Power Pro 300 MP Load Data

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Sig220
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Re: Power Pro 300 MP Load Data

Post by Sig220 »

I would agree 100% that CAUTION should be exercised in all reloading and even more so when using a powder such as 300-MP.

As there is NO published data to rely upon, and Alliant is not interested in doing the R&D for the 300 Blackout. So if you venture down this trail, you are travelling alone for the most part and must rely upon your experiences and knowledge to get you through safely.

Alien, I look forward to seeing more of your experiences loading with 300-MP posted as well.
Alien
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Re: Power Pro 300 MP Load Data

Post by Alien »

Okay!

I have several that I have worked on and several more that I am currently working on. My work load has been increasing and it is taking all my trigger time. I will post them all in the pet load section as soon as I have completed these last three.
tallburnedmidget
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Re: Power Pro 300 MP Load Data

Post by tallburnedmidget »

Alien wrote:Okay!

I have several that I have worked on and several more that I am currently working on. My work load has been increasing and it is taking all my trigger time. I will post them all in the pet load section as soon as I have completed these last three.
Excellent!
Jeff H
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Re: Power Pro 300 MP Load Data

Post by Jeff H »

I did not get that he was talking about the faster powders. What did I miss?

I agree that sub/super results do not necessarily correlate either, but I think it's more likely there will be air space with subs.

So, regarding consideration of load density, what have your observations been relevant to 300 MP in the 300 BLK supers? I know you said you haven't compressed it, but roughly what kind of void are you leaving and still getting good results?
Alien
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Re: Power Pro 300 MP Load Data

Post by Alien »

Jeff H wrote:I did not get that he was talking about the faster powders. What did I miss?

I agree that sub/super results do not necessarily correlate either, but I think it's more likely there will be air space with subs.

So, regarding consideration of load density, what have your observations been relevant to 300 MP in the 300 BLK supers? I know you said you haven't compressed it, but roughly what kind of void are you leaving and still getting good results?
I was just giving a word of caution about load density with this powder nothing more nothing less.

I used the subsonic as an example only. Was not referencing any specific load data but stating that I noticed that there is a significant increase in speed when the powder is slightly compressed which could be easily done with the mid weight bullets that Sig220 stated he was working on.
Jeff H
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Re: Power Pro 300 MP Load Data

Post by Jeff H »

Alien wrote:
Jeff H wrote:........

I was just giving a word of caution about load density with this powder nothing more nothing less.

I used the subsonic as an example only. Was not referencing any specific load data but stating that I noticed that there is a significant increase in speed when the powder is slightly compressed which could be easily done with the mid weight bullets that Sig220 stated he was working on.
OK, I was lost all the sudden and thought there was a related discussion in another thread or something I missed.
Sig220
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Re: Power Pro 300 MP Load Data

Post by Sig220 »

Alien wrote:
Jeff H wrote:I did not get that he was talking about the faster powders. What did I miss?

I agree that sub/super results do not necessarily correlate either, but I think it's more likely there will be air space with subs.

So, regarding consideration of load density, what have your observations been relevant to 300 MP in the 300 BLK supers? I know you said you haven't compressed it, but roughly what kind of void are you leaving and still getting good results?
I was just giving a word of caution about load density with this powder nothing more nothing less.

I used the subsonic as an example only. Was not referencing any specific load data but stating that I noticed that there is a significant increase in speed when the powder is slightly compressed which could be easily done with the mid weight bullets that Sig220 stated he was working on.
Had to delay my trip by a day.....so I am still here :)

I understand your word of caution, but I have to question what we are talking about. Did I miss a example of of "significant increase in speed when the powder is slightly compressed" other then the subsonic load you talked about?

Do you consider "mid weight" bullets to be 147gn when we are talking about supersonic loads? I think of them along with the 165 to be on the heavier end of the bullets in the supersonic realm.

I really think we are talking about two different things...subsonic loads which I personally could care less about and supersonic loads which I work on very cautiously and watch for any signs of adverse pressures like a mad scientist.

