New Barrel vs Stock and Barrel Chamber Dimension

[Doc7]

Hello all,

I have tried a variety of bullets in my Savage model 11 but I really can't get it to group consistently under 2". I just order a new set of 1-piece DNZ mounts and am hopeful that may fix the issue.

The rifle was purchased used for $300 (7mm-08 in Accustock). I have installed torqued the accustock (not the wedge screw version) per specifications. I believe the barrel may be "shot out". I also have a used Vortex Viper 3-9x40 on it of which I am not sure of the history (maybe it was banged around?). I notice that the scope adjustments seem to go way farther than they are supposed to (have to dial half as many clicks as it says, at 100 yards, to move the approximate center of the point of impact) so I already plan on sending it back to vortex at the end of this upcoming hunting season. The scope is currently on Weaver bases (the $3 ones) and a Zee Signature set of rings but I am swapping them out for a DNZ One piece game reaper low mount.

For right now a 2-3" group is acceptable for under 100 yard shots at whitetail for this upcoming season but I really want to try and improve it afterward. If the scope mount and scope look-over by Vortex do not work out, would you expect better increase in accuracy from either a barrel swap (let's say a drop-in Savage replacement barrel from Shilen) or by placing it in a Macmillan hunting stock and bedding it?

My follow up question is about the Shilen barrel - they offer custom chamber cuttings if I want a certain cartridge OAL. If I am about to start reloading (I have all the gear, none of the consumable items), or may end up using factory cartridges, how does one pre-determine a desired OAL chamber? Presumably when you order a new barrel you have no idea what bullet weight it will like best so I don't understand how one can order a custom chamber length.

Thanks for any advice!

I might end up calling them, per their advice in the FAQ:

What do you mean by "Throat to a dummy cartridge"?
Factory rifles are made with throats long enough to accept the largest bullet that is offered in factory ammunition for that chambering. So if the throat is long enough to accept a 200 grain bullet and you only want to use 150 grain bullets, then the throat is so deep you can't get the bullets close to the lands and keep them in the case. What this amounts to is the factory reamed out a couple of hundred thousandths (or more) of lands and grooves in the throat, which shortens the accurate life of the barrel by as much as 50%. All bullets and throats have a "preferred" stand-off or "jump" distance from ogive of the bullet to the lands. Handloaders "tune" their ammunition by experimenting with this distance. Generally speaking, all calibers tend to shoot better when close tot he lands. Weatherby rifles come with about 3/8ths of an inch of "free-bore" in them to help compensate for the high pressure the factory ammunition develops. If you intend to shoot factory ammunition in your rifle, then stay with a factory length throat as shortening the throat will probably show little or no increase in accuracy and may even prove detrimental. In fact, in Weatherby cartridges, this free-bore is necessary to avoid pressure problems when using factory ammunition. However, if you intend to hand load for your Weatherby cartridge for better accuracy, then throating to a dummy round is the ticket. When you send us dummy rounds to throat to you are, in effect, asking us to make the chamber to fit your ammunition instead of you being required to make your ammunition to fit the factory chamber. Make sure that your dummies will fit into the magazine of the rifle. If you aren't sure what to do. Don't be embarrassed. Just pick up the phone, call us, and we'll help you get it straight.

 

[NWcityguy2]

The logical thing would be to take another rifle with an optic and swap them. That way, you are testing a different optic on the Savage and the Vortex on a rifle that you already know to expect accuracy wise. Adjustments on entry level scopes are always going to be approximate. What is far more important is that they hold zero. For most scopes in the $300 price range, they are perfectly suited for setting a zero and running with it. Most people who are dialing in adjustments and expecting first shot hits, are spending a bit more on glass.

I personally doubt your barrel is shot out. Most rifles just don't get shot that much. A 2" group with off the shelf hunting ammo is average. If you plan on using the rifle to hunt big game, there is no reason to spend money on a match barrel. Just reloading ammo will likely cut your group size down, perhaps in half. If you were to get a custom barrel, I wouldn't mess around with the throat size. That is generally used for people who long load bullets to make room for more powder in the case, or only plan on using one bullet for the life of the rifle.

For most of what you want, if you are shooting hunting bullets in hunting conditions, there would be no point.

 

[Bart B.]

Weatherby's ammo is no different than other stuff; same max average peak pressure as several have. But SAAMI specs say its freebore is .361". Compare that to the .30-06, .300 H&H and .300 Win Mag freebores of zero inch. And that of the .308 Win is .090".

Note that for a given chamber freebore (cylindrical bore length in front of the case mouth that's free of any rifling; hence its term), the angle of the throat/leade will determine how far a given seated bullet moves before it touches the rifling. More with a 1.5 degree than one with a 2.5 degree angle.

 

[eldon519]

I don't know if it's the best or most important factor for figuring out what COL you want, but you can determine how long your magazine is capable of holding.

 

[Bart B.]

Whatever length your ammo's loaded to keeps the bullet jump to rifling the same within .001" for only a few dozen rounds. I've not seen any significant difference in .308 Win. barrels' accuracy while eroding/advancing their throats near .070" through 3000 rounds of barrel life.

