Choosing a barrel

[steelcomp]

HI,
my name is Scott, and I'm an addict.

I'm taking on a new project and I'm in the information gathering phase. I've just purchased a Sako TRG-S M995 in 7mm rm, and I'm going to re-stock and re-barrel it to build a long range tactical surgical instrument in hopes of becoming somewhat proficient at long range shooting. I know that one of the first things I need to do is decide on a barrel. Some of the "choices" I guess I need to make are:
Button or cut rifling
twist rate
material
length
profile,
most of which will probably dictate what make of barrel I buy.
I would like min. 1000m accuracy. That, I'm sure, will help dictate the bullet, and therefore the twist rate and length. (am I correct?) My choices will ultimately be based on what I learn, not just because someone tells me, but I'm open for suggestions and reasons as part of learning. I know nothing.
Material pros and cons...chromoly or stainless...
Profile and/or taper...I don't think I need a straight barrel, nor do I want one because of weight, so a taper that will help save a little weight, but still maintain good shot consistency after warming up sounds right. I intend to have it straight fluted as well.
I know there's many different schools of thought here, but I'm open to any good input, and appreciate it in advance. I'll be doing my homework, too.

Oh, and thanks to Jason, AKA glock24 for doing a lousy job at talking me out of this. This is your fault.

 

[6Dasher]

Re: Choosing a barrel

You have a long action with magnum bolt face. I would look into a 7mm-270WSM, not much that can beat that in terms of low recoil and high performance at 1000y. 1:9 or 1:8.5 twist using 175SMK bullets.

I personally haven't had that much success with cut-rifling, but I am sure others have. My personal choice would be a Broughton 5C, in 26" with a palma taper (or longer up to 30" if you only shoot on the range and want the extra speed).

 

[valentine]

Re: Choosing a barrel

If I wanted a true longe range tool I would strongly look into the 300 Lapua Mag aka 30-338 Lapua. Therefor I would want a Barrel with al twist of 1:9 for the 240 gr SMK. I would have it 30" long and a rather large contour with an agressive straight fluting (about six flutes). The action takes it, but you will have to open up your bolt face. Barrel manufacturer would bei Bartlein because http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1360575#Post1360575 .
This round is a barrel burner, but there is nothing for free in life.

 

[steelcomp]

Re: Choosing a barrel

Thanks for the suggestions on a cartridge, but I'm going to stick with the 7mm rm.
I know there's a big debate about cut vs, button rifling...I'd like some input on that if possible.

 

[Sig685]

Re: Choosing a barrel

Your decision to stick with the 7mm is an excellent one, the 7mm has some fantastic bullets to pick from for long range.

If you want a debate on cut vs button rifling, I think you will be disappointed because I don't think there really is much to debate. If you get a barrel from a quality manufacturer, their rifling method is immaterial because you will get a quality barrel. And that is what is important.

I would definitely go for stainless steel and blast beading. I am not sure of fluting, but whatever flutes your boat. (ha ha).

I like longer barrels for the long distance, definitely 26 inch and up, depending on how you will use the rifle. Finally I like heavy contours but I think the Palma countour mentioned by FD would be a great choice also. I guess it depend on how many rounds you will put down range in a session and how fast. In F-class we can put 17-22 rounds down range in just a few minutes (as fast as the puller can go) and that barrel will be hot.

 

[Hummer]

Re: Choosing a barrel

There are several good barrel manufacturers. Some that I can think off are:

Cut riflers are Obermeyer, Kreiger, Broughton,Mike Rock and Chanlyn in the US and maybe more???
Button riflers are Douglas, Hart,Pacnor, Lilja, Walther, Shilen and a bunch of others I can't remember. Button rifling is the cheapest to produce.

I have personally used both types with good success. You want one that is hand lapped for sure to cut down on fouling.

CM/Stainless: CM is considered to have the longest barrel life and accuracy tends to taper off in upper rounds denoted by decreased Xs and a few more 9s. Stainless on the other hand will maintain top performance a hair longer but when it goes you better have your jock strap snugged up because it is gonna be wild. In other words you can go from good to zip in the same string.

7MM RM is known for two things regardless of manufacturing method. Copper build up and decreased barrel life.

One of the most critical things in magnums is getting a good barrel chamber and to insure this will require getting your own custom reamer made with min dimension above the belt, a tight neck and a slightly shorter throat to increase barrel life. For the factory standard ammunition the drawings developed by Ray Steele (formerly the sniper rifle builder for the Secret Service who unfortunately left us about a year ago) are the best I have ever seen/used. The USSS rifle team uses 7MM Mag as a counter sniper round and thusly they have done more research on 7 Mag than anyone else. Ray probably ordered a couple dozen reamers until he found the one that worked best and then he ordered his own. The USSS team set a National Record with his guns.

