I recently picked up a couple pounds of Accurate Magpro to load under Bergers in .243 and 7mm mag. It is a spherical powder, and it meters like water thru both my RCBS and Redding powder measures. The impacts were about the same or slightly higher than with IMR 4350, but Magpro is extremely easy to use. The impacts vs previous zero could have been affected by the warm temptertures during testing. No trickling needed with the Redding. The RCBS couldn't throw big enough charges for the 7mm mag. There will be no chronographing until after deer season for obvious reasons. My testing was done on a range instead of out behind the barn. The biggest plus for me was MOA or better accuracy at max -.5 grain charges! The rifles are both known good shooters. In my reloading adventures, I have noticed that with many powders, max loads don't always deliver stellar accuracy. Also, I was very pleased with the degree of pressure signs left on the case heads and CCI primers. Please start low and carefully work up charges, as all rifles are different. Hope this helps other reloaders shooting overbore rounds.
Accurate Magpro
- Thread starter Liberty
- Start date
RCBS is where it's at. IMR 4064 is the most versatile non-magnum rifle powder, though it doesn't meter very well. Unique is the most versatile pistol powder. If you can only choose 2, those are where I would start.
The Magpro delivered 100 fps and better velocity confirmed with a chronograph than box listed velocity from my .270. My rifle is a 22 inch barrel Savage with 130's. Bullets were seated longer than sammi minimum, but under cartridge oal. This is my new powder for .243, .270, and 7mm Mag. I am not impressed often, but Accurate/ Western Powders really delivers more than expected! 7mm Mag with Bergers kills humanely in real world testing.
Just remember that Magpro is a spherical double base powder and temp sensitive. If you redline it in the fall/winter, the summer may get a bit to exciting. I'm sure you know this @handloader , but others may not. I've chased velocity in the past, shooting at 1k plus, and 100 fps isn't worth the temp sensitivity - to me at least. I'd rather have the more consistent load shooting from 20 degrees to 105. Hell, the main reason I roll my own is for high consistency. RL16, H4350, etc. Just my two cents.
I wish I understood what all of this meant. I really need to start doing some research and acquiring some reloading gear/components. With stocking 300 BLK, .44 Mag, .500 S&W Mag, and .308 now it would be worth it to get into reloading. I had consolidated calibers down to 9mm, .45 ACP, 5.56, 5.45 and 7.62x39 so it wasn't really worth it before but now it would be.
So very much there to try and explain, but I'll attempt a quick synopsis. There are two basic powder mixes. Double base and single base. Single based is made from nitrocellulose. In double base powder, nitro glycerin is added. Double based powders burn faster. Faster burn = more velocity. BUT, nitroglycerin is very temp sensitive. So, it is going to have pretty dramatic (relatively) burn rates at 20 vs 50 vs 80 vs 100 degree temps. For rifles and what people are trying to determine, is where the bullet leaves the barrel on a particular node over a range of powder charge weights. The varying charge weights is pretty well telling of how a charge will shoot over temp variences. higher charge weight equals higher temps. Lower charge rates equal lower temps. In theory, with a single base, you need less of a consistent window than you do with a double base as the single base is not as temp sensitive. Some single bases are more consistent than others. Varget, H4350, RL16, RL17 are just a few. They are different powders from different companies.
Pistol powders burn extremely fast. Throw a pistol powder in a rifle, and kaboom.
It's all very sciency. That's why there are different powders for different cartridges. Trying to time the powder burn rate to a rate at which it will completely burn, but not too fast as to turn the trigger into a detonation control. Different powder composites, shapes, size. It all matters.
Best advice I can give, get with someone who know what they are talking about. Talk to them. See their set-up. Also, READ A DAMN RELOADING BOOK. My suggestion, start with The ABC's of Reloading. Then, get reloading manuals from the bullet manufacturers or press manufacturers. They give a quick intro, and then give you min and max charges for various powders and projectiles. Not to mention other key measurements of each cartridge. If you really want to dive into ballistics, particularly rifle, read Applied Ballistics. Wonderful resource. Bryan Litz does a great job of getting all nerd sciency, but stating things in a way the rest of us can understand. Absolutely the leading ballistician today.
@Jake , redlining means pushing your load to the max. The books and bottles of powder will give min and max loads. The max loads are lawyered. Rifle shooters in particular like to push that charge weight above advertised max charge to get more velocity and the next "node." When doing this, we are always looking for signs of excessive pressure - case head swipe, flattened primers, blown primers is tell-tale, tough case removal, bolt handle stuck, etc. You red line it in when doing load development in the winter, especially with a temp sensitive powder, and you could have catastrophic results in the summer.
Good day to refresh this post. I was shooting the .270 about an hour ago. I discovered that Nosler ballistic tips and Accubombs shoot within 1 inch of each other in my rifle. That is a huge plus.
One thing that I try and do when working up a load is to keep my firearms and ammunition at room temperature for testing no matter what time of year. It is about 200 yards from my house thru the woods and across the field to my range. I thank God for his many blessing on my life. In years past when some driving was involved, the ammo for testing was placed in a small cooler if conditions were very cold or hot. Using this method, hunting zero will be good if the temperature is 45 or 80 as poi at 100 shouldn't move more than 1". Also, you shouldn't be hotrodding so much that 70° tested ammunition will be blowing up your rifle at 90°. I always stay within published limits, and encourage other to do the same. Some powders are just much better at delivering the goods than others. Thank you for the safety warning, we need to hear them as much after 15 years of loading as on day 1, lest we become careless. Happy shooting.
One thing that I try and do when working up a load is to keep my firearms and ammunition at room temperature for testing no matter what time of year. It is about 200 yards from my house thru the woods and across the field to my range. I thank God for his many blessing on my life. In years past when some driving was involved, the ammo for testing was placed in a small cooler if conditions were very cold or hot. Using this method, hunting zero will be good if the temperature is 45 or 80 as poi at 100 shouldn't move more than 1". Also, you shouldn't be hotrodding so much that 70° tested ammunition will be blowing up your rifle at 90°. I always stay within published limits, and encourage other to do the same. Some powders are just much better at delivering the goods than others. Thank you for the safety warning, we need to hear them as much after 15 years of loading as on day 1, lest we become careless. Happy shooting.
If just coming up with a hunting load, agreed, not that big of deal if shooting a few hundo and in.
You shouldering be pushing your round that hard at 70degrees, and I doubt most do. But if you do load development on a 30 degree day, and you push it, you could be in trouble at high temps. Hell, I got a buddy who wasn't even showing pressure signs at 30. Though he had the perfect load. Loaded a bunch up and we shot a match in August. Had a tough time extracting and was blowing a few primers.
