Alternate Powders for overbore cartridges

[Glassaholic]

I am building a new custom rifle in 7mm RSAUM and only have 2 lbs of H4831sc left. With the powder shortages I have been unable to find H4831sc and many other powders anywhere.

I am mostly going to be shooting Sierra and Berger 180's (and Nosler ABLR 175gr for hunting) out of my rig and while H4831sc and Reloder 25 seem to be the goto powders, I cannot find them in stock anywhere (or I'm too late and they're sold out); however, I am able to find Norma MRP and IMR 7828ssc in stock and I am curious if any of you have ever worked with MRP or 7828ssc?

Looking at the burn rate charts Norma MRP seems to be a dead match for H4831sc and IMR 7828ssc seems to match up with Reloder 25. That being said, just because they are close in burn rate doesn't mean they'll perform the same way, so I'm looking for some experience here. For those of you who have played with MRP and 7828ssc with overbore cartridges, what has been your experience with ES/SD?

I'm leaning toward MRP because there seems to be more information out there. The Berger reloading manual actually lists MRP and 7828ssc and shows them both at 97% fill ratio and very close in the velocity they yield with only .5 gr difference; however, 7828ssc is a slower powder so I'm not sure what is going on here. The big question then becomes does either have an advantage in the ES/SD dept? Thank you

Bill

 

[lte82]

Win 780 may be another to look at. Meters well and has better velocities with the heavies than most other powders. Its also been an easy one to find during the shortage of 2013.

I cant comment on es/sd differences on mrp vs others...

 

[cav has been]

I have a good 7 saum load using H1000 and am working (sporadicaly) on a Retumbo load that seems promising. Haven't tried mrp or 7828.

 

[jbailey]

First, look on the Reloading Recipe section of this website, there is a great two or three page reloading thread on all the ins and outs of 7SAUM. That thread is loaded with great info.

H4831sc would NOT be my first choice for the heavy 180gr in the SAUM. Its too fast and pressure peaks too early. Reloder 25 very good choice, although temp sensitivity is issue. My understanding is that Norma MRP is very similar to Reloder 25, again with the temp sensitivity issues.

My go-to powder would be H1000 and/or Retumbo. Guys say Retumbo is too slow. I question if those guys have actually tried Retumbo in the 7 SAUM. If you have 26" of barrel, it is simply awesome. 50fps or so better than H1000, plus the recoil push is so much gentler - leading me to believe the peak pressure is likely also less.

ES/SD is super easy to keep low in the SAUM, with just about whatever powder you are using. This is clearly a function of the short powder column. Some guys say that the short powder column is a marketing gimmick of the cartridge companies... I disagree. They are super easy to get low ES/SDs from, no fighting with load development. My 7 SAUM, in just about any powder, gives me SD's <10, all the time. ES <20 as well, although I don't track ES as closely as SD.

If you do end up trying Norma MRP and/or IMR 7828ssc, please post up your results on the reloading thread I highlighted about. Thanks and good luck w/ your 7 SAUM!

 

[jbailey]

Bill,
here is a link to the 7 SAUM reloading thread I mentioned:

http://www.snipershide.com/shooting/snipers-hide-reloading-depot/127920-7rsaum-loads.html

 

[Glassaholic]

Thank you. Jbaily, that is what I thought about H4831sc but the Berger manual lists it right up there with the others. MRP is a bit slower and 7828 is right there next to Reloder 25, however, Retumbo is slower still but you mention a 26" barrel and that's what I'm getting

 

[Glassaholic]

Of course I can't find Retumbo anywhere in stock either. So looks like I'm back to MRP AND 7838ssc

 

[rdinak]

this may help you select alternate powders

ADI Powders Handloaders' Guide

 

[Glassaholic]

Thank you rdinak, that is very helpful indeed. Obviously all powders exhibit different characteristics because of their different chemical makeups but this at least lets me know what's close.

 

[Aimsmall55]

Thank you rdinak, that is very helpful indeed. Obviously all powders exhibit different characteristics because of their different chemical makeups but this at least lets me know what's close.

