Accurizing a centerfire rifle

[Brad Y]

After reading JR's post in general discussion- I thought I would start a thread up with my personal experiences in accurizing centerfire rifles.

Im a spotlighter and hunter but also shoot F class so I have learnt a few things in both forms of shooting that I think are worth sharing. I also spend a bit of time in the workshop at the LGS and try to pay attention to the things that go on in there.

To start with I think the most important part of a rifle is the crown on the barrel. Without a square crown that shows even flash marks on the muzzle then your pushing shit uphill trying to get your groups down- for repeatable and reliable hitting your aiming mark. So after you have fired a few shots, and before you clean your rifle and put it away make sure it is unloaded and the bolt is out and with a small magnifying glass take a peek at your crown. It might be a bit harder with blued barrels but you should still be able to see the soot marks that come off the rifling in the right light. Look for any marks that arent the same as the rest of the others- they might indicate the crown is out of square or a small mark causing it to flash differently. If you see any marks on the crown or notice uneven flashing then take it to your smiths for them to redo it in the lathe.

The second thing I see alot of through the shop is bad carbon fouling. Everyone has their own way of cleaning and plenty of cockies use the simplest method around- not doing it. But eventually lots of people come in saying their gun isnt shooting straight or as good as it used to. Inspection down a barrel with a borescope is something I wish alot more people had access to. When you get the round count up in a barrel you get ceramic caked on carbon in the throat. Cleaning it with solvents does get rid of the loose powder fouling after a days shooting but monitoring it when cleaning, the best solvents you can think of dont necessarily get rid of this caked on carbon. The only way I, and lots of other competitive shooters in my area have been able to remove it is with paste cleaners such as iosso or JB's. Im not going to go into my method here but if your rifle isnt doing what it used to do and you dont know why, this may be the problem. Barrels with faster twists and overbore calibres tend to foul faster in my experience. Maybe a chat to your dealer or smith will be able to sort your accuracy problem out.

I wont bother talking about run in on barrels other than the fact that I do it and I do it the way that seems to work for me. If in doubt google it and decide if you wish to do it or not.

The next thing I think is important in accurizing a rifle is bedding. Often on factory stocks you dont have a decent support on the action that is solid and does not stress the action when tightened up. Wood stocks can also warp in humid climates adding to stress. A good pillar and glass bedding job goes a long way into getting a rifle that is ok to a rifle that is good. You can also be with V blocks like the whidden style blocks or go a full glue in which is often what is done on target rifles.

Free floating a barrel is another thing you can do and best of all you can do it at home. Grab a business card and wrap around your barrel underneath it and slide it up til it touches your action. If you cant get it all the way up through the fore end of the stock then you can take out where it touches with sandpaper. This lets the barrel vibrate how it wants to vibrate when a bullet travels through it.

I guess if your hell bent on accuracy then your up for a match grade barrel straight away. But dont give up on your current one- there are the odd ones around that will do quite well- especially for hunting needs. But if it doesnt work then get a good name brand one installed. Good brands are krieger, lilja, truflite, maddco, pac nor, hart... the list is actually really long. I have heard good reports of the quality of barrels coming through MAB (TSE they are called now) but havent looked down one myself. You will need a reputable smith to chamber and fit the barrel for you. There are quite a few bits to chambering a barrel and installing it and even if you have a lathe, I would still lay out the money for a pro to do it. As Lowndsie found out recently there are people around who advertise as being a gunsmith that arent competent to set headspace properly so go for someone with a good reputation. They will thread, chamber and crown your barrel and install it on your action and should test fire it first to prove it is safe.

At the same time a new barrel goes onto your action, you should look at getting the action trued. Actions such as remington, savage, howa can be given anything from a small trick up to a full blueprint if they need it. Of course if your a target shooter then you may want to price up a custom action versus buying a donor rifle first and getting work done. Basic things like making sure the lugs bear up evenly, bushing firing pin holes to reduce primer piercing, maybe installing a better firing pin spring and squaring the bolt face can make a difference.

You can also look at aftermarket triggers. I recently found my rem 700 Xmark Pro trigger to be the weak link in my target rifle. It wasnt breaking consistently and the pull was too heavy to the point the rifle was movin in the bags differently at each shot. For hunting it isnt too bad, but definitely not a target trigger. If your not happy with yours there are rifle basix, timney, jewel and a few others to choose from.

I think that is pretty much all I have to add to start with- would love to hear other peoples opinions, experiences and findings.

[Tony Z]

I will add a little to what Brad has touched on, but with regard to an existing factory barrel. I agree, the crown should be re cut as a matter of course as this is the last link to the bullet and the most important one for best accuracy.

