Opinions wanted on 338 barrel

[azsugarbear]

I have a 277 AM, but can't seem to get my hands on any heavy-for-caliber, high BC bullets. Next barrel will be in a more common caliber with readily-available lr bullets, such as .308 or .338. Since my bolt face is already opened up for the 338 LM, I will probably stay with the 338 LM brass for the next caliber as well.

At this point, I'm not looking so much for advice on caliber, as I am on what barrel to order. Current set up is Rem 700 action, McMillan A-5, Nightforce NXS 5.5-22. Looking for barrel recommendations on:

Length (28-30") ?
Twist (probaly shooting 250 gr. NAB) ?
Contour (just heavy enough for good lr accuracy - this is a hunting rig) ?
Fluting ?
Brand/maker ?
SS or CM ?
anything else you consider important ?

Thanks in advance guys.

 

[jwp475]

I went with a Rock Creek barrel on my 338 Lapua and I love it. Mine is 30" long and a Sendero contour Carbon wrapped by ABS. A medium Palma Contour Fluted would be about the same wieght and 28" is long enough.
I went with a recomend a 10 twist that will work well with the 250 AccuBond as well as the 300 SMK. The 300 grqin SMK wil have much less wind drift and it is wicked on game

 

[BountyHunter]

Ok, lets figure this out.

28-32" depending on MV desired and weight. Each 1" will normally give you maybe 25 fps.

Decide on max weight first. That will drive the diameter and taper.

For example, if weight is not an issue, you could consider the breach going 5 inches and then taper. That allows one complete setback and new chamber. Compare that to a straight taper right off and there is a weight difference of over 8 ounces or more right there.

Dan Lilja has program on his site to figure a blank weight and most of the mftrs will give you info that is accurate within a couple ounces.

The canted rifling (Rock, Obermyer, Border and Broughton) for example seem to give a little more MV compared to standard rifling. I have seen as much as 50-75 fps in my Rock and Broughton barrels.

IMO definetly SS. Just makes sense.

Final twist 9.5 to 10. Cannot go wrong anywhere in there.

Oooh, gain twist. Now that throws a monkey wrench in the system. Peak pressure is at the breach and the tighter the twist the higher the pressure. Bartlein is using a gain twist (starting at say 1-12 and finishing at muzzle at 1-10), that might be a consideration.

Delivery time: check with each barrel mftr. They all run different at different times. One is 6 weeks and the other is 16 weeks. What is your timeframe?

blanks come oversize and you can order a 1.25 blank at max size and it should come out in the neighborhood of 1.27 to 1.28. Talk to the mftr and tell him you want max blank diameter. I would start there and go with straight taper to about .850-.870 if weight is issue.

Fluting is $150-185 normally. Saves 8 ounces. Do you need it?

BH

 

[azsugarbear]

Thanks for your input, guys. It kind of confirms for me that I am heading in the right direction. Krieger seems to have the lowest pricing right now, but Rock Creek isn't too far behind. Maybe it makes sense to spend a few $$ more to try the 5R rifling from Rock Creek. Any idea on how much ABS charges to carbon wrap your barrel? Do you save weight this way? Is the cost of the wrap offset by the savings on not fluting the barrel?

Looks like it will be a 30" medium Palma tube for me. Trying to keep total weight of the rifle around 13-14 lbs.

 

[dirtball]

Just to throw another wrench in the gears, a new bolt from Dave Kiff at PTG would only be about $150.00 +/- unless you want fluting. Then you could do an Edge or some other .532 bolt face cartridge. That would allow you to sell the 270 AM barrel with a 700 bolt to go with it, If you were planning to sell it.
Just a thought
Dave

 

[davewilson]

dirtball, not sure i understand your statement. why would he sell a 532 bolt so he could get another 532 bolt? isn't the 270AM based of the ultra mag case or does it use the Lapua? can't quite keep up with all of the Kirby wildcats.

 

[azsugarbear]

Kirby's magnums (.30 cal and under) - are based on the 338 Lapua Case. Above .30 cal., the magnums shift to the Cheytac case and the Lapua case is used for his "Express" line. Under .30 cal., the express line is based on the 300 dakota.

If I am not mistaken, the 338 Lapua case was originally based on the 416 Rigby (or Rem 416), while the 7mm/300 RUM case was based on the 404 Jeffries. If I am wrong, please correct.

