Barrels, blanks and lengths

[jbjh]

All things being equal, isn't buying a prechambered barrel and cutting it to the length I want the same as buying a blank from a barrel maker and getting it made how I want it?

[stangfish]

Hmmmm. I think I know what you're asking. Essentialy you are doing a "setback" If that is what you want do it. It might make sense to get a chamber that will just need to be openned up for your new cartridge. It don't really matter. Just get yourself a long one and do it to it.

[jbjh]

Really, I was just getting discouraged by the long wait for a barrel, and was going to order what was in stock and have a local machinist cut and crown it to my length. The barrel maker was trying to discourage this, saying that the harmonics wouldn't be right and they couldn't guarantee accuracy.

I'd call BS on, but hey, maybe there's something I'm ignorant about. Always willing to learn

[bodywerks]

What are you having a hard time finding? "prefit" barrels specifically for savage, or something else? I ask because, while i don't have experience with savage prefit barrels, i have bought a couple barrel blanks recently. They are available all over the dang place!
To answer your question a little without knowing exactly what you're asking, yes, you can take a, say, 26" prefit barrel and have a Smith (or diy with some shadetree gunsmithing tools from brownels) cut the muzzle to length and recrown. Even the crappiest Smith would have a hard time diminishing the barrels accuracy.
And the other side of it, yes, you can take a partially chambered diy barrel or barrel blank and fit it to your savage as well, but it may have to be done like a Remington with a shouldered barrel and no barrel nut. That's how I'm doing my savage. Byebye barrel nut!

[Dennis]

Really, I was just getting discouraged by the long wait for a barrel, and was going to order what was in stock and have a local machinist cut and crown it to my length. The barrel maker was trying to discourage this, saying that the harmonics wouldn't be right and they couldn't guarantee accuracy.

I'd call BS on, but hey, maybe there's something I'm ignorant about. Always willing to learn

Once a centerline is estabished on a barrel, it's best to stick with it. We have found altering the barrel in any way will affect accuracy and harmonics. "Maybe" a few might pass successfully when shortening a barrel. I could take a 26" and make it a 20" barrel. It would void the warranty on the barrel.

I have a take off 308. I am going to set it back and cut it to 20 inches. I am going to use my proven load and see what happens. I will report the results.

What is the perfered twist on a 20" barrel?

Dennis

I am interested in hearing comments on this. I have recieved may calls from people concerning 20" barrels or less.

[bodywerks]

Barrel length has very little affect on spin stability of a bullet. Whatever twist works on a 26"barrel will work on a 20"barrel. For a .308 win, a 10 or 11 would be just dandy.
I find it interesting that you are saying that shortening the barrel will void the warranty. Of course it is going to affect the harmonics of the barrel, but so what - work up a new load that's in its accuracy node. I don't see how it would void the warranty if it was done properly. If we are talking about a prefit barrel, then the manufacturer warrants that the chamber depth is correct and was indicated with the bore prior to cutting and that the tenon threads are also true to the bore centerline. And of course that the bore of the rifle is straight and the rifling is within the manufacturers tolerance standards. Shortening the barrel at the muzzle affects none of that.

[JCalhoun]

I used to have a .223 that started out as a 26" factory barrel and I had it cut to 20". It shot the same load of 25gr Varget with 69gr SMK into small ragged holes as before but with better balance and a shorter rifle bag.

[bodywerks]

Yep. I know of guys that used hacksaws to cut the barrel down. Still shot accurate. Brownels sells a DIY barrel crowning kit that doesn't require special tooling, and the first order of business calls for curing the barrel to length with a hack saw...

[Werewolf]

I am with the OP on this. I am frustrated with how hard it is to get a pre fit barrel that is less than 26 inches and in smaller contours than varmint. That is just way too long for carrying in the woods.

Even the new McGowen outlet only gives options down to 26.

[82boy]

I have a take off 308. I am going to set it back and cut it to 20 inches. I am going to use my proven load and see what happens. I will report the results.
What is the perfered twist on a 20" barrel?
Dennis

To start, I have had many barrels cut down, set back, contours changed, all after they have been chambered, and I have yet to see where this drastically changed the way the barrel behaves. Yes, when you cut down a barrel it is possible to change the harmonics, this is why you have to do a load development and find where this new set up shoots best. Using the same load that worked in one barrel length, may or most likely may not work in another barrel length. So when cutting down a barrel you have to go right back to the drawling board and find a new load that works. Barrel length has nothing to do with twist rate, twist rate is directly related to the bullet weight, and design used in the application.

[sinman]

I have modified hundreds of barrels that have been completely finished and most have been shot. I have never had any negative effect to them and most of the time they were improved.

You can take an off the shelf barrel blank and make it into a prefit barrel no problem. Usually it is more work but it is done everyday. When I make prefits I always order barrels contoured correctly but I have made many from customer supplied blanks.

[JCalhoun]

My .300 Savage barrel is a 20in sporter contour 1-10 twist pre-fit E.R. Shaw.

[Dennis]

My .300 Savage barrel is a 20in sporter contour 1-10 twist pre-fit E.R. Shaw

Did you cut the barrel or was it purchased as a 20"?

[Westcliffe01]

This article by Dan Lilja http://www.riflebarrels.com/articles/bullets_ballastics/long_barrel_velocity.htm documents his experiment in making a barrel for his 338/378 Weatherby Magnum.

It started as a 46" barrel and it was shot and chronoed and then cut down 2" at a time until the final length was 24".

Dan Lilja is someone who few would contend to be a crackpot and he found the accuracy to be around 1MOA across the entire length spectrum. This is just based on 20 rounds fired at each length (including re-sighting) with no change to the load throughout the entire process. This was essentially a study in velocity as a function of length.

If folks want 20" barrels, I would agree that they should buy the 26" barrels, shoot them as is and get a load worked up, then shoot that same load after chopping down and re-crowning. The original load would be a good starting point since the chamber is untouched. The shorter barrel should be stiffer than the original, but it might be necessary to tweak the powder charge a little.

I have considered this same process for re-barreling military rifles, for which good quality barrels are simply not available. Its a bit more drastic in that it would require re-profiling and the cutting of a new barrel tenon and clearly I could not expect any manufacturer to honor their warranty in such circumstances. But it alleviates the need for me to have to cut the chamber, which is one of the most critical tasks in the making of a match barrel. And reamers are not exactly cheap either... This process is way cheaper than working directly from a blank. Most Savage pre-fits are either the same price or cheaper than blanks from the usual sources.

[JCalhoun]

Dennis,

I purchased it that way. I called E.R. Shaw and told them what I needed and had it in about 8 weeks. Granted, that was a few years ago.

[jbjh]

Thanks fellas! Like I said, not trying to doubt a manufacturers process and how they ensure quality control, just trying to do what I want without crapping things up.

[Dennis]

jbjh, this thread has been throughly inspected and discussed. We will cut one 2"'s, but that is the limit with our process. I wish I could go into more detail . . . . Dennis, PS: there may be 22's on the horizon somewhere.