243AI forming loads

[skeetlee]

What have some of you fellas used to fire form your 243Ai rounds? Can you start load development while fireforming? I also have some RE17 anyone have a load for this in 243 and 243AI? Thanks lee

 

[jimm]

Skeet ,

I use 38 grs of H4350 under a 107 smk to fireform for my 243ackley . It is very accurate as a fireform load, less than half moa ) and does good job of bringing the shoulder out .

Sorry , but I have not used the RL 17 yet so no help there . I have however , used RL 25 to great success under a 117 DTAC . Out of two identical twist rate bbls, 7.5 ) by a single mfg I experienced everything from total bullet failure to face deforming, grin splitting accuracy, 4 bullets in the ones at 100 more than once) at a very exciting 3175 fps level . Suffice it to say it was a boatload of RL 25 .

Also , my top load with that velocity level has not been proofed to see if it will pass the test of a 20 plus shot string as would be encountered at a f class shot . My personal opinion on that is ' NO ! it wont go there ' One of the two bbls mentioned did fail that test while the other was iffy .

But, for varmint whacking it is a joy !!

Reckon it depends on what you wanna do .

jim b

 

[ChuckMiller]

As a rule any max load for a specific bullet/powder combo in a std 243 will usually do the trick. I think load development while fireforming may give you some indication which components might do well but that's about it. Fireforming an improved case usually includes jamming into the lands and there's no guarantee that your rifle will do well, it might like to be jumped. In mine accuracy was average while forming brass,1.0'-2.0') with formed brass doing well. Another thing to consider is that this chambering is not known for long barrel life. I had a friend that fireformed 300 rounds just to find out he wasted 30% of his barrel life on rounds that would hardly break an inch. What's the twist of the barrel and it's intended use?

 

[jimm]

Skeet ,

Dont get skeered ! I read a lot of stuff about the BBL burning 243 AI . Some of what I read is from folks that dont own one and some is from folks that have one but dont shoot it much . I have four and shoot them all a bunch . One in particular is well past the ' predicted ' bbl failure stage and is still shooting under a half moa if I do my part .

Some things I've seen while working with these four rifles :
1. The ones that I ran too hot , too fast show the most fire cracking in the first bit of the bbl . They still shoot good but only after a bit of scrubbing with the JB bore paste, concentrating on the first 3 or 4 inches of bbl .
2. The ones I have babied still have the ' dried mud ' cracks but are not as bad and dont need any polishing to keep the accuracy at the original levels .

3. The brass simply doesnt grow after the initial fireform, size , trim, shoot again then trim any errant cases . I only collet neck size after the initial fireform . I have a body die to bump the shoulder back when required but havent had to do so in 5 firings of the rifles that have more than a thousand rounds down .

The 243 AI is a really good cartridge that is very capable of world class performance in the accuracy dept and more than acceptable performance in the ' rounds down the tube ' dept .

Many years ago I realized that if I only took the path that was touted by others then I was coming up severely deficient in the ' hands on' department .

Build one , shoot one , tell us all how it went !

jim b

 

[number40Fan]

I currently have 2 243AI barrels. One is a 10 twist while the other is an 8. The 10 shot best while forming rounds. I still need to spend a little time with it to see if I can't get the formed rounds to shoot better. The 8 twist has been killer from the beginning.

10 twist is a range gun. Shot all of the shots at the range. 8 twist is a field gun. First 10 shots were at the range while sighting in and also fireforming, and the rest were shot while killing things. I babied the 10 twist, beat the crap out of the 8 twist.

Fireformed both barrels with a healthy charge.

 

[skeetlee]

Thanks for the info guys. My rifle should be home in a couple weeks. The barrel on my build is an shilen 8 twist. I was hopeing to use up some of the 58gr and 65gr bullets i dont usually shoot in my other 243. Lee

 

[number40Fan]

Only thing you can do is try them. Might blow them all to heck when they leave the barrel, but as long as the case forms nicely you are doing ok.<--my opinion