Vitavouri n560 is a great powder for the heavys. I know it's a little more $ but it shot the 180 vlds out of a Surgeon Scalpal 7 short mag as good as a bench rest rifle. I loaded them up for a buddy of mine and they were AWSOME

 

[Glassaholic]

Unfortunately I can't find any VV in stock either. The only powders that seem to be in stock are MRP, 7828ssc and Magpro. I could wait (and wait and wait) but in lieu of the current trends of a lack of products I would like to get something while it's still available. I am very tempted to get a pound of each of the above and run through different scenarios to find out what works best with my setup.

 

[Glassaholic]

Because I mostly want to shoot the 180's it seems prudent that I focus on powders slower than 7828SSC and MRP, they might get the job done but have their drawbacks. I'm going to mainly focus on H1000, Retumbo and RL-25. Accurate Magpro appears to be right up there but I'm concerned about it being as pericarp powder and thus potentially causing some temp issues; however, it may be worth it to grab some while I break in the rifle and hopefully one of the other 3 will show up somewhere. Thank you all for your help

 

[Powermac]

There are several powders you can try.
All of those i list should work quite well in the SAUM, running a 7 RM myself so no direct comparsion.
As for Norma being temperature sensitive that is true to some degree, same for VV's 5xx series.
Norma MRP is very close to RL 22, just a tad slower burning, and held to a higher quality.
Both Norma and most RL powders are produced by Bofors in Sweden and therefore they are very similar.

VV N163,5 , N165, N170, N560, N570.

Norma MRP and the new Norma 217 that replaces the older MRP 2.

I do prefer VV powders and to run heavy bullets in a 7 SAUM i would try N570, N170, N560, N165 in that order.
Norma powders the 217 would be the natural choice.

If you have Hodgon available though i would look into H 1000 and possibly Retumbo first.

Where i live RL powders are not available, Hodgon just to some degree, can be lucky and find a can of H4831SC or H1000 once in a while.
The state has import taxes on gunpowder,witch makes it so expensive that Norma and VV are the only powders being sold here in big amounts.
So they pretty much have monopoly on the market, since Nammo is owned by the state and owns VV and parts of Norma this sadly will not change.
So much for democracy and free market.

 

[milo 2.0]

Look for Ramshot Magnum, or IMR 7828, they've been around lately. 4831 makes me cringe, 55gr of powder in this case, wow, I'm on my fifth saum, and 67gr of slower powder has been my lightest charge. MRP2, N570, RL25 is what I've used.

Powermac, you don't list MRP2, not for sale over there? A year and a half ago, I talked to a Norma dude, he said they had 170,000 lbs warehoused. Distributors over here quit ordering it because it was discontinued, thought you guys would have happy days for years!

Here's a link to Western Powders, any ffl holder can buy from them. Sole distributor of Norma powders.
If you do buy, don't stock up on 217, it didn't work here, have had some reports it's working, I don't buy it.
If you're in the same circles as Kevin U, he'll be here in Feb, and we could get you a couple lbs of 217 to try.

http://www.westernpowders.com/

 

[Glassaholic]

VV N163,5 , N165, N170, N560, N570.

Norma MRP and the new Norma 217 that replaces the older MRP 2.

Thank you Powermac, I was unaware of Norma 217 so I will definitely look into that. I have been looking for VV N170 and N570; however, I have read the "5" series have been more problematic with temperature swings, have you found that to be the case? It is difficult to sift through all the information as there is a lot of great information and a lot of great mis-information available on the web

Unfortunately, you would think the Hodgdon powder company was producing a 1lb a day with how scarce their powders have been over here, same with the RL series. Oddly enough, Norma seems to be in abundance over here, go figure.

milo 2.0, have you tried the Norma 217 that Powermac mentions? Maybe not since it sounds like you have a bunch of MRP2, was just curious if anyone has played with 217 in the 7mm SAUM.

Thanks guys, this gives me another powder to search for...

