Don't know whats going on w/308

[FFAZ]

Hey guys, I've been reloading for a year and got a new rifle to do load development from scratch. Did a ladder/OCW test, and found 2 sills.
Loaded 10 rounds of the 2 sills and went to test them.

Got horrible ESs. 50 and 60 for both sets, grouped sub-MOA though.

I cannot figure out what's causing it, so heres my process for my virgin brass:

-Trim to uniform length
-Chamfer/deburr
-Primer pocket uniform
-Flash hole uniform
-Expand necks with mandrel to 1 thou neck tension
-Weigh and sort cases within half a grain
-Weigh and sort bullets within half a grain
-Seat primers within 2 thou of same depth (limit of accuracy of my priming tool)
-Warm-up, Calibrate, and charge to equal weight
-Seat bullets within 1 thou of same CBTO, 20 thou off lands

Using Alpha Munitions cases, RL-15, Federal match primers, 175 SMKs

My ESs are in the 50s and 60s... usually 3 rounds in a 10 round string go haywire and shoot 30/60 fps high or low. The other 7 or so generally will have an ES around 10 or below.

What's going on with those 3 rounds?

At this point I think it's my scale (Chargemaster Lite). I don't have another one to make sure its throwing powder accurately. I have thrown a charge, taken it off the scale, and put it back on to check and it's good. But should I get another one to reference it to? Or what could I be doing wrong?

 

[Huskydriver]

Scale is def suspect but how did you measure your velocity and get your stats?

 

[FFAZ]

Scale is def suspect but how did you measure your velocity and get your stats?

Magnetospeed V3

 

[hafejd30]

Guessing either issue with neck tension

Or the fed primers

I had a similar incident but don’t remember exactly which caliber it was 308 or 260 most likely. Shooting federal primers. Switched to CCI 200 and issue went away.

 

[FFAZ]

Guessing either issue with neck tension

Or the fed primers

I had a similar incident but don’t remember exactly which caliber it was 308 or 260 most likely. Shooting federal primers. Switched to CCI 200 and issue went away.

Is expanding on a mandrel a good enough method? I dont turn necks, but I'm trying to get down to a lower ES before I feel the need to start squeezing the maximum I can.

I'll try the CCI 200s next. Thanks for the intel.

 

[hafejd30]

Is expanding on a mandrel a good enough method? I dont turn necks, but I'm trying to get down to a lower ES before I feel the need to start squeezing the maximum I can.

I'll try the CCI 200s next. Thanks for the intel.

I just remembered it was my 338 Lapua that I had the federal issues. Swapped Fed 215 for CCI 250’s.

 

[straightshooter1]

At this point I think it's my scale (Chargemaster Lite). I don't have another one to make sure its throwing powder accurately. I have thrown a charge, taken it off the scale, and put it back on to check and it's good. But should I get another one to reference it to? Or what could I be doing wrong?

I think you're right. In any case, with that much ES, powder charge consistency is the first place I'd look. Until you confirm that, doing anything else at this point is a waist of time and supplies. So, yes . . . you should get some other scale that is accurate and consistent. You might look to borrow one from someone you know . . .???

 

[918v]

It’s not the Fed primers. Your load is crap. First of all .001” neck tension is too light. Your .020” off the lands is too arbitrary. You need to find a good node where small changes to powder charge or coal don’t affect accuracy and then see what the Es/sd is.

 

[FFAZ]

It’s not the Fed primers. Your load is crap. First of all .001” neck tension is too light. Your .020” off the lands is too arbitrary. You need to find a good node where small changes to powder charge or coal don’t affect accuracy and then see what the Es/sd is.

Talking around I for sure need to tighten the necks up. So roger on that.
The .020" off the lands is just my start point until I determine a decent load then I was going to start tweaking the seating depth to squeeze tighter groups out of the gun.
Is that reasonable?

 

[hafejd30]

Talking around I for sure need to tighten the necks up. So roger on that.
The .020" off the lands is just my start point until I determine a decent load then I was going to start tweaking the seating depth to squeeze tighter groups out of the gun.
Is that reasonable?

The neck tension is where I would start once you confirm your scale is correct

I run .0015 on my lightest neck tension. That’s fired brass annealed every firing.

