Help troubleshooting low 6.5 creedmoor velocity

[zabada]

Hello all -

It seems I’m getting pretty low comparative velocities with some reloads and I’m hoping someone can help me troubleshoot why.

TL;DR I think it’s the choice of powder, and looking for potential confirmation.

Gun:
Ultimatum Deadline action
Hawk Hill 24” - ~600 rounds through it

Load:
Hornady 140 BTHP
Hornady once fired brass cut to 1.910-1.915
CCI 400 primers (not the best but have worked fine for me lately given availability)
Accurate 4350 - min 40.4 gr, max 41.8 gr in .2 increments

Results of ladder test:
1. 2401
2. 2426
3. 2448
4. 2474
5. 2463
6. 2500
7. 2521
8. 2529

Based on my searching and reading about 140 gr 6.5 with Accurate 4350, I think I should be getting about 2700 fps with 41.8 gr.

I have worked up loads with 147 ELDM that shoot true to expectations out of the same once fired brass, and factory loads shoot true enough to their stated velocities for me to rule out the barrel
having lost velocity and the chrono (magnetospeed v3) having issues.

Is accurate 4350 just not good at getting high velocities with this cartridge?

Or am I making a mistake elsewhere.

Thank you!

 

[acudaowner]

if no pressure signs try 42gr or faster your barrel is only 24 inches your going to have slower speeds than someone with a longer barrel personally I have never tried over 42.4 it was way faster than I needed or wanted so I set my cap at 42gr of h4350 and imr 4350 which will pick up a few fps in summer heat , you could also try powders like rl 17 and I think 16 which should be the temp-stable version of rl17 . of which I have only tried up to 41.4gr . at 41.3 I am getting the same speeds I get with 42 gr of h4350 another powder that's pretty fast is h hybrid 100 v it's not temp stable but plenty fast for me 41.3 gr of it is the same as the h4350 at 42.4 gr and the rl17 at 41.4 best of luck with what ever powder or load you try going up slowly is a good thing .

 

[straightshooter1]

Hello all -

It seems I’m getting pretty low comparative velocities with some reloads and I’m hoping someone can help me troubleshoot why.

TL;DR I think it’s the choice of powder, and looking for potential confirmation.

Gun:
Ultimatum Deadline action
Hawk Hill 24” - ~600 rounds through it

Load:
Hornady 140 BTHP
Hornady once fired brass cut to 1.910-1.915
CCI 400 primers (not the best but have worked fine for me lately given availability)
Accurate 4350 - min 40.4 gr, max 41.8 gr in .2 increments

Results of ladder test:
1. 2401
2. 2426
3. 2448
4. 2474
5. 2463
6. 2500
7. 2521
8. 2529

Based on my searching and reading about 140 gr 6.5 with Accurate 4350, I think I should be getting about 2700 fps with 41.8 gr.

I have worked up loads with 147 ELDM that shoot true to expectations out of the same once fired brass, and factory loads shoot true enough to their stated velocities for me to rule out the barrel
having lost velocity and the chrono (magnetospeed v3) having issues.

Is accurate 4350 just not good at getting high velocities with this cartridge?

Or am I making a mistake elsewhere.

Thank you!

What's your cartridge COAL?

You're right, that you should be getting much higher MV's than that. Base on what little information there is, two things off hand that I can think might be an issue:

1. Somethings going on and may be wrong with your chronograph.

2. IF the powder has been exposed to high humidity for a while, it can have absorbed enough moisture to really slow the powder burn rate down.

 

[rmfield]

Something wrong there. QuickLoad predicts 2770 FPS with 41.8 gr. Accurate 4350, Hdy 140 BTHP, 24" barrel. Other values are defaulted to a COAL of 2.8" and a case H2O capacity of 51.5 gr. Predicted pressure for this load is about 5000 psi under the max.

 

[zabada]

What's your cartridge COAL?

You're right, that you should be getting much higher MV's than that. Base on what little information there is, two things off hand that I can think might be an issue:

1. Somethings going on and may be wrong with your chronograph.

2. IF the powder has been exposed to high humidity for a while, it can have absorbed enough moisture to really slow the powder burn rate down.

