243 AI question

[204sniper]

I've been looking at barrels for a rifle build in .243 Ackley Improved. I'm currently looking at a Shilen Select Match, but when I was looking at there list of chamber options they list two options for the .243AI. They are listed as .243 Ack. Imp. (.270) and .243 Ack. Imp. (.266). So the question I have is, what is the difference between the two, and what would be the benefits of choosing one over the other?

[Pilgrim]

Neck diameter,or tightness, chamber fit...

Think of in terms of tolerances. 'Tighter' demands finer precision brass & bullet fit particulars/ one of those "one step closer to perfection" deals. Best you have a conversation with rifle builder that hunts. Probably all comes down to whether you're willing to anticipate feeding problems when hunting. Less tight is simply more tolerant of subtle differences in ammo.

[22-250AI]

Tight neck is a waste of time.

I havn't seen anything good come out of Texas yet. ( Shilen )

[204sniper]

I'll likely go with the .270 neeck diameter then. Thanks for the input.

The shilen barrel is more of a convience thing. I'm gonna build the rifle off of a Savage varmint action, and Shilen makes pre-threaded, chambered barrels that drop right into a Savage action. Provided I still need to properly headspace it, but it should save me a little time and money.

[Tim Anderson]

They are listed as .243 Ack. Imp. (.270) and .243 Ack. Imp. (.266). So the question I have is, what is the difference between the two, and what would be the benefits of choosing one over the other?

One has a neck dia. of .270 and the other is .266 dia. (outside dia. for neck in chamber)
What are the advantages:::: It keeps you from over working the neck brass when you resize. (split necks)
As for the two dia. i think without checking, one is a little titer than a factory chamber so you can just touch up the necks with a neck -turning tool and still shoot factory loads if you choose.
The other wouldbe a tight neck where you would have to turn the necks in order to get a case to chamber..
The reason for a tite neck or just under sized is to keep youre cartridge in line every time with the chamber, so the bullet jumps straight out without hitting the edges of youre throat which also helps improve accuracy and keeps youre loads more consistant compared to just factory brass..
Some factory cases tend to have to thick of a wall on one side and the chamber is a little on the loose side so the case just lays there off centered...

For a big-game cartridge its not needed since you have a pretty big target to begin with..
As for Pred. it depends on how much accuracy you want out of a rifle and how far you want to shoot it... If its just at called in coyotes under 300 yds its not needed...
Most of my rifles are chambered for a wildcat cartridge and have tight necks, i want to get as much accuracy and consistancey as i can ...Hope this helps...

Edit for correction:: If you chamber neck dia is .266 the neck on the brass case would be .263

[22-250AI]

Almost all tube builders pre thread and chamber for common actions and calibers.

Your not saving that much money....

What bullits ?

What twist U pondering ?? I recomend 1-9 as mine is far frum unfantastic.

Brux will save you some cash and build em fairly quick got mine 3 weeks after I called it in.

Hart,Pacnor,Rock,Lilja,Broughton,Krieger, you will be waiting 8 or so weeks... the wait is well worth it IMHO for excactly what you want.

You have a favorite gunplumber to screw it together ?

Shilens are/is good tubes I just like to dog texerans

[Tim Anderson]

Almost all tube builders pre thread for common actions.

Yes they do and also cut a chamber leaveing it a little on the long side for the gunsmith to finish up. If you go this route don't plan on haveing most of them close to perfect and on center...
A barrel manufacture is spinning out barrels as fast as they can and they just get them with-in specks but canbe off some.. By going the gunsmith route start to finish on a blank barrel they will insure the barrel is closer to center than the barrel maker makes them..A good gunsmith builds a perfect rifle compared to one that uses short cuts like pre-threaded and chambered barrels...

[22-250AI]

Almost all tube builders pre thread for common actions.

