POI change when shooting a BP in hot weather?

[A.J.]

Hey Guys! I've had my new Winchester Apex 50 cal. in-line for awhile, but have been slow getting all the other stuff I need. All I'm waiting on now is my powder measure to come in. I'll be starting off trying 100 grains of loose BlackMag 2. (I don't even know where I got this stuff. I just found it in my garage...almost a full can). I heard this is supposed to be pretty good powder, but I heard it was discontinued. Anyway, I'll be stuffing a 250 grain Hornady SST in a sabot in front of it. My problem now is becoming the weather. It's got warm here in Oklahoma...will probably be around 80 when I finally make it out to the range. I'm gonna chrono the first shot. I'll probably sight this in for about 3" high at a hundred yards. I know with the warmer weather I'm going to be getting higher velocities. Does anybody here have any experience with how much the point of impact will shift from warm to cold weather? Just wandering if it's negligible at Muzzleloader ranges, or will I be re-sighting it in in October?

[sabotmaker]

I would expect very little change in point of impact. Maybe as much as an inch at 100 yards.

[Redhawk1]

Hey Guys! I've had my new Winchester Apex 50 cal. in-line for awhile, but have been slow getting all the other stuff I need. All I'm waiting on now is my powder measure to come in. I'll be starting off trying 100 grains of loose BlackMag 2. (I don't even know where I got this stuff. I just found it in my garage...almost a full can). I heard this is supposed to be pretty good powder, but I heard it was discontinued. Anyway, I'll be stuffing a 250 grain Hornady SST in a sabot in front of it. My problem now is becoming the weather. It's got warm here in Oklahoma...will probably be around 80 when I finally make it out to the range. I'm gonna chrono the first shot. I'll probably sight this in for about 3" high at a hundred yards. I know with the warmer weather I'm going to be getting higher velocities. Does anybody here have any experience with how much the point of impact will shift from warm to cold weather? Just wandering if it's negligible at Muzzleloader ranges, or will I be re-sighting it in in October?

Was the powder any good? If it was stored in the garage it is subject to moisture. All my powder stays in my house in a storage locker.  Also once you get sighted in and run out of powder, you will no longer be able to get BM2. You will need to get a new powder and you point of aim will be off.  JMHO.  

[A.J.]

Took it out and shot it finally. The powder was just fine, and very clean burning. Since it's nearly full, I'm going to go ahead and use it. Probably go to Shockey's gold when it runs out. Didn't have any chance to group it though. The scope was a piece of crap (adjustments didn't work) and had to send it back.

[oneshotonekill]

I have no experience with Black-Mag2 so I don't know what to expect in warm vs cold weather.  Some powders are more sensitive to temp than others.  I shoot Pyrodex (RS and P) and Goex FFg year round and see very little difference (1-1.5 inches @ 100yds) in point of impact with the loads I'm shooting (90-110 grains).  With a hotter load the difference may be greater.  Either way I'd shoot it again prior to hunting just to make sure all is well.

[A.J.]

Thanks guys...I appreciate the info...Looks like by the time I get another scope on this thing, it's gonna be summer.

[WylieKy]

I say, go ahead and shoot in warm weather.  When it starts to cool down, go to the range again.  Because it's cooler.  Go again when it is cold to see the difference.  Yeah, that sounds good.  Might want to go back in the rain to see how it shoots, snow too..... Sorry,  I'm always looking for good excuses to go shooting, and like to work them out ahead of time.  :grin: