[King4]

Handloads not getting anywhere near manual velocities

Hi guys, I hope this is right place for this.

Lately none of my hand loads have been anywhere near the published velocities for that particular load. For example, for my 30-06 I worked up a load from the Nosler 9th edition manual using their 150 grain E-tip. I used 57.5 grains of IMR 4350 with a case over ll length of 3.300", using CCI Br2 primers, case trimmed to lengh 2.484". I'm shooting it out of a Thompson Center Icon Classic, 24" barrel with the 5r rifling. I put each shell through a Lee factory crimp as well and my tolerances are within 0.0005 of the c.o.a.l. using a digital caliper. It should be around 2880/2900 fps but as you can kind of see in the picture, I barely got 2775. I was using a F1 Master Chronograph 10' away from the barrel. It was 57 out, sunny, no wind and with 72% humidity at an altitude of 2,200 feet above sea level. What am I doing wrong? Should Io seat them lower? I mean the grouping at 100m is stellar but at this velocity its basically a long .308 win. Thanks for your input.

http://i941.photobucket.com/albums/ad252/smeagdelphi/2014-05-18122313.jpg

http://i941.photobucket.com/albums/ad252/smeagdelphi/2014-05-18074029.jpg

 

[rifter]

Hi guys, I hope this is right place for this.

Lately none of my hand loads have been anywhere near the published velocities for that particular load. For example, for my 30-06 I worked up a load from the Nosler 9th edition manual using their 150 grain E-tip. I used 57.5 grains of IMR 4350 with a case over ll length of 3.300", using CCI Br2 primers, case trimmed to lengh 2.484". I'm shooting it out of a Thompson Center Icon Classic, 24" barrel with the 5r rifling. I put each shell through a Lee factory crimp as well and my tolerances are within 0.0005 of the c.o.a.l. using a digital caliper. It should be around 2880/2900 fps but as you can kind of see in the picture, I barely got 2775. I was using a F1 Master Chronograph 10' away from the barrel. It was 57 out, sunny, no wind and with 72% humidity at an altitude of 2,200 feet above sea level. What am I doing wrong? Should Io seat them lower? I mean the grouping at 100m is stellar but at this velocity its basically a long .308 win. Thanks for your input.

http://i941.photobucket.com/albums/ad252/smeagdelphi/2014-05-18122313.jpg

http://i941.photobucket.com/albums/ad252/smeagdelphi/2014-05-18074029.jpg

Could be several things at work here. First, I would set up the Chrony at 15 ft., just to make sure muzzle blast isn't causing false readings. I've got the same one and it works very well at 15.

Next, what rifle did they test their loads in? There could easily be 100 fps difference even between two identical rifles with the same barrel and twist. The Hornady #9 manual shows about the same fps as Nosler for their various 150 gr. bullets from a 24" Model 70 1:10 twist. If you're not getting any pressure signs at 57.5, try working up to 59 to see if the velocity improves. You may just have a 'slow' barrel. If you can get your hands on some CCI-250 primers, give them a try. The BR2 is a bit on the mild side. The hotter mag primer may boost your initial pressure for a better burn. If you do that, be sure to drop back a couple grains and work back up.

You're not doing anything wrong. 3.33" is what I load my '06 at for the M1, and same for my .280 Rem Ruger 77 bolt. Frankly, though, accuracy is far more important than velocity, and if the group you showed is typical of that load, I'd leave it alone.

 

[WASR-10/63]

Maybe your bore is a bit different than the test barrel.

I share a few of the same loads in two of my 30-06s, one rifle is always 100fps or more faster. The bores are the same length and slug very close, the lands are thinner on the faster bore.

My Hornady 7th Edition says for a 30-06 with a 26 inch barrel to expect about 2850fps with that charge weight. Your velocity sounds about right.

 

[kdub]

1) No two chronys are going to record exactly the same.

2) Velocity loss from muzzle to 10' or 15' needs to be compensated for.

3) As stated above, you may have a "slow" barrel compared to the Nosler testing rig.

4) Your powder and primer lots will surely differ from those used at the time by Nosler.

5) If grouping is more than satisfactory, why mess with a good thing?

