Reloading help? Velocities

[CBH Australia]

I'm not doubting the chrony.

I do have some differences in the load batches etc that I understand may cause some recordable difference it I'm thinking the up to 100fps might be something more than something I am aware of.

The test will be to try some ammo with better quality control, recording and methodology.

This was a quick test to get some average speeds of loads for a reference point.

To date it's been looking at the published load data and taking that as a reference with consideration of barrel length effect on velocity.

I have not done any ballistic tables but have not had a recorded velocity to verify a true reference value.

Having a 20" 7mm-08 and a 26" .280ai I'm interested to see the actual recorded difference. I'm using Nosler BT for both but running 120gm and 140 GN respectively.

I'm planning on loading some 150gn for the .280ai. I just hope to have one load that when I take it out I know it's range and ability to 300',ish and it just works.

Ive shot well I in the field but it's mostly all under 200 and I am making time to learn more and understand longer range shooting. Determining accuracy over the bench for confidence in the field.

I will also be using a 20" Tikka CTR .308 for club comp as I have it.

Small steps and one at a time just looking for the most likely cause of ES

 

[Rum Runner]

I was loaned a Chrongraph so today it was a nice day went to test a few rifles and loads.
I have loaded thousands of rounds on a single stage press and have good success in the field.
I am now starting to shoot some club events with sporting rifles.
I don't use match grade components but my rifles are decent and I know the chrony works ok.

My problem is several tests of several rifles were getting an extreme spread of up to 100fps and I expect it should be a lot less.

I understand there are many factors but which would you change first to improve the ES in velocities???

I identified one lot of ammo were jammed to the lands and that can increase pressure s. This came about by trying another projectile while loading without measuring to the Ogive.

I have loaded some .308 in new Lapua cases to shoot in a club match. But still using a 168gn Z-Max and hope to burn these off first. I'm not competitive but I'm gonna burn up what components I have in trial and error and improving my target technique.

One lot of ammo were loaded using a Lee Collett neck die and a Forster seater. A test run for reloading for club events.

Most of my die sets are Redding or Hornady.

Working with what I have , What would you change first in the load technique or proccess???

I have indivually measured powder on some of these loadings so I believe the charge is consistent at least.

I'm sure I can improve something in the process before purchasing different tools and components

If it helps, I recently found that the first shot, from a cold barrel, is considerably slower than shots after that. I'm not saying this happens to everyone, but it does with my hand loads on my Rem 7mm Mag, AND my 270 Win. So much so, it blows the Standard Deviation all to heck.

 

[CBH Australia]

I’ll throw one more tunnel in the rabbit hole: neck tension.
This echos @fourfive8, If you have consistent powder charges, but your necks aren’t consistent you’ll see a velocity spread. After checking everything else mentioned, may need to anneal/trim/deburr etc.
Same goes for primer pocket deburr. It can cause powder ignition changes.

If the chrono is accurate I would start there personally. Maybe back them back a little from the lands?

I switched to a magnetospeed because I found those optical ones to be very troubling to work with. Much more accurate. I think a quality chronograph is essential.

Good luck, this is a weird one.

Along with the reiteration of "Consistency" in posts I read Neck Tension"
Without going down the proverbial Rabbit Warren I looked at my seating die adjustment.

I have lowered the die a little to ensure I get. Tension along as much of the neck as possible. I have seated the projectile in so it is clearing the lands.

I have gone to a batch of 150gn Nosler BT as I might run them but I think the adjustment might be the key.

This is a Bold statement as I have not tested them yet but I'm leaning toward neck tension being the first or main fault. Without getting into neck turning or anything else I think the die adjustment on necks and seating needed looking at.

Some of my ammo is hunting some is target but this has highlighted something measurable and there is room for improvement.

I have a few I reload for so if I sort a couple short term I can learn from it.

 

[Bob Nelson 35Whelen]

I was loaned a Chrongraph so today it was a nice day went to test a few rifles and loads.
I have loaded thousands of rounds on a single stage press and have good success in the field.
I am now starting to shoot some club events with sporting rifles.
I don't use match grade components but my rifles are decent and I know the chrony works ok.

My problem is several tests of several rifles were getting an extreme spread of up to 100fps and I expect it should be a lot less.

I understand there are many factors but which would you change first to improve the ES in velocities???

I identified one lot of ammo were jammed to the lands and that can increase pressure s. This came about by trying another projectile while loading without measuring to the Ogive.

