Three, 10 shot groups—any conclusions?

[willfrye027]

I decided to shoot some 10 shot groups and “test” a new scale I purchased against my old reliable RCBC 505. This is my 25 creedmoor on a tikka action. Typical 3-5 shot groups are 1/2 to 3/4 moa depending on the day.

This group is with my “new” scale, an old-school Oahus triple beam balance. It seems to resolve a single grain of powder when I’m trickling in.



This is with my old 505 scale.

 

[willfrye027]

And this group was from ammo loaded a few months ago. I believe I may have switched over to a new jug of powder in the interim. I did a few 3 shot groups with the new jug and my velocity was the same for a small sample size, 3 shot groups seemed about the same, but it seems like something changed between the old load and the new loads? In any case I thought it was very interesting to see what 10 shot groups look like as it’s not something I’ve done much in the past.

 

[willfrye027]

To shoot these groups I shot 5 of each of the three “different” loads, then went back and shot 5 more. Shot in fairly quick succession with some time to cool before each new group.

 

[ResearchinStuff]

I need to double check the #s off that Hornady podcast, but I think this is within the expected variation for 10 shot groups. They're only about 10% different extreme spread, and 0.1 mil off.

Ballistic x is worth the $ for this type of thing.

 

[JjamesIII]

Switching powder lots will nullify the test unfortunately, despite the similar velocities. I would expect .10 grain weight accuracy on my beam, with a close eye/trickler you can see one kernel of 4350 move the needle. It’s definitely not that important in the grand scheme of practical accuracy. But it gives me confidence that each of my bullets is as accurate as I’m able to make. I don’t shoot more than two fun matches a year, so I can take my time as a hobbyists making bullets. If I was actively smoking a barrel a year, I’d not spend the time.

 

[ResearchinStuff]

Couldn't make out #10, doubtful it would have changed the result much.

 

[willfrye027]

Couldn't make out #10, doubtful it would have changed the result much.
View attachment 492253

Thanks for doing that, I do need to check that program out. Interesting to me that the mean radius is pretty similar for all three groups, even though I’d “pick” the last group as looking much better.

I will say that I shot about 100 rounds of the 1.2-ish moa ammo last week on steel from 500-1400 and had no issues making hits, other than making bad wind calls.

I’ve got a ton of components for this barrel and enjoy shooting it. Have a new blank ordered and feel no pressure to “save” this one. Might try a similar test at 5-600..or maybe try to fine tune powder charge at that distance and see if I can tighten things up a little.

In any case, shooting is fun as hell.

 

[ResearchinStuff]

No problem, have fun shooting

 

[willfrye027]

Switching powder lots will nullify the test unfortunately, despite the similar velocities. I would expect .10 grain weight accuracy on my beam, with a close eye/trickler you can see one kernel of 4350 move the needle. It’s definitely not that important in the grand scheme of practical accuracy. But it gives me confidence that each of my bullets is as accurate as I’m able to make. I don’t shoot more than two fun matches a year, so I can take my time as a hobbyists making bullets. If I was actively smoking a barrel a year, I’d not spend the time.

I am guessing the new lot has changed things slightly…but the difference is probably not significant. I’ll try another ladder and see if things tighten up, although I do not think it is truly necessary. I’ll probably be into a new barrel by next hunting season.

 

[sndmn11]

They look interchangeable to me.

 

[JjamesIII]

I am guessing the new lot has changed things slightly…but the difference is probably not significant. I’ll try another ladder and see if things tighten up, although I do not think it is truly necessary. I’ll probably be into a new barrel by next hunting season.

That’s what sucks, you start playing with load development then the honeymoon is over so soon because your barrel gets shot out. I’d love to run some of the hot rod calibers, but 1500 round barrel life sounds like an endless game of wasting time and money at the reloading bench.

 

[Formidilosus]

I am guessing the new lot has changed things slightly…but the difference is probably not significant. I’ll try another ladder and see if things tighten up

It won’t. At least not with real shot group sizes. “Load development” is mostly nonsense. Either the bullet and powder shoots or it doesn’t. Once you start putting statistical group sizes on paper, all the “development” is just noise. Do the ladder over, and it’s more likely that your worst load the first time, shoots “better” the second time than the “best” load from the first.