For me, once I have paid Kirby to accurize an action, it doesn't make sense to break the package up. The 338 Edge and the 338 Lapua are very close ballistically. The Edge is more economical in using Remington brass. The Lapua is more expensive, but it is more accurate and you get more rounds out of it before brass fatigue. Kind of a toss-up. I could go one steo further and have Kirby make me a 300 Allen Express. It is a 338 Lapua that is blown out to "Kirby standards" - kind of like an Ackley Improved version.

Right now, getting the right .338 barrel design & specifications is my primary focus. Once it is ordered and in hand, then choosing caliber will be my next pleasant problem.

 

[jwp475]

I chose the 338 Lapua over the 338 Edge, because of the quality of the Lapua brass, but I am wondering what makes you believe that the 338 Lapau is more accurate than a 338 Edge?

 

[davewilson]

sugarbear, the 270AM uses the RUM case, not the Lapua. it's improved a little, but still a 532 bolt face.

 

[dirtball]

sugarbear, the 270AM uses the RUM case, not the Lapua. it's improved a little, but still a 532 bolt face.

Dave
Yes the 270 AM is based on the 300 RUM case BUT the 277 AM, which is Sugerbear referred to is based on the 338 Lapua case.

"270 Allen Magnum
300 Rem Ultra Magnum parent case, necked to 270 and fireformed to min body taper and sharper shoulder angle.
130 gr.(3800 fps) up to 169.5 gr ULD RBBT(.740 bc) 3300 fps in 27" barrel length, 3400 fps in 30" barrel length
Designed for game up to 500 lbs at long range, deer and pronghorn out to any range a shooter can place the bullet in the vital zone of his target.
Appropriate powders: H-870, H-US869, AA8700 and WC872


277 Allen Magnum
338 Lapua Magnum parent case, necked down to 270 and fireformed to min body taper and shoulder angle.
140 gr.(3750 fps) up to 195 gr ULD RBBT(.920 bc) 3250 to 3300 fps from 28 to 30" barrel lengths
Designed for long range precision big game hunting. Usible on game up to and including elk and moose even out to 1000 yards.
Appropriate powders: H-US869, H-870, AA8700 and WC872"

Dave

 

[azsugarbear]

Regarding comment by jwp475:

My apologies to you. I probably stated my position on accuracy incorrectly. I did not mean to imply that the 338 Edge as a cartridge is any more or less accurate than the 338 Lapua. However, I do believe that uniformity of brass contributes to accuracy in a rifle and that Lapua brass is simply more uniform than Remington, Winchester, or even Norma brass.

Having said that, the brand of brass I use is not that critcal to me. I recognize that with all the technology, knowledge and quality materials available today, the weak link in my shooting system is me and not the brass. While I understand the theoretical arguments for better brass such as Lapua, my poor shooting abilities more than mask any improvement that Lapua brass brings to the table. I guess I am just trying to hang on to any advantage I can.

Regarding comment by Dave:

Good catch. My mistake once again. There are probably a few Allen Magums under .30 cal that are not based on the .338 Lapua case and the 270 Allen Magnum is one. It is in fact based on the 300 RUM as you indicated. The confusion centering around the 277 Allen Magnum probably comes from the fact that there are not many of them around. To my knowledge, Kirby has only made two of them. I own one and Richard of Wildcat Bullets owns the other. The 277 Allen Magnum is based on the .338 Lapua case. Kirby...see what you have started????

 

[davewilson]

277 was stated in the original post but my brain just had 270AM on it and like i said, i'm not particularly well versed in all the AM's. now i know the difference. i see where a different bolt would be necessary.

 

[trueblue]

Sugarbear,
On a 338 EDGE or Lapua, I would go with a Remington Sendero or Varmint contour.. Carry the .830 muzzle diameter to 30" length. You could also go with the medium palma contour , which might be slightly lighter. Fluted if you like.
If Sierra doesn't start putting out some 300gr SMK, the 338 cal might not be the way to go.

 

[azsugarbear]

To everyone:

Thanks for your insights and suggestions. Whether it is putting a stalk on an animal, or simply making a purchase, it always helps to look at something from several different angles before moving forward. That is why I keep coming back to these forums. I apprciate your willingness to share what you have learned.