Barrel and Caliber choice for unleaded

[bigngreen]

A 1-8 twist rate would be the only way I'd go for a 284 cal, no reason to go slower and much more to gain by having a better twist rate so you can take advantage of the better, heavier bullets like Cutting Edge and Barnes.

 

[Deleted member 46119]

Not according to what I looked at. The long monometal/unleaded are sub optimal stability at sea level where I do most if my shooting. Actually 273' ASL.

Yes, up to 180grain jacketed will stabilize.

What are you gaining by going 9 twist? IMO Nothing.
What are you loosing by going 8 twist? IMO Nothing.

ergo

8 twist. Ok, maybe 8.5.

It has already been documented that monometal/unleaded prefer to go faster and spin faster. Fighting physics and empirical data is the same as p______ into the wind. That's a joke son, except the physics/data part.

 

[benchracer]

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.

8 twist still won't have a negative effect at the velocities the .280 class cartridge are capable of generating. No sale. There really is NO downside to going with the tighter twist.

 

[pods8]

If we're still talking 280AI then I wouldn't want to be chasing extra long unleaded and run into velocity on impact issues regardless. I don't see much gained in 8twist since the OP wasn't walking about a 1000yr rig shooting pencils but perhaps we loose nothing either. Any concern with launching a 120 lead core down an 8twist at 3300-3400fps (honest question, I don't know)?

 

[Deleted member 46119]

If we're still talking 280AI then I wouldn't want to be chasing extra long unleaded and run into velocity on impact issues regardless. I don't see much gained in 8twist since the OP wasn't walking about a 1000yr rig shooting pencils but perhaps we loose nothing either. Any concern with launching a 120 lead core down an 8twist at 3300-3400fps (honest question, I don't know)?

At those velocities, you are talking about 295,000 RPM in an 8 twist and 264,000 in a 9 twist.

We are talking a dedicated unleaded rifle but for the sake of discussion. The 120 grain V-Max being a little thin skinned might be an issue but no "normal" jacketed game hunting bullet.

 

[pods8]

At those velocities, you are talking about 295,000 RPM in an 8 twist and 264,000 in a 9 twist.

We are talking a dedicated unleaded rifle but for the sake of discussion. The 120 grain V-Max being a little thin skinned might be an issue but no "normal" jacketed game hunting bullet.

Well we seemed to be mixing what we were talking. If it was a dedicated unleaded hunting rifle we wouldn't be looking at excessively long unleaded either from a normal size bolt face cartridge.

Thanks for the input on the 120s. Doesn't sound like there is much downside on 8 or 8.5 if desired.


I went 9 on my 280AI but generally plan to shoot 140-168s. (Being at 5500' I could stabilize more than others with a 9twist but I wouldn't want to paint myself into a corner if I ever traveled to shoot/hunt).

 

[ofdscooby]

Just so I can get us back on course and I love all the input even if some of it is a little above my head(I've only been doing this a couple years). This will be my California game gun its main job will be killing game in California. I love the lathe based bullets but I just can't afford to shoot them I'm a blue collar guy with a family. The guys I've talked to say the lathe turned bullets shoot great in everything so if I have to fall back on these later to get accuracy I will entertain it . But I am going to try the GMX, Nosler, Barnes offerings first . I'm chasing speed to gain effective killing range because of the advertised minimum effective velocities but will not sarafice accuracy if I can only turn out a 800 yard gun that's life in CA I guess.

 

[bigngreen]

Just so I can get us back on course and I love all the input even if some of it is a little above my head(I've only been doing this a couple years). This will be my California game gun its main job will be killing game in California. I love the lathe based bullets but I just can't afford to shoot them I'm a blue collar guy with a family. The guys I've talked to say the lathe turned bullets shoot great in everything so if I have to fall back on these later to get accuracy I will entertain it . But I am going to try the GMX, Nosler, Barnes offerings first . I'm chasing speed to gain effective killing range because of the advertised minimum effective velocities but will not sarafice accuracy if I can only turn out a 800 yard gun that's life in CA I guess.

