cold weather load development question

D

djtjr

New member
ok guys i know that cold weather can have a fairly substantial effect on persure etc but this weekend i needed to get out to pull the trigger a bit and wanted to build up a load for a 30 Hart that i have. My question is really this if the gun stayed relatively warm from shooting and i left the ammo in the car with the heat on (for each set i went to the car took out ammo and put it in a warm pocket away from the elements), will the fact that it was 9 deg outside really hurt the process and potentially mask dangerous presure levels? My best group was prob in the low .3s if not .2s @100 towards the high end of my buildup 78gr of RL 22. There were no presure marks or signs but it was 9 out.

What are your thoughts?

1) Is it a waste of time to do development in the extreme cold if i will not be likely be shooting or hunting in it?

2) Will my results not likely be the same as under less extreme circumstances?

2) Does the fact that the gun and ammo stayed warm BUT NOT HOT (from shooting and from being in the warm car respectively) mitigate the effect the cold would have vs being out in the cold and shot cold bore and cold ammo?

Thanks
Don
 
Something to consider:

I shot my VFS rifle this morning in a 50'sF and wind blowing down my back most of the time. Before going to the range I pre-loaded 50 rounds using a powder and bullets I had not previously used in that rifle.

I began with two foulers and then shot a three shot Mickey Mouse with tall ears. I have one of Jim Borden's tuners on that rifle so I turned the tuner out by three graduations. Mickey pulled his ears down but they were still visable. I moved the tuner one more graduation and got a diagonal group high right to low left. I turned the tuner one more graduation and got a round hole mebby .010 bigger than a bullet. Tried a second and got a round hole mebby .020 bigger than a bullet.

This was witnessed by two experienced BR shooters.

Conclusion: if'n ya got a tuner on your rifle and you load up some reasonable rounds there is a very good chance one can tune the load in for the conditions.
 
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That sounds like proof enough for anyone that tuners work, Pete. Did you happen to go back to the original setting to see if the mouse ears came back? I've got a few different collars I've made up and tinkered with; this may be the season to put one on a good barrel and tote it to a match.....

-Dave-
 
I have not done that Dave

Dave Short said:
That sounds like proof enough for anyone that tuners work, Pete. Did you happen to go back to the original setting to see if the mouse ears came back? I've got a few different collars I've made up and tinkered with; this may be the season to put one on a good barrel and tote it to a match.....

-Dave-
Click to expand...

It would be a good exercise though. Back when I use to shoot RF I tried that using a tuner that had detent clicks and it would repeat. One of the issues with using scribed marks vs a click detent is one would need to measure from some place like from that collar where the threads end to the tuner or something like that.

I think there are folks who have worked out the DA/movement thing to a certainty, in fact, I know of some folks who have done it and recorded their finding; probably won't publish them for a while though :).

I don't think the exact positioning is much of a necessity but it would save a few bullets I suppose. If one tests then re-tests after movent and finds success, nothing is left to chance.
 
I wouldn't call it a waste of time..............

Just keep careful notes. If you're using a magnum primer, when the hot summer comes around, switch to a regular primer and come down two grains, then work back up. This way you have the info. for the two extremes, I never feel that time like that is a waste. As a matter of fact, I'd go back, after leaving the rifle and ammo out in the cold overnight and re-shoot it to see if there were any differences.
Then you'd have three different conditions logged for that rifle and load.
The rifle doesn't have a stainless barrel, does it? That might be a limiting factor, of course......
 
Please explain the stainless barrel being a limiting factor......
 
I don't think the air temp has any measurable effect. I shoot from a heated indoor range house all winter.

al
 
TimG

There is a concern among many barrel manufacturers about using 416R with very thin barrel profiles in large magnum calibers. The reason being that 416 exibits a marked reduction in ductility at low temperatures. The culprit lies in the free machining quality of 416.

Krieger states that if you wish to build something like a 300RUM with a stainless barrel in one of the lighter profiles, they will use 410 as a substitute.........jackie
 
A construction workers perspective :D

I pour concrete for a living..... work with rebar. My guys and I were arguing recently about steel. One of them said that rebar carries funny in hot weather and it deforms easily when dropped off the truck.... and we all kinda' agreed that in cold weather (out here that's 25-35degrees) it tends to snap when we fabricate it....

And I'm really ARGUING with the concept! I'm saying "steel melts at 2500 frickin' degrees, HOW can we really see/feel differences in the tiny temp span from 20 to 90 degrees???

but we can.

I growed up a while in Minndesoda where it gets quite cold. And steel axes and saws and axles WILL shatter at 30-50 below..... and you can wear the tracks out on a dozer working one week plowing snow...... You drop steel on ice in cold weather and it's likely to break.....

So I think the problems associated with fluted SS barrels in cold weather are real. I mean there's youtube videos of the things blowing up! That makes it fact don't it?? Dennis Sorenson our neighborly Native of the Great White North collects pix..... ;)

al
 
Trying to be a little funny - but not really

Anything I would be shooting at with the temperature at 9 degrees would not require load development. It would be something large, close and perhaps dangerous.
 
Jackie, I believe it was..............

August, or a bit before, that Krieger stated they no longer offer 410 as an alternative, as it wasn't cost effective with their tooling; too many problems. I don't know of anyone offering any other alternatives. :(
 
Just my $.02 worth... Any load that I've developed for any rifle, was not nearly the same come target shooting time!
As hot as many benchrest shooters load their ammo...don't take for granted anything that you work up a the low temps that I'm experiencing, 10 F tp 35 F!
Mark
 
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