[Lucky]

Got a Mossberg ATR100, shooting SMK180's at ranges to 900m, and I like it a lot. It's already pillar-bedded and free-floated, so for the first few shots it's quite straight and fun, but then it opens up and is less fun. I want a heavier barrel but don't know what contour to get. The guys I'm starting to shoot with (me newb) form a line and take turns shooting one shot, usually about 5 of us at a time. Expect to shoot aout 1 shot every 30 seconds to a minute, for 10-20 minute periods. Would also like to hypothetically be able to take the rifle hunting, but that's a distant distant second consideration and if it's too heavy to comfortably shoot off-hand I can live with it.

I've been told that a Douglas #7 (http://www.benchrest.com/douglas/dimensions.html) profile is the USMC and US Army standard, a Palma or light Palma taper is good if you're doing a pure target rifle. How many shots can you get out of each before the groups start to open up from heat?

And I'm planning on 1:10 twist, because though I have 500 180's to shoot off I might like to go above 200grs if bullets become available.

The folks at Shilen said they could accommodate me if I send them the action, and it seems the best way unless a local contact comes through.

So anyone know what the best contour and length would be, their personal recommended compromise?

http://www.shilen.com/contours.html

http://www.shilen.com/images/standardRifle.jpg

[USSR]

Lucky,

Seven years ago, I did exactly what you are debating doing. I sent my barreled action to Jack Krieger and told him to build a heavy tactical rifle in .30-06. Here is a link to his contours:

http://www.kriegerbarrels.com/RapidCat/catalog/pagetemplate.cfm?template=/RapidCat/common/viewPage.cfm&PageId=3382&CompanyId=1246

I went with the #10 MTU contour and had him flute it to remove 1/2 # of weight from it. If I didn't have it fluted, I would have gone with the #9 Heavy Target contour. Whatever contour you go with, make sure you have a muzzle diameter of atleast .875" at 26". I have used this rifle in 1,000 yard F Class competitions for several years and have done well with it. My standard load is a 190SMK at 2900fps. "How many shots can you get out of each before the groups start to open up from heat?" LOL, we fire about 50 rounds in 30 minutes, and there is no "open up from heat". Hope that helps.

Don

http://www.ussr.baka.com/Win06t1.jpg

[Jim Watson]

Agree with USSR. A good barrel does not walk as it heats up but a lot of steel for heat sink is desirable. Your factory barrel opens up as it heats because it is cheap. Blank value maybe $50 vs $200 for a real name brand target blank.

I have a Pac-Nor #7 on my .308 which is .875" at 28" on their chart. (Not all #7 contours are the same.) I picked it as one size bigger than the Savage Varmint profile. If you want more, a Heavy Palma 31" should be good.

[Lucky]

Thanks man, again. You've both been very helpful, and this isn't the first time:) Great to hear the contour advice and the non-effect of multiple shots, I look forward to that greatly!

About the 'B' dimension on Krieger barrels, how does it affect things?

[rangerruck]

I also agree with the 26 inches, the only other thing I may would change would be a solid 1 inch straight taper, the whole length. if not that, then the next lightest taper i could get. Super stiff bbl is the goal here.

[rangerruck]

I really like the idea of tuning a Mossy action/receiver. If you decide to do this, please let us know how this goes, and how you like the work done, etc.

[Zak Smith]

I run a medium Palma on my 260. It does not degrade as it passes being too hot to grab. Blank was a Rock.

[Lucky]

Oh wait, does the 4" section allow you to cut it off, and re-chamber it at 2.5" after you get too much throat erosion?

[USSR]

Oh wait, does the 4" section allow you to cut it off, and re-chamber it at 2.5" after you get too much throat erosion?

You got it.

Don

[Lucky]

rgr thx