Extreme ES caused by barrel?

[jdavistx]

It's all about the lands.

 

[jdavistx]

It's all about the lands.

It only takes a few 1000's. Accuracy and Precision. Brian Litz.

 

[Saskquatch6]

here is an analysis of error in different chronos. It is about 2/3rds of the way thru the article but is very interesting. Look for a table.

Practical statistics for shooters (autotrickler.com)

Good article Bro Dave - thanks for the reference

 

[Paladin300]

I haven't read all the post, so not sure of everything that has been suggested but I would lean in one of two areas based on the information you have provided. First I would weigh and measure all my brass. Sort it first by name brand and then according to weight. Measure it for length and case thickness. Using different brass can cause this though possibly not to the extent you are seeing. Second, I agree with what someone else has said, I think, that it could be a seating depth issue pertaining to either an inconsistent seating depth or neck tension issue. If you have a load that is shooting well but producing a high ES play with your seating depth and see if it changes. Depending on the bullet you may see the issue resolved by moving it further out towards the lands instead of running a factory coal. I have one rifle that will not shoot factory ammo at all and gives me similar issues but if I seat the bullets out (ABLRs) .050 of the lands with R23 I get SD's in the 3-5 range and the smallest groups of any gun I own. Also I had a seating die that would from time to time seat the bullets and different lengths from one bullet to the next, so that one round to the next in a batch of twenty could be off as much as .050. Could possibly be both/and as well. You could have an inconsistent brass issue as well as an inconsistent seating depth issue thus giving you the ES you are seeing. Just a thought.

 

[Susquatch]

Yes, this is the only rifle I have this issue with. Ive got Nosler brass and Remington brass both new and once fired. Ive ran H4350, superformance and R15 though it with the same results. I ran standard and Mag primers with superformance with no change. Maybe I should try neck sizing only a few pieces of once fired and see what happens. I normally bump .002 with a FL die on fired brass but I have a Lee Neck die laying around somewhere i could try.

Really dumb question. Please don't take offense. Are you mixing the Nosler and Remington Brass? If so, that's a huge no-no and would explain everything.

Also, I am a huge fan of the LabRadar Chronograph. It's a whole new paradigm. Beg, buy, or borrow one to compare against your chrono. I note that your other chrono testing is on larger diameter bullets. Generally, I would say that it's normal to see this. Faster and smaller is harder to see for a lot of reasons. That's true of the LabRadar too, but if you get data, it's almost always good data which is not true of other chronographs. Another poster said, chronographs lie, paper doesn't. I would modify that to say that most chronographs lie, Labradar and paper don't. Anyway, try it.

 

[lancetkenyon]

Possible the barrel is touching stock as it warms up. Something could be loose... Check action screws and scope mounts, then go from there.

I gotta bust your balls on this one.

Never had action or scope screws mess with my ES....

 

[Dirtrax]

You can full length size AND run it through the collet die. The mandrel is just that,a mandrel. The collet forces the neck against the mandrel at a tension YOU, not the instructions determine. It can be set up to avoid the collet and use only the mandrel if so desired. It's a very versatile tool.

 

[Dirtrax]

Just for yucks I drilled the cap out on a collet die and removed the mandrel. I use it to "lightly" compress the neck against the bullet after sizing with a different mandrel and seating the bullet. It completely eliminated any vertical in this rifle/load.

 

[Cookie114]

Goodness I can't even begin to respond to 4 pages worth of questions, But I'm taking notes. Thanks for the information

 

[Brandon Starkel]

Mine has always seemed to be accurate as long as I don't use while the sun is out. LABRADAR is what I want but $500 is good chunk

 

[Brandon Starkel]

Mine has always seemed to be accurate as long as I don't use while the sun is out. LABRADAR is what I want but $500 is good chunk

You won't be disappointed with the LABRADAR .

 

[Tulsa Reiner]

Caldwell and I agree with you. Ill only use it on overcast days or it's all over the place with all my loads. Yesterday when I was using it I was also shooting 6.5 over it and wasn't getting crazy readings. But maybe the 6mm projectile running appox 3200fps is harder for it to read correctly vs a 6.5 projectile running 2800?

It sounds like you are a serious reloader, in which case you will save yourself a LOT of ammo components, time, and frustration by purchasing a Magnetospeed or Labradar. (I speak from experience.)

 

[Tulsa Reiner]

For New bees working up loads in the Reloading process what does ES mean

Keep reading this forum and you will find out how simple it is to determine (the difference between your highest and lowest muzzle velocities) and how valuable it is in working up your best loads. Most reloaders want a SD (standard deviation) in the single digits, and an ES below 20 for a 5 or 10 shot group, for their optimum load.

 

[jdavistx]

Keep reading this forum and you will find out how simple it is to determine (the difference between your highest and lowest muzzle velocities) and how valuable it is in working up your best loads. Most reloaders want a SD (standard deviation) in the single digits, and an ES below 20 for a 5 or 10 shot group, for their optimum load.

6 sigma....