Alliant 300-MP powder?

[Hoot]

I was just wondering if anyone has tried Alliant 300-MP yet for the 450? ...

I may have been the first person to try 300-MP in the 450B.

I didn't report the results from more than two-and-a-half years ago, because they were not encouraging. However, it's perhaps time to release them, so I wrote a description that turned out to be so long that it needs it's own thread.

(Link to thread: Some Early Trials of Alliant 300-MP Powder in the 450B.)

Your results with the lighter bullets and to a lesser degree with CCI 41 primers don't surprise me given the burn rate of 300-MP, which falls slower than W296, but faster than 1680. In my 20" 450b, I had lackluster results with 1680 and the 300 grainers. While faster powders like Lil Gun and W296 worked with them, the recoil impulse felt like they were popping fast and burning out long before the bullet left the barrel. I am hoping that 300-MP helps fill the gap between those powders. Also, I'm hoping that the lower end of the sweet zone for 300-MP drops down to include 275gr and possible 250gr bullets, to take advantage of the entire 20" of barrel and yield good velocities at lower pressures and acceptable accuracy. To that end, I wish I were testing with XTP Mag 300s as in the case of my rifle, I got better accuracy from the XTP Mag family than from their Speer counterparts. For me, accuracy falls a little higher up the importance ladder than milking every last fps out of the recipe.

The purpose of my first rage outing of the season will be to characterize 300-MP with the 300gr bullets I have. Since it is not supported in my version of QL, I'm also taking long my 7.62x40 upper and a ladder test progression to try and characterize it in that caliber, which loves Lil Gun, W296 and according to other owner/experimenters, 1680. Seems like a perfect candidate for 300-MP. For all the setup I do during a range visit, I like to conduct several tests before I knock it all down.

Hoot

[Stealthshooter]

I am wanting to see the results of 300-MP with the 300 grain and heavier bullets. I already have a very nice nice load for my 200's and I'm going to give 2400 another go with the 200's as well.

[wildcatter]

PB, I read your results and like Hoot, as expected, the burn rate for the MP powder is far too slow in light for caliber bullets and in that respect, there was no surprises. And, I do believe you were the first to use this powder, in our cartridge, which may pan out to be the best, in some respects.

Hoot, prolly, you will find the 250's will function and group well, it's just not the most efficient powder of choice. The 275's will fair much better and you'll prolly like the MP powder well, at that point. As you go up in bullet weights, 300's, you will find even better results. But, the burn rate, for the MP really won't take-off until you hit 325's or better. At that point, we'll make you a born again Heavy-Weight Shooter, as if 200gr isn't a heavy bullet (200gr in a 300 mag is a brute), but when we get you shooting the 275's and better on a regular basis, it might just Rock Your World.

But all my hyperbole on the side, I will wait with baited breath, for your results with those 300's. And can't wait for the results you obtain using the 275 Barnes. To which, you can find better powders for the 275's but as a one stop shopping kind of thing, 300MP will be a Great Trade-Off.. When you get to resized 350's (resized .458's to .452's), you will be astound at the results.

..t

[Hoot]

I do, "Looks" like a good safe starting charge should be 25gr with a Speer 300 gr UCSP. You'll prolly make it to 30gr+ before you are done. But, thoroughly check the first shot round to make sure everything is to your std's..

..t

I'm glad you set me straight. Looking at translations from 460 S&W using 300MP, gave me the impression that a good starting point for our caliber would be about 34 gr. Alliant recommended 38 gr for the 460 S&W pushing the Speer 300 Gold Dot, so 34 seemed like a logical starting point for the 450b. Boy was I off.

Hoot

That was mean Tim

I know you all like to chide me for being so cautious, but 25gr? Really? Was that a late April fools thing?
I just got back from the range and I spent more time preparing to go, setting up and knocking down, than I spent shooting.

I should have gone with my 460 S&W translation because at the 26gr starting point, they came out of the barrel at 1425fps avg. Amazingly, they cycled the action, even with my CCWS, but anemically. Rather than waste my time progressing up 3 rounds at each 1gr increment, I jumped to 30gr and was rewarded with 1645fps avg. Still way below what 300s typically go safely out of my 450b. Lastly, I jumped to 33gr and they were still only traveling 1775fps avg. That was as high as I loaded since I only had 25 bullets. So looking back, perhaps my intended starting point of 34gr would probably have been a better choice.

Even with those 300gr Gold Dots seated to the cannelure (2.06" COL), there was a lot of room for more powder. 300MP is heavy for it's volume. Sized cases will hold 60gr of uncompressed 300MP and with the Gold Dots seated to the cannelure you can fit ~42gr. So, if I had more bullets, I would start at 34gr and work up to the limit of ~42gr or until there were signs of distress. Then again, if one ignored the cannelure and loaded to max COL of 2.26", one could get even more powder in. Looking at the pulled, unfired loads I brought back home, you can clearly see the bullet is slightly narrower where it seated into the case, so just like my other pulled bullets, they go into the scrap can, because they do not mimic new bullets and the experiment's accuracy would be compromised. I still have about 15 of the 300gr SST/ML bullets, but they behaved strange when I tried them the last time. By that, I mean they gave the impression that they needed higher RPMs to stabilize and tighten up the groups, than I was launching them at. Could be the long bearing surface. I may try them since I have no other use for them but their data would not translate to the 300gr Gold Dots or XTP Mags, so perhaps yard work is in store for this beautiful 72 deg spring day

Hoot

[wildcatter]

I do, "Looks" like a good safe starting charge should be 25gr with a Speer 300 gr UCSP. You'll prolly make it to 30gr+ before you are done. But, thoroughly check the first shot round to make sure everything is to your std's..

..t

I'm glad you set me straight. Looking at translations from 460 S&W using 300MP, gave me the impression that a good starting point for our caliber would be about 34 gr. Alliant recommended 38 gr for the 460 S&W pushing the Speer 300 Gold Dot, so 34 seemed like a logical starting point for the 450b. Boy was I off.

Hoot

That was mean Tim

I know you all like to chide me for being so cautious, but 25gr? Really? Was that a late April fools thing?
I just got back from the range and I spent more time preparing to go, setting up and knocking down, than I spent shooting.

I should have gone with my 460 S&W translation because at the 26gr starting point, they came out of the barrel at 1425fps avg. Amazingly, they cycled the action, even with my CCWS, but anemically. Rather than waste my time progressing up 3 rounds at each 1gr increment, I jumped to 30gr and was rewarded with 1645fps avg. Still way below what 300s typically go safely out of my 450b. Lastly, I jumped to 33gr and they were still only traveling 1775fps avg. That was as high as I loaded since I only had 25 bullets. So looking back, perhaps my intended starting point of 34gr would probably have been a better choice.

Even with those 300gr Gold Dots seated to the cannelure (2.06" COL), there was a lot of room for more powder. 300MP is heavy for it's volume. Sized cases will hold 60gr of uncompressed 300MP and with the Gold Dots seated to the cannelure you can fit ~42gr. So, if I had more bullets, I would start at 34gr and work up to the limit of ~42gr or until there were signs of distress. Then again, if one ignored the cannelure and loaded to max COL of 2.26", one could get even more powder in. Looking at the pulled, unfired loads I brought back home, you can clearly see the bullet is slightly narrower where it seated into the case, so just like my other pulled bullets, they go into the scrap can, because they do not mimic new bullets and the experiment's accuracy would be compromised. I still have about 15 of the 300gr SST/ML bullets, but they behaved strange when I tried them the last time. By that, I mean they gave the impression that they needed higher RPMs to stabilize and tighten up the groups, than I was launching them at. Could be the long bearing surface. I may try them since I have no other use for them but their data would not translate to the 300gr Gold Dots or XTP Mags, so perhaps yard work is in store for this beautiful 72 deg spring day

Hoot

As I said 30+ grains. Did I understand you correctly, you shoot three rounds before changing the charge? If this is the case, then I don't care for your methodology. If you are getting ZIPPO for pressures, then only one shot is necessary before a powder change is in order, this is a method to keep you from wasting two other shots.

Question, do you take a reloading set-up to the range with you??

..t

[Hoot]

As I said 30+ grains. Did I understand you correctly, you shoot three rounds before changing the charge? If this is the case, then I don't care for your methodology. If you are getting ZIPPO for pressures, then only one shot is necessary before a powder change is in order, this is a method to keep you from wasting two other shots.

Question, do you take a reloading set-up to the range with you??

