Long Range Precision 30 cal.

RockChucker

RockChucker

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Time to start another project. Will have a 30 caliber 1000 yard Unlimited BR rifle built for next years Burns Lake shoot.:sniper:
Found a source for the Sierra 240gr MK looks to be a good candiate for 1000 yards. May have to go to a 1-8" twist barrel to stabilize. Would appreciate feedback regarding the twist to use.
Also undecided as to which 30 mag cartridge to chamber in. So lets hear your suggestions and what your decision would be based on.
I would like to see this new rifle to weigh in at the 30 lb + mark, as using a muzzle brake will be not an option! Its going to be a bench gun not a walk around varmiter.
So lets hear from the guys in the know about such things.
 
My last 30cal boomer was a 10 twist 30RUM which stabilized the 240gr MK's no problem.

The rifle weighed 35lbs and the recoil was still pretty strong. A long push.

Velocity was around 2900 fps which was slower then I was wanting. Still flew pretty good at LR. Was not a true high end BR rifle so can't say how well the bullet could have shot. Mine was a solid 1/2 min at 200yds.

I eventually ported the barrel which made the rifle a real pussycat to shoot. Had that howitzer muzzle blast.

You can check the other LR BR forums but I would say a 30STW or improved weathery would be a minimum. These are very popular and have done very well over the years. You can use a 338 RUM case and neck it down if you don't want such a large case as a 300RUM.

Do look at the 180gr Bergers in 7mm. Ballistics are superb and some have done very well at 1000yds with 7WSM's. I would personally build a 7RM for an unlimited rifle.

Ballistics are great and right up there with the big 30's/338's with so much less recoil for faster follow up shots.

Some are doing very well with 6.5's and 6's too but wind can be a tough mistress that far out.

Good luck with your build and let us know what you come up with.

Jerry

PS just remember that some lots of 240gr MK's have been the pits. I ended up shooting 220gr MK's and would have given the 208gr Amax and other Bergers a real look if I still had the cannon.
 
The 30-338 Lapua is another viable option, bearing in mind the case is larger than a standard magnum, but the brass is exceptional. I was also going to pitch a 1:10 or 1:9 as a twist for the 240, as this will stabilize and give you the option of optimizing velocity. ...oh, and apparently you should get Bill Mackereth to build it!!
 
Hard to beat the RUM, but brass supply has been up and down. Nosler Custom brass had great feed back but is next to impossible to get. So your stuck with Remington factory brass...which can vary dramatically. Retumbo and RL25 are the powders of choice and do not measure easily. Buy lots as you'll find your stuffing about 92 - 94 grains in each case with a magnum primer. I too went with a muzzle break to tame some of that recoil. Very accurate cartridge which likes slow powders and heavy bullets.
 
My last 30 was a 30 Cody....1-9....if I can recall: 190 Berger VLDs to 3400?
Only 23lbs so had brake...
Got off on a tangent and rebarreled before I ever had it up to full potential.......kinda wish I still had it...
 
I shot the 240 in a 300WM with a Bevon King barrel and 1-9 twist. Hope you got deep pockets. Id find a barrel maker to do a 1-9 1/2 twist and it should handle 180 and up just fine. If I was going to make another Id go 300 RUM. No belt and good availability of brass.
 
So far I've just ordered a 1-9" twist 30 cal. barrel 30" long 1.250" no taper blank from Brux Barrels. Haven't decided on the cartridge but leaning towards a throated 300 Win mag. From the loading data available 240gr Sierra MK 2700 to 2800 fps without pushing to the limit of case size. Match brass is available through Lapua.
Still open to suggestion regarding chambering.
 
6mmbr has an awesome article on the big boomers used by East Coast 1000yd BR shooters. If you want to see some serious machining, this is it. Gorgeous!!!!!

There are a bunch of 300Wby/STW variants and I think you should have a look there. A wildcat usually refered to as a 300AI, which strikes me as a 30STW, holds many records at 1000yds.

The 300WM is a wonderful cartridge but the case is small for the super heavy bullets. For 208gr, pretty much max in my books.

For these super big cases, you don't want to run pressures as hard as a 6BR. The brass simply will not put up with the abuse - trust me. Especially if the case has a belt. Here case volume is a huge aid.

Also, if you are building a BR boomer, why not get the extra 100 to 200fps. That could help when conditions get twitchy.

One suggestion I would make is get your dies BEFORE having the chamber cut. Use sized cases to headspace your chamber. You will more then likely need a FL sizer to keep up with brass growth so you may as well set the chamber so that the FL sizer ends up workings as a body bump die.

Best to chat with your smith on setting this up properly. A great way to save on custom dies and wearing out brass.

If you decide to go with a belted case, get the cases first too. Measure the belt and compare to the reamer so that this is min spec with a sharp edge from belt to case body. Most belted reamers have a slope to ease with chambering.

If you really want to get fancy, cut the reamer so that the belt area is undersized so that you need to turn your cases to be a perfect match at both the belt AND shoulder. Might allow you to run a 300WM hotter....maybe.

Or why not use one of the new Ruger cases and get rid of the belt altogether???????
Jerry
 
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