temerature change and effects on rifle ammo

[LD375]

He looks a lot like a massive helping of brats! Yeah, he would taste very good.

Thanks Mike, I'm going to try my best for sure, if I connect, it's all smoked sausage and another nice mount, we'll see, gotta hunt first and spend time in the woods as you know, gotta wear my bug suit for sure, it's nasty in the spring, going to hook up with some Americans too, one young fella from Virginia USA, I wonder if our good friend Scotty knows him?..Heck maybe we'll trade beers and stuff :grin: ...I'm going to bring up some moose steak and sausage for the boys, I can't wait!

Lou :wink:

 

[Guy Miner]

Best of luck on your hunt!

 

[LD375]

Best of luck on your hunt!

Thanks fellas

I'm going back to the range again on Sunday to re confirm my zero with the 180gr nosler Partition bullet, any shots for this bear hunt could be anywhere from 40-100yds depending on if I need to move into a new stand, so I'm going to zero in for about 1" high @ 100yds, which would be about dead on @200yds, I'll post an update on Sunday along with a photo of my groups as well, thanks again,
Lou :wink:

 

[Vince]

Lou,
May your hold be true, your sight unfettered, and your bullet sullied with a bruin.

Vince


Sent from my iPhone using Tapatalk

 

[SJB358]

He looks a lot like a massive helping of brats! Yeah, he would taste very good.

You and I must shop in the same store. That's all I saw was a heap of chow! :lol:

 

[DrMike]

Now, to get out and tag a bear. The hides are already going to be rubbed (it has been a warm spring); but they will make some excellent sausage and brats, nevertheless.

 

[longrangehunter]

Wow Lou,

Good luck and you should take a front shoulder to cook up like a chuck roast, taste as good as any beef I've ever made. Soak and rinse the meat in cold water 3-5 times to remove the blood in the meat before cooking it always helps. Season the meat with Lawer's seasoned salt, pepper and some garlic powder and place it on a pile of sliced onions along with a 1/4" of water in the pan with the lid on and cook it for 4-5 hours. During the last hour add some carrots. I think you'll be surprised how good it will taste?

 

[DrMike]

Kevin gave you great advice. Fresh bear ribs on the grill is a genuine treat. And a roast smoked in your smoker is excellent!

 

[300 H&H]

Today I took the 375 Ruger to the range. I shot at 100yds with my 300gr. Nosler AccuBond load. I was originally sighted in 2" high at 100yds. when temperature was 45 to 50 degrees. Today was about 74 degrees. I shot 3-1/2" high at 100yds. Windage was dead on. I am using RL17 powder. Primers looked fine and not flattened out so the higher the temperature more pressure you get.

 

[LD375]

Today I took the 375 Ruger to the range. I shot at 100yds with my 300gr. Nosler AccuBond load. I was originally sighted in 2" high at 100yds. when temperature was 45 to 50 degrees. Today was about 74 degrees. I shot 3-1/2" high at 100yds. Windage was dead on. I am using RL17 powder. Primers looked fine and not flattened out so the higher the temperature more pressure you get.

Yes, more pressure = more velocity, my windage was dead on too, I was sighted in back in march when temperature was 40 degrees, then tried again last week when temperature was 80 degrees (that's double) I would bet I was getting atleast close to if not more than 100fps faster in the hotter weather and thinner air,
Lou

 

[Silent Sam]

How did it group at the higher temp?

 

[LD375]

How did it group at the higher temp?

Grouping was the exact same consistently grouping about .5" or less, just more velocity hitting about 1.5" higher shooting in 80 degrees vs 40 degrees when I did my original sight in,

Lou

 

[300 H&H]

How did it group at the higher temp?

Grouping was the exact same consistently grouping about .5" or less, just more velocity hitting about 1.5" higher shooting in 80 degrees vs 40 degrees when I did my original sight in,

Lou

Same thing. Group was same just 1.5" higher.

 

[LD375]

How did it group at the higher temp?

Grouping was the exact same consistently grouping about .5" or less, just more velocity hitting about 1.5" higher shooting in 80 degrees vs 40 degrees when I did my original sight in,

Lou

Same thing. Group was same just 1.5" higher.

I haven't been on a spring hunt in warmer weather for about 20 years, I always sight in my rifles a few weeks before the fall hunt, but I had no choice for this hunt, no big deal, the rifle is ready to go, just had to make a few adjustments with the elevation that's all, leaving first thing come Saturday morning :grin:

Lou

 

[300 H&H]

How did it group at the higher temp?