The federal I had issues with came from a buddy as I couldn’t find any. So maybe improper storage was my issue, not sure. But the CCI were significantly more consistent and are what I use across the board now

 

[918v]

Talking around I for sure need to tighten the necks up. So roger on that.
The .020" off the lands is just my start point until I determine a decent load then I was going to start tweaking the seating depth to squeeze tighter groups out of the gun.
Is that reasonable?

It’s reasonable but do that before fucking around with the magnetospeed. Plot charge weight vs coal. Find a node. Pick a charge and coal that puts you in the center of the node, then check the velocity. The ES will be single digit.

 

[FFAZ]

Plot charge weight vs coal. Find a node. Pick a charge and coal that puts you in the center

Just one charge weight with various COALs or one COAL with various charge weights? Or both?

And you're talking accuracy mode right? I was under the impression that you can find velocity nodes. I was testing various charge weights for flat spots in velocity.

 

[Mr Tibbs]

FFAZ the components your using are known for very tight groups, the high ES would lead me to suspect your neck tension.

 

[918v]

Pick a charge weight somewhere below but close to max. Test different coals. You’ll find one that is more accurate than the rest. That is your starting point. Let’s say it’s 43.5 grains at 2.830” and that combo shot .5” at 100. Now try 43.3 and 43.7 grains and 43.5 at 2.825” and 2.835”. Plot your results on paper, charge weight vs coal. You’ll see a pattern emerge. For example, if 43.5 grains at 2.830” is the center of the node, then lower and higher charge weights and longer and shorter coals will shoot good too. But you won’t know until you test them.

 

[FFAZ]

Okay gents so heres what I looked at:

I have Alpha brass that comes in at .305/.306 inside diameter. I have been running them over a sinclair expander mandrel that is .307 resulting in a .001" neck tension.

Completely unneeded step. The neck tension from the factory is completely acceptable for the first firing.

When I bump the shoulders back from the first firing, I can use a bushing in my die to get a consistent .002" neck tension.

 

[straightshooter1]

Okay gents so heres what I looked at:

I have Alpha brass that comes in at .305/.306 inside diameter. I have been running them over a sinclair expander mandrel that is .307 resulting in a .001" neck tension.

Completely unneeded step. The neck tension from the factory is completely acceptable for the first firing.

When I bump the shoulders back from the first firing, I can use a bushing in my die to get a consistent .002" neck tension.

.002 is what I use and what I think most use also. With that (and some good powder measures) I can get this:

And I'm just an old geezer . . .

 

[JBELL74]

What straigtshooter1 said. The expander mandrels are typically .001" under, whereas the turning mandrels are .002" under. This has worked well for me also... fwiw.

 

[FFAZ]

What straigtshooter1 said. The expander mandrels are typically .001" under, whereas the turning mandrels are .002" under. This has worked well for me also... fwiw.

I just found them by looking up turning mandrel instead of expander mandrel. Just ordered the .306" one. Thanks for the proper verbiage!

 

[charnicus]

Hey guys, I've been reloading for a year and got a new rifle to do load development from scratch. Did a ladder/OCW test, and found 2 sills.
Loaded 10 rounds of the 2 sills and went to test them.

Got horrible ESs. 50 and 60 for both sets, grouped sub-MOA though.

I cannot figure out what's causing it, so heres my process for my virgin brass:

-Trim to uniform length
-Chamfer/deburr
-Primer pocket uniform
-Flash hole uniform
-Expand necks with mandrel to 1 thou neck tension
-Weigh and sort cases within half a grain
-Weigh and sort bullets within half a grain
-Seat primers within 2 thou of same depth (limit of accuracy of my priming tool)
-Warm-up, Calibrate, and charge to equal weight
-Seat bullets within 1 thou of same CBTO, 20 thou off lands

Using Alpha Munitions cases, RL-15, Federal match primers, 175 SMKs

My ESs are in the 50s and 60s... usually 3 rounds in a 10 round string go haywire and shoot 30/60 fps high or low. The other 7 or so generally will have an ES around 10 or below.

What's going on with those 3 rounds?

At this point I think it's my scale (Chargemaster Lite). I don't have another one to make sure its throwing powder accurately. I have thrown a charge, taken it off the scale, and put it back on to check and it's good. But should I get another one to reference it to? Or what could I be doing wrong?