 

[Model 52]

1. More generous chamber, throat and barrel dimensions can reduce pressure and velocity.

Tools wear and a chamber and or barrel made with new tooling will have large dimensions the same items made with older tooling.

2. Most loads are developed at standard temps of 70 degrees. You're probably losing around 10 fps at 57 degrees with IMR 4350, so it's noticeable but not significant.

3. I agree that setting the chronograph farther away is a better practice as it avoids the potential for the muzzle blast to trip the first sensor, but in most cases that won't be an issue at 10' unless you're using black powder. I set mine up so that the cord runs from the bench to the chronograph in a long arc that just touches the ground. I can't tell you what that distance is exactly, but it's consistent each and every time i set it up.

4. You will want to correct the measured velocity to a muzzle velocity but it's not large. For the load in question the velocity loss from the muzzle to a chronograph at 15' will be about 10 fps.

5. Powder lots vary and 50-100 fps difference in a given charge weight in a 30-06 sized case with 50-60 grain charge weights would not be unexpected. Way too many people regard the stated charge in a loading manual as being meaningful when it's really not.

It's made worse when they read a website that gives the nominal charge for military specification ammo, for example .30-06 M2 Ball with a 150 gr FMJ and 46.5 gr of IMR 4895 and a velocity of 2,740 fps, and then fail to understand a) what "nominal" means, and b) that the critical number here is the velocity of the load, not the powder charge. The actual charge weight for any given lot of IMR 4895 (or any other powder will be what it needs to be, and you'll load for velocity while watching for any signs of excess pressure. In some military calibers, especially 5.56mm NATO where the mil spec load was warm to start with and the chamber and throats were very generously cut, you may or may not be able to achieve a specified maximum velocity in your particular rifle. But that's also not real important as accuracy matters a lot more than velocity.

6. It's also largely irrelevant. For example, you're only getting 2775 fps with your 159 gr E-tip rather than 2880 fps, with a 300 yard zero it will make the following difference at 400 and 500 yards:

2775 fps:
Max mid range trajectory = +5.5" at 175 yards
400 yards = -12 low, 2064 fps, 1418 ft pounds
500 yards = -32" low, 1902 fps,1205 ft pounds

2880 fps
Max mid range trajectory = +5" at 175 yards
400 yards = -11" low, 2152 fps, 1543 ft pounds
500 yards = -30" low, 1987 fps, 1315 ft pounds

Basically, that loss of 105 fps means only 1" more drop at 400 yards and 2" more drop at 500 yards. That's equal to a 5 yard error in range estimation at those same distances, so it's not even on the top 10 list of things you need to worry about when shooting at those ranges.

Accuracy is far more important than velocity or energy in a .308-.30-06 class round and I would not fret over my .30-06 producing .308 velocities if you're getting MOA accuracy out of it with a hunting load.

And by the way I shoot a .308 anyway as they tend to be more accurate than a .30-06, as well as slightly more efficient.

 

[King4]

Thanks for the input guys. According to Nosler, they use a 24" lilja barrel. The group shown is typical of that load, I shot 4, 3 shot groups (12 total) and they all averaged less than 0.4". I didn't know that barrels could be slow compared to others but a good point was brought up about one barrel's lands being thinner than another and I guess it makes sense, the less surface contact the less friction and faster the velocity. I have the CCI 250's I use for my brothers 300 wsm, but I thought your not supposed to use magnum primers in non magnum calibers?

Here's another pic of what this rifle is capable of producing.

http://i941.photobucket.com/albums/ad252/smeagdelphi/20130609_163852-2.jpg

 

[old roper]

Thanks for the input guys. According to Nosler, they use a 24" lilja barrel. The group shown is typical of that load, I shot 4, 3 shot groups (12 total) and they all averaged less than 0.4". I didn't know that barrels could be slow compared to others but a good point was brought up about one barrel's lands being thinner than another and I guess it makes sense, the less surface contact the less friction and faster the velocity. I have the CCI 250's I use for my brothers 300 wsm, but I thought your not supposed to use magnum primers in non magnum calibers?