I have loaded some .308 in new Lapua cases to shoot in a club match. But still using a 168gn Z-Max and hope to burn these off first. I'm not competitive but I'm gonna burn up what components I have in trial and error and improving my target technique.

One lot of ammo were loaded using a Lee Collett neck die and a Forster seater. A test run for reloading for club events.

Most of my die sets are Redding or Hornady.

Working with what I have , What would you change first in the load technique or proccess???

I have indivually measured powder on some of these loadings so I believe the charge is consistent at least.

I'm sure I can improve something in the process before purchasing different tools and components

@CBH
Chris what powder are you using. I tried RL15 with piss poor patterns (Not groups).
2208 worked very well along with BM8208
CFE223 was a fraction better than 2208 both higher velocity. As that is my go to powder for hunting I don't use it and stuck with 2208.
How far off the lands are you. Try 30 thou.
Bob

 

[Bob Nelson 35Whelen]

Thanks,
I meant I have indivually measured every charge on given batches. That is slow using a balance scale.

Yes , I know it's a rabbit hole just hoping there is a single thing that I should try first.

I guess I thought an ES of no more than 50 would be acceptable .

If I were just throwing charges from a thrower I figured ES should still be below 100

Any idea what to expect if it was factory ammo.?

It's a learning curve and an exercise. It never mattered until I chronographed some loads.

@CBH
Those chronograph are great they tell you real world velocities and at times they make the book velocity look pie in the sky
Bob

 

[ZG47]

@CBH If you are worried about inconsistency of case neck tension, one way to minimise that issue is to do your neck expansion with a Lyman M die. I stopped pulling buttons upward to expand case necks at least a dozen years back. Your cases will also stretch at a significantly lower rate. The majority of case stretching in my experience has been due to using expander buttons in sizing dies.
I hope that the step by step approach gives you a definitive answer sooner than later.

 

[Inline6]

Varget is my powder of choice for a 308. Not sure what you have access to down there.

I would not rely on that chronology, it will get you ballpark (you just don't know how big the park is)

Neck tension first, I would not crimp any match ammo. It sounded like you might if you are try 5 not crimped. See what that gets you.

Don't jam the bullets you will get pressure spikes that will effect your ES. Hornady bullets are pretty forgiving when it comes to jump.

What condition is your rifle barrel? If it has been shoot 200-300 times and not been cleaned well. You could have a build up of carbon and/ or copper. Powder plays a role in how fast carbon builds up. That leads to pressure spikes.

Federal Gold Medal Match factory ammo 185s out of my 20" 308 bolt gun was 2545 SD 4.6 ES 12 and Creedmoor Sports 155s was 2739 SD 19.1. ES 48. Maybe that will help you with expectations.

 

[Bob Nelson 35Whelen]

I'm not doubting the chrony.

I do have some differences in the load batches etc that I understand may cause some recordable difference it I'm thinking the up to 100fps might be something more than something I am aware of.

The test will be to try some ammo with better quality control, recording and methodology.

This was a quick test to get some average speeds of loads for a reference point.

To date it's been looking at the published load data and taking that as a reference with consideration of barrel length effect on velocity.

I have not done any ballistic tables but have not had a recorded velocity to verify a true reference value.

Having a 20" 7mm-08 and a 26" .280ai I'm interested to see the actual recorded difference. I'm using Nosler BT for both but running 120gm and 140 GN respectively.

I'm planning on loading some 150gn for the .280ai. I just hope to have one load that when I take it out I know it's range and ability to 300',ish and it just works.

Ive shot well I in the field but it's mostly all under 200 and I am making time to learn more and understand longer range shooting. Determining accuracy over the bench for confidence in the field.

I will also be using a 20" Tikka CTR .308 for club comp as I have it.

Small steps and one at a time just looking for the most likely cause of ES

@cbh

 

[Bob Nelson 35Whelen]

Along with the reiteration of "Consistency" in posts I read Neck Tension"
Without going down the proverbial Rabbit Warren I looked at my seating die adjustment.

I have lowered the die a little to ensure I get. Tension along as much of the neck as possible. I have seated the projectile in so it is clearing the lands.

I have gone to a batch of 150gn Nosler BT as I might run them but I think the adjustment might be the key.

This is a Bold statement as I have not tested them yet but I'm leaning toward neck tension being the first or main fault. Without getting into neck turning or anything else I think the die adjustment on necks and seating needed looking at.

Some of my ammo is hunting some is target but this has highlighted something measurable and there is room for improvement.

I have a few I reload for so if I sort a couple short term I can learn from it.