I’d be curious if you’re using 205ms. I ran one charge set with BR4s and it’s the best group I’ve ever shot in my life let alone with the rifle. Could be a fluke. My loads with Feds and Varget have had a few head scratchers. Granted different brass and powder but same bullet. I’m a far from perfect reloaded but if it ain’t right it ain’t right. I may be on to tuning primer depth but that’s a different discussion.

 

[Dthomas3523]

Few things.

1: how are you measuring neck tension? Many people do the math for bushing and/or mandrels to figure their designed tension, but forget to factor in spring back. I routinely see .001 spring back.

2: verify your charge weights are correct and consistent

3: forget the brass sorting when using quality brass. Same with bullets unless your groups fall apart at distance (if you have consistent muzzle velocity, the reason groups fall apart is the bullet/BC being inconsistent from bullet to bullet)

4: sometimes you need to switch primers or powder to get the best combination of primer/powder

5: it doesn’t matter if you test/pick your charge weight or your seating depth first. Both are valid methods. I personally do powder first and use an arbitrary .020 jump. But I also will either not shoot at paper or if I do, ignore groups in the powder phase

6: if you’re shooting practical/prs type stuff, you don’t need to worry being too much of a node or flat spot. As long as your powder isn’t terribly temp sensitive, and you have a good BC for your bullet.....you can chrono the day you are shooting and your dope with work out fine. If using a good scale, your charge weights will be consistent enough that your ES won’t be an issue vs practical target sizes.

 

[FFAZ]

Verified the consistency of the CM lite, so now I will be testing .003" .002" neck tension to remove that variable before I buy new primers and powder.

Thanks for your help gentlemen and I will keep the thread updated for anyone in the future who could use the data

 

[tnc]

Unless I missed it, you started with virgin brass and didn’t run it through a die first. A buddy had a similar issue with virgin brass. Once fired and run through the FL die issue went away.

 

[kthomas]

Unless I missed it, you started with virgin brass and didn’t run it through a die first. A buddy had a similar issue with virgin brass. Once fired and run through the FL die issue went away.

The only thing I do with virgin brass is size the necks. I'm using Lapua brass, not Alpha, but have shot some of my very best groups with virgin brass. If Alpha has the same quality as Lapua, I wouldn't worry about doing too much brass prep. I'm just making sure the necks are uniform and remove any dents and dings from shipping.

You shouldn't have to do anything with the primer pocket or flash holes, I think that's a waste of time personally. I don't even clean primer pockets. Weight sorting cases and bullets is also a waste of time IMO, especially cases. Using quality components also really helps, that's why my preference is to stick to Lapua brass and Berger bullets.

As far as your ES issues go, I would also look to neck tension first. I would try 3 thou. After that, then I would look to your powder thrower.

 

[FFAZ]

Okay gents, I promised I would get back to you all on the issue. I also wanted to update this thread for archival reasons, that way anyone reading it for tips will learn what worked.

I ended up tightening up my necks by running it in my bushing die and then using a neck turning mandrel.

These are the results, same components, seating depth, charge weight, etc.

OLD .001" Neck tension:
ES: 87
SD: 49

NEW .0025"-.003" Neck tension:
ES: 25
SD: 9

I dropped the ES/SD by:

• Resized my once-fired cases on a bushing die
  • Bumped the shoulders back .002"
  • Changed neck tension using a .333" bushing (did the math with my case thickness)
• Ran the cases over a neck turning mandrel (T30) (.306 diameter)
  • NOT AN EXPANDER MANDREL (E30) (.307 diameter) this made them too loose on my first batch, which was the problem.

CASE IN POINT:
Neck tension will highly affect your ES/SD if it is too loose.