Here's another pic of what this rifle is capable of producing.

http://i941.photobucket.com/albums/ad252/smeagdelphi/20130609_163852-2.jpg

Hodgdon 2014 manual has loading data just for the 30-06 with 150gr E-Tip. They don't list who's barrel there using but it's 24" long,1/10 twist,Win Cases,WLR primers.

This is from that manual

54gr/IMR-4350 @ 2744 max 57.5gr/IMR-4350 @ 2930fps.

Nosler data

55gr/IMR-4350 @ 2760 max 59gr/IMR-4350 @ 3000fps.

Hard to say on factory barrels.

 

[Darkker]

I have the CCI 250's I use for my brothers 300 wsm, but I thought your not supposed to use magnum primers in non magnum calibers?

Generally doesn't matter on many cases. According to my chrono, in my 308, there isn't a statistically valid difference. So I interchange WLR/WLRM/CCI/CCI Mag without pause. That doesn't mean ANY primer in any case. But it means those primers with my 2 loads tested, it doesn't matter.

 

[dmsbandit]

Maybe your bore is a bit different than the test barrel.

I share a few of the same loads in two of my 30-06s, one rifle is always 100fps or more faster. The bores are the same length and slug very close, the lands are thinner on the faster bore.

My Hornady 7th Edition says for a 30-06 with a 26 inch barrel to expect about 2850fps with that charge weight. Your velocity sounds about right.

there must be alot of slow barrels out there.

My Marlin XL-7 in 30-06 sends a 165gr SST out the barrel at 2850fps with 56grs of IMR4350 and a CCI200 primer. That is measured at 15' and using a 22" barrel.

A 150gr bullet out of a 30-06 should be closer to 3000fps, not 2800fps. Heck, my 18" remington 750 in 308 win shoots 150gr bullets at 2700fps with little trouble. 41grs of 3031 I do believe.

 

[mikld]

Lot of good answers so far. I believe reloading manuals give the results that a particular technician found when he used the listed powder (prolly a different lot than yours) with the listed bullet (different lots may have slightly different ballistics) in a specific case (also different lots may have a slightly different alloy, capacity, etc.), with a specific primer (also different lots may not be exactly the same as those used by the technician) in a particular test fixture (some use universal receivers with barrels of unknown wear) on a particular day. Pretty difficult to duplicate exactly...

 

[recoil junky]

Who cares what the velocity is with groups under an inch at 100 yards, especially with Etips!!!

RJ

 

[WASR-10/63]

there must be alot of slow barrels out there.

My Marlin XL-7 in 30-06 sends a 165gr SST out the barrel at 2850fps with 56grs of IMR4350 and a CCI200 primer. That is measured at 15' and using a 22" barrel.

A 150gr bullet out of a 30-06 should be closer to 3000fps, not 2800fps. Heck, my 18" remington 750 in 308 win shoots 150gr bullets at 2700fps with little trouble. 41grs of 3031 I do believe.

Maybe there are lot of fast barrels out there?
One of my 30-06 barrels is a lot faster than what the book says, with the same length 95 year old barrel; and another barrel, (mentioned above,) shoots almost 100fps faster than I would have expected.
I'm not surprised at all with your velocities.

But like others have said, I don't really care what the velocity is, beyond knowing the extreme spread to gauge precision, and the average velocity for my range card.

 

[MikeG]

You don't have a clue if your chronograph is accurate. Without calibrating it, any reading is just that, a reading. Some numbers on a display. After you use it over a period of years, with a number of different guns, you might get a better feel for how accurate it is. But most of us will never know, because we can't calibrate them. That includes me.

If it is an accurate load.... who cares. I do agree with the suggestions to move it farther out. Muzzle blast will set them off, sometimes.

 

[Crusty Ol'Coot]

King4,

As MikeG says, it could be a chronograph thing ----

However it has been my experience that there are basically three groups of rifles as far as velocity goes.

The largest group by far are those who do not match published velocities many times falling short by 1 - 200fps or more.

The a smaller group are those that about match published data.

Then the smallest group are those that exceed published data all while showing no excessive pressure signs of any kind.

A few Speer manuals back, they had data for a 300Win Mag load that would make a velocity hounds blood run hot, but in real life in a rifle I had with a 26" barrel fell hundreds of fps slower.

