Tight Bore Barrels and Cast Bullets

[gzig5]

I'm building my daughter a deer rifle in 30BR on a mini-mauser action. I had planned on using an extra barrel from my .308 Palma rifle because I'll never shoot enough to go through the three I have for the rifle. This is a Krieger medium Palma profile with .3075 x .298 bore dimensions, 13 twist. This is a common configuration for Palma shooting. I'll set it back enough to clean up the chamber and slim down the profile. I'm pretty confident it will shoot fine with the 125-150gr class of jacketed bullets, but I'd like to use something like the Lee soup can ( or similar design) in reduced loads for the majority of her practice. My concern is that the reamer has a .050" freebore and I'm concerned about the nose of the bullet not having enough room in front of the full diameter portion and end up deep seated. I guess I'll probably just have to find out, but if it's not going to work out, I'll get a standard bore barrel blank. So, I thought I'd throw it out there for comments because I know the 30BR is popular with heavier cast bullets for BR shooting. What say ye?

[rhbrink]

I would bet that it would work just fine and there should be plenty of undersized Lyman molds around that work work. A really good Saeco mold to try would be the 315. I have a buddy that is starting to shoot a 14" twist Krieger barrel on a 40X that he picked up for a song and has no problems holding 5 shots down around 1/2" at 100 yards. I don't know the dimensions of his barrel but it was originally set up to shoot Benchrest. It is chambered in the 30BR I don't remember the powder but he isn't pushing it very fast 1600 to 1700 fps I think.

Richard

[beagle]

With that small of a barrel and .050" freebore, you might have a problem.

If you want to try it, get a bullet like the Lyman 311465 and size it down to, I'd say, .309" and give it a try. You might have to seat pretty deep but that small Louverin nose would probably work. I don't know about the soup can design.

The little 311465 will give you about a 130 grain bullet and I've had great results in the .30/06 and .30/30 with it./beagle

[Larry Gibson]

Based on my experience with 12" hunting and target barrels and 14" twist Palma barrels I'd venture that the RD 30-160-WFN will shoot very well and be deadly on deer. I shoot lots of them in 12" twists at 1600 fps or so upwards of 2400 fps out of my 24" barrel 30-30 and accuracy is excellent. It also is an excellent performer in the 14" twist Palma so the 13" twist of your barrel should be just fine. I would seriously recomend trying Leverevolution powder with the 150-160 gr bullets, cast and jacketed in that 30BR, might be just the ticket if not too slow burning.

Larry Gibson

[robroy]

You might try a throating reamer to get a little more space. Make up a dummy round and fit the chamber to the boolit instead of the other way around. I think the best time for this to work is when you're building one from scratch.

[runfiverun]

that 307x298 is real close to the k-31 bbl dimensions.
if you are having the bbl rechambered you could easily have the throat cut also.
a custom mold from mountain,lbt,owm,or accurate would save a lot of grief,not really cost that much, and provide a lifetime rifle that sure would cover a lot of bases.
150 grs of naked lead at 2500 fps from a good bbl what's not to like.

i have a 14 twist bbl that i am gonna do something similar with [just not for the girl]

[stubshaft]

I usually have the same problem with MGM barrels in my Encores and Contenders. MGM has a tendency to cut a very short freebore, unless the buyers specifies a specific length. For my 7mm I am stuck with either having most of the boolit shank below the neck or using a bore rider like the RCBS SIL series of molds. Luckily I can adjust the nose diameter with a change in alloy and the gun will shoot very accurately. You might take a look the the RCBS 165 SIL mold and see if it will suit you purposes.

[Shooternz]

I have 2 .308's with PALMA barrels .3075x.298 I use Lyman moulds 311332 and 311291,
both shoot very well at 1800-1900fps don't have a problem with leading.
Robert.

[leadman]

If you can find the discontinued RCBS 30-150-SP this would work great for what you want. Has kinda a semi-spitzer nose so does not need alot of freebore.
It shoots great our of my K-31 with no issues on length.

[excess650]

I'm surprised that nobdy has suggested the NOE K31 boolit.:confused: Its diameters and short shank were designed for little to no throat and tight bores.

[Char-Gar]

From time to time we run into barrels/chambers with very little or no leade/freebore/throat. I have an old Remington 14 in 30 Remington that has this problem. The solution is a 30 caliber throating reamer.

[stubshaft]

If you can find the discontinued RCBS 30-150-SP this would work great for what you want. Has kinda a semi-spitzer nose so does not need alot of freebore.
It shoots great our of my K-31 with no issues on length.

Like these?

[gzig5]

Thanks for the ideas. I'd really like to stay with the lighter bullets, but up to 150 gr should still fit in the mag if the nose doesn't get pinched. I've got a couple K31's but have never run cast through them, only my Vetterli, so a bullet set up for the Swiss bore would be a good idea. I can use the reamer to cut a test chamber in a piece of scrap and maybe pick up a couple of these bullets from members and test the seating depth. Worst case, I'll machine my own mold with a bore rider nose. Extending the throat could be an option as well.

I've got two of these Mini-Mauser actions. The first will be the 30BR for my daughter and the second will be a 30 AR Turbo Improved. Essentially a 6.5 Grendel necked up and blown out. Because it was designed to work in an AR, I think the free bore and throat are a little more generous. As soon as I get my South Bend 10L rebuilt, I'll start the build on the 30BR.

[DonH]

Sounds like a perfect place (barrel) to use the bore rider Lymans. Their noses tend to run small anyway. I had to "beagle" an old 311291 mold to get the nose up to .300+. Could have used that .298 bore.