It's been my experience that 95% of your accuracy comes from how much a gun likes a particular load...ie bullet, powder seating depth. Still alot of people put alot of effort into concentricity. The following pic is from the latest Shooting times. They shot a bunch of factory ammo in a rail gun. The surprising thing is the ver best runnout ammo finished in last place. The worst runnout finished in the middle of the pack. And the top finishers had .004-.005 runnout. Probably not a perfect test but certainly enough to slow my efforts to "chase" runnout so hard.
The first column is runnout, the 2nd column is the the variance of "jump to the lands"...or seating consistancy.

Nice.
That's the kind of article that makes a magazine worth reading.

My experience as well. I see more impact on accuracy from the amount of buller grip. most of my hunting loads run out as much as .005" and still shoot moa. the lee collet dies help with run out problems but it has to start with streight brass .
Dave

Thank you for sharing the above article.
I would add that for Benchrest competition, when you are trying to agg. in the "teens" runout will be important.
That said. For field shooting, including fine varmint shooting, minutia is not likely to yield notable results.
The only caveat would be the mental side of the shooting game. Meaning that if you think it makes a difference for you, then it does.

muck

bullet runout has been far over rated....sit down and try to design one sometime.....it'll drive you nuts because the locating points don't actually exist.

There's a lot of reloading practices that yield little to no return on investment! Runout is one of them.

quote:

Originally posted by vapodog:
bullet runout has been far over rated....sit down and try to design one sometime.....it'll drive you nuts because the locating points don't actually exist.

There's a lot of reloading practices that yield little to no return on investment! Runout is one of them.

Sorry but I disagree because this is quantifiable in a rifle built correctly and with a shooter that knows what he or she is doing. On a factory rifle it is a waste of time. I am a handloader not a reloader.

I read that and all my loads for hunting are never checked for runout.It just doesn't make sense if it hit where you want it to.Just my opinion

What muck said +1. I particularly liked his comment about the mental aspects of the things we do.

Speaking of psychology, runnout is something I have always chased, and put a lot of time and effort into, but it is the one thing that we cannot totally control. I bought 1,000 300Win Mag cases (by Winchester) for the purpose of making some match ammo several years ago. Out of 1,000 cases I found less than fifty with .002" runnout or less.

I still have a box or two of Lapua 300 Win Mag brass that is nice and straight. If I load that up I wil be crying because there is not any to be had...

Runnout shows its nasty head at and beyond 600 yards. On a calm day (if only), with a GOOD rifle, shoot a 20 round group at 600 yards with ammo with 0.001" runnout and another with 0.010" runnot and check the vertical size of the group. There will be a significant difference.

LD

Years ago the Army marksmanship Unit ran a run out test using a machine rested rifle at some distance. Cartridge was the .7.62 Match using both M118 bullets and 168 gr MKs. They found that runout made a difference down to .003 - .004". Under that there was no noticeable difference.

I've shot a lot of palma and 1000 yard matches with my .308W M70 Match rifle. I always check my ammo for concentricity. Out of 100 rounds most are .00 to .002. I will have 2-5 that run .0035 to .004. When I shoot those they always go to the same group at 600 to 1000 yards as the more concentric ones. Other rounds with the same load but with a concentricity of .004+ definatly do not shoot as well at longer ranges. There is a difference and concentricity is important if one is indeed shooting long range. How important depends on the chamber dimensions and the fit of the cartridge and bullet to the chamber and throat.

Larry Gibson

quote:

I am a handloader not a reloader.

Boss,
At the risk of getting off topic, your statement is very confusing for us novices. Am I wasting my time fire forming my new brass to fit my chamber? From what I have read in most reloading manuals, fire forming brass is the 1st step in loading accurate loads.
Please elaborate on your methods for achieving accuracy since you say you are not a reloader.

Three of the very Best groups I've ever printed had 85 Fps or more deviation . One group actually had

121 Fps high deviation . Worst group had less than 15 Fps !! . # 1 fouler with # 3 groups of #5 shots

duplicated # 3 times on #3 targets for scoring an last target is shot with # 5 rounds for a 50 round

total scoring system .

An here is the absolute stunner, Cases weren't prepped and bullets were BULK ! for the BEST GROUPS !!!.