Grouping was the exact same consistently grouping about .5" or less, just more velocity hitting about 1.5" higher shooting in 80 degrees vs 40 degrees when I did my original sight in,

Lou

Same thing. Group was same just 1.5" higher.

I haven't been on a spring hunt in warmer weather for about 20 years, I always sight in my rifles a few weeks before the fall hunt, but I had no choice for this hunt, no big deal, the rifle is ready to go, just had to make a few adjustments with the elevation that's all, leaving first thing come Saturday morning :grin:

Lou

I always go at least a few days before the hunt and early in the morning when it is cooler temperatures to do a final sight in. Good luck on your hunt and looking forward to hearing about the hunt!

 

[LD375]

I well most certainly do just that, I'm looking forward to it, I'll put in my time and try my best, any bear is a bonus :wink:

 

[Silent Sam]

I'd be awful curious to know what the velocity difference is w/ no change in groups other than elevation.

 

[Guy Miner]

So, you guys who swear you have these BIG changes in zero at short ranges, due to a 30 or 40 degree change in temps...

Do you sight in again, or compensate during the hunting day when it's 30 at dawn and 75 at noon? :wink: And your looking at maybe a 250 - 350 yard shot, not a 50 - 100 yard shot?

Just wondering...

I've NEVER seen zero shifts like you guys are talking about, from mere temp changes... NEVER.

A couple of clicks at 600 yards? Maybe even one MOA out at 600 yards? Sure...

Here's an interesting little test I ran as the SWAT sniper team leader - years ago. It was ZERO degrees (F). We took the rifles, and the ammo, and sat them out on the firing line for an hour. Our rifles were bolt action Remington 700s, the ammo was factory loaded Federal 168 grain Gold Medal match ammo.

This was before Hodgdon introduced "temp insensitive" powder.

During that hour we put up targets at 100, 200 and 300 yards. Then we did some pistol training at modest ranges. Just to keep busy for an hour.

After the rifles & ammo had been exposed to ZERO degree cold for an hour... We fired our "cold bore" and subsequent shots. The "cold bore" we always did at 100 yards. Then we fired groups at 100, 200 and 300 yards.

Everything was MOA or better, and NONE of us had any shift from our 60-70 degree zeros...

So - I'm simply not buying a big shift in zero from a relatively modest change in temps. Sorry.

Regards, Guy

 

[300 H&H]

So, you guys who swear you have these BIG changes in zero at short ranges, due to a 30 or 40 degree change in temps...

Do you sight in again, or compensate during the hunting day when it's 30 at dawn and 75 at noon? :wink: And your looking at maybe a 250 - 350 yard shot, not a 50 - 100 yard shot?

Just wondering...

I've NEVER seen zero shifts like you guys are talking about, from mere temp changes... NEVER.

A couple of clicks at 600 yards? Maybe even one MOA out at 600 yards? Sure...

Here's an interesting little test I ran as the SWAT sniper team leader - years ago. It was ZERO degrees (F). We took the rifles, and the ammo, and sat them out on the firing line for an hour. Our rifles were bolt action Remington 700s, the ammo was factory loaded Federal 168 grain Gold Medal match ammo.

This was before Hodgdon introduced "temp insensitive" powder.

During that hour we put up targets at 100, 200 and 300 yards. Then we did some pistol training at modest ranges. Just to keep busy for an hour.

After the rifles & ammo had been exposed to ZERO degree cold for an hour... We fired our "cold bore" and subsequent shots. The "cold bore" we always did at 100 yards. Then we fired groups at 100, 200 and 300 yards.

Everything was MOA or better, and NONE of us had any shift from our 60-70 degree zeros...

So - I'm simply not buying a big shift in zero from a relatively modest change in temps. Sorry.

Regards, Guy

So Guy what do I you think is causing 1.5" higher then ? Coworker has same gun and scopes email set up as my 375 Ruger Guide Gun. He was shooting high too! Dead on with windage and grouping was the same. Both rifles are free floated and action bedded Both Leupold VX3 2.5-8x36mm. Rings are tight. If temperature doesn't make a difference then why do scope manufacturer needs velocity, allitude and temperature to make custom dial turrets?

 

[Ridgerunner665]

Guy isn't saying temperature doesn't make "any" difference...he is saying it doesn't make that much difference at the ranges you are shooting.

And he is correct, it doesn't...

As he said...a click or 3-4 at 600 yards, yes...but not anything measured in inches at 100 yards.

Earlier I mentioned parallax...that would cause the group size to remain the same while the group itself moved around depending on how the gun was shouldered.

Also, when scope manufacturers request the temperature for turrets....they are not asking because of powder characteristics, they are asking because temperature affects air density, which affects trajectory.