That's about 42 rounds per .001" of throat advancement.

Are you going to measure your rifle's throat and seat bullets .001" shallower every few dozen rounds?

 

[Doc7]

I guess I was too wordy and rambled - neither of my questions has been answered directly, though I much appreciate the comments provided!

- what is a bigger impact on rifle accuracy, new stock or new barrel? Is my gut feel correct that a new barrel is essentially a "new rifle"?

- how does one decide upon a custom throat dimension for a new barrel, given that obviously one has not come up with a load for that barrel? Is it a matter of saying "I want to shoot 150 and 139 grain .284 bullets" and going from there?

 

[243winxb]

7mm-08 remington

or may end up using factory cartridges

Then you want a standard SAAMI chamber, unless your going to shoot 120gr bullets all the time. http://www.saami.org/PubResources/CC_Drawings/Rifle/7mm-08%20Remington.pdf A new barrel is a better choice than a stock and bedding. The current stock should be checked for fit or problems. Before you do anything, correct the mount and scope problems, if there are any.

 

[243winxb]

Hodgdon has load data for 100 gr to 175 gr bullets, if you reload. Not only is the chamber important, but the new barrels rate of twist has to match the bullet for best accuracy. http://www.bergerbullets.com/twist-rate-calculator/

 

[Edarnold]

"2 to 3 inch groups are adequate for under-100 yard shots at whitetail"

I'm sorry, but I'm having a problem visualizing a whitetail deer so small that an effective shot must be within a 3 inch diameter area.

 

[Txhillbilly]

Doc,I would say try a different scope on the rifle first. Vortex scopes have been known to fail. I doubt the barrel is anywhere close to being shot out.
Nothing wrong with using Weaver bases and Burris Signature Zee rings,those are the only rings that I will use,but I prefer a Weaver/Picatinny rail base instead of 2 pc bases.

An aftermarket stock will aid in getting better accuracy from a factory rifle,and since you have basically an entry level/package rifle the stock isn't as good as other models of the Accu-stock.

Unless you plan on competing,there's really no need to try a custom chambered barrel,IMO. An aftermarket barrel chambered in a standard spec 7mm-08 chamber will shoot better than you can in most cases.
If you really want an aftermarket barrel,I'll make you a great deal on a 7mm-08 26" Stainless varmint contour barrel - low round count,a set of dies,brass and a bunch of bullets. I have too many different rifles,and have decided to stick with my 6.5mm barrels. Send me a PM if you are interested.

 

[gamestalker]

I agree with rings and scope first before doing anything else. I just sent my 4th Vortex in for service in the last year-ish. I'm not trashing Vortex, they do make some decent glass, but they seem to be a bit more prone to problems than say Leupold.

So get some better rings, I have used Warne and Burris Zee rings, both have been stellar.

Then ship the scope off, it will cost you $5.95 for flat rate shipping. Vortex will almost always have it back to you in about 10 days. They're customer service is top notch, no complaints there.

I might also suggest getting your reloading operation up and running. Reloading, when done correctly, will just about always improve accuracy, has for me. It does often require some load development and testing to know what works best in your rifle, but the pay off is generally very rewarding.

If you haven't already done so, I would maybe do a serious cleaning job on the barrel, especially from the lands out the first 6" or so. This is where barrels will commonly get heavily fouled, which sort of swags the bullet down during the first few inches, and it doesn't engrave properly. Then it will struggle to stay in the lands and grooves after existing the fouled region.

GS

 

[MCMXI]

I have a Savage Weather Warrior in 7mm-08 Rem that came in an AccuStock and with an AccuTrigger. When I bought the rifle Savage had screwed up royally and shipped 7mm-08 rifles with a 1:11 twist barrel which isn't ideal for that cartridge. I ended up ordering a really nice McGowen barrel with a 1:9 twist. Your accuracy issues may be due to the twist rate if you have an early model. Savage ended up changing the twist rate to 1:9.5 so you might want to check. I could never get the Savage barrel to group with factory ammunition or reloads. Another issue I had with that rifle is that the top of the front and rear bridges on the receiver weren't in the same plane ... terrible quality and it's soured me to Savage ever since.

As for Vortex, I own four of their products, ordered and use one of their scopes for work, and bought a scope for a friend and all have been perfect up to this point. I have zero complaints about Vortex optics and have yet to need their CS department.

 

[d2wing]

My guess is that it is a 2 MOA rifle, but I can't be certain. If your scope checks out and the rings don't help, most likely a good barrel will. While other factors count, the shooter makes the most difference followed by the barrel and quality sights or scope including mounts. I too am soured on Savage but some guys get very good results with them. Lots of factory guns especially cheaper ones, don't shoot any better than that. You could have other issues as well. You might consider trading it for a better quality gun. Rifles can vary even in the same brand. I know a gunsmith that starts with five different rifles, usually Remington and shoots them all and picks the best one for a build and sells the rest. Good luck.

 

[d2wing]

P.S. I agree with others that chamber demensions are a poor place to start messing around especially for a hunting rifle.unless the scope is bad and you want to keep the gun just get a new quality barrel