I suspect that a number factors entered in here. Of course the barrel and chamber Speer was using, but maybe more importantly was the lot number of the powder they had.

I have seen velocity drop by nearly a 100fps with just a change in powder lot numbers.

So, as has already been said, if your rifle is grouping well you really have no issue to worry about. The critter will never know it was killed with a bullet moving slower then the published data.

Now, I think that the Chronographs are mostly close enough, and if over the same chronograph I am seeing consistent results with a given firearm on a given day and following shooting sessions, and also seeing velocities with different firearms that are running in the normal ranges of Slow, about on and fast velocities, and all on the same chronograph, I really feel it is more a firearm to firearm difference.

Look at it this way, knowing what you now know, think of the fun you will have when taking a friend out with his wiz bang super duper whatever and it shows velocities a couple hundred fps off the published data he was grooving on. Fun, been there and it is great fun watching the expressions.

Then you can explain the facts of life/reality to him, and if his rifle happens to be one of the fast ones, you can both marvel at the great results he got. Just don't bet any money on that happening.

Crusty Deary Ol'Coot

 

[broom_jm]

Back when chronographs cost as much a good used car, guys didn't have a clue if their ammo was getting the velocity claimed on the box or in their reloading manual. They grabbed some rounds, sighted in their rifle, shot at longer distances if they had the chance, and went hunting.

The difference in resultant trajectories between rounds going 2900fps and 3100fps is measured in tenths of an inch, at hunting distances of 300 yards or less. The difference in energy (which doesn't matter much anyway) is also nominal. So, don't get wrapped around the axle if your speed machine says your bullets are a little slower than "book"...load, shoot, hunt!

 

[Sus Scrofa]

Plus 1 with jm. If it shoots that well the animal ain't going to notice the difference.

 

[Model 52]

You don't have a clue if your chronograph is accurate. Without calibrating it, any reading is just that, a reading. Some numbers on a display. After you use it over a period of years, with a number of different guns, you might get a better feel for how accurate it is. But most of us will never know, because we can't calibrate them. That includes me.

If it is an accurate load.... who cares. I do agree with the suggestions to move it farther out. Muzzle blast will set them off, sometimes.

I can't calibrate my chronographs, but I can validate the results to a great extent, and it's the validity that matters.

For example, if I shoot over a chronograph and get a particular average velocity, then I should be able to predict the anticipated trajectory given the number of very good ballistics programs that are out there.

So if I get an average velocity with a low SD (and it's the ability to measure consistency that is one of the major advantages of a chronograph) then I should be able to expect a specific amount of drop at long range. Consequently on a calm day with more or less standard conditions, I can zero the rifle as a known distance, then increase the range to another know distance with the required sight correction and either get a series of hits near the point of aim, and validate the chronograph results, or find they are shooting consistently high or low, and invalidate the chronograph results.

----

This is of course also another back door argument for accuracy and consistency over velocity, as getting the rounds on target consistently is what matters, whether you are hunting or target shooting, and accuracy will help you do that, while an extra 100-150 fps makes very little difference, and is counterproductive if it comes at the expense of accuracy.

 

[rifter]

Here's some real world data that is so fresh, you can still smell the powder smoke. Its a good illustration of how expectations and manual data don't always line up with real numbers.

I spent most of the winter gathering information on loads for the .280 Remington. I used data from the 70's (Speer), Ken Waters Pet Loads book, loads from recent magazine tests, and the new Hornady #9. Knowing that factory ammo is downloaded for autoloaders like the Rem 742, I ended up doing a fair amount of guesstimating. Anyway, I came up with a set of ladder loads for 139, 150, and 162 gr. bullets. Yesterday was finally range day.

Since I was also using a new scope that hadn't been sighted in under fire, I used some old leftover 160 gr. loads from silhouette shooting days. Only took three rounds to adjust things sufficiently for testing.

The surprise was in just how far off my velocity estimates were. The old loads turned in speeds of 2950, which is at least 100 fps over what I was getting in my original .280 Ruger. The 139 gr. loads hit an average of 3112 fps, at least 200 over what I expected for the first rung of that ladder. The 150 gr. was only 75 fps over. The 162 gr. was about right at 2800 fps, but again only on the first rung.

