Barrel run in"break in" revisited

[BoydAllen]

I don't know if that's average or largest group size.

The most accurate benchrest rifles' barrels shoot all groups in 100 yard aggregate matches up to about 3/10ths inch/MOA setting records. They're bigger MOA wise at 200 and 300 yards. All the barrel's other groups in matches are sometimes bigger

As a little review/update, the current NBRSA record aggregates for 100 yards are Unlimited 0.1233; Heavy Varmint 0.1485; Light Varmint 0.147; Sporter 0.1523 At 200 the aggregates are the averages of actual group sizes divided by two, to render them into 100 yard equivalent dispersions so that they can be averaged with the 100 yard aggs to come up with two, three, or four gun winners. A 200 yard agg. of .2500 would be the result of an average group size of .500. The 200 yard record aggregates for the listed classes, in the same order are 0.1233, 0.1485, 0.147, and 0.1523.
One other point needs to be made, the variations in group sizes that one sees at matches are often representative of the shooters' abilities to read conditions and keep their rifles in tune, rather than being direct reflections of their rifles' accuracy potentials.

 

[Bart B.]

What about the larger groups shot in perfect shooter and weather conditions that don't do well in aggregates?

Biggest groups shot are not well publicized (nor talked about) and typically only seen by scanning the complete results.

 

[BoydAllen]

What about the larger groups shot in perfect shooter and weather conditions that don't do well in aggregates?

There is still the matter of tune. It is not an accident that most competitors load between matches rather than preload (for group shooting). The only way to know if the problem was the rifle is to talk a really accomplished shooter into tuning up a load for it and shooting it himself. On the subject of conditions, locally, I have never seen perfect conditions all the way through an agg. Some days are better than others, but none are perfect. Some years ago, I was shooting a three day match at Visalia as were both Eunice and Walt Berger. I was standing next to Eunice and said something to the effect that it looked like the first match of the day was going to be a trigger pulling contest, ( an expression that means that conditions would be near perfect, minimizing the advantage of flag reading skills) because the high side berm had the floor of the range in shadow from the morning sun and there was not much moving in the field of flags. Her reply was that I should not kid myself, that there were things out there that would move a bullet that the flags would not show, and that there was no mirage.and that she shot mirage. I asked her if that meant that she would perferr a light consistent condition to no wind and she said that she would. She won the match, over a field of shooters that included world record holders and Hall of Fame members with groups that were centered in the mothballs. Benchrest aside, she was a woman of exceptional quality and intellect.

 

[lathoto]

After we sighted in my new rifle (Sako TRG 22 6.5 Creedmoor), my first group was good. I let my instructor shoot the next group and it was "scary accurate." He told me to do nothing but monitor the barrel performance and that it will tell me when it needs conditioning/cleaning. We projected that the barrel will last 4-5 years. Lots of room for improvement as I log everything.

 

[jkl]

Does anyone remember German Salazar's Break in artical?
We were having lunch shortly after he posted it on the blog. His phone had been busy telling him his artical was not properly posted. It was 2 full pages of the seceret process.

A title on the first page and on the bottom of the second page "Shoot a Match"
Followed by German Salazar!

John

 

[Bart B.]

There is still the matter of tune. It is not an accident that most competitors load between matches rather than preload (for group shooting).

I agree. But I wish agg's results would include the largest group shot for it. If I ever ran a benchrest match, everyone would shoot five 5-shot and five 10-shot groups at each range. The winner would be the one whose largest group was the smallest for each shot count and range. A Lucky Guy prize would be awarded for the smallest group shot at each range for each shot count.

The only way to know if the problem was the rifle is to talk a really accomplished shooter into tuning up a load for it and shooting it himself.

What about clamping the rifle in a machine rest at 5 AM then testing ammo in it? That's how human errors are eliminated and environment variables are minimized.

 

[BoydAllen]

I agree. But I wish agg's results would include the largest group shot for it. If I ever ran a benchrest match, everyone would shoot five 5-shot and five 10-shot groups at each range. The winner would be the one whose largest group was the smallest for each shot count and range. A Lucky Guy prize would be awarded for the smallest group shot at each range for each shot count.

What about clamping the rifle in a machine rest at 5 AM then testing ammo in it? That's how human errors are eliminated and environment variables are minimized.

Machine rests do not let rifles vibrate as they would in use, therefore the results may not represent the potential of the rifle in normal operation. A friend has been to both Lapua and Ely ammo lot testing facilities, while they are of some value, he did not find the results clamped down to be the same as when shot normally, this is a shooter that has produced a number of perfect score targets with the rifle that has done it. Some years back, many, I asked a small bore prone shooter why they did not test ammo off of the bench. He told me that it was because the rifles did not shoot as well that way as they did when shot as they were designed for. Top benchrest shooters are neither stupid or in some cases short of resources. I know of a couple that have their own well engineered shooting tunnels. There is a lot more to the sport than meets the eye.

 

[Bart B.]

Machine rests do not let rifles vibrate as they would in use,

I agree for the most part; most don't.

They do if the rifle's held like the human does.

 

[BoydAllen]

The best way to get some understanding of a shooting sport is to shoot a match or two.

 

[Bart B.]

What's the best way to figure out whether the tiniest groups of several was the result of all the rifle, ammo and shooter's variables were at or near zero in their spread, or pretty much cancelled each other out?

 

[BoydAllen]

I see groups on the internet and read discussions that lead me to believe two things. People who do not really understand how to ask a rifle how it wants to be shot, are in the vast majority, as are those that do not want to look at dealing with all of the relevant variables that they have a reasonable opportunity to influence. A third thing that I see is methods of load investigation that involve an unnecessary number of rounds fired and trips to the range. The best way to learn is to find a mentor who has the best equipment and who likes to teach. Bottom line, making that sort of determination requires some skills that may not be present. We have all been there. It is about the journey.

 

[K22]

1/2 MOA at what long range?

They'll open up about 1/10ths MOA for each hundred yards past the first hundred.

Sorry for the confusion - it's like this - New Rifle - I go to load development - for my varmint rifles once I get in the range of 1/2 moa at 100 yards off the bench the rifle has a 'qualified' load. The rifle will never see the bench again unless I encounter a problem.

Next phase is sight in off shooting cross sticks which is the way I hunt. I practice weekly, sometime twice a week off shooting stick and by doing so I determine my limits and get to know how my rifle / load / shooting system performs under field conditions. All I care about is hitting a ghog or predator. With my 223's my range is limited to about 250 yards + or -. Recently got one a 264 yards but that about my limit off the sticks with a 223. I shot some further with my 22 250 and 243 but most of the places I hunt it's rare that I get a shot beyond 250 yards.

But your assertion is correct, groups open up the further the distance due to mirage, wind, and shooter error. Just because I have a load that shoots 1/2 moa off the bench under ideal condition does not mean it will shoot 1" at 200 yards, etc. under field conditions.

PS: I don't hit everyone - I do miss - I'm about 80 to 90 % depending of field conditions and whether I'm in the zone mentally.