Load Development Issues...

[griff383]

I tried a few different powder and bullet combinations for my 243 (1:10") and found one that gave really good results, 75gr V-Max and IMR 4064.

My problem is that out of a 5 shot group 3-4 shots will darn near touch and 1-2 will be off. Im pretty its not me as two other people had the same results. I tried seating just off the lands (0.005") at first and figured oal was the cause. Then I tried backing off 0.010" from the lands and the groups opened up just a bit. Should I try going up to 0.020" or is that a waste of time? Any information is appreciated.

 

[esheato]

Reloading is all about experimentation and making educated guesses using all the information at your disposal.

Load development is never a waste of time...you're outdoors, doing what you love to do (shooting). Try everything, enjoy the process for what it is and when you're happy with your results, buy a new gun.

Ohh...which shots in the string of five (ie, last two, first two, etc) are grouping separately? If if's the last two, the gun heating up could be part of the issue. Try giving a bit more time between shots towards the end of the string.

 

[Funshooter45]

I agree with esheato that you might have too much el heato in the barrel. But that is only a guess because you didn't really tell us if it was the first two or last two or random occurrence of the two offending holes in the target.

As far as bullet seating depth relative to the lands, there really isn't one magic number. Just like when you vary the amount of powder charge in your load, that powder charge changes the harmonic vibration of the barrel. You kept the seating depth constant and varied the powder weight until you found one where the harmonic vibration was consistent enough to give good groups. Likewise, you can keep the powder weight constant and just vary the seating depth. Different seating depths will give different harmonic vibrations. It might be touching the lands, but it might be 0.020" off the lands, or 0.040" or it might be 0.073" for all we know. You won't know until you try several different OALs. Chances are you will find a couple different depths a fair distance apart that yield the best results.

 

[Arkansas Paul]

Ohh...which shots in the string of five (ie, last two, first two, etc) are grouping separately? If if's the last two, the gun heating up could be part of the issue.

This is what I'm thinking as well.

 

[243winxb]

If its a factory gun/barrel and all 5 shot groups average under 1", call it a day. Other wise do bench rest prep of the brass. Use busing dies. Change bullets, try Bergers. Use wing flags.

 

[Grumulkin]

I tried a few different powder and bullet combinations for my 243 (1:10") and found one that gave really good results, 75gr V-Max and IMR 4064.

My problem is that out of a 5 shot group 3-4 shots will darn near touch and 1-2 will be off. Im pretty its not me as two other people had the same results. I tried seating just off the lands (0.005") at first and figured oal was the cause. Then I tried backing off 0.010" from the lands and the groups opened up just a bit. Should I try going up to 0.020" or is that a waste of time? Any information is appreciated.

You need to tell us:

1. What group sizes you're getting?

2. As noted above, it would be nice to know if there is any consistency as to which of the 5 shots are off.

3. Are the 2 shot that are off in a small group by themselves?

4. From a cold barrel, are two shots off or does that only happen when more shots have been fired?

Though heat can be the cause of "flyers" if that's the cause it's a defect in the gun. Heat caused inaccuracy would be caused by part of the forend touching the barrel that shouldn't or by a barrel that isn't adequately stress relieved and warps when it gets hot.

Other causes of your problem could include:

1. Something loose in the scope or mount thereof.

2. Inconsistent primer ignition. In this case going to a hotter primer or increasing the load might help.

I have an Encore 30/06 shots that used to throw shots. I returned it to T/C and they did a minor modification to the crown and fire lapped it and it doesn't do that any more. What was explained to me was that in cutting the crown, sometimes a tiny burr will form at the muzzle; it can be so minor as to be hard to see and yet will cause this problem.

 

[griff383]

Usually its the 2nd or 3rd and 4th or 5th shots that fly.

The rifle is a Stevens 200 that was rebarreled with a 26" HB and free floated. Everything is tight, I thought that might be it at first but all is tight as it should be.

I have a pic of the target from when I was dialing in the load. The top left is el cheapo factory rounds for fouling shots. But the rest you can kind of see what I am talking about, and you can see which load groups the best (minus the fliers). At first I though it was me causing the fliers but then it happened again the other day when I was messing with OAL. IIRC the shorter OAL was causing fliers high and right about an inch, I pretty much got two groups with one point of aim.

*Squares on paper are 1"

 

[PCCUSNRET]

Personally, I would adjust my scope 4 clicks to the right and 2 clicks up and be a very happy shooter if it was my 243. Unless you are shooting from a fixed rest and not touching the gun, my guess would be you, your scope or barrel heat that is causing the flier. Right now I'd love to have groups like this with my newest Remington 700 in 243. My best group so far with Varget and IMR4350 has been 1 1/2". If you do figure this out please let us know as I think most of us have had the same problem one time or another with a gun or two.

 

[ranger335v]

Those look like like a typical run of 1" groups to me. Such "fliers" are just part of the groups.

 

[griff383]

I just got back from the range, I think I am on to something.

Pushed the bullet in so its 0.020" off of the lands for an OAL of 2.625" (originaly using 2.640" OAL) and these are the results.

*orange targets are the size of a quarter

 

[esheato]

I think I am on to something.

Uhh, yes.

Every gun is different and it looks like you're on the right track.

Your first group is fantastic, but you're wide horizontally on the second group. If you could consistently do the first group you have a keeper.

IME, vertical spread is load and horizontal is shooter. Luckily, this is an easy fix. Use good support and remove the horizontal wiggle you got going on.

Other than that, I might take some lessons from ya.