Home Forums Hunting & Shooting Gunsmithing .243 ai chamber question

Just had a barrel chambered in 243ai. I am using lapua brass. When I put a un primed .243 lapua brass in and close the bolt I feel no resistance at all. On my other ackley I do. I placed one layer of scotch tape on the back of the brass still no resistance but with two pieces I feel the normal ackley crush fit! Some will say seat the bullets into the lands but I feel this chamber might be .008 too long. Smith already marked the barrel so I'm thinking set back would be messy! Maybe a new bolt and set it up correctly! Any thoughts guys?

New, unprimed brass often comes from the factory short. The best way to check the headspace on your barrel is with a Go Gage.

If it is tight on one chamber and not on this one, the possibility exists the guy who did the rechamber didn't set it back. Get a recheck on the headspace. Remember, the 243 "go" gauge is the "no-go" for the Ackley chamber.

Correct information given here. AI go gauges are .004 shorter than the standard cartridge go gauge!

Was this a rechamber of a standard .243 barrel or was it chambered from a blank?

It was not a re chamber this chamber is the only one cut. Brand spanking new!

Then setback wouldn't be an issue. Only way to tell if the chamber was cut too deep is to use a 243 AI nogo gage (you can also use a std .243 go gage). In perfect world, using a proper go gage the bolt would "just" close on it.

If it was mine, I'd ask the 'smith to check the headspace. If he cut the chamber too deep, he should fix it on his dime and he should do so immediately.

I agree with 260! I would ask the gunsmith what gauge he used to setup the chamber and check headspace. From his answers I would proceed accordingly. If he thinks the headspace is acceptable I'd find another gunsmith.
Some people don't understand the Correct way to setup an AI chamber.

I do not agree with 260...if he did it wrong to start with, especially if he doesn't know he did it wrong what do you think you are going to hear from him????? Maybe another way of saying it is; if he couldn't get it right to start with then you had the wrong man...why take the chance of going back to that???? I have barreled many actions and I have to say this; there is less than zero chance any gunsmith can miss headspace and NOT KNOW IT unless he doesn't know what he is doing to start with. If this is the case then he is someone to steer clear of, he is going to get somebody hurt.
In all fairness, the rifle may be right and have perfect headspace. What I am not hearing here is that you have a case that is sized properly to check it with and/or that you have the gauges to properly assess the rifle. I am also not hearing the most important thing....that you have the tools to check and make sure you have properly sized cases. Without that, the chances you will ever have cases sized right are slim. Having cases that fit the rifle properly is not the gunsmiths problem, that is on you!!!
There is another way out of this so that you can safely shoot the rifle. It wont be SAAMI spec {if it is really not right to begin with}, but it will work fine and be safe....size and load the cases you have being sure to seat the bullet out touching well into the lands. This will allow you to safely fire form them in the chamber. Now they will fit and be long enough to be able to have zero headspace when loaded next time. Just be sure you don't size them too small, you will have to back up the size die so it is only setting the cases back .002". Either way, you need the tools to measure case length and I am not talking about trim length...I mean case headspace length.

Edit: I should add that not having the rifle headspaced to SAAMI specs means you cannot do the one thing why Ackley chambers were spaced the way they are....if it is a long chamber then you cannot take factory ammo and shoot or fire form it safely in that rifle. At least not unless you pull the bullets and reseat them touching the lands.

Aren't you forgetting the standard way to fix this? You know, running an oversize button in first to expand the necks, then running them through a standard neck-sizing die to leave a little bump at exactly the right spot to produce the crush fit. Running bullets out to the lands leads to magazine issues, random bullet-pulling (in the rifle) and possible overpressures...

I once received a .223AI from a smith and noticed the lack of crush fit when I first took it out to sight in (factory ammo). Had a couple of fail to fires. Contacted him, sent it back, he took care of it, and it was good after that. He said he just messed up and made it right.

No, I am not. He has new cases that are not fired or expanded and they are too small for his chamber. In fact, he just received this rifle...probably not his first, but I very seriously doubt he has ever heard of over sized buttons, let alone owns one at this time. Magazine issues??? load them one at a time if needed.....bullet pulling??? He's forming some cases, not doing load/unload drills......over pressure??? Not if he loads them right.



All gunsmiths have to learn how to do it right sooner or later....but they need to learn this on something other than a customers gun......"just messed up" headspace and handed it to a customer???? What exactly did he say??? "Here you go, if it don't blow up and kill you I'll make it right later....." Again, you cannot mess up headspace that bad and not know.
All that said, "lack of crush fit with factory ammo" may not have anything to do with the rifle, his could be fine...I have seen factory ammo that bad and it is not uncommon. Another reason to own the tools to check case headspace length.

All 'smiths are human and every single one of them has made a mistake. If the OP doesn't let the 'smith who originally did the work inspect it and fix it as is necessary, I doubt that the 'smith will ever accept any responsibility for causing an error in the first place.

Any 'smith who is worth a damn will stand behind his work and I think that the customer needs to tell him that there is a problem and then give him a chance to inspect the work and fix it if necessary. If I pay someone to do a job and the job isn't done to my satisfaction, I explain my concerns to that person and try to work with that person with the intention of reaching a mutually agreeable solution. I realize that there are usually multiple ways to address a problem and I never intended to infer that my way was the only way, but it is what I would probably do if I encountered the issue that the OP described.

Excellent post - and spot on...

I was thinking you are the one unaware of using a 25 caliber expander button (must be at least a couple bucks at most stores with reloading supplies) to create a false shoulder. Using the bullet jammed in the lands is flat wrong...