If you overlay all three of your groups on one target, you’ll see that it just fills in your true cone.

 

[SDHNTR]

When my groups change, good or bad, it’s me, rarely the load or rifle. I have good days and less good days.

 

[willfrye027]

It won’t. At least not with real shot group sizes. “Load development” is mostly nonsense. Either the bullet and powder shoots or it doesn’t. Once you start putting statistical group sizes on paper, all the “development” is just noise. Do the ladder over, and it’s more likely that your worst load the first time, shoots “better” the second time than the “best” load from the first.

If you overlay all three of your groups on one target, you’ll see that it just fills in your true cone.

I want to believe this and I listened to that hornady podcast…it would make reloading sooo much easier. It is hard to believe that the benchrest and F class guys are doing so much load development for nothing though. Old habits die hard but I’ve been slowly moving away from a lot of the voodoo reloading methods…just not entirely

 

[willfrye027]

When my groups change, good or bad, it’s me, rarely the load or rifle. I have good days and less good days.

Yeah I am behind this to an extent. All these were shot on the same day, essentially round robin style within about an hour. I was “doing my part” in the shooting department.

 

[willfrye027]

That’s what sucks, you start playing with load development then the honeymoon is over so soon because your barrel gets shot out. I’d love to run some of the hot rod calibers, but 1500 round barrel life sounds like an endless game of wasting time and money at the reloading bench.

1500 rounds in this cartridge is roughly $1300 in components.

This cheap prefit I installed myself was $380.

Barrel is the cheapest part of the equation…I say smoke em while you got em. Plus I worked up this load in about 40 rounds just been shooting steel and critters for the most part since then. Occasionally shooting paper to recheck zero.

 

[Formidilosus]

I want to believe this and I listened to that hornady podcast…it would make reloading sooo much easier. It is hard to believe that the benchrest and F class guys are doing so much load development for nothing though. Old habits die hard but I’ve been slowly moving away from a lot of the voodoo reloading methods…just not entirely

I didn’t get it from a podcast. However, equating bench rest loading and shooting, with field shooting is…. Less than helpful. You’re not trying to set world records based on hundredths of an inch at 100 yards. Your hit rate in the field on deer vitals won’t change from a real .5 MOA rifle to a real 1.5 MOA rifle. It’s vaulting over mouse turds.

 

[willfrye027]

I didn’t get it from a podcast. However, equating bench rest loading and shooting, with field shooting is…. Less than helpful. You’re not trying to set world records based on hundredths of an inch at 100 yards. Your hit rate in the field on deer vitals won’t change from a real .5 MOA rifle to a real 1.5 MOA rifle. It’s vaulting over mouse turds.

Yeah I know you didn’t, I’ve followed your stuff for awhile. they did show the math/statistics for “why” 30 shot groups, which was helpful, and hinted at there being very little difference in accuracy at incremental charge weight or seating depth adjustments.

I’m going to burn out the current barrel shooting steel this spring and just keep shooting what I have (which incidentally is about 1 grain below pressure signs). Next barrel will focus on trying a few powder/bullet combos without screwing around much with charge weight or seating depth.

Big fan of the WEZ calculator, which if anything has shown me that my “misses” at distance are me, usually my wind call, and not my load.

 

[willfrye027]

I will say that I’d rather shoot .8 moa than 1.3 moa, and if I can easily change a few things to get there I would do it. I will shoot another 10-20 into that same .8moa group and see what happens. See if there is truly a difference. Not because I need that to make hits, but it’s more fun to have that “.25 moa all day” group

 

[Formidilosus]

I will say that I’d rather shoot .8 moa than 1.3 moa, and if I can easily change a few things to get there I would do it. I will shoot another 10-20 into that same .8moa group and see what happens. See if there is truly a difference. Not because I need that to make hits, but it’s more fun to have that “.25 moa all day” group

Haha. I’d like to see what it looks like with more rounds.

The fact that you are shooting a barrel out matters more than everything else.