400 FPS under manual?

I bought a pound of IMR4451. Supposed to be wonderful. I worked up loads for 243 Win. With a couple different bullets, the velocities were low by around 300 fps. Tried H4350, and the Nosler data was considerably different than my loads. So, I used data from Hodgdon for H4350 and 90 gr. Bullets. My results correlated closely to the Hodgdon data. Hodgdon uses heavier powder charges than Nosler in this combination. It bumfuzzles me why Nosler loads are 2-3 gr. less than Hodgdon.

Nothing is set in stone for load data vs. actual results.
Powder varies from lot to lot. Individual guns are different. Chrony accuracy may be off. Etc etc.

My jug of IMR4451 may be from a wimpy lot.
 
"I have never used a chrono. I don't really care how fast they are going, what I do care about is hitting the target!"
Not everyone has those parameters. A hunting load that's "good enough" and 200 fps faster is a PLUS in the field.
 
I may be able to get some H414 to try as well.

How do you check if the scales are accurate? I have the RCBS beam scale....I recently weighed some bullets that were supposed to be 250 grains and my scale showed them at 249.9.
Also, how can you verify a chrono? I really do not think that is off since I used it the same day to chronograph a 308 with 130 grain ttsx. According to manual I should have been at 3130 fps and i was at 3015 with a 20 inch barrel, which seemed much more reasonable to me.
 
Is there any chance you may have been using your 7828? Quickload puts your data very close to the velocity you gave with that powder. If you were on the lands it puts the velocity right at 3510. I know it's hypothetical but I have made some dandy mistakes in reloading.

The fact that you had "wimpy" velocities with another powder may suggest other issues. 400 fps is pretty far off.

Also .1 grain is not worth fretting over as far as bullet weight. You could verify your chronograph with a magnetospeed.
 
I wondered about that as well, but i keep powder separate so I have to walk over and get it. I did think that maybe I set my scales wrong or forgot to change from the previous load. I was loading in the 42-46 grain range. It is possible that I forgot to change from the 46 grain and loaded that as 50.... I was trying to load for 3 rifles in one evening. There is a very real possibility of operator error of some sort....
 
46 grains of H4350 calculates to 3311 fps. Whenever I have loaded different batches in one shift I always put everything away and clean up between batches. Another good practice is to begin each session with a zero'd scale.
 
How do you check if the scales are accurate? I have the RCBS beam scale.
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well you just answered your own question

if you have a few minutes a needle and a smartphone you can modify that beam to where you can tell if it is off a single grain of powder

https://www.youtube.com/watch?v=slqE3kodO8Y&t=58s

the only way to check the chrono is if you have a place to shoot beyond 100 yards or so and a accurate rifle and that you can regulary shoot .5 MOA or better at 100 with. Then consult a ballistics calculator. For example set up a large target at 500 yards and come up 9 inches if your shots is are hitting consistently 9 inches low at 500 then it is chrono error. If it is hitting within 2 or 3 inches the numbers are good assuming the gun and the shooter are accurate. Mind you that depends on the shooters and the guns precision but if you or the gun are not capable of MOA precision at distance then a 400 FPS error is of little concern

I have a old inexpensive pro chrono and can move from 100 to 800 after chronoing the load and be within 2 or 3 inches of vertical using it's numbers. Generally I am within a inch unless I have a error in my dial up
 
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Not uncommon at all. I have 2 rifles that do the same thing, one is a .22-250 and the other is a .308, both are off by over 350 fps.

The .22-250 was an eye opener, should have been somewhere around 3800 fps and it showed just over 3400 fps.

One thing in common is both are shooting Varget and I believe the batch I have is running slower then normal.

But, other things effect speed too like the case volume and bearing surface of bullets.

In my case I upped the charge of Varget and got to where I should be. The load I use in both these rifles is listed in a Lyman manual too. This is one of the reasons I try to look at as much data as I can get my hands on when deciding on a load.
 
I just looked at Hodgdon website . They don’t list either of the 4350 powders for that weight bullet . Any time i see that I assume they don’t think that powder is good for that weight bullet . They pretty much suggest all powders that work great for 308 for this application which are all "EDIT" faster then 4350 .

As for checking your scale , get your self a set of check weights . I use the RCBS set .
 
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Cold temps and chrony accuracy

Earlier I posted about some IMR4451 being wimpy. Today the temperature was dropping by the time I got started shooting. Was probably around 35 degrees. The velocities were sub par by 2-300 fps. Since I was at the range, I decided to continue trying loads. Worked up to max load with IMR4451 and shot 8 rounds over 20 minutes or so. Temp was dropping, and the displayed velicities dropped too. Soooo, got on Google Foo, and found some interesting stuff. Looks like Shooting Chronys are affected by cold temps. Just my experience, and in the future, if there is a warmer day I will try the same loads again to see if in fact the cold was the issue.
 
Looks like Shooting Chronys are affected by cold temps.
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If you get a wiener dog parka and put some hand warmers in it with your chrony your velocities will perk right up. Just don't forget to cut peep holes for your sensors. :P
 
Just kidding. I get consistent velocities(+or-10fps) with the same ammo at 10F and at 50F. Use a fresh warm battery when you set up in the cold.
 
Looks like Shooting Chronys are affected by cold temps. Just my experience, and in the future, if there is a warmer day I will try the same loads again to see if in fact the cold was the issue.
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That is a very real possibility. My shop temp got fairly cold this winter and my electronic scales had multiple grains not tenths of a grain of creep. I eventually just left them on twenty four and and seven so I could get a stable reading when I wanted to load. Got to figure all these things use cheap Chinese made circuit boards
 
YosemiteSteve--do you have an F1 Shooting Chrony? The battery was replaced a couple weeks ago. I'm hoping the temps are the issue, and there is some evidence to support that. The first time this happened was a few weeks ago, and it was cold...maybe 30 degrees. Then a week later on a 40 degree day, the chrony showed credible velicities but it was a different powder. I blamed the previous results on the powder. Today I used two different powders, and both were showing up 10% low, even more by the time I finished shooting.
 
I have the Caldwell Precision model. It runs on a 9 volt battery.
I have tested it against a magnetospeed and mine reads 11 fps slow +or- 3 at 40F. I loaded up some rounds for my 10mm that have an average SD of 15 fps. At 50F outside I shot my rounds which were 70F as well as the gun at 1046 fps - SD was 17. That battery was about an hour old. At 10F outside I shot my rounds and gun at 70F (inside my truck temp) and got 1055 fps SD with a brand new warm battery from my truck. Today the same loads on an almost dead battery at 30F shot 1026 FPS - (SD was 24) with both the ammo and the gun at 30F.

I hope that helps. I think the cold ammo was the difference.
6.5 grains of Unique behind a 165 grain TMJ.

Also, as your ammo sat and cooled off it should have had an effect but I could not say how much. You could look up the temperature sensitivities for your powder.
 
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