Be careful chasing speed with light bullets, been down that road and it was not all sunshine and roses. I've gone to as heavy and high of BC mono just the same as I do my cup and core and the performance has just been much better terminally. BC will give you down range velocity and less wind drift, it works for mono's the same as cup and core just a little harder to do it.

 

[davkrat]

I've done some milk jug expansion tests with the 150 Etips out of my .308. Starting off a couple hundred fps slower than the 7mag with fewer RPMs too and the expansion at 1800 fps is nothing I would right home about. Like was posted above 2000 fps if not 2200 fps is probably a more realistic threshold for mono metal expansion. In my experience they are not competitive with a cup and core high BC like a Berger at extended ranges. One more reason I set a limit of 600 yards on myself.

 

[benchracer]

Just so I can get us back on course and I love all the input even if some of it is a little above my head(I've only been doing this a couple years). This will be my California game gun its main job will be killing game in California. I love the lathe based bullets but I just can't afford to shoot them I'm a blue collar guy with a family. The guys I've talked to say the lathe turned bullets shoot great in everything so if I have to fall back on these later to get accuracy I will entertain it . But I am going to try the GMX, Nosler, Barnes offerings first . I'm chasing speed to gain effective killing range because of the advertised minimum effective velocities but will not sarafice accuracy if I can only turn out a 800 yard gun that's life in CA I guess.

Read the reviews for the following Barnes bullet and you will see why the faster twist is a good idea: Barnes Long-Range Hunting Bullets 284 Cal 7mm (284 Diameter) 168 Grain

Though bullets like the Cutting Edge are about 1/3 more expensive than the Barnes bullets, even the Barnes bullets are not inexpensive.

One approach that I have found to be an effective cost control measure is to pair the more expensive bullet with a cup and core bullet of similar characteristics. The less expensive bullet can be used for the majority of shooting in practice (I am assuming that standard cup and core bullets are still permitted on shooting ranges in CA), with a smaller number of practice shots taken with the bullet you will use in the field.

For example, the Barnes 168 LRX and Hornady 162 SST should closely match one another in ballistic terms. Loaded to the same velocity, the SST should serve as a functional practice bullet, either saving money in the process or allowing more practice for your shooting dollar.

The Cutting Edge 155 MTH and Hornady 162 AMAX could be paired in similar fashion.

Going with a tighter than standard twist and pairing your bullets in this manner are both techniques than can give you a lot of flexibility to match your bullet choices with desired performance characteristics. Once again, plenty of upside and ZERO downside.

 

[davkrat]

Benchracer I've done exactly that. The Nosler 155 Custom Comp is directly swappable in "my" .308 for the 150 ETip. Same charge of Varget, same OAL and nearly identical flight out to 500 yards. That idea was recently poo-pooed on another thread. It's worked for me. In my more dedicated LR 7mm Rem Mag rig I only shoot the ETips and only a handful at each range session.

 

[RevJim]

If finances are a big issue right now, buy you a "factory take off" barrel for your Remington. I've seen some 24" .270 Winchester barrels on Ebay for $100 bucks or so. Then you could use existing 110TTSX Barnes and kill everything you shoot at! ha. Just a thought. My .270 BAR just prefers the 110 TTSX ( Federal factory load) to anything, and I'm talking cloverleafs. I haven't clocked them, but they have to be humming!

 

[Shane Lindsey]

Have copper loads for most guns.
My 30-06 is running the 175 LRX at 2775 fps in a 22 inch barrel. If it was a purpse built "California" hunting rig, I would be inclined to go with what you could find at the Wally World where you may be hunting. Never know when you need to pick up the factory stuff. I haven't seen many 280/ai cartridges in the shops out here. I've seen the 7mm, 30-06, 270 variety in the copper loads though.