These are good things to look for.

1. The powder has been stored for 1 year capped and in a Plano bin in a cool dry place (in my house, not a garage).

2. I thought that as well but my S&B 140 factory loads that I use as burners or to warm up the barrel clock at 2,700.

 

[zabada]

Something wrong there. QuickLoad predicts 2770 FPS with 41.8 gr. Accurate 4350, Hdy 140 BTHP, 24" barrel. Other values are defaulted to a COAL of 2.8" and a case H2O capacity of 51.5 gr. Predicted pressure for this load is about 5000 psi under the max.

My CBTO is about .04 off the lands, so nothing crazy there. I believe I have factory loads that sit way farther back.

Edit: land measurement incorrect.

 

[918v]

Weigh an empty deprimed case. How much does it weigh? Hornady used to make very light cases a few years ago.

 

[straightshooter1]

My CBTO is about .04 off the lands, so nothing crazy there. I believe I have factory loads that sit way farther back.

Edit: land measurement incorrect.

Because different chambers are often different lengths, .040 off the lands doesn't really tell me anything about seating depth. The COAL helps better to understand.

 

[zabada]

Because different chambers are often different lengths, .040 off the lands doesn't really tell me anything about seating depth. The COAL helps better to understand.

That makes sense. I’ll load and measure a few more (haven’t removed my seating die).

I’m also going to adjust the chronograph distance as after looking at the magnetospeed manual it seems I may have put my chronograph bayo way too close to the end of my MD, so @straightshooter1ay be right on the money.

More data tomorrow!

 

[zabada]

Weigh an empty deprimed case. How much does it weigh? Hornady used to make very light cases a few years ago.

Here is a random sample of 5 of my deprimed, tumbled hornady cases:

1. 153.6 gr
2. 153.9 gr
3. 153.9 gr
4. 154 gr
5. 153.5 gr

I also have brand new Lapua 6.5 SRP on hand and it seems to measure slightly heavier at about 166 gr, but I’m assuming this is because of the extra material in the case to take up the diameter of the LRP.

 

[straightshooter1]

That makes sense. I’ll load and measure a few more (haven’t removed my seating die).

I’m also going to adjust the chronograph distance as after looking at the magnetospeed manual it seems I may have put my chronograph bayo way too close to the end of my MD, so @straightshooter1ay be right on the money.

More data tomorrow!

Since you had mentioned your MagnetoSpeed, I was going to suggest you take a close look at how its mounted so that it can properly sense the projectile moving over it. Hopefully, this is it and easily fixed.

 

[918v]

Here is a random sample of 5 of my deprimed, tumbled hornady cases:

1. 153.6 gr
2. 153.9 gr
3. 153.9 gr
4. 154 gr
5. 153.5 gr

I also have brand new Lapua 6.5 SRP on hand and it seems to measure slightly heavier at about 166 gr, but I’m assuming this is because of the extra material in the case to take up the diameter of the LRP.

OK so you have the new production brass. That is not it. It’s got to be your powder burning rate.

 

[zabada]

OK so you have the new production brass. That is not it. It’s got to be your powder burning rate.

I’m going to check a more concentrated ladder as well as my chrono position tomorrow and will report back. Appreciate the info, as I had no idea hornady had a change to their brass weight.

I had shot factory 147 ELDMs for my whole (short) 6.5 bolt gun career and decided it was time to load (been saving up components for over a year).

I was about to switch over to my Lapua brass but glad to know this hornady brass is still GTG, as I have about 500 once fired cases.

 

[Mike Casselton]

Have you verified the accuracy of your scale?

Otherwise, I'd be looking at the chrono next, but you said you're getting 2700 with the S&B. That's pretty normal.
That would lead me to verify scale/powder charge.