 

[FFAZ]

ALSO checked the accuracy of my chargemaster lite by:

FIRST:
-Used a manual beam scale to compare a bunch of random charges

SECOND:
-Weighed primed cases with no powder, recorded each cases primed weight. (varied by .1 grain)
-then charged each case
-then weighed each charged case, subtracted that case's primed weight, to see what the weight of the charge was mathematically.
-only 1 case was off by .1 grain

 

[straightshooter1]

ALSO checked the accuracy of my chargemaster lite by:

FIRST:
-Used a manual beam scale to compare a bunch of random charges

SECOND:
-Weighed primed cases with no powder, recorded each cases primed weight. (varied by .1 grain)
-then charged each case
-then weighed each charged case, subtracted that case's primed weight, to see what the weight of the charge was mathematically.
-only 1 case was off by .1 grain

Hmmmm??? Unless your beam scale is something like the Prometheus I don't think a manual beam scale is going to have enough resolution to tell you much in that comparison with your CM Lite.

Here's a comparison I did for my ChargeMaster 1500 with a very accurate scale, the FX-210i. My CM would read 40.9 grs, which was the target charge that has been a verily accurate load in my gun, but the FX had enough resolution to show something significantly different (the FX weights shown in the blue shaded area). Then you can see the difference in chrono data (as taken from a Magnetospeed v3) as well as some difference on paper in terms of MOA:

 

[918v]

Hmmmm??? Unless your beam scale is something like the Prometheus I don't think a manual beam scale is going to have enough resolution to tell you much in that comparison with your CM Lite.

Here's a comparison I did for my ChargeMaster 1500 with a very accurate scale, the FX-210i. My CM would read 40.9 grs, which was the target charge that has been a verily accurate load in my gun, but the FX had enough resolution to show something significantly different (the FX weights shown in the blue shaded area). Then you can see the difference in chrono data (as taken from a Magnetospeed v3) as well as some difference on paper in terms of MOA:

View attachment 7605069

Your FX does not measure within .02gr

Your FX measures within .08gr if you were to compare it to a better scale.

 

[FFAZ]

Hmmmm??? Unless your beam scale is something like the Prometheus I don't think a manual beam scale is going to have enough resolution to tell you much in that comparison with your CM Lite.

@straightshooter1

I'm not invested enough to spend close to 1k on a scale combo. That being said, I'm attempting to get as precise as I can, with the equipment that I have. Right now, the margin of error in my equipment is my external limiting factor. That being said, I'm trying to reduce my own margin of error to work within my equipment's margin of error.

I would love a scale like that, but if I can squeeze single digit SDs and low ESs out of what I currently have in a consistent way, then I know I have bottomed out and its worth upgrading my scale to something like that FX-210i.

I like the data you presented, definetly clarifies why I get a flux in velocities even when I think everything is consistent. When my CM lite reads 43.9gr it could actually be off within a margin, which I cannot fix unless I upgrade my equipment.

 

[straightshooter1]

Your FX does not measure within .02gr

Your FX measures within .08gr if you were to compare it to a better scale.

Yeah, I know it's not within .02gr. Based on the spec sheet, I figured it to be more like +/- .03gr . . . saying within .06 gr if you will.

 

[Baron23]

Yeah, I know it's not within .02gr. Based on the spec sheet, I figured it to be more like +/- .03gr . . . saying within .06 gr if you will.

View attachment 7605198

What am I missing, does it not say accuracy is +-a tenth of a grain?

 

[Steel head]

@straightshooter1

I'm not invested enough to spend close to 1k on a scale combo. That being said, I'm attempting to get as precise as I can, with the equipment that I have. Right now, the margin of error in my equipment is my external limiting factor. That being said, I'm trying to reduce my own margin of error to work within my equipment's margin of error.

I would love a scale like that, but if I can squeeze single digit SDs and low ESs out of what I currently have in a consistent way, then I know I have bottomed out and its worth upgrading my scale to something like that FX-210i.

I like the data you presented, definetly clarifies why I get a flux in velocities even when I think everything is consistent. When my CM lite reads 43.9gr it could actually be off within a margin, which I cannot fix unless I upgrade my equipment.

I never had any difficulties getting 6-7SD’s or better for 10-20 shots with my Hornandy and the RCBS is definitely a bit better scale than the Hornandy.

My old 5-0-5 easily resolves individual grains of H4350 like my FX-120 does and I Didn’t see any major improvement in SD since I started running the V3 setup.
But it’s so much faster and quicker to get set up.

 

[straightshooter1]

What am I missing, does it not say accuracy is +-a tenth of a grain?

The "g" is for grams, not grains.

 

[Baron23]

Well dang, you are right.