Referencing the pissing match thread with the new title that used to be about shooting doubles with loads the rifle was not regulated with, in this case a Searcy which again have an IMPECABBLE reputation with regulation, I noticed some significant changes in point of aim and regulation today at the range with loads that hitherto had been super and I posted pics here. Here in hot-hell Florida, I had been doing all of my shooting with temps ranging from the low 70s to the mid 90s. At that temperature range my VC was printing exactly as advertised, that is perfectly regulated groups and pretty much center of bull at 50 yards.

I also loaded and commented that I had fantastic success with my own loads consisting of 96gr H-4831 and Hornady DGXs and Woodleighs, often times surpassing factory loads with even tighter groups and velocities right around 2150 fps (my barrel is 25").

Today the temp was 40 degrees (F) and all of a sudden my groups printed almost 5" higher and about 1.5" left of aimpoint and more importantly with SIGNIFICANTLY slower velocities in the 2030-2050 range with factory, and handloaded DGXs and Woodleighs. Also, the groups tended towards the vertical (not quite) but I had no crossovers.

I know chronos can sometimes be unrealiable, so I also fired some rounds out of my 405 loaded with N-133, which is an "extreme" powder, that is not that succeptible to temperature swings. Those were SPOT on at 2250-2260 fps.

In my experience if a round is SLOWER it will print higher. I even upped the load by .5gr and the speed bumped to 2060, but still printing high and to the left with and I've said, pretty good groups regardless.

Fortunately here in Florida the cold never stays and once it warms up again I'll repeat and get back to you guys.

Lesson? PATIENCE is a MUST with doubles....

Interesting, the things that affect doubles.

That is the reason that I use H-4831 powder in my 470 amd 465 doubles. Extreme powders take the worry about temperatures varying out of the equasion.

465H&H

Okay guys, define "extreme" powders.

465, I was using H-4831 which is what Hornady ues in their factory loads. If 4831 is not temp sensitive, then one can only conclude Hornady has a quality control issue OR my chrono is suspect, but being that I shot a load with another rifle/caliber and the loads shot to spec, the logical conclusion is again Hornady has QC issues.

jorge,

???????

465H&H

I had the same thing happen to me with my Searcy .470NE here in Virginia. All summer long, the rifle shot fabulously - 2 shots basically together at 25 yards. Then I took the 470 out one November morning, and the barrels were printing 6" apart at 25 yards. I called Butch and asked him what was wrong with my rifle. Butch laughed and told me all I was seeing was the effect of temperature on the burn rate of my IMR-4831 powder in my loads. He asked if I kept my ammo in the house or outside somewhere. When I told him I kept it in the detached garage and the temperature was below freezing the night before, he laughed again and told me to bring my ammo inside. Once the .470 ammo was in the house overnight, he asked me to go out to the range, shoot again, and call him. Sure enough, the barrels printed exactly together just like they had done during the summer. As we used to say in the Navy, no NEW lessons were learned! So, when you go to Africa in the June - August time frame, make sure you keep your ammo warm at night in case you get one of those early morning shots when it is still pretty crisp outside. You want to make sure you hit that nyati where you are aiming and not 6" off!
Mangwana

Jorge in your 3rd paragraph did you not say you shot both factory rounds and your reloads which you know is H4831... So it might not be the Hornady ammo... Perhaps you need to dig into HOW temp insensitive H4831 really is

Correct sir. All the loads with H-4831 were off by considerable margin. I'll shoot the exact same hand loads and factory ammo next week when the weather is warmer and report back

Makes me think you might have a rib coming loose?

quote:

Originally posted by surestrike:
Makes me think you might have a rib coming loose?

At first I went back to reread Jorge's posts to see if he fell or was hit in the chest or some other injury ... then I realized you meant the rib between the barrels ...

given that subsailor had the same experience and that Butch Searcy himself was not surprised, perhaps 4831 is more temperature sensitive than otherwise believed.

Nothing loose. Groups are tight, just slower and higher.

Glad your ribs are OK, Jorge

What primer are you using for your load?
Reason I ask, is that I have a 6.5 Swede Ruger #1 that shot fine this summer, but a few weeks ago, I re-shot it before hunting season. Temps in the 50's. Way off from Summer. Went to a magnum primer, problem solved.
Was using an Accurate Arms powder 4831 equivalent.

F215 Match

Jorge: Just carry your ammo stuffed in your undies until it is time to shoot and all will be well, assuming you grab the right items when it is time to load the gun!

On the upside Jorge, I have seen many doubles that would only shoot 5 inch groups!

Me too - and that is at 50 yards!!