 

[Simonsza1]

I’m going to be the oddball out and say you may be about right. If you possibly have a barrel that’s not super fast and those loads are pretty light. I know they may not say it in the book but I think most guys are mid 42- 43 with 4350ish powders and there in the 2,700 l-2,800 area. You also are 24” barrel so there’s 50 or so there cause a lot of the numbers you may be seeing are 26”. Unless I’m reading it wrong I’d say your doing nothing wrong and that’s just your speed. I bet if you get up towards 43 like lots of guys are with those speeds you’ll jump up considerably. Go with caution. Just my lame opinion on your situation though!

 

[918v]

Something wrong there. QuickLoad predicts 2770 FPS with 41.8 gr. Accurate 4350, Hdy 140 BTHP, 24" barrel. Other values are defaulted to a COAL of 2.8" and a case H2O capacity of 51.5 gr. Predicted pressure for this load is about 5000 psi under the max.

Hornady data predicts 2695 FPS with 43.5grs in a Hornady case. It’s prolly because A4350 is slower burning than H4350.

 

[zabada]

Have you verified the accuracy of your scale?

Otherwise, I'd be looking at the chrono next, but you said you're getting 2700 with the S&B. That's pretty normal.
That would lead me to verify scale/powder charge.

I am using a properly calibrated and zeroed RCBS link and verifying with an independently calibrated and zeroed hornady bench scale.

 

[zabada]

I’m going to be the oddball out and say you may be about right. If you possibly have a barrel that’s not super fast and those loads are pretty light. I know they may not say it in the book but I think most guys are mid 42- 43 with 4350ish powders and there in the 2,700 l-2,800 area. You also are 24” barrel so there’s 50 or so there cause a lot of the numbers you may be seeing are 26”. Unless I’m reading it wrong I’d say your doing nothing wrong and that’s just your speed. I bet if you get up towards 43 like lots of guys are with those speeds you’ll jump up considerably. Go with caution. Just my lame opinion on your situation though!

I always appreciate a “dissenting” opinion! If this troubleshooting doesn’t resolve the velocity, I will likely end up slowly working up the load to around that range.

 

[Mike Casselton]

I am using a properly calibrated and zeroed RCBS link and verifying with an independently calibrated and zeroed hornady bench scale.

Then you have: (pick one, or all three)

1. Lighter brass than the loads were developed in.
2. A slow barrel. (It happens) Although, your S&B ammo is right on the money.
3. Powder is bulkier and a tad slower.

Combining 1 & 3 could be your cause.

I would cautiously go up in powder charge until you get pressure signs or the velocity you're seeking.

 

[Kadams1563]

Go take a small amount of powder and dry it out in the oven. I know sounds crazy but see if it increases your velocity a lot.

Could be humidity innthe powder. Or keep going up in charge until you either get the velocity you want or see pressure.

I have H4350 that I was loading 43+ grains with in 6.5 CM without issue.

 

[supercorndogs]

Hornady data predicts 2695 FPS with 43.5grs in a Hornady case. It’s prolly because A4350 is slower burning than H4350.

Don't skim past this comment. The velocity is right where it should be for those loads.

 

[straightshooter1]

These are good things to look for.

1. The powder has been stored for 1 year capped and in a Plano bin in a cool dry place (in my house, not a garage).

2. I thought that as well but my S&B 140 factory loads that I use as burners or to warm up the barrel clock at 2,700.

Here's some numbers for you to look and and maybe give you some perspective; burn rate factor here is a default rate and actual can be higher or lower, which would changes the numbers of course, as would different seating depths:

Compare that to estimated numbers for H-4350:

 

[357Max]

FWIW - I just recently got around to putting some loads together for my 24” 6.5.C PVA Rock Creek Button rifled barrel.
Lapua SR brass with cci #41
41.6 of H4350 with 142 Sierra’s loaded @2.830/2.295= 2821
41.5 H4350 with Hornady 147 loaded @ 2.835/2.259 = 2812
41.9 H4350 with Norma 130 Golden targets loaded @ 2.848/2.291 =2898
This was with Magneto V3

 

[JMGlasgow]

When I used AA4350 with 140gr bullets I got less velocity and I remember my powder charge being around 43gr in a Hornady case. A 23" barrel got me to 2670fps.

