 2 rifles will like the same exact load, seated to the same exact depth... Constantly adjusting dies is a pain in the ***. You would be better off buying a 2nd set of dies or a 2nd seater die and mark them for each rifle.

It's your rifle and money, just trying to give you a suggestion, since you asked for them.

Just my opinion, which is only worth what you want it to be.

 

[Slaysesh]

100% agree with mud and what he said above. Opening the bolt face is expensive (to me) cost not needed for game in Ca
Plus you can reach ALMOST 7mag velocitys with the 280 AI

 

[Engineering101]

I will second (or third) the 280 AI. My hunting buddy used his last season and a 145 grain Barnes LRX to hammer a nice muley. The bullet performed as expected with a lot of penetration but minimal meat damage. That rig/bullet will take anything you are likely to encounter in CA.

 

[davkrat]

Another Californian. I've been real happy with the performance of the 150 ETips out of my .308. I haven't shot any game with the 7mm 150 ETips but the two 7mm Rem Mags I load them for have shot them very accurately.

 

[benchracer]

If you are going to set your rifle up specifically for copper/non-lead bullets, you would be wise to go with a faster than normal twist for whatever caliber you choose. For example, if you are going with 7mm, I would recommend an 8 twist barrel 24"-26" in length.

The standard twists are fine for existing Hornady and Barnes bullets, but there are new generations of long range-oriented bullets being introduced (both lead and non-lead). These bullets are trending toward faster twists. Going with a faster twist barrel than the current standard will help you keep your options open, with no down side.

 

[Deleted member 46119]

+1 benchracer said...

I do a lot of shooting and testing of unleaded bullets. I will hunt with nothing else.

1) Go up one caliber or more from lead. IE if you were going to use .243 go .264 or .277. In your case a non-issue because .284/7mm is plenty of caliber.
2) Get a faster twist than you might. For .284/7mm normal is 9 but 8 would serve you well in the long run.

If you go with an 8 twist, your future options will be good. A 9 might be limiting.

Since this is already a 30-06 a 280 based design would be "easy" though you may still run into magazine feed issues with those long range coppers.

 

[ofdscooby]

So if I stayed with 7mag or .280 I should go with a 1:8 even if I stay with a GMX I hear what you guys are sayin about the faster twists but it seems those are for the really long lathe made bullets and I don't plan staying with Barnes or the GMX. I really want the .280ai but can I get the same velocities as a 7 mag when dealing with the lighter 140 bullets. I only ask because while normally chasing accuracy it seems you need to chase speed as well when dealing with the un-leaded for the long shots to guarantee expansion. As it sits right now I'm leaning toward a Bartline 3b fluted 26 in and a brake.

 

[pods8]

I shoot the barnes 145gr LRX from a 7-08 at 2700 (that's where the best accuracy was) and it opened fine on antlope (low resistance) out at 350yds (impact should have been around 2200fps at my altitude). Under my conditions a 280AI should carry that same velocity out to 600yds, even a normal 280rem would do that to 500yd. Now mind you barnes advertises 1600fps as minimum but really when you look at expansion pictures 2200 seems to be where you get a decent opening of the petals so I try and keep over that.

I've got a 280AI due from the smith next month (24" 9 twist obermeyer rem 700 sporter contour). I didn't see the need to chase into the larger 7s for my practical hunting purposes.

 

[benchracer]

So if I stayed with 7mag or .280 I should go with a 1:8 even if I stay with a GMX I hear what you guys are sayin about the faster twists but it seems those are for the really long lathe made bullets and I don't plan staying with Barnes or the GMX. I really want the .280ai but can I get the same velocities as a 7 mag when dealing with the lighter 140 bullets. I only ask because while normally chasing accuracy it seems you need to chase speed as well when dealing with the un-leaded for the long shots to guarantee expansion. As it sits right now I'm leaning toward a Bartline 3b fluted 26 in and a brake.

Bryan Litz has done a lot of testing on this subject. The tighter twist will not cost you velocity. There is no such thing as overstabilizing a bullet. Since we are discussing mono-metal bullets, there is no risk of jacket failure. There is no down side to the tighter twist. While you may plan to stay with the Barnes or GMX for now, there are any number of reasons why that plan may change. Why paint yourself into a corner?

 

[pods8]

Bryan Litz has done a lot of testing on this subject. The tighter twist will not cost you velocity. There is no such thing as overstabilizing a bullet. Since we are discussing mono-metal bullets, there is no risk of jacket failure. There is no down side to the tighter twist. While you may plan to stay with the Barnes or GMX for now, there are any number of reasons why that plan may change. Why paint yourself into a corner?

Devils advocate: 9twist in 280AI velocity would already stabilize the largest 7mm bullets at sea level, how far are you going to chase that dragon of what if? You say what if he wants to shoot some future 7mm pencil, well what if he wants to just shoot a 120gr lead core instead? Goes both ways. Generally you'd expect a 280AI shooter to mostly shoot stuff in the 140-168gr turf (maybe 180s), no? If he was talking up a larger 7 and focused on the ultra long range game where chasing that future 210gr VLD would be beneficial then I'd see the merit.