So what does it all mean ?. Beats the hell out of me , because it goes contrary to everything serious

reloaders strive for !. Damnedest thing I've yet to experience in over 44 years now of reloading .

One of those groupings of .223 from a Bushmaster XM15 E2S 20" target chrome bore was .187" an average

for all # 4 of those targets were .318" at a measured 100 meters with witnesses and targets saved for

proof !.

I do not think most folks will see any real difference at 100yds with small velocity deviations or a little runout.

I'm more than willing to accept folks word for it that "runout" can make a noticeable difference at long distances.

I've shot at prairie dogs at 800 yards and the wind usually makes it impossible no matter how accurate my ammo or shooting is.

I'm primarily a hunter and once shot a deer a bit over 400 yards.....This is as far as I'm willing to shoot as it's just not in the cards for me to judge distances good enough to properly achieve good hits at that distance. Holdover at that range is roughly 24".....

Folks are welcome to fight the concentricity thing all they want.....I still find it a waste of time for my hunting. I do roll them across a formica tabletop and check to see that they roll fairly good...this is as good as I need them.

First of all I don't think this so called test is valid. My question is did they use the same brand of brass from the same lot#? Did they use the same set of dies to reload all cases? Were these cases fire formed or FL sized? I can see they did not use the same bullet,bullet weight and brand. Were all the charge weights the same?
I just see to many flaws in this test its just not a valid test IMHO. To have a valid test the only thing that can be different is the ONE thing that is different. That is what you test. It's Just like working up a load Keep all of the variables to a minimum and compare the one thing that is different or you have changed.
You don't change primers and powder charge at the same time and go to the range for a comparison test. Because you will not know which change you made had what effect.I am not the smartest cat in the sandbox but the article is a crock of BS.

quote:

the article is a crock of BS.

yep.

Hey Vapo,

I have some 300 Win Mag brass that you can have if you need some. Otherwise, I think I will sell it on classifieds and check out some of the new Hornady.

If you look at the description of the ammo it doesn't take alot of imagination to realize that it is all factory ammo. So all the stuff about dies and lots kind of go out the window.
It's my opinion that what they are trying to prove is that how well your gun likes the bullet, powder, seat depth combo will have the bigger effect on accuracy and in this case runnout didn't matter much.
It would have been nice to have a test at longer yardage. AND, I wish they hadn't tested the small little 22 cal bullets. It's been my experience that short small bullet DO GET straightened out by the barrel. I would say longer and bigger caliber bullets could be effected more by runnout.

quote:

Originally posted by lawndart:

quote:

the article is a crock of BS.

yep.

Hey Vapo,

I have some 300 Win Mag brass that you can have if you need some. Otherwise, I think I will sell it on classifieds and check out some of the new Hornady.

Thanks but the only .300 Magnum I now own is an H&H!

I JUST WANT TO KNOW HOW IN THE HELL FEDERAL MAKES THEIR 308 GOLD MATCH SO GOOD IN A VOLUME LOADED CARTRIDGE.................. I have tried until I am blue in the face and I can't seem to replicate that load that will shoot that well in such a wide variety of rifles..

Have you tried the BHA Match? I shot some my last serious year of Hunter Bench Rest. Just pulled the bullets, turned the casenecks and reloaded the components. Rifle shot as good as my standard 150gr SMK in front of 41.5gr of H4895.

Rich

quote:

Originally posted by kraky:
If you look at the description of the ammo it doesn't take alot of imagination to realize that it is all factory ammo. So all the stuff about dies and lots kind of go out the window.
It's my opinion that what they are trying to prove is that how well your gun likes the bullet, powder, seat depth combo will have the bigger effect on accuracy and in this case runnout didn't matter much.
It would have been nice to have a test at longer yardage. AND, I wish they hadn't tested the small little 22 cal bullets. It's been my experience that short small bullet DO GET straightened out by the barrel. I would say longer and bigger caliber bullets could be effected more by runnout.

The barrel forms the bullet to fit long or short...it has to, it is a press fit at 50,000+ CPU

The run out only exists in the non formed areas...from the ogive to the tip (also the second lightest part of the projectile)
and the rear section or base (but only in boat tails and extremely light in comparison to the center mass)

I believe Boss Hoss' post was misinterpreted. He was saying that he doesn't just throw components together. He is very anal about his handloading.
Butch