500 S&W Federal Fusion Temperature Sensitive

G

GelatinousPig

Inactive
Range report on temperature: yesterday was sighting in my 500 Performance Center at 50 yards. It was about 2" high in 34 degree weather. Today, it was 15 degrees and had to move up to 25 yards to get it on the bottom of the paper. You get what you pay for I guess.
 
Last edited:
Possible, but not probable. I'll check tomorrow with some HSM Pro Hunter cartridges and post back results of that. Side note, the ammo stayed in the Jeep over night, the gun did not. It was cool when fired, but the ammo was cold.
 
A 20º temp change shouldn't do that.
34º to -15º maybe, but +15º shouldn't bother modern ammo.
Something else is going on. (sights?)
 
Range report on temperature: yesterday was sighting in my 500 Performance Center at 50 yards. It was about 2" high in 34 degree weather. Today, it was 15 degrees and had to move up to 25 yards to get it on the bottom of the paper. You get what you pay for I guess.
Click to expand...

Are you doing using Iron Sights, conventional Long/intermediate eye relief scope or a red dot sighting system?
 
"...to get it on the bottom..." Very much doubt that was caused by the ammo alone. More likely to be the operator that's temperature sensitive.
 
ATCDoktor: iron sights (gun has not suffered a fall or other potential sight misalignment handling).

T. O'Heir: never rule out the human factor. However, I have been known to ride the motorcycle at 6 degrees on the interstate - just saying.
 
iron sights (gun has not suffered a fall or other potential sight misalignment handling).
Click to expand...

Ok, let’s get a little more info so the group can try and evaluate (from afar) what’s going on:

What was the exact amount of drop from 34 degrees to 15 degrees at 50 yards?

Were you firing from the bench or two hand unsupported (standing)?

Was there any noticeable change in recoil/report from 34 degrees to 15 degrees?

In my mind (on the warm day) if you were shooting at the center of a standard 8.5X11 sheet of copy paper (and your Point of Aim was the center of of the sheet) and your Point of Impact was 2 inches high; and, on the (cold day) the POI was so low that you had to move to 25 yards just to hit 8 inches lower than the POI from the day before; your rounds on the cold day were impacting nearly 2 feet lower than the day prior (at 50 yards).

For your trajectory to change that much the bullets had to be barely rolling to the target.

In my mind (if your sights weren’t damaged or moved from one day to the next) there had to be a noticeable change in recoil/report when firing th gun.

If not (and you Sights were not damaged/have come loose in the frame/been changed by recoil) you have acquired a significant flinch.
 
I gotta agree with ATCDoktor. There's sumpthin' else goin' on. While some powders are sensitive to temperature, 20 degrees and still on the plus side of zero, is not that much of a change, even to the most sensitive of powders.
 
I doubt I would be hitting well with the temperature that low. Chances are I would probably be flinching if my hands were going to take a beating like that while they are cold.

I would not be outside if I did not have to be. I am in Texas, and we just wait it out a few days, and then go back to normal life. LOL
 
There's no free lunch.

Temperature does affect chemical reactions. Should there have been that much of a change with that "little" change in temp??

That's an opinion on our part, and may, or may not be an accurate one.

First off, its not just "20 degrees" its also from above to well below freezing.

20 degrees from 80F down to 60F is one thing, from 34 to 15 is still the same amount of change but could be a much different matter.

Also remember that same ammo has to shoot at 100F (or higher) without blowing up your gun.

The powder charge has to be safe at both ends of the temp spectrum, and this can lead to diminished performance in extreme cold.

Maybe your front sight shrank in the cold???:rolleyes:
 
Update: today's temp climbed back up to a sultry 33 degrees at the range. Same box of ammo started out 6 inches high (I had adjusted the rear sight yesterday to try and bring up the POI). Stance I am using is down on my right knee with my support arm's forearm resting on my left knee. I switched to my tripod shooting stick with small change, improved about 2 inches towards POA in all directions (got tighter). Ran out of Federal and switched to HSM. Still high, but only about 2 inches (100gr heavier bullets, so understandable). Switched to a box of Hornady 300gr FTX and got a bullseye after zeroing for that ammo. Had to re-zero because that ammo is over 600fps faster, and I know the zero for the other two would be way off. Conclusion: I believe several things are in play: 1) the Federal's are somewhat temperature sensitive below freezing; 2) the barrel is still settling down as today makes only 80 rounds through it; and 3) I am certain the cold had to effect me for at least 2 inches of the drop. Bottom line though, and something I learned from this, double check your zero if temps drop well below freezing.
 
2" high at 50 yards? Most guns are lucky to shoot 2" groups at fifty yards from a ransom rest. Since you are using freehand support on a knee, I wonder about the accuracy of your testing methods. A ransom rest would give more positive proof of change in drop for temp and ammo.
The ten ring is 3.3" for bullseye at the 50 yard slow fire line.
 
I've hunting deer from temps ranging from 60s to -15, I've always shot Corelokts, brother using Winchester Power points, and my Dad has been using Fusions in 30-06. Never really noticed much difference in POI in any of them. Not saying it doesn't happen but would rule out any other issues first.
 
You must log in or register to reply here.
Back
Top