chronos and sun

[OU812]

Well I just returned from the range with my 8mm and was quite surprised at the lower than expected velocities. The 4 shot ave was 2850 for a 200 tsx, fed 215, 81.5 7828, chrono setting level at 12 feet. My range faces East so my chrono was setting East-West with the sun at a 45 degree angle (give or take a degree or 2) to the back of the chrono, I had my sky screens on. I got no errors and no real odd ball velocities other than being less than I figured. Could the angle of the sun have caused or shown a slower than expected velocity?

Thoughts?

Bill

 

[SJB358]

I know my chrono has been ultra sensitive to sun blazing directly on it, but mine gave some big errors and wouldn't read at all.

How close are you to a max load and what kinda speed is the book saying you should be getting Bill. Might be enough excuse to push a little more, although I'm betting an elk would never notice. It is a very good shooting load so you always have something to fall back to. The good thing is TSXs usually respond well with more speed. Scotty

 

[OU812]

Scotty,

Fotis ran a quick load for me and I am about 1 grain below "near max". QL says 3070 at 82.6 grains near max. Nice thing is cases are not stretching, primer pockets still tight but this is only 3 firings. I was figuring on 3000 fps but every gun is different. As accurate as this load is I can't see my self doing much else than going with 2850. Like you said no elk will ever know the difference and I'm Ok with it if they are.

Bill

 

[NoelW]

Noslers load data for their 200 gr. spitzer shows.

IMR7828
Max. 83.5 gr. 2930 - 98% case fill
81.5 gr. 2850 - 95%
79.5 gr. 2770 - 93% being the accuracy load.

 

[SJB358]

Good point Bill and your right about every rifle being different. Seems like a good load to me Bill. I know I would have a hard time messing with it. Chronos are the death of many great loads. Scotty

 

[OU812]

Noslers load data for their 200 gr. spitzer shows.

IMR7828
Max. 83.5 gr. 2930 - 98% case fill
81.5 gr. 2850 - 95%
79.5 gr. 2770 - 93% being the accuracy load.

So maybe the 2850 with the tsx is right on the money.

 

[Antelope_Sniper]

Quick load is just an estimate.
Velocities can change 200 fps just changing brass and primers.
Not that is always will, but it sure can.

 

[OU812]

I guess if I want more speed I'll shoot 180's until then I'll keep .5 moa @ 2850.

Bill

 

[NoelW]

Maybe try some Retumbo, but don't know if the case will hold enough for any gains. If the case will hold enough you will probably see 100-150 fps gain without sacrificing any accuracy with a 26" or longer barrel. Sometime accuracy even improves. Although I doubt it will get better than .5.

 

[OU812]

Maybe try some Retumbo, but don't know if the case will hold enough for any gains. If the case will hold enough you will probably see 100-150 fps gain without sacrificing any accuracy with a 26" or longer barrel. Sometime accuracy even improves. Although I doubt it will get better than .5.

Noel my gun has a 24 inch barrel. I'm not disapointed at the speed just thought it would have been a little higher. I'm pleased with the accuracy and the speed is fine but I'm sure I will try other powders, retumbo, RL-25 and would like to try N560 but I stand a better chance in getting pregnant than finding that around here.

Bill

 

[SJB358]

but I stand a better chance in getting pregnant than finding that around here.

Bill

Now that was funny!

What about RL22 Bill? Think it would be a good powder as well. Seems like if 7828 works, then RL22 should work as well in some cases. Scotty

 

[OU812]

but I stand a better chance in getting pregnant than finding that around here.

Bill

Now that was funny!

What about RL22 Bill? Think it would be a good powder as well. Seems like if 7828 works, then RL22 should work as well in some cases. Scotty

Your right Scotty it would be a very good choice, maybe next on my list to try. I've seen in several place that RL22 is used quite often in the 8 with favorable results.

Bill

 

[SJB358]

but I stand a better chance in getting pregnant than finding that around here.

Bill

Now that was funny!

What about RL22 Bill? Think it would be a good powder as well. Seems like if 7828 works, then RL22 should work as well in some cases. Scotty

Your right Scotty it would be a very good choice, maybe next on my list to try. I've seen in several place that RL22 is used quite often in the 8 with favorable results.

Bill

Overall, RL22 has been excellent in the 270WSM, 7WSM, 7RM, 300WM and even a few others. I just like to try it, if it fits. Seems to work better for me accuracy wise than a few others and man, it always turns in great speeds as well. Scotty

 

[Bruce Mc]

Good point Bill and your right about every rifle being different. Seems like a good load to me Bill. I know I would have a hard time messing with it. Chronos are the death of many great loads. Scotty

To me chrono's are the birth of a good load. For hunting, imho, velocity is a must. If it don't shoot fast it don't count. I want a good group and top velocity. One thing is for sure, every rifle is different.

 

[FOTIS]

A dark colored sharpie and some bullet painting works well.

 

[DrMike]

Just looking at what you've posted wouldn't lead me to conclude that you were getting aberrant readings. I am aware that shooting into the setting sun with the Oehler can distort readings, but I haven't observed that phenomenon with my Chrony. I do shoot early on many days with the sun at 180 degrees to the target, and I can't say that I've ever observed an aberrant reading I could correlate to position of the sun. On the whole, it sounds as if you have an enviable rifle and a good load for it.

 

[OU812]

Just looking at what you've posted wouldn't lead me to conclude that you were getting aberrant readings. I am aware that shooting into the setting sun with the Oehler can distort readings, but I haven't observed that phenomenon with my Chrony. I do shoot early on many days with the sun at 180 degrees to the target, and I can't say that I've ever observed an aberrant reading I could correlate to position of the sun. On the whole, it sounds as if you have an enviable rifle and a good load for it.

The load is good but I thought it would have had a little more steam to it. Going to keep this load for sure but I'm sure I will tinker with other powders, RL25, RL22, and try running up to max with 7828.

 

[SJB358]

Good point Bill and your right about every rifle being different. Seems like a good load to me Bill. I know I would have a hard time messing with it. Chronos are the death of many great loads. Scotty

To me chrono's are the birth of a good load. For hunting, imho, velocity is a must. If it don't shoot fast it don't count. I want a good group and top velocity. One thing is for sure, every rifle is different.

Your right about that Bruce but I have seen folks scrap excellent loads in order to get another 50-100 FPS. I like speed as much or more than the next guy. Heck I'm guilty of the same thing. I just revamped my 150gr PT load since it was only running 3000. I wanted 3100! It only took another grain and a half and I was there plus I kept the accuracy but I am doubting any deer would have noticed. But I did! Scotty

 

[Bruce Mc]

Having a load that is as flat shooting as possible gives me a little more confidence when I'm in the field. Especially when you're thinking about that 600 yd cross canyon on a big'un. Shooting that far is kinda iffy for me, but I still think about it and want a load that can handle it.

 

[OU812]

Having a load that is as flat shooting as possible gives me a little more confidence when I'm in the field. Especially when you're thinking about that 600 yd cross canyon on a big'un. Shooting that far is kinda iffy for me, but I still think about it and want a load that can handle it.

I too want a load to be as flat as possible but I won't give up accuracy to get it. But then again that's what turrets and practice are for.