I found that AA4350 likes to be compressed, and that I got slower velocity than I could with H4350. It's a good powder if you don't mind a bit slower velocity.

 

[Dot3]

CCI 400 primers (not the best but have worked fine for me lately given availability)

Is the brass you’re using SRP? 400s are small primers.

I say that to say this: I had to make the switch from Cci 200s to 250s some time ago in a 30-06. I had to drop powder by over two grains to keep away from pressure.

If you are in fact shooting 400s when the recipe calls for 450s, you may be seeing a slight velo decrease there.

 

[zabada]

Is the brass you’re using SRP? 400s are small primers.

I say that to say this: I had to make the switch from Cci 200s to 250s some time ago in a 30-06. I had to drop powder by over two grains to keep away from pressure.

If you are in fact shooting 400s when the recipe calls for 450s, you may be seeing a slight velo decrease there.

Good catch. I meant to say 200. I have 200 and 250 but haven’t tried the 250 yet.

 

[Jmccracken1214]

My last 6.5, was running 2800 with berger 140 hybrid and 43.8gr of h4350. I had those bullets seated very long, barely fit in non binder mags… I was bored one day and messed with the load, seated it to 2.800 and got pressure, of course.
I had to back off almost 2 full grains to be at the same speed with the bullet seated deeper.

Not sure what’s going on with your load, but if you’re seated long, go deeper and possibly bump up the powder.
I use cci 450

 

[Dot3]

Good catch. I meant to say 200. I have 200 and 250 but haven’t tried the 250 yet.

I’m not saying switch to 250s but my uneducated theory is that the higher flash saturates the powder column quicker than a standard primer thereby making the powder appear to have a faster burn rate.

 

[zabada]

I’m not saying switch to 250s but my uneducated theory is that the higher flash saturates the powder column quicker than a standard primer thereby making the powder appear to have a faster burn rate

Here's some numbers for you to look and and maybe give you some perspective; burn rate factor here is a default rate and actual can be higher or lower, which would changes the numbers of course, as would different seating depths:

View attachment 7923071

Compare that to estimated numbers for H-4350:
View attachment 7923077

This is great info, thanks. It turns out my COAL was 2.76”.

I’ve adjusted it to 2.805” and loaded some with 41gr and some with 41.5gr.

Based on quickload’s warnings, and not being an experienced enough loader, I will not be going over 41.5. I’d rather crack open the H4350 I have. I just would rather be able to get a good training round with this Accurate 4350 first. Results in a few hours.

 

[zabada]

This is great info, thanks. It turns out my COAL was 2.76”.

I’ve adjusted it to 2.805” and loaded some with 41gr and some with 41.5gr.

Based on quickload’s warnings, and not being an experienced enough loader, I will not be going over 41.5. I’d rather crack open the H4350 I have. I just would rather be able to get a good training round with this Accurate 4350 first. Results in a few hours.

Ok so the numbers were the same. Low to mid 2500 for the 140 gr with a properly set up and functioning chrono and a COAL of 2.805”.

Can I get confirmation that there are no pressure signs on this brass and that I should move up in charge weight?

 

[918v]

No pressure signs. You should up the charge to be in line with Hornady data tho. Start at 42.5 and go up.

 

[zabada]

No pressure signs. You should up the charge to be in line with Hornady data tho. Start at 42.5 and go up.

I have the hornady app and bought the 6.5 data and it doesn’t have anything for Accurate 4350. Where are you seeing this?!

 

[Jmccracken1214]

I have the hornady app and bought the 6.5 data and it doesn’t have anything for Accurate 4350. Where are you seeing this?!

The book is so underrated for safety. You have super slow speeds, and not even the slightest sign of pressure beginning. Up the charge. You’ll see primers start to flatten a little, which is still fine.

Go up to 42.5-43 and see what you get.
You won’t blow up your rifle lol. Promise

 

[Jmccracken1214]

Even their website shows 44gr of accurate 4350 with a 153gr bullet!
I’d start at 42.5 and go up to 43.5-44 after seeing this.
You’re being waayyyyyy to conservative with the powder.

