I've got a .250-3000 double rifle that I'm trying to develop a load for that will regulate the two barrels at 100 yards. I was fooling with it last night and discovered that the throats on both barrels are so long that you can put a Nosler 100 grain Ballistic Tip just far enough into the case to hold it and still not touch the lands. I didn't measure, but I'm guessing the Nosler was into the case only about 0.1 inches plus the boattail.

I'm thinking that the overly long throats suggest a heavier bullet - either a very straight walled 100 grain roundnose or a 115-120 grain of the same design. I can't imagine any other reason for throats that long.

The rifle did not come with any information about the load for which it was originally regulated. It's a typical German double rifle from the 1920s with double underlugs and a Greener cross bolt, so I'm assuming that any load safe in a Savage 99 or similar strength action will be o.k. I'm not looking for something that will max out a modern bolt action.

Any suggestions on how to proceed?

Thanks.

I have a custom built 250-3000 on a 722 action that I have bored with a longer throat to make better use of the 2.8" mag. I intended it for 100 gr minimum, and mostly 115-120.

Try some flat base 117 and 120s. The hornady 120 for example is quite long.

Also, try some loads, you may find that seating right up to the land isn't necessary for good accuracy in your rifle. Many CIP reamers, for example, have very long leades, but that doesn't stop them from delivery excellent accuracy. I've got an 8x57 that shoots 5-shot 0.5 MOA with a load where the bullet is nowhere near the lands.

I'm curious to know what the rate of twist is in that double rifle..??

Just ignore the lands and seat the bullet to a normal depth of one caliber and see how it shoots. Most factory load and barrel combinations don't come close to touching either.

It is a double rifle, it is designed to pressures of 16 tons max or about 30,000 PSI, much less than a Savage 99 and those factory loads will probably shoot it off the face pretty darn quick...

I would load a 120 gr. RN at about 2250 FPS if it was mine...

the world of the double rifle is a whole nuther planet...

Another very good reason for a long throat in any rifle is that it is shot out. A gun built in the 20s more than likely does not have the quality barrel steel of today, and could be well worn over the years.

quote:

Originally posted by ireload2:
Just ignore the lands and seat the bullet to a normal depth of one caliber and see how it shoots. Most factory load and barrel combinations don't come close to touching either.

Yup....I agree

The rate of twist is 1 full revolution every 10 inches.

I disagree about the pressures for which this rifle was designed. The standard 9.3x74, 8x57R and other similar cartridges of the period were mid-40K pressures. The medium bore British cartridges of the period were similar. Plus, once you regulate the thing, you only shoot it a couple of times a year, which allows for a long, long life.

The bores are definitely not shot out - the throat is quite good and the rifling sharp. Just a lot longer than any throat on any rifle I ever owned before.

Hello,
In a modern day rifle, a very, very long throat would lead you to believe it may be shot "out..." but agree that is doubtful with a sporting rifle unless it was used as "pass around..." gun on hunts over a number of years??
As mentioned earlier, would suggest loading to one caliber, .250 or so in the neck, and use the heaviest bullet available and check for accuracy.

As to pressures, not at all up to speed on double rifles and their characteristics, and would go along with those who have considerable experience. Better to go on the safe side.
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dsiteman

PS Find someone with a Hawkeye bore scope set up and a viewing will tell you or your 'smith a great deal about the condition of the bore and the wear patterns observed. Just a suggestion.