Yes they do and also cut a chamber leaveing it a little on the long side for the gunsmith to finish up. If you go this route don't plan on haveing most of them close to perfect and on center...
A barrel manufacture is spinning out barrels as fast as they can and they just get them with-in specks but canbe off some.. By going the gunsmith route start to finish on a blank barrel they will insure the barrel is closer to center than the barrel maker makes them..A good gunsmith builds a perfect rifle compared to one that uses short cuts like pre-threaded and chambered barrels...

+ 2

Only one person screws my junk together and he starts from scratch.

[Red Fox]

What does the pre threaded barrel have to do with poor quality? Savage is headspaced from the barrel nut and can be headspaced to your brass.What do gunsmiths do to make barrels shoot better than the barrel makers?

[Tim Anderson]

A gunsmith takes a barrel blank and mounts it on his lathe and makes sure everything is perfectly on center. The barrel is cut down in dia. and is even all the way around. Now the barrel is on center and uniform all the way around and when the threads are cut they are also uniform.. You screw the barrel into the action and there is no wobble and the barrel is straight..

To give you an example: Take a new rem. and shoot a few groups with it.. Say its shooting 1" groups consistantly. now take that same rifle to a gunsmith and have him Blue-print the action. Gets everything squared up and straight and he also checks the thread on the action and cleans them up and makes sure they are also straight.. next the barrel willbe put on centers to check if its out of round and if he can fix it or get it uniform. The threads are also checked and willbe cleaned up..The chamber may also be checked for being on center and if not you either have to live with it or he maybe able to re-cut the chamber and then re-thread..Now you take this rifle and go out and shoot it again, the groups willbe smaller in most cases and it will print a nice group..
A friend has a Rem. 700 in 243 that came from the factory with a chamber off center, it was so badd you could see it with the naked eye..The gun did'nt shoot too badd so he just left it the way it was but it did cause him problems on the longer shots.. He finally broke down this year and got a different rifle and it has made a big difference in the longer shots he takes..( getting more Kills)


Some barrels are mass produced like the 22 l.r. barrels for the 10-22 and now the savage barrels with the nut for changeing them over. You may get some good shooters then again you may not.. If you are going to spend the money for a rebarrel job just as well have it done right..

When barrels are made by another company or mass produced they are built with-in certain spec.s useing a scale from 1-5 they can fall into anyone of the numbers (1 being tightest tolerence and 5 a little on the sloppy side but still under.
If the barrel is done from scratch it will fall into 1 & 2 depending on how good youre gunsmith is and his equipement..

[204sniper]

Looks like I've got a lot to think about. Good thing I've got a lot of time to think about it. I'll have to talk to the gunsmith I use and see what he's comfortable doing. This isn't going to be a rebarrelling of an existing rifle, I'm going to buy a new action and buy a barrel to mate to that action. Thanks for all of the input so far!

[Red Fox]

What I am saying is the average shooter cannot shoot well enough to see the difference that 1/2 minute can make. Gordy Gritters is chambering square to the bore and not the barrel. Most barrels are not straight from one end to the other. When shot they are sent into a vibration that would cause barrel flex also. I was convinced that I needed a better barrel on my Remingtons to shoot better. Then I shot Savage with cheap factory barrels. I honestly can say out of the 8 I have loaded for none would shoot over 1/2 inch if I was shooting well. It takes alot of effort on the shooter to shoot group anfter group under 1/2" and most don't spend enough time or effort to learn how. That is why I can't go along with the gunsmith needs to make your gun shoot better theory.

[Coyotehunter]

Lots of good info guys

[243ackleyassasin]

Hello everyone! Im new to this site and think it is wonderfull! i shoot a 243ai with a .265 neck and is a fantastic shooter. but the neck turning has its ups and downs. its great for accuracy, but i use mine for hunting so in a lot of ways isnt worth the time turning the necks just to plow down yotes. but when you have a friendly competition of accuracy with a friend it comes in handy. But of course the gun is never to blame for a poor shot