.243 rebarrel

[Jimm]

I trying to decide whether or not to have my .243 rebarreled in std. 243 or go to the .243ai. I would like to hear from those of you that have done this or have owned both. Is it a simple fireform to the new dimensions? thanks ,Jim

 

[Fiftydriver]

Jimm,

I have do not own either at this time but I have built several 243 AIs for customers and like the other AI rounds, they are about the easiest wildcats to load for.

Basically take a mid-upper level load in the parent 243 and load and shoot, easy as that. A properly set up rifle chambered for an AI round should deliever 1/2 moa grouping or slightly better with fireforming loads making them totally suitable for field use, even varminting.

As far as performance goes, the AI rounds based on the 308 family of case will not produce the increased velocity as say a 22-250 AI would or a 257 Roberts AI compared to their parent cases.

THis is because the 308 case is built to pretty minimum taper as is for a factory round and case capacity is not as dramatic as some AI rounds.

Still you will generally get at least 100 fps over the 243 plus your brass will last longer in the AI chamber as the sharp shoulder will limit case stretching.

Its a heck of a little round. Fireforming is extremely easy.

Good Shooting!!

Kirby Allen(50)

 

[Centre Punch]

Jimm,
Go for it! Having abandoned my 6mm AI project, as i posted previously its just to expensive, i have decided to re-barrel my 243 remmy PSS to 243 Ackley.
I shoot mainly 90grn Scenars in the 243 and will stick with this bullet for the Ackley, thus i am going to have a 1-9 twist, 28" long in straight HV taper

I'll keep you posted to how its going and would be gratefull if you would do likewise. /ubbthreads/images/graemlins/smile.gif

Ian.

 

[bailey1474]

I am thinking of rebarreling by 243 with a 6-284 bbl. Gives much better performance with the heavier bullets and doesn't use all that much more powder. Anything in the 6mm caliber gives great versatility.

 

[Jimm]

Thanks Kirby, Are you saying the initial fireform loads will have half moa accuracy?I will probably use 85 gr. to 107gr bullets , what in your experience would be a good twist rate?Would 1 in 8 be to fast for the 85's? Thanks again,Jim

 

[Jimm]

Hey Centrepunch,I will definitely keep you posted. What is the bc of the 90 scenars? I would'nt think it would be as high as the 107 sierra matchkings.Have you ever used or considered them?

 

[Fiftydriver]

Jimm,

For the 243 AI with the 107 gr Smk you will need the 1-8" twist. This would probably work fine with the 85 gr pills as well. You would have no problem at all with the Ballistic Tip family of bullets as they will handle any twist rate at these velocities.

For a conventional cup jacketed bullet you may see some problem with bullet integrity failures.

A properly chambered AI rifle will shoot in the 1/2 moa range with fireforming loads given it is a quality rifle to begin with. If you take a factory 243 and rechamber it you will probably not get this level of consistancy with fireforming loads but in a properly machined match barrel, this is fairly easy to get.

Good Shooting!!

Kirby Allen(50)

 

[Aussie]

Jimm ,
I have a 1 in 9 twist and it shoots best with 55gn Noslers . Work that out !
Bear in mind that you probably won't be able to use the magazine in a Remy with VLD bullets unless you get a very short throat .

 

[Fiftydriver]

Aussie,

The most accurate rifle I have ever built for conventional range shooting used a 1-9 twist and put the 55 gr Ballistic Tips into groups consistantly in the low to mid .1"s.

On top of that, the rifle was chambered for a 6mm-06!!

Velocity was 4350 fps.

So we have a very long and skinny case design(supposedly bad for accuracy) combined with a vry light bullet at very high velocities that is vastly over stabilized.

Again, it is my opinion that if the rifle is built properly and the bullet will survive the launch velocity and RPMs, ase design means very little as far as accuracy goes.

Youe example is just another example of this fact!

Good Shooting!!

Kirby Allen(50)

 

[Centre Punch]

Jimm,
The listed BC for the 90grn Scenar is .420, they are very nicely made and shoot superbly.
I have not tried the 105grn SMK yet but have had success with the 105grn Scenar which has a listed BC of .530,out of my 1-9 (and a bit) twist factory barrel.

In standard common calibres, Lapua brass and bullets are one of the things that are cheaper to buy here in Britain then the american equivalents.
I'm looking to forward to a progress report. /ubbthreads/images/graemlins/smile.gif

Ian.

 

[3sixbits]

Poor guy! It's just a shame you don't have the benifit of cheap REMINGTON brass and are stuck with LAUPA brass! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/tongue.gif

 

[Jimm]

3sixbits,Why is it so hard for rem.,win., etc. USA mfgs to produce quality brass?It's does'nt make sense !We will pay for it! ,be glad to have it usa, and ,and, and, sheesh,I just don't get it.The facilities are here and just for the record how /what percentage of shooters world wide are here vs. there/elsewhere? /ubbthreads/images/graemlins/confused.gif

 

[Fiftydriver]

Jimm,

Its a money issue my friend, while most everyone on this board will shell out the green for quality brass, the VAST majority of American shooters and hunters could care less about brass quality of even load consistancy. Just look at how much factory ammo is sold every year and if oyu go hang out in your local gun shop for a period of time, you will see it is not the quality premium factory ammo that is flying off the selves, its the cheap stuff.

Point being, US brass makers make a load of money with the product they offer, why cut into their profit margins for added quality when their support base does not demand it?

For most of us here, we will happily pay more for better brass or spend hours prepping and machining US brass to get true match grade performance.

Money talks!!

Kirby Allen(50)

 

[Aussie]

Centrepunch ,
What loads and velocities work best for you with the 90gn Scenar ? Am interested in trying it in my .243 AI.