The biggest fail i see in factory barrels is shoulder squareness to bore line, or more specifically to the muzzle orientation. A simple squaring up of the barrel shoulder while it is set between centers is the biggest single improvement a factory rifle can get outside of having a proper crown cut.
There is not one manufacturer that i have seen that has this simple process under control. The alignment of the muzzle, chamber, action threads through to bolt line is the process that all long range rifle builders concentrate on to eliminate errant shots from inconsistent moments both in the linear and lateral planes. Factory rifles can benefit greatly from these basic principles.

[stinkitup]

Is that where a Savage comes into it's own Tony, no shoulder to worry about

Ryan

[Brad Y]

Hi Tony- great point there. I take it you part off a small amount of barrel and re cut the shoulder,thread and then re chamber for this?

[Tony Z]

No Brad, set up between centers. By centers i mean grab the muzzle in a 4 jaw and the chamber with a quality live center in it. Just lightly touch a tool to the shoulder and inspect. Clean up the shoulder until no shadowing is left. This will usually take only a few thou off the shoulder where often factory chambers are usually loose enough to not need re setting of the head space. Maybe just a tickle with a reamer at worst but your old brass will most likely need to be tossed either way. This is a fifteen minute job once the barrel is out and is in no way any great machining task, just a simple correction like machinists do to axles and pump shafts every day.
If you see that the barrel is bent, and it will often be bent, don't be tempted to try and straighten it. A square shoulder and concentric muzzle venting down the center line gives you a good chance whereas a stressed barrel gives you little to no chance.
Brad this is the tiniest of tiny corrections, but is so important to how a rifle (barrel) reacts during the rearward moment of the initial recoil just prior to bullet exit and then again when the bullet has exited. The emphasis is to reduce the number of vectors, preferably down to a singular one, that being a directly rearward vector. Rearward and sideways is unrepeatable in what we do. Rearward and very slightly up is OK with the type of rests and stock angles we use.

What i didn't mention prior is that a barrel that has a shoulder that is not square, like an action that has its face not square, sets up a barrel in an unevenly stressed state when tensioned up tight. Upon firing the heat transfer slightly relieves this tension in an undesirable way where the barrels POI can shift. Often the bedding is blamed, but it is not always the culprit.

[Brad Y]

Awesome mate thank you. Especially interesting to read about squaring face of actions. I totally never thought of that. You just assume these things are square when you put a new barrel on (with a square shoulder of course)

[Vermingone]

Can you guys post illustrations to emphasize what you mean please ?

[Brad Y]

Definitely no Van Gogh but this shows it. Uneven or not square shoulder on the barrel and the same on the face of the action. Just checked my pierce action before the barrel gets done on it. Quite good. Another point to note is if your running something with a removable recoil lug such as a remington then you can grind the lug flat or purchase an aftermarket one.

[Vermingone]

Perfect thanks Brad

[Bidgee]

I will add a little to what Brad has touched on, but with regard to an existing factory barrel. I agree, the crown should be re cut as a matter of course as this is the last link to the bullet and the most important one for best accuracy.

The biggest fail i see in factory barrels is shoulder squareness to bore line, or more specifically to the muzzle orientation. A simple squaring up of the barrel shoulder while it is set between centers is the biggest single improvement a factory rifle can get outside of having a proper crown cut.
There is not one manufacturer that i have seen that has this simple process under control. The alignment of the muzzle, chamber, action threads through to bolt line is the process that all long range rifle builders concentrate on to eliminate errant shots from inconsistent moments both in the linear and lateral planes. Factory rifles can benefit greatly from these basic principles.

The action face on remmy actions appear to be sawn off with no attempt to true them in factory. Some of them are significantly out of true. Howa seems better.

Interested in why you do this between centres rather than through the headstock?

Edit: Tony, as you mentioned barrels tend to be bent. Do you index them north/south when chambering?

[MISSED]

Interesting point Bidgee i was wondering that myself.

[Brad Y]

My gunsmith now indexes the barrel so the muzzle is at its highest point at 12 oclock. For interchanging barrels this is good as windage zeros are rarely too far out. Im thinking it helps with long range load tuning as well. Ive got a copy of the Gordy Gritters chambering a match barrel DVD and its easy to see how he does it.

[Bidgee]

My gunsmith now indexes the barrel so the muzzle is at its highest point at 12 oclock. For interchanging barrels this is good as windage zeros are rarely too far out. Im thinking it helps with long range load tuning as well. Ive got a copy of the Gordy Gritters chambering a match barrel DVD and its easy to see how he does it.

Good DVD that! Seems to make sense to index to 12O'clock.

[DSD]

There is also a really good article somewhere on the internet where a guy does it with his 2013 anschutz and shows photos of the groups as he rotates the barrel. From memory it is pretty discriptive
I think he may do it with 2 barrels on the same action.

[Brad Y]

Rimfire im guessing would be a whole different kettle of fish as you cant tune the ammo to the gun.