To be sure Ray was not only a fine rifle builder but a fine shooter as well. He was a member of US Palma, Dewar and Pershing Rifle Teams and to my knowledge only two people did this, he and Larry Moore (also a friend). There are perhaps less than a dozen who have been on Palma Teams and Dewar Teams. Bottom line was Ray was a lifelong competition shooter of the highest caliber and one hell of a fine guy to boot.

Ray also designed a reamer for 300 Win Mag. Karl Kovalchek, formerly USSS Counter Sniper set and still holds the 1000 yard individual record with it of only 200-19X and this is prone sling supported.

Prone sling supported is a much tougher game than F class because you not only have to have a rifle that will run with the big dogs, you have to control its movement with the sling and your muscles.

Dave Manson made these reamers when he worked for Clymer.
http://www.mansonreamers.com/ and has the drawings. He made them for me and others I got from Ray over the years.

Ray also designed reamers for 30.06, 7 Mauser and 308 and they deliver fired cases very close to factory dimensions. A case that moves very little lasts much longer.

Magnums are beefy and you know when you touch it off. In prone matches you may shoot 22 to 30 rounds in 30 minute time limit thusly stock design is critical to make it comfortable.

Ray used McMillan Prone stocks exclusively in last 20 years or I guess maybe 30 years as they are completely adjustable (if you get all the bells and whistles) and indestructable to boot.

Basically Ray built both calibers on 28" heavy barrels for long range guns. Last time I saw him he drove down from Indiana about four years back and built two rifles on my lathe after tuning the actions with Manson's Action Truing set ups.

NOTE: If your action is not right you are spinning your wheels. To define what is right get Hinnants book on Fitting of Precision Rifle Barrels. The best work I have seen on the subject as he will explain to the reader exactly what needs to be accomplished to insure a good launch platform.

A top class scope is critical because if you don't have repeatability and positive movement per click you are also screwing yourself and name of scope and amount spent don't necessarily mean success in this area. You need to learn the procedure for checking out a scope for repeatability.

Action selection is critical to long range success as well and they are not like Nascar products. It may look like a Detroit/Dearborn production on the outside but the inside isn't.

You are also going to need a good trigger. Make that a very good trigger.

The only square bottom action I have seen that have done well at 1000 are the Mod 70s and I have never seen any others but who knows. Rem 700s are the most prevalent of the mass produced but as indicated above need to be reworked for maximum results. Thusly if you are wanting to be serious you need to consider a 700 action tuned up or one of the custom actions that are becoming more available. All the ones I have seen are small and medium bolt face and I don't know if any have been made in magnum bolt face.

You need to find a top flight gunsmith preferably one that is a shooter to do this. In the long range game pretty is not the first criteria. It is what you can't see that makes it like a Nascar rocket.

There are a few more things that need to be considered as well but I just thought before you dump a bunch of bucks in this rodeo that you know what a rodeo actually consists of. Hope this helps.

 

[Sig685]

Re: Choosing a barrel

7mm does not have to be the 7mm Remington Magnum, it should be a pure .284 Winchester or .284 WSM which is what dominated the F-Open this year.

 

[Geno C.]

Re: Choosing a barrel

I'll start by saying this is just my opinion... I like Rock Creek, not just because they are top notch barrels but also because I have the upmost respect for Paul. He is a great guy to talk to and they do all they can to help you out if you have questions. I'm sure the other companies might do the same thing but I have found a barrel that shoots better than I can ever hope to, and nice people on top of that. Unless either one of those things changes,(which I doubt) I don't need to look any farther.

 

[6Dasher]

Re: Choosing a barrel

Sig685.. he has a magnum bolt face, the 284Win will not extract.

The 7-270WSM holds about 70-72gr of powder, so it too will burn the barrel away pretty quickly. I get 3100-3150fps with the 175SMK out of a 32" barrel, but I expect it to last 1000-1200 rounds max.

 

[steelcomp]

Re: Choosing a barrel

Thanks for the great input here.
I know barrel life will be a concern, and so will heat and recoil. It makes sense that a stainless barrel in a heavy profile will help adress these few primary issues. That still leaves a wide selection. I've heard that cut rifling lasts longer than button. Is this true, and can someone tell my why?
It sounds like Bartlein is getting their act together.

 

[glock24]

Re: Choosing a barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body">HI,
Oh, and thanks to Jason, AKA glock24 for doing a lousy job at talking me out of this. This is your fault.

</div></div>

Misery loves company.

<span style="font-style: italic">look deep into my eye . . .</span>

 

[glock24]

Re: Choosing a barrel

I thought these were good reads . . .

http://www.rifleshootermag.com/gunsmithing/RSgunsmith1/

http://bettincustomguns.com/Technical%20Information/Barrel%20rifling%20techniques.htm

http://www.obermeyerbarrels.com/steel.html

http://www.riflebarrels.com/articles/barrel_making/rifle_barrel_accurate.htm

http://www.varmintal.com/aflut.htm

 

[steelcomp]

Re: Choosing a barrel

Wow...there's a lot of information there. Thanks Jason. I had to stop about half way through the fluted barrel page...I'll finish that tomorrow. All great redaing.