New to reloading, need some advice round #2

[Tengo1]

Shot my very first reloaded rounds ever yesterday. Loaded one round each in .3 grain increments from essentially minimum to max per the Hornady loading manual.

Did 140 grain ELD match in my 6.5 with H4350.

And did 168 SMK, 175 SMK, and 178 ELD’s for my .308 using IMR 4064.

I used a Magnetospeed V3 to collect my FOS data and then threw all the data into excel to get the following (see next post. Pic loader wasn’t working right)

 

[Tengo1]

 

[Tengo1]

The interesting thing to me is the much sharper dips in FPS the 178 ELD’s had vs the 175 SMK at different points. Which doesn’t have as many obvious “nodes”.

So my question is this. Now that I can see the points where the FPS flattens or dips despite the powder grains being increased. Is it as those points that I should now do like 5 rounds at each .1 grain difference for the .3-.5 spread that I see my assumed nodes?

And do you even bother with the lower ones? The suprising thing on the on the 168 SMK is that my shots from 36.3 to 36.9 were essentially one ragged hole at 200 yards. But that seems to weak to develop a normal load to me. Maybe not. Thoughts?

 

[Tengo1]

I should also add I had no pressure signs in any of the rounds. No flattened primers, no cracks, no difficulty raising the bolt handle. Even with the 140 ELD’s that I went over max a bit in .1 increments and the 178 ELD’s that were compressed loads at the two highest grain rounds.

 

[KZP]

I'm assuming you're trying to find flat spots in velocity? If not, disregard my post.

IMO that's a fools errand. Look at the target results, make sure you're not getting over pressure, ignore velocity charts like this. Once you have an accurate reloading charge, check velocity for ballistic calculations.

For .308 I load up 8 or so cartridges .3g apart until max book value, set seating depth 20 thou off jam, then check which load doesn't give me any over pressure signs. After that I load a hundred, tune seating depths at the range until I get a satisfactory grouping and that's my load data. Velocity is only important to me when setting up the ballistic profile.

 

[Tengo1]

Speaking of pressure signs. I did shoot some factory Hornady 6.5 Creedmoor ammo just to check factory velocity vs my reloads. Is the circle mark over the 6.5 and C in Creedmoor a pressure sign? Like an extractor mark? This was on a factory Hornday round

 

[918v]

Speaking of pressure signs. I did shoot some factory Hornady 6.5 Creedmoor ammo just to check factory velocity vs my reloads. Is the circle mark over the 6.5 and C in Creedmoor a pressure sign? Like an extractor mark? This was on a factory Hornday roundView attachment 7821803

Yes but that one is very slight

 

[Rocketmandb]

Is the circle mark over the 6.5 and C in Creedmoor a pressure sign?

Usually, but not necessarily. A heavy spring behind the extractor can cause this too.

 

[Rocketmandb]

So my question is this. Now that I can see the points where the FPS flattens or dips despite the powder grains being increased. Is it as those points that I should now do like 5 rounds at each .1 grain difference for the .3-.5 spread that I see my assumed nodes?

Recommendations:

- Pick one of the bullets to focus on first and save the others for later - even between the two calibers. Do it once with one, get used to it, then do the other caliber, then other 30 cal, if necessary.

- When you do a ladder, do 3 of each. I like to set one target per charge weight and cycle through. That way you have essentially similar conditions as you go through. Looking at a graph of single rounds, each weight with a likely 20-30+ fps ES at this stage, will get you limited useful data (the only thing I'd trust with a single-round ladder at this point is a rough idea of fps and possible pressure limitations).

- Look for a combo of ES and group size and play around those charge weights.

 

[FLIGHT762]

In you 6.5 CM, it is a slight ejector mark, not an extractor mark.

 

[Tengo1]

In you 6.5 CM, it is a slight ejector mark, not an extractor mark.

Your right. Thats what I meant.

 

[MarkyMark007]

So my question is this. Now that I can see the points where the FPS flattens or dips despite the powder grains being increased. Is it as those points that I should now do like 5 rounds at each .1 grain difference for the .3-.5 spread that I see my assumed nodes?

velocity flat spots are not nodes. those are your mistakes. velocity flat spots does not exists. but velocity 'ES/SD flat spots' are good indicator of promising long range load...
you are looking for Point Of Impact flat spots. those are 'nodes'. better at longer ranges. but again dont confuse them with inaccurate load.

low velocities are important if you want to save money on brass, powder, barrel; for plinking. if you have gun for hunting and competition, you are looking for better ballistics with higher velocity.

 

[Pickle Rick]

The interesting thing to me is the much sharper dips in FPS the 178 ELD’s had vs the 175 SMK at different points. Which doesn’t have as many obvious “nodes”.

So my question is this. Now that I can see the points where the FPS flattens or dips despite the powder grains being increased. Is it as those points that I should now do like 5 rounds at each .1 grain difference for the .3-.5 spread that I see my assumed nodes?

And do you even bother with the lower ones? The suprising thing on the on the 168 SMK is that my shots from 36.3 to 36.9 were essentially one ragged hole at 200 yards. But that seems to weak to develop a normal load to me. Maybe not. Thoughts?

What you did was great, but if you want solid data I would test at least 3-5 rounds per charge weight. If you ran the exact same test tomorrow, the graph would may look different.