 

[918v]

I have the hornady app and bought the 6.5 data and it doesn’t have anything for Accurate 4350. Where are you seeing this?!

On their reloading data center.

 

[zabada]

Even their website shows 44gr of accurate 4350 with a 153gr bullet!
I’d start at 42.5 and go up to 43.5-44 after seeing this.
You’re being waayyyyyy to conservative with the powder.
View attachment 7923462

Ah. Going to load up some fast ones now. I was staying conservative and following what I had for their H4350 charge weight for the 140, though I know H4350 is faster.

 

[straightshooter1]

Ah. Going to load up some fast ones now. I was staying conservative and following what I had for their H4350 charge weight for the 140, though I know H4350 is faster.

Based on your second round of testing and getting the same results, there's defiantly something unusual about your particular bottle/jug of powder that it's burning so slow. You should be able to You should be able to work up to around 44 grains. Just don't expect to get very high velocities. Find an accuracy node for that powder and to practice with. You'll probably find the H4350 much faster where you need to start a little low and work up to somewhere near 43 grs. for the higher velocities.

 

[Leland T]

How old is your powder? I test an older bottle of H4350 and it was 125 fps slower. Also 918v mentioned Burn rate, here is the chart

https://hodgdon.com/wp-content/uploads/2019/11/burn-rate-color.pdf

 

[rayvandervort]

OK so you have the new production brass. That is not it. It’s got to be your powder burning rate.

In developing loads and measuring with Labradar, I found the 6.5CM velocity was far more effected by the distance off the lands than other cartridges I have reloaded. I also found guys on-line finding the sweet spot at .100 off the lands. One consistant thing I found in my load workup was the farther of the lands, the greater the velocity. I attribute this to burn before thru the lands, thus less burn for the push down the barrel. I believe one of the differences in 6.5cm is the depth of the barrel grooves or in reverse, the greater the bullet swaging, thus more energy to engage and move forward. ALL my loads across all powders were less than published values in my gun, and only came close when I was beyond .060 off the lands, yet still under published data. To further this is the "published" data will be on a deeper set bullet to be conforming.

 

[spife7980]

In developing loads and measuring with Labradar, I found the 6.5CM velocity was far more effected by the distance off the lands than other cartridges I have reloaded. I also found guys on-line finding the sweet spot at .100 off the lands. One consistant thing I found in my load workup was the farther of the lands, the greater the velocity. I attribute this to burn before thru the lands, thus less burn for the push down the barrel. I believe one of the differences in 6.5cm is the depth of the barrel grooves or in reverse, the greater the bullet swaging, thus more energy to engage and move forward. ALL my loads across all powders were less than published values in my gun, and only came close when I was beyond .060 off the lands, yet still under published data. To further this is the "published" data will be on a deeper set bullet to be conforming.

That’s not it at all.

 

[zabada]

Thanks everyone for the help troubleshooting!

Changing the COAL and upping the powder charge by about a grain got me into the 2630+ range with 1/2 moa accuracy. I can’t ask for much more out of a bthp training load.

Even at the high end of my ladder I saw no pressure signs. The primer hadn’t even flattened more than in the picture I shared earlier. I know <2700 is nothing special for a 140, but I was still worried about cartridge pressure.

Thanks again!

 

[Jmccracken1214]

Thanks everyone for the help troubleshooting!

Changing the COAL and upping the powder charge by about a grain got me into the 2630+ range with 1/2 moa accuracy. I can’t ask for much more out of a bthp training load.

Even at the high end of my ladder I saw no pressure signs. The primer hadn’t even flattened more than in the picture I shared earlier. I know <2700 is nothing special for a 140, but I was still worried about cartridge pressure.

Thanks again!

What charge got you to 2630?

 

[zabada]

Cartridge specs:

Hornady once fired brass trimmed to 1.912”
CCI 200
Hornady 140 BTHP
Accurate 4350

COAL: 2.76
2630 FPS at 43 gr

This is not financial or reloading advice.

 

[zabada]

What charge got you to 2630?