@CBH
Chris chrono that muddy girl in 243.
You will be in for a rude shock at the slowness of it.
Bov

 

[CBH Australia]

@ZG47
I will look into the M die. I have a Lee Collett die for the .308 this is the .280ai that I've been toying with.

@Inline6 I use Varget in the 7mm-08

Most of my reloading has always been acceptable and I'm just twerking some stuff and improving things.

Until now the velocity was unknown.

 

[ZG47]

@CBH Australia When you get into velocity measurements, the standard deviation (s.d.) is completely meaningless; in and of itself. You need to divide the s.d. by the average velocity of your (minimum) 10 shot string in order to obtain the coefficient of variation, which is expressed as a percentage. This fact is not covered in any chronograph manual I have read, although it is probably mentioned in the various Oehler manuals. I prefer a coefficient of variation below 3% for general purposes and could probably get by with up to 10% for close bush hunting, i.e. below 50m. As with everything, it is important not to get lost in the numbers.

 

[Bob Nelson 35Whelen]

@ZG47
I will look into the M die. I have a Lee Collett die for the .308 this is the .280ai that I've been toying with.

@Inline6 I use Varget in the 7mm-08

Most of my reloading has always been acceptable and I'm just twerking some stuff and improving things.

Until now the velocity was unknown.

@CBH
I can see you now in your tutu TWERKING while you are reloading, it would be something I would pay to see.
Auto correct is a pain . I think you meant tweaking.
Bob

 

[Bob Nelson 35Whelen]

@CBH Australia When you get into velocity measurements, the standard deviation (s.d.) is completely meaningless; in and of itself. You need to divide the s.d. by the average velocity of your (minimum) 10 shot string in order to obtain the coefficient of variation, which is expressed as a percentage. This fact is not covered in any chronograph manual I have read, although it is probably mentioned in the various Oehler manuals. I prefer a coefficient of variation below 3% for general purposes and could probably get by with up to 10% for close bush hunting, i.e. below 50m. As with everything, it is important not to get lost in the numbers.

@ZG47
All to complicated for this little black duck. I just fire half a dozen shots get the average go home and work out my trajectories and go and shoot shit.
Works for me.
If the velocity is all over the place I try a different powder. My 22K Hornet on the first 3 shots had a 600fps variation from 2,700 to 3,300 fps. I tried it over a different chronograph at the range and got the same results. The powder was Lilgun at 13 grains and chronograph were Magneto V3 and Chrony.
A change to aid 2205 and settled on 12 grains. Loads showed a max of 13 fps from memory and average velocity was 3,000 odd fps with 40 grain VMax..
Bob

 

[ZG47]

@CBH
I can see you now in your tutu TWERKING while you are reloading, it would be something I would pay to see.
Auto correct is a pain . I think you meant tweaking.
Bob

An image I did not want to have in my mind. I have just told my 81 year old mother that I am taking her into town for coffee, browsing, lunch, etc and that *#&@! Bob Nelson puts up this post! You can take some people anywhere once (possibly twice - to apologise). I suspect that Bob might sometimes be in that category and … my friends/acquaintances might say the same about me, at times.
Have a good weekend, all.

 

[Bob Nelson 35Whelen]

An image I did not want to have in my mind. I have just told my 81 year old mother that I am taking her into town for coffee, browsing, lunch, etc and that *#&@! Bob Nelson puts up this post! You can take some people anywhere once (possibly twice - to apologise). I suspect that Bob might sometimes be in that category and … my friends/acquaintances might say the same about me, at times.
Have a good weekend, all.

@ZG47
It's just my warped Ozzie humour and any little mistake Chris makes I love having a stir. He's a great bloke with a good sense of fun. It keeps people wondering what I will come up with next. Just ask grasshopper @ CoElkHunter I stir the crap out of him and a few others as well.
Bob

 

[ZG47]

@ZG47
All to complicated for this little black duck. I just fire half a dozen shots get the average go home and work out my trajectories and go and shoot shit.
Works for me.
If the velocity is all over the place I try a different powder. My 22K Hornet on the first 3 shots had a 600fps variation from 2,700 to 3,300 fps. I tried it over a different chronograph at the range and got the same results. The powder was Lilgun at 13 grains and chronograph were Magneto V3 and Chrony.
A change to aid 2205 and settled on 12 grains. Loads showed a max of 13 fps from memory and average velocity was 3,000 odd fps with 40 grain VMax..
Bob

All good. The point was to avoid the bullshit and provide useful information that, like the mentioned glare issue does not always get into the user manuals. Bob, have you not heard of calculators and calculator apps on mobile phones. Did they not make it past the black stump?
Chrony does mention the glare issue in my 20-25 year old manual. I bought that device because I wanted an economic purchase that would give me useful data. I did not intend to spend a huge amount of time measuring velocities and I have not done so. My dial/digital calipers get far more use than my chronograph and much of that for nonshooting purposes.

