400 FPS under manual? - Page 2

Jevyod · February 14, 2018, 07:56 AM

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....

Yosemite Steve · February 14, 2018, 08:04 AM

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.

hounddawg · February 14, 2018, 08:17 AM

Quote:

How do you check if the scales are accurate? I have the RCBS beam scale.

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

mehavey · February 14, 2018, 08:28 AM

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joed · February 14, 2018, 09:15 AM

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.

Metal god · February 14, 2018, 03:31 PM

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 .

Yosemite Steve · February 14, 2018, 03:36 PM

A U.S. nickle weighs 5.000 grams

Colorado Redneck · February 16, 2018, 10:15 PM

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.

Yosemite Steve · February 16, 2018, 10:26 PM

Quote:

Looks like Shooting Chronys are affected by cold temps.

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

Yosemite Steve · February 16, 2018, 10:29 PM

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.

hounddawg · February 16, 2018, 10:30 PM

Quote:

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.

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

Colorado Redneck · February 16, 2018, 10:59 PM

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.

Yosemite Steve · February 16, 2018, 11:36 PM

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.

February 14, 2018, 09:15 AM	#30
joed Senior Member Join Date: November 28, 2014 Posts: 442	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. __________________ The 6 gun was once as common as the cellphone is today, and just as annoying when it went off in the theater.

February 14, 2018, 03:31 PM	#31
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	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 . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; February 14, 2018 at 07:41 PM.

February 16, 2018, 10:15 PM	#33
Colorado Redneck Senior Member Join Date: January 6, 2008 Location: Northeast Colorado Posts: 1,993	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.

February 14, 2018, 07:56 AM	#26
Jevyod Senior Member Join Date: May 5, 2012 Location: Pennsylvania Posts: 172	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....

February 14, 2018, 08:04 AM	#27
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	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.

February 14, 2018, 08:28 AM	#29
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,894	-- delete --

February 14, 2018, 03:36 PM	#32
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	A U.S. nickle weighs 5.000 grams

February 16, 2018, 10:29 PM	#35
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	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.

February 16, 2018, 10:59 PM	#37
Colorado Redneck Senior Member Join Date: January 6, 2008 Location: Northeast Colorado Posts: 1,993	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.

February 16, 2018, 11:36 PM	#38
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	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.