.257 Roberts conversion

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Feb 11, 2013
I ran across a custom .257 with a lilja SS tapered bull barrel, bench rest stock, and a ridiculously awesome trigger.

What are my options to get this gun to be a bench rest .30 caliber? I don't want to add a caliber to my reloading components so I am very sold on converting to .308" projectiles.

But, .308 cartridge is short action while .257 Roberts is long while 30-06 is long but not as accurate as .308.

Any suggestions?
When you change out the barrel you could have a block installed in the magazine to shorten it for the .308. That said, generally when folks are shooting bench rest they're single loading so mag length is a non-issue. If it were me, instead of paying the $600+ for a barrel change, I'd buy the components to load the .257.

Good luck.
The gun was purchased in a lot of weapons by a buddy of mine. He doesn't want it and asked if I did.

I seriously doubt he will get anywhere near what the gun is really worth on gunbroker considering we don't know the history of the weapon. No clue how many rounds through the barrel, not to mention the stock is ugly (may have been spray painted camo) and has nicks here and there. The receiver is cheap but obviously has had work done to it. What work? We dunno.

That being said, I could get an excellent receiver and stock for next to nothing and then have a 600 dollar benchrest grade rifle in what I want, .30 cal.

I just don't know what cartridge to utilize. I only have reloading supplies for .30-06 but that seems unreasonable under these circumstances. Plus I would want to get better dies for this future cartridge we have yet to determine.
That all make sense. Since your options are wide open, and you want to use 30 caliber bullets, you might take a look at the 30BR. Accurate and easy to find good loads.

Rock on.
The Whitworth was made in (the old) Yugoslavia. Just another variation of the Interarms Mark X, which is nothing more than a commercial Mauser copy. It is an excellent action.
Thanks. Good to know. Any ideas on the stock?
No thumbhole or anything special other than it getting wide towards the front.
The action is a good hunting action, it takes a lot of work (= lots of money) to get a Mauser to shoot like a bench rest gun, not just a new barrel. The barrel is a seriously good barrel, Lilja is among the best, and by the looks of the brake, I doubt it has been shot much. I suspect some one built this gun as a coyote gun, the sock isn't a bench rest stock but more of a varminter, this is probably one hell of a deer/coyote gun.
I cant wait to get this thing to the range. There is only 200m at my club but I'm eager to see what it will do out to 200. If it is crazy accurate I may just get the Roberts dies based on the feedback I have gotten here. There was some over the counter ammo and some reloads with the gun. If the reloads are really good it will be really easy to replicate OAL, powder charge, etc.

Is there a way to identify powder type/burn rate? Or would I have to measure the grains and use the chrony to work backwards to determine powder type?
I know you didn't ask, and I apologize for offering this - but after seeing that bbl and muzzle brake, I'd get it converted to 25-06 and have myself a blast! (tha's just my preference...)
Unfortunately the muzzle brake was homegrown and whoever did it didn't do a good job.. Holes are not symmetrical. I had already considered contacting lilja if I keep it in .257 to see if they could make me a new.. End cap? It is threaded.
I would shoot it, if you like it, but not the brake, cut the barrel and recrown it. Like he old man used to say "gold is where you find it". If you still don't like the caliber, you could rechamber to .25/06 or .257 Weatherby. Now you are cookin'.
I'm reading Ackley Improved on your barrel, and that is not a standard 257 Roberts. It's a reloading proposition that requires specific dies. The good part is that a 257 Ackley improved runs close to 25-06 velocities with less powder. You usually fireform standard 257 Roberts in the improved chamber to make the brass, and reload the fireformed brass.
It is a great round, and will likely satisfy any long range urges that you may have.

IMHO, you're foolish to convert the metal, just select another stock to please your personal taste.

Here's a link to Nosler's load data for the 257 Roberts Ackley Improved to compare, just select the weight of the bullet desired on the menu.


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IMHO, you're foolish to convert the metal, just select another stock to please your personal taste.

Not sure what you mean by this - I would be foolish to change calibers or mess with the messed up muzzle brake? I actually like the stock - heavy as mess but would look and feel awesome with a bipod.

If I want to give my buddy fair value for the weapon what do you guys think is reasonable?

Trigger pic - has an "H" on it.

not to mention the stock is ugly

That's from your #4 post.

Any ideas on the stock?

That's from your #9 post, so I thought that perhaps you wanted to replace the stock. Apparently it's grown on you.

The Lilja barrel sells for $335 for the SS 1.250" version, and the all the installation work is performed by an outside gunsmith, as Lilja does not do gunsmith work on customer receivers. Get rid of the brake if you think it's detrimental to the package.
I would ask your buddy what he wants for the rifle so everyone can be happy. I certainly wouldn't get rid of the Lilja 257 AI barrel as they are hand lapped premium barrels, and that caliber is a very good round for deer, and a decent target round in that heavy barrel. As I mentioned before in my other post, it's around 100fps slower than a 25-06 with the same bullet.
Not sure what trigger is installed, but your picture shows a trigger shoe that fits the installed trigger assy.
Buy the rifle and use it, and I think you'll be impressed, and satisfied.

The guy that has it asked me to basically tell him what its worth as he has intentions of selling it if I don't want it. If I get it from him I will still want to give him fair value for it. I shared what I have learned in this thread with him earlier and he immediately asked what it was worth. 5-600 seem too low? Or is this more like 1k? Not counting optics.
That rifle seems pretty special just the way it is ( cept the stock), that barrel/caliber combo will pay
excellent dividends given the patience at the reloading bench.
Seems a waste to tear it all apart and change it after somebody went to all the trouble to create a tackdriver !!
Taking it to the range this weekend perhaps. I'll post some 200m targets if I make it out. I wish I had my chrony with me... I would love to see the difference between the stock bullets vs the reloads.
I got some better pics of the rifle so I should be able to answer any specific questions about it. Not sure if we should shoot the reloads. They have a reload data card that indicates around 110% of the maximum powder charge. 47 grains of 4895 although I have read online that shooters have used 47 grains with success.

I will hopefully be able to take it to the range in a couple weekends. My question is still: what is a fair price to pay for this rifle?
I know you didn't ask, and I apologize for offering this - but after seeing that bbl and muzzle brake, I'd get it converted to 25-06 and have myself a blast! (tha's just my preference...)
Ditto on that plan. Many years ago I had a .257 Ackley improved (step below .25-06) and is was very accurate out to 500 yards, which was the farthest I put it on paper.
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