 

[ZG47]

@ZG47
It's just my warped Ozzie humour and any little mistake Chris makes I love having a stir. He's a great bloke with a good sense of fun. It keeps people wondering what I will come up with next. Just ask grasshopper @ CoElkHunter I stir the crap out of him and a few others as well.
Bob

I have noticed. Much better on a work site, where you can stir without having to worry about censorship.

 

[Bob Nelson 35Whelen]

All good. The point was to avoid the bullshit and provide useful information that, like the mentioned glare issue does not always get into the user manuals. Bob, have you not heard of calculators and calculator apps on mobile phones. Did they not make it past the black stump?
Chrony does mention the glare issue in my 20-25 year old manual. I bought that device because I wanted an economic purchase that would give me useful data. I did not intend to spend a huge amount of time measuring velocities and I have not done so. My dial/digital calipers get far more use than my chronograph and much of that for nonshooting purposes.

@ZG47 I bought my CHRONY chronograph just to check the velocity of my loads.
I use this to input into my load from a disc program to predict trajectories. I also use the program in developing loads along with my manuals. All very yg useful little tools.
The CHRONY I have found likes the diffusers at times like bright sunny days but when it's overcast I leave them off. It might be a pain to set up but it's simple, cheap and does the job I need and gives results jimust as good as the Magneto models but still allows you to sight in as you don't interfere with the barrel harmonics.
I have found it to be a useful tool. I have had people tell me rheirvloads are doing X velocity according to the book but in a lot of cases this is far from the truth and they become disheartened. I just say you were happy with it and it did a good job before you put it over the chronograph so be happy. It's accurate and kills game so what more do you need.
It also helps when developing loads. If velocities don't go up with powder increases you know you are over the top and need to back off to a SAFE WORKING LOAD, usually 2 to 3 grains.
I usually work up to a velocity and accuracy load at the s as me time. If I get the accuracy I want but not the velocity I call that the load I want for that powder then try a different powder to see if I can get what I want. Fortunately with lots of research beforehand and a bit of luck I get the results I want first time around but not always. Just look at the results I got with Lilgun in the KHornet. Velocity all over the shop despite everything saying it was the ducks guts, high velocity, low pressure and outstanding accuracy, just not in my rifle. The old standby of ADI 2205 gave the results desired.
Without the chronograph I would not have known this.
Bob

 

[Bob Nelson 35Whelen]

I have noticed. Much better on a work site, where you can stir without having to worry about censorship.

@ZG47
I'm the same on this site as in real life. I don't believe in PC as I'm not into politics. I was bought up to say it how I see it BUT if your wrong be big enough to admit it and apologize, if right stick by your guns.
I had a t shirt that said CAUTION opinion contained within may offend. One stupid person asked me a question at a team meeting that I answered they were not happy with the answer even when it was the truth.
Maybe I could have been a bit more diplomatic. We had a very strict dress code where I worked as one of the clients was a sexual predator. The dress code was to protect both the client and the staff and they could understand why the client was like he was.
All I said was if you didn't dress like a two dollar store met be you would have s problem that's why the dress code is in place. The other staff agreed and the team leader said she had spoken to her about it but still did the same thing. When she got my answer she didn't like it but understood.
So as you can see in the same pain in the arse person in an the situation.
Bob

 

[ZG47]

@Bob Nelson 35Whelen I agree with all that. Same page on everything, especially in regard to velocity. Why burn the barrel out more quickly to match what someone claims on a piece of paper in a book?

What I meant, in terms of censorship, is that I have to moderate what I say on line, as compared to some of the things I say on a work site. Things can get a bit ‘off colour’, especially when I have to correct the action of an apprentice and add a bit of rough humour to soften the reprimand.

I have posted this info before BUT for those who do not know, if a bullet maker publishes a single table for a certain bullet weight but with three bullet profiles:

the top third of the table (fastest propellants) is for the bullet with the smallest bearing surface;

the bottom third is for the bullet with the greatest bearing surface;

and the middle third is for the bullet in the middle.

Reloaders should also note that if the bullet maker lists a nice long pressure barrel and a standard rifle as having been used to develop the data:

It is quite possible that the most of the velocities in the top third of the published table were obtained with the pressure barrel.