..t

No, I get odd looks for bringing as much equipment as I already do. Everyone has to wait for me to set up my chrony as it is. I'm fussy about my alignment, so that's 4 or 5 trips back and forth leveling and lining everything up perfectly. I don't care for reloading out in the wind and humidity, but I know it can be done. Just not for me. BTW, there was a fellow there with a new Oehler 35P. Very nice 3-screen chrony. If I had the dough-re-me with nothing else more important to spend it on, that would be a nice addition. Interesting that you can order them from Oehler, yet Midway says that they no longer make them. Go figure...

I shoot three rounds so I can honestly report that is was an average, albeit a small sample average. Also, when I see velocities vary 50-100fps in this caliber for the same load, I don't want to catch one shot extremes and think I have plateaued. I decided that since this is a new learning opportunity, that I would reload the pulled down bullets after all. This time, I started at 34gr and up to 41, almost 100% fill with the 300 GD seated to the cannelure. I could feel that they seated with a little less force the second time around, but you go to war this the army you have. It should still allow me to get an idea whether the powder is worth following up on. It sure would be nice to find a powder that hit max safe load about the time it uses up all the case capacity.

The range does not open until noon on Sundays. Some tribute to blue laws no doubt, but a little outdated IMHO. As a board member (one of the youngest at 58), I've tried to introduce a motion to do like all the other clubs in town and open at 9 AM like the other 6 days, but the old-timers like to make sure we all know who is in charge and it gets shot down. They're retired, so they don't seem to realize the importance of cramming as much as possible into the weekends as working stiffs do. Anyway, despite today's perfect weather, it's supposed to rain tomorrow starting of course around noon. If it doesn't, I'll try and re-shoot these re-loads.

Hoot

[gunnut]

I'm using imr4227 to fill the gap from 296 to 1680 with 275gr and up bullets in the 450LM. Just doesn't give the velocities I'm looking for. Can't wait to see your results!

[Hoot]

Y'know, I didn't cover another aspect of yesterday's first outing. That being, using the DPMS Stainless Steel lower. As they say, no news is good news. Seriously, it was good news. It ran fine. It felt almost the same in the bags as my RRA NM lower. The weight was a non-event since the shake weight I normally had in the RRA lower made it almost identical in feel. The recoil moment was different since the weight in the DPMS is static weight and further forward than the shake weight. Since I switched out from my hunting season scope to my load development scope, I had to recheck and re-zero it. For that task I took along 5 loads of 250gr FTX over 38gr of Lil Gun. They averaged 2268 with the first fouling shot clocking 2320. Take away that shot and they averaged 2250. The gun did jump around more in the bags than I recall it doing with the RRA and shake weight. No surprise there. The loads using 300MP besides being light, noticeably turned on more gently and seemed to use more of the barrel getting up to speed. I realize that is an anecdotal observation, but after 2k rounds, you do develop a memory for how things generally feel. Even the last ones that were in the upper 1600s, lower 1700s felt more tame. As always, I was using Rem 7 1/2 primers. No hang fires, even with the rounds that clocked in the 1300 to 1400fps range. After zeroing the scope using those 250s traveling in the 2200's, it was no surprise that the 300s hit the target board between 12 and 15 inches lower at 100 yards and 4-5 inches right of center.

They lowered the chance of rain to 30% and moved the time out to 4 PM, so I will definitely give these retreads a second go at noon. I'll be there earlier doing preventive maintenance on the range which was surprisingly not as soupy as I expected it to be given that a week ago, we had over a foot of snow on it. All of that melted the past four days, but the frost was already out out and the water absorbed quickly. You still have to watch where you walk as there are some squishy spots. Though a lot of the local lakes have open water at the shore, they all still have ice on them, some have as much as a foot or more, further out. Definitely a near record, late spring. I'll get my results up later today.

Hoot

ETA: Almost forgot the obligatory target pics:

[Hoot]

I got the range report all documented, but am too tired to compose it tonight. Will get it up tomorrow morning in a separate thread. This powder has great potential with the right 300gr projectiles. It looks like it will hit top performance around the time the fill rate is at 100%, with hollow points seated to the cannelure and a firm taper crimp applied. Unfortunately, due to a false start with loads that were too low, I was unable to find the max load before seeing adverse pressure signs because I ran out of bullets. This powder warrants further investigation with the different 300 grain bullets at our disposal. It truly fills the gap between W296 and AA1680!

More in the range report tomorrow.

Hoot

[Stealthshooter]

I really wish I could find a supplier near by. Since my load of choice includes 300gr SST/ftx's I'm thinking this may be a better choice than the H110 that I have been using. Look forward to the report.