Vertical stringing

[tvc15]

Shot some .243 rounds today I had some vertical stringing. It seems to rise about .625 inches each shot. (3 shot groups) I was waiting 3-4 min between shots. BTW 100 grain hornady, IMR 4350, range from 39.5-41 grains, and a Remington adl rifle. Any ideas? thanks, TVC15

[Luckyducker]

You are into some good territory with your load,  my best load with 100 grainers was with 40 grains IMR 4350.   The vertical stringing sounds like barrel heat-up.  I would guess that your rifle still has the pressure spot between the fore stock and the barrel,  about 1.5" from the end of the stock.  You didn't say whether your rifle is wearing a synthetic or wood stock but it sounds like it is overdue for a free floating barrel job.  You can check you barrel to stock fit by taking a paper dollar and try sliding it around the barrel between the barrel and stock.  If the barrel is free from stock pressure the dollar should move unobstructed all the way to the action.  It is easy to open up the barrel channel on a wood stock but have never done a tupperware stock.  You should check the stock/barrel clearance and see what you've got before jumping to conclusions.

[victorcharlie]

If you can't see anything wrong with the rifle, why not try another powder and/or bullet.......?

Maybe try as slower powder such as IMR4831......

[jhalcott]

  If you put 3 shots in 1 1/4" you are doing well. What kind of rifle is it? How does FACTORY ammo do? A stringing problem is often a primer/powder mismatch. Try a magnum primer,back off a couple grains and work up for safety. By kind of rifle I mean is it a varmint weight or skinny barrel !

[tvc15]

All good stuff. The barrel is free floated. I will try the 4831, and the magnum primers. My first plan was to use magnum primers. I had posted a topic on that combo and got mixed reviews. Thanks, TVC15

[tvc15]

Barrel was filthy after 18 rounds. My thought now is to use a hotter primer not necessarily a magnum. TVC15

[victorcharlie]

There's a lot of information in previous threads in regard to loading for the .243.........

While I know some people like 4350, my experience has been a slower powder works better, especially with the heavier bullets.......

I've had very good results loading the 85 grain sierra bthp using IMR4831......never tried a magnum primer, but it might be necessary if loading a very slow powder.......

[Old Syko]

Before you devote too much time into trying to cure an equipment problem take a look at the sample rifle targets down the page in this supplied link and adjust accordingly.  Not all failures are equipment failure.  Proper shooting techniques eliminate many such problems.

http://www.frfrogspad.com/miscellq.htm#duplicate

[Catfish]

Vertical stringing is often bad ignition causing a variation in velocity. I have run into that with old primers. Could be barrel heating or you could need to have your action bedded.