8208 ?

[Bearcatrp]

How much of a 20 degree temp drop would you expect POI @100 yards? I went to the range yesterday to check out 3 different 120 gr bullets with same load, 5 each. It was around 35 degrees. Last time out before this was around 50 degrees? According to strelok pro, my zero at 50 yards should produce very close to same POI @100 yards. And this verified when it was around 50 degrees shooting 120 SMK and speer gold dot bullets in the fall. I had almost a 5 inch drop on all 3 bullets. All 3 were 28.0 grains of 8208. Grouping wasnt fantastic but around 2 moa. But they did group low. 8208 isnt supposed to be temperature sensitive. I could see a little drop but not almost 5 inches. Will be making up 10 per bullet, 5 for 50 yard range to verify then 5 for the 100 yard range. If this turns to shit again, will be getting out of grendel. Rifle is a 12 inch upper from sulzar arms with a faxon match barrel. Brass is hornady. Magnum primers CCI.

[Londerko]

[A5BLASTER]

Seems like 20 grains is more then a bit low on the charge to me.

But I'm sure if your ready to give up members here would give you good price on your loading gear and weapon parts.

[Bearcatrp]

Sorry, 28.0 grains. Am down in reload room and saw my notes. Anyways, will be full length sizing and verifying each load carefully to insure next test is as accurate as possible. I like this caliber but have put allot into in but little satisfaction to this point.

[A5BLASTER]

What was the chrongraphed speed of those loads at 50 degrees?

[Chev2500]

Prob not an ammo issue. scope/mounts is where i would look first

[grayfox]

50 yds never tells you much anyway imo.
Get your chrony out to see what's up.

[Bearcatrp]

Did not use labradar this time as I have chrono'd these when it was around 50 degrees last time out. I'll go check my data and post it later. Will be bringing it out next time though. Scope is secured nice and tight. When I installed it, I used blue loctite so it doesnt move on me. I still check it before I go out to insure its tight. Hoping for another good day this week to go shoot again. Goofy weather here in Minnesota. In 40's lately.

[Klem]

Bearcat,

A crazy result like a 5" difference at 50yds (=10MOA) for the same load is obviously unrelated to temp difference. Then to consider blaming the calibre is also crazy. Something is grossly wrong and you just need to find it. Like maybe the elevation dial is an entire revolution from zero. I say this because 10MOA seems a coincidentally neat number.

[NugginFutz]

Bearcat,

A crazy result like a 5" difference at 50yds (=10MOA) for the same load is obviously unrelated to temp difference. Then to consider blaming the calibre is also crazy. Something is grossly wrong and you just need to find it. Like maybe the elevation dial is an entire revolution from zero. I say this because 10MOA seems a coincidentally neat number.

^ This! I can't recall the # of times I returned to the range after shoot some long distance steel and not be able to spot first round shots on a 100 yard target. Another reason why I adore RTZ scopes.

[Kilco]

I shoot my 8208 loads (max charge under a 123 eld-m) year round from 90 degree summer heat to the recent -20 degree cold snap we have had recently, and although I've never brought out the chronograph below 40 degrees my load remains stable enough for atmospheric changes only to my ballistics out to 620 yards.. I use 8208 in 223 Rem and 204 Ruger as well and haven't ever seen a significant temp sensitivity.

I dont think it's quite as stable as hodgdens extreme line, yet for a non "Enduron" IMR powder it does quite well.

[Bearcatrp]

Bearcat,

A crazy result like a 5" difference at 50yds (=10MOA) for the same load is obviously unrelated to temp difference. Then to consider blaming the calibre is also crazy. Something is grossly wrong and you just need to find it. Like maybe the elevation dial is an entire revolution from zero. I say this because 10MOA seems a coincidentally neat number.

The drops were at 100 yards. Have previously zero’d at 50 yards on all three bullets when it was around 50 degrees. All were consistently on target. Tried them at 100 yards with ok results when it was warmer. Was more than pissed seeing all three drop that much @100 yards yesterday. Made my loads this morning, 5 each for 50 yards, and 5 each for 100 yards. Will chrono this batch too. Monday looks like a good day before temps drop below 30 degrees so hope I can get out there. Will post my results.

[Klem]

Do all your testing at the same range. 100 is better than 50yds. Once you're on target at 100 and zeroed stick to it.

You need more than a few rounds to start making inferences about what's happening. 5MOA at 100 is still too much to be the effect of temp on powder (unless you left them on the dashboard of your truck on a stinking hot day). Bench Mark 8208 is a single-based powder made in Mulwala, New South Wales (Australia). Hodgdon imports 8208 and rebadges it under their subsidiary IMR, hence IMR 8208XBR. Single-based powders vary less with temperature change than double-based powders. Your 5MOA variation was not caused by any temperature differences of the powder.

[204 AR]

I've burned about 16 pounds of 8208, and just bought another keg, great great stuff for this size round. It is not as stable as, say, Varget, but it's not bad. I use it year round. I can see changes of 30 fps iirc, and honestly that could as easily be the different lighting on the crony on different days. The powder isn't causing a change in poi. You'll get it worked out, maybe someone messed with the scope, got kids?

[Bearcatrp]

No kids at home. Just bought another 8 lb jug myself. I use it for my short barrel 308 also. Supposed to be good weather tomorrow so should know then.