43 gr. Posted the specs as a separate reply.

 

[Jmccracken1214]

43 gr. Posted the specs as a separate reply.

If you’re happy with that, run it, but if it were me, since you atleast have an accurate load, I’d still try up to 44 and see if you can get another 100+fps and shoot good

 

[zabada]

If you’re happy with that, run it, but if it were me, since you atleast have an accurate load, I’d still try up to 44 and see if you can get another 100+fps and shoot good

I got up to 2670 at the top of my ladder, which I think was 43.8 or 43.6 gr.

My thought process is that it’s a training load, so I can save both powder and barrel life with this powder puff load.

 

[rottenruger]

Hello all -

It seems I’m getting pretty low comparative velocities with some reloads and I’m hoping someone can help me troubleshoot why.

TL;DR I think it’s the choice of powder, and looking for potential confirmation.

Gun:
Ultimatum Deadline action
Hawk Hill 24” - ~600 rounds through it

Load:
Hornady 140 BTHP
Hornady once fired brass cut to 1.910-1.915
CCI 400 primers (not the best but have worked fine for me lately given availability)
Accurate 4350 - min 40.4 gr, max 41.8 gr in .2 increments

Results of ladder test:
1. 2401
2. 2426
3. 2448
4. 2474
5. 2463
6. 2500
7. 2521
8. 2529

Based on my searching and reading about 140 gr 6.5 with Accurate 4350, I think I should be getting about 2700 fps with 41.8 gr.

I have worked up loads with 147 ELDM that shoot true to expectations out of the same once fired brass, and factory loads shoot true enough to their stated velocities for me to rule out the barrel
having lost velocity and the chrono (magnetospeed v3) having issues.

Is accurate 4350 just not good at getting high velocities with this cartridge?

Or am I making a mistake elsewhere.

Thank you!

And I just bought 8 pounds of 4350......Don't know if Hodgson's will be better than Accurate. I prefer Varget or Superperformance. Luck!

 

[10X Rifles]

The 6.5 needmoor. Was designed to shoot 600 yds. it was made for HP shooters, for X course. 2-3-600 yds.
If you want speed, rechamber to a 260 AI, or better yet, Shoot a 6.5X284 with your 140's.
Or only shoot 130 gr pills. you can get almost 2900 with 130's
at 2650 fps, you might as well shoot a .308 with 175's.

 

[918v]

In developing loads and measuring with Labradar, I found the 6.5CM velocity was far more effected by the distance off the lands than other cartridges I have reloaded. I also found guys on-line finding the sweet spot at .100 off the lands. One consistant thing I found in my load workup was the farther of the lands, the greater the velocity. I attribute this to burn before thru the lands, thus less burn for the push down the barrel. I believe one of the differences in 6.5cm is the depth of the barrel grooves or in reverse, the greater the bullet swaging, thus more energy to engage and move forward. ALL my loads across all powders were less than published values in my gun, and only came close when I was beyond .060 off the lands, yet still under published data. To further this is the "published" data will be on a deeper set bullet to be conforming.

I didn’t see that in two different Bartleins with two different chambers. Maybe your rifling type is inducing this phenomenon uniquely in your gun.

 

[Yondering]

This is great info, thanks. It turns out my COAL was 2.76”.

I’ve adjusted it to 2.805” and loaded some with 41gr and some with 41.5gr.

Based on quickload’s warnings, and not being an experienced enough loader, I will not be going over 41.5. I’d rather crack open the H4350 I have. I just would rather be able to get a good training round with this Accurate 4350 first. Results in a few hours.

There’s a lesson here about using actual tested and published data, NOT Quickload, as well as using data for the correct powder. Don’t mix up data between the three different 4350 powders, they are not the same thing.

Accurate publishes data for their powder, and it’s free online. Western Powders 8.0
Their data for AA4350 and the old 140 Amax (which became the ELD-M) shows a max of 43.5gr at 2.740”.
Hodgdons free online data shows the same thing.

Use real data and back away from the Quickload; it’s the least reliable “data” you’ll find.