These two types of loads.....subsonic with light powder charges and heavy bullets and supersonic with heavier powder charges and "mid weight" bullets are on opposite ends of the spectrum in problems and characteristics in reloading. With supersonic, I start with a suitable/safe powder weight and increase it until I am happy or I see pressure signs. I assume that with subsonic you start with a suitable/safe powder weight and decrease it until you are happy or see problems or powder detonation. To me working up a subsonic load is much more dangerous.

Once I get a load which will function in MY rifle, I shoot almost all subsequent rounds over a chrony, I save every target and record all relevant details of firing each round. I don't post a lot of workup data here, don't think most of it is even relevant as these loads are tailored to MY rifle on MY equipment. But in this workup, I change the COAL to see if it results in more or less accuracy/velocity and/or any adverse pressure signs. I can't say my results reflect your results so far. In general, I see a slight change of velocity and a bigger jump in velocity deviation which will affect accuracy.

I only post MY loads as examples that it is possible to get good accuracy with SAFE loads using 300-MP powder on my equipment in MY rifle. If another wants to use this powder, they should work up SAFE loads carefully on their equipment for their rifle.

I got great accuracy out of a COAL of 2.150 with the 147fmjbt, I never mentioned a length of the projectile. To infer that it was a compressed load is not supportable. I know by "feel" that it was not compressed. When working with a long shank like a GMX is where one must really exercise extreme caution......and in my post I have indicated that.

I appreciate your words of caution, but mind you I am probably one of the few posters who will put a cautionary note at the end of every thread that contains a load I am working on.

Sorry for the long "windedness".......but it is what it is...... :)
Alien
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Re: Power Pro 300 MP Load Data

Post by Alien »

My sincere apology for my writing skills or lack of, they seem to be a total failure.

My post was never meant to imply any negativity to anyone’s reloading skill or practices. I have read to many stories of experienced and novice re-loaders having kabooms with cartridges that have been around for 30 years or more with enough published data to make a library. It was meant to be taken as a watch your step sign would convey. If you are not careful you could fall and bust your ass.

We are using 300-MP to create the pressure to send a bullet downrange; whether it is a 95 gr or a 240 gr bullet the subject is 300-MP. I myself do not have any means to measure the actual pressure itself or any published data that might lend some Idea of what that pressure might be in a 300 Blackout. Hell even if we had published data it is not exact because of the number of variables. I have observed that 300-MP exhibits a sharp increase in pressure when it is very slightly compressed. Without the proper tools I have no way of knowing exactly how much or how fast this pressure occurs.

Sig220 you said that you noticed a decrease in FPS when you lengthened your OAL without a decrease in powder would suggest to “me” that your load had the bullet pressing on the powder slightly. I have no idea by how much or the actual number of FPS that was lost since you did not post that information but I was guessing it was somewhere between 70 and 120 FPS. This is the reason I posted the caution, I did not mean to suggest that the load was not safe or reloading practices were flawed in some way. Again, my apology!
Sig220
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Re: Power Pro 300 MP Load Data

Post by Sig220 »

Alien, apoligy accepted.....and thanks for clarifying everthing. I will offer an apoligy as well.

Now, even though I am away from home I found some 125 sp at midsouth shooter supply.....do you think we can come up with some load data on that round before I get home? :) Really, I have them ordered and plan on working a load up for them!!
As usual for me this will not be a rushed job, they (the load ) must be safe, accurate and hopefully fast. Figure these projectiles should be in later next week, so I will be looking at others experiences until then.
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ThreeHundredTraveler
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Re: Power Pro 300 MP Load Data

Post by ThreeHundredTraveler »

I have 150 and 125 that I intend to load. I have both 300MP and 1680. There is data out there for 1680 for both the 125 and 150 grain weights. And since the 300MP is a bit more hot than 1680 it too should fill the bill. 110 is impossible to find.
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