Why shouldn't I get a .243?

[TEAMSENDIT]

Re: Why shouldn't I get a .243?

I just rebarreled my aiae mkii with a 28" 7.7twist 243ai barrel. So far the feeding is reliable but i am only 150rds into it. I did ai mostly out of curiosity and wanting to explore the velocity capabilities of it.

I think the biggest advantage of the ai is the fact that you don't have to trim it. However there are many disadvantages fire forming, possible feeding issues, comp speed limits.

My solution to this was that i also had a 24.5" 7.7 twist standard 243 barrel made for comps with speed limits.

 

[21Bravo]

Re: Why shouldn't I get a .243?

LoneWolfUSMC

Outstanding timing on this post for me. I too have been pouring over the +/-'s of getting a 243 barrel for my AE MKIII. For the very same reason, minimized wind drift! I'm going to go with GAP for the barrel at 26" but have yet to decide on contour.

Now, the cost of the barrel change kit from AI is crazy! If I recall correctly MHSA quoted in the $700 range. I understand they can be pieced together by getting the action wrench from a couple of different vendors but the proper barrel vise is the concern. Chances are I will likely go with varying contours on the AE barrels so, will different "inserts" be needed for the barrel vise? I'm interesting in seeing how this works out for you.

Craig

 

[SONIC SAAMI]

Re: Why shouldn't I get a .243?

Why shouldn't you get a 243? This is why...

The 6mm Competition Match is the way to go.
40 degree shoulder
Runs the 105s @3150 with no pressure signs (28 inch barrel with 49g of H-1000)
Barrel life reported to be in the 3,000 round range
Uses Winchester brand 243 brass
When fire forming brass it has the accuracy of a STD 243win


Chad Dixon (who by the way is a super stand up guy) has a reamer for this cambering
http://www.longriflesinc.com/

 

[Rob01]

Re: Why shouldn't I get a .243?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">We had the discussion with Terry Cross regarding the 260AI at the K&M competition and the discussion ended, that AI changes the case to the point that goes against all reliability. It changes the angle in an unfavorable way, it does not lend to good magazine feeding and all for maybe 100fps. In the end its a non-starter for those in the know.

If you are gonna go 243, don't' waste your time with a AI in anything if you can't do it with the speed a straight 243s give you, then you'll never do it. </div></div>

What he said. The standard .243 will do anything those other rounds mentioned will do with no fireforming, and excellent brass and bullet choices. You can lose brass at a match and not stress out because it's your fireformed brass and now you have to fireform more.

 

[RemingtonSPS]

Re: Why shouldn't I get a .243?

260 remington. Lapua brass. Alpha aics Mag's. 28" barrel. 2,500 plus rounds barrel life. Jlk 140 vld. 639bc at 2,850fps.

That's why I wouldn't build the .243...that said robs results are hard to argue with having had to compete against him

 

[KYpatriot]

Re: Why shouldn't I get a .243?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MuleHunter</div><div class="ubbcode-body">260 remington. Lapua brass. Alpha aics Mag's. 28" barrel. 2,500 plus rounds barrel life. Jlk 140 vld. 639bc at 2,850fps.

That's why I wouldn't build the .243...that said robs results are hard to argue with having had to compete against him

</div></div>

Good round, but if you're gonna do that why not just move up some more to the .284? Same barrel life, matching or better wind drift at 1000 with the cheaper 162Amax, and more energy on arrival too.

My answer to the OP's question would be this: If you don't need more downrange energy, then there is no reason not to build that .243!

 

[LoneWolfUSMC]

Re: Why shouldn't I get a .243?

The advantage is if I don't build a .243, then I still have an excuse when Rob kicks my ass.

 

[clmayfield]

Re: Why shouldn't I get a .243?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KYpatriot</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MuleHunter</div><div class="ubbcode-body">260 remington. Lapua brass. Alpha aics Mag's. 28" barrel. 2,500 plus rounds barrel life. Jlk 140 vld. 639bc at 2,850fps.

That's why I wouldn't build the .243...that said robs results are hard to argue with having had to compete against him

</div></div>

Good round, but if you're gonna do that why not just move up some more to the .284? Same barrel life, matching or better wind drift at 1000 with the cheaper 162Amax, and more energy on arrival too.

My answer to the OP's question would be this: If you don't need more downrange energy, then there is no reason not to build that .243!</div></div>

Short action?

 

[LoneWolfUSMC]

Re: Why shouldn't I get a .243?

Yes, whatever choice I make needs to be on a short action.

For speed-limited matches it doesn't make much sense to me to go with a long action. For unlimited matches, I believe there are better options.

 

[RemingtonSPS]

Re: Why shouldn't I get a .243?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">The advantage is if I don't build a .243, then I still have an excuse when Rob kicks my ass. </div></div>

...LOL

The 162 Amax is a .599bc and at 2,700fps it would be slower than the 140 JLK. Thats why i wouldn't build the 284. If you use alpha mags and a reamer with .060" freebore you can chase the lands in the 260 and still mag feed until the barrel toasts. Or you could shoot the 130 JLK at a .593bc at 3,000fps easily with H4350.

 

[Lowe Left]

Re: Why shouldn't I get a .243?

Just to add another to the mix, rather than the 40 degree shouldered AI, what about the 30 degree Improved??

http://www.6mmar.com/243_Imp_30_.php