Re-loads WTF???

Charlie38

Charlie38

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Location
Northwest (Prince Rupert), BC
257 Wby, 115 gr, Barnes TSX, 68 gr IMR 7828, Wby case, Fed 215 LRM primer.

Manual says 3400 fps max load. I have loaded this one before in my Vanguard 24" barrel. Over chony 3300 fps.
Everything is the same but changed to new WBY brass ( fire formed Remington 7mm Mag brass before) , new speed 3480 fps!!!
Does not seem to be any high pressure signs on brass and bolt opens like butter.

Manual says 2747 fps with 165 and 58 gr IMR 4350
My 30/06 Tikka got 3008 fps with a 165 gr Speer Grand Slam with this load but with the Hornady 165 Spire point it only gets 2880 fps.

I am using the same powders and primers from all the loads so its not a new lot of powder or primers.

I moved from the Okanagan to the Kootenays. It is arid and dry in the Okanagan and way more humid here. Also I have gained altitude.Here's the question, Will this affect velocity in my loads? And all my rifles were printing higher than the sight ins at lower altitude. Just wondering....


In theory, elevation affects both - gravity and air density... How much is humidity/elevation difference are we talking?
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Elevation : West Kelowna = 1129 ft. Rainfall = monthly , 22 mm annual , 234.6 mm

Creston = 2005 ft. RF: monthly 44 mm, annual 528 mm

Humidity was at 87% (15 deg C ) when I was at the range the other day. It was as dry as a popcorn fart (37 deg C ish, 3 wks straight) in the Okanagan when I took my readings.
 
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In theory, elevation affects both - gravity and air density... How much is humidity/elevation difference are we talking?
 
The velocities listed in manuels are the ones obtained from their test rifles. What your rifles does and how it reacts to the same load can be entirely different. Different barrels react differently to different components as well. Pretty basic knowledge.
 
As I said, if you go way up elevation wise = less gravity + less air resistance/density; but at the same time - less dense air means less pressure (velocity) cartridge can provide. Combination of them can cause what you see.
 
I'm not sure about chronographs and accuracy. I should have shot some .22cal before I did this load test. I wasn't at book max and had no pressure signs but the fps was high for a 17 Rem Fireball. Approx 1550' elevation.

IMG_2437Medium.jpg
 
Velocity will be off or way off if you are close to chrono when shooting. Make sure batteries are good too, you may get very odd (thou consistent) readings if battery is low.
 
I too, suspect the chrony. I checked my notes and 30-06, 165 Hornady, 60 grains 4350 didn't even get 2900.
 
The reloading manual is just a basic guideline comprised of date generated under ideal lab conditions to develop safe load ranges for a giver cartridge. No two rifles are alike and neither is the reloading date for that given cartridge the same between the various manuals.

Several manuals actually use a specific firearm to develop there loads while others use a universal receiver and other get there date from the powder mfg.

Then there is the reloading component variables,powder is mfg. in lots on average it can vary by as much as 2% in there burn rates from one lot to the next theres also the bullets,primers and cases these variables all have an affect on your reloads.

As others have mentioned you also have to take into account environmental affects,Temperature, Humidity, Elevation / Barometric Pressure, Wind. For your purposes in load development Wind isn't much of a factory. All the above affects many thing mainly Bullet trajectory and velocity,it affect your barrel and it affect the load your shooting,it's a good idea to evaluate you load especially if it's loaded near Max if you develop it in one climate and shoot it in another ambient temperature will in some instances with some powder affect load pressure,a load that shows no pressure in winter might show pressure signs in summer.


All these things affect MV in your particular gun,you may or may not be able to duplicate the reloading manuals results in your situation or with same load it may even shoot faster depending on all the above variables and how they affect your load at any given time.
 
yesterday at the range with two rifles both 30-06, both with the same run of hand loads, the 98 mauser was consistantly 100 ft slower than the p17 enfield, which had an inch more barrel, and the enfield had much less pressure if you believe the extent to which the primer was flattened. some times it just does not make sense....
 
Make sure chrony is FULLY open. IF you are truly getting those velocities then your loads are over max pressure no matter what the manual says.
 
Chrony

Sometimes the best you can do with your Chrony is put the cross-hairs right in the middle of the LED screen and with a gentle squeeze you can solve the problems these abortions cause. I was never able to get more than five shots without error. I send two units back numerous times for repairs, still had problems. Found an Oehler 35P, it works great. No missed shots, no errors.
 
I have a 35P as well, but when I'm in a hurry I still use a Chroney. But the Oehler is the only chronograph that seems to work reliably in the cold. We worked up loads for the .375 Ruger in an Alaskan model rifle on a bright sunny day with low humidity due to the -32 C temperature. Both the rifle and ammo was allowed to reach ambient air temperature before shooting. We found our sea level velocities considerably lower with the same powder (H-4350) than Gatehouse had observed with his loads in what I assume was higher elevation, higher humidity, and warmer temperatures, so I think where and when you chroney your loads does make a measurable difference.
 
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