Is this a problem?

[msr243ai]

On my 22-243. I was talking to my smith today and just got curious. Asked him how he dialed in my barrel before he started the reaming process his way. He said that he used a 10,000 th. Dial indicator on the inside of the bore. Said that he was 1-2 10,000 TRUE. Anyways he chambered the barrel this way. Is this right or wrong? Thanks. That might be why I can't seem to get the groups to pull in....Thanks

 

[X Ring Accuracy]

If it is dialed in to .0001 then thats not the problem. ALOT of other variables. Give us some more info. Ammo, twist, etc. Look at the crown, is the carbon print symetrical? What are the group sizes you are getting?

 

[msr243ai]

Hornady 75 grain A Max. Have tried a lot of powder charges from 44 grains up to 48.5 grains. RL -25. 1-9 twist shilen CM. Any ideas? Thanks

 

[bozo699]

You may not have enough twist for that bullet, for a 75 grain berger bullet they recommend a 1:8 twist.
Wayne.

 

[Geronimo Jim]

I have a 1 in 8 twist 22 BR. 75 grain A-Max shot great for the one box I had. Got 500 more and they wouldln't shoot no matter what I tried. Switched to 75 Grain Berger and it was magic.............never looked back. Try Berger.

 

[jscandale]

The need for barrel twist is a function of how much rotational velocity is needed. If a .243 is necked down to .22, you could probably get 4000 fps with a 75 ( just a guess). At 4000 fps with an 8" twist bbl, the rotational velocity is 360,000 rpm. In my experience, and I have quite a bit with .22 cal bullets specifically, the 75 Amax will probably shed it's skin at about 320,000 rpm.
Food for thought...

JS

 

[p17enfeild]

he sounds like a good man to me
i have heared it said to much that smiths can work to half a .0001'' the truth is that .0001 clock's form new are only accurate to .0003 on repaetablity ( as pre good clock makers tech sheet)
so at least he is truthful

 

[Larryh128]

The 1st thing that I would try is a primer change. I would also try a magnum primer for comparison. Chambering accuracy isn't your issue. Most barrels aren't that close.