So, what I found out was that I have a tight fast bore, with a slower twist than I expected. It really likes the 139 and 150 gr., but the 162 was just barely being stabilized. The barrel is a custom Douglas XX Air Gauge, but it could be had in several different twists. The usual twist in most .280 factory rifles is 1:9, but this one appears to be 1:12 which is a common twist for custom barrels and which won't handle the long heavy boattail spitzers. In contrast, the old 160 Speer sptizer flat base stabilized just fine leaving nice clean, round holes. They're shorter.

The end result is that I will have to reduce the charge at least a full grain on the 139 and 150 (they were pretty flat and had the beginnings of craters), have to use flat based 160 gr., and break down 20 rounds of ladder loads that are too hot to risk firing. That's OK though, as both of the lighter bullets gave decent groups even though this trip was mainly to find the top end in terms of pressure. It just turned out to be earlier than I expected.

 

[dmsbandit]

Maybe there are lot of fast barrels out there?
One of my 30-06 barrels is a lot faster than what the book says, with the same length 95 year old barrel; and another barrel, (mentioned above,) shoots almost 100fps faster than I would have expected.
I'm not surprised at all with your velocities.

But like others have said, I don't really care what the velocity is, beyond knowing the extreme spread to gauge precision, and the average velocity for my range card.

that same marlin 30-06 will shoot between .5"-.75" all day every day with just about any 165gr bullet tried. I have over 2500rounds thru the barrel and no signs of accuracy fading yet. And my loads are 1-2grs under max with the IMR4350 powder, so No hot rodding here.

 

[broom_jm]

Here's some real world data that is so fresh, you can still smell the powder smoke. Its a good illustration of how expectations and manual data don't always line up with real numbers.

I spent most of the winter gathering information on loads for the .280 Remington. I used data from the 70's (Speer), Ken Waters Pet Loads book, loads from recent magazine tests, and the new Hornady #9. Knowing that factory ammo is downloaded for autoloaders like the Rem 742, I ended up doing a fair amount of guesstimating. Anyway, I came up with a set of ladder loads for 139, 150, and 162 gr. bullets. Yesterday was finally range day.

Since I was also using a new scope that hadn't been sighted in under fire, I used some old leftover 160 gr. loads from silhouette shooting days. Only took three rounds to adjust things sufficiently for testing.

The surprise was in just how far off my velocity estimates were. The old loads turned in speeds of 2950, which is at least 100 fps over what I was getting in my original .280 Ruger. The 139 gr. loads hit an average of 3112 fps, at least 200 over what I expected for the first rung of that ladder. The 150 gr. was only 75 fps over. The 162 gr. was about right at 2800 fps, but again only on the first rung.

So, what I found out was that I have a tight fast bore, with a slower twist than I expected. It really likes the 139 and 150 gr., but the 162 was just barely being stabilized. The barrel is a custom Douglas XX Air Gauge, but it could be had in several different twists. The usual twist in most .280 factory rifles is 1:9, but this one appears to be 1:12 which is a common twist for custom barrels and which won't handle the long heavy boattail spitzers. In contrast, the old 160 Speer sptizer flat base stabilized just fine leaving nice clean, round holes. They're shorter.

The end result is that I will have to reduce the charge at least a full grain on the 139 and 150 (they were pretty flat and had the beginnings of craters), have to use flat based 160 gr., and break down 20 rounds of ladder loads that are too hot to risk firing. That's OK though, as both of the lighter bullets gave decent groups even though this trip was mainly to find the top end in terms of pressure. It just turned out to be earlier than I expected.

I am going to play the devil's advocate, so take these comments with a grain of salt:

What if the increased velocity you're seeing is because of the slower twist, which does not impede the bullets as much in their travel down the bore? Did you see any indications of excessive pressure? Maybe what you're seeing is perfectly normal velocity from a 1:12 twist barrel? Maybe your bore isn't tight or fast at all?

The interdependent relationships that exist between case capacity, bullet weight, powder burn rate, chamber size, bore diameter and rate-of-twist, among others, makes it nigh impossible to predict just how fast a given load combination will be from a specific cartridge. All we can really say is if you're shooting great groups, test 'em at longer distances and then go shoot some stuff!