 

[milo 2.0]

Thank you Powermac, I was unaware of Norma 217 so I will definitely look into that. I have been looking for VV N170 and N570; however, I have read the "5" series have been more problematic with temperature swings, have you found that to be the case? It is difficult to sift through all the information as there is a lot of great information and a lot of great mis-information available on the web

Unfortunately, you would think the Hodgdon powder company was producing a 1lb a day with how scarce their powders have been over here, same with the RL series. Oddly enough, Norma seems to be in abundance over here, go figure.

milo 2.0, have you tried the Norma 217 that Powermac mentions? Maybe not since it sounds like you have a bunch of MRP2, was just curious if anyone has played with 217 in the 7mm SAUM.

Thanks guys, this gives me another powder to search for...

I edited my post, 217 did not work in my gun. I pressured up at 67.5gr, 2734fps, 180 hybrid. I sold all my MRP2 a couple years ago, know a guy with 13 lbs, he's milking it!

Email western powders, ask about Ram Magnum availability. Their nice people!

 

[Glassaholic]

I emailed a guy about the 300 Norma mag, he said for accuracy it'd be good, not velocity. It didn't do well in the 7mm SAUM, but both these cases are overbore, I bought 5 lbs. I don't believe we tested it in the Norma mag. It might very well kick butt in the 338's.

Milo 2.0, I just read your post on another thread about Norma 217 not being good in the 7mm SAUM, can you elaborate at all? Was it too slow, not accurate, etc. Thank you

Bill

 

[milo 2.0]

Milo 2.0, I just read your post on another thread about Norma 217 not being good in the 7mm SAUM, can you elaborate at all? Was it too slow, not accurate, etc. Thank you

Bill

I was typing the same time you were, look down in previous posts.

 

[Glassaholic]

Thank you Milo. I believe Ramshot Magnum and Accurate Magpro are pretty much the same, they are both spherical powders and give close to the same velocity/pressure, etc.

 

[milo 2.0]

Western handles Accurate also, try them! They're easy to deal with.

 

[Powermac]

Thank you Powermac, I was unaware of Norma 217 so I will definitely look into that. I have been looking for VV N170 and N570; however, I have read the "5" series have been more problematic with temperature swings, have you found that to be the case? It is difficult to sift through all the information as there is a lot of great information and a lot of great mis-information available on the web

Unfortunately, you would think the Hodgdon powder company was producing a 1lb a day with how scarce their powders have been over here, same with the RL series. Oddly enough, Norma seems to be in abundance over here, go figure.

milo 2.0, have you tried the Norma 217 that Powermac mentions? Maybe not since it sounds like you have a bunch of MRP2, was just curious if anyone has played with 217 in the 7mm SAUM.

Thanks guys, this gives me another powder to search for...

Seems Milo has experience with the 217 in his SAUM, as it's designed to operate at higher pressures it's not that much of a suprise.
Did use the MRP 2 in 7 RM and 168 with success, have stuck to VV powders last few years though.

As for the Lapua 5xx series, they are double based powders, added Nitroglycerol witch makes them more temperature sensitive then they're single base powders 1xx.
The advantage of course is the extra velocity you normally gain, but depending on where you live the temp sensitivity can become bothersome.
Here i live the temperature is within 25 Celsius all year around generally,and has not given me any trouble, just some slight velocity variation on hot summer days.
I do believe the RL powders are worse though, from what info i have found on the net.
Rl is not sold here so can't say for sure, and if it was imported the taxes would make the cost twice of VV ,Norma and even Hodgon when i can find some.
Norma is pretty much the same powders as RL though, produced in same factory, almost identical ingredients, and slightly different QC and burn rates.
The 1xx series of VV is certainly more temperature stable, and to my findings have better lot consistency normally.

Have never compared the 5xx temp sensitivity to Normas directly so can't give you any valueable numbers, you can notice it between the 5xx and 1xx series slightly, if you let a round cook in a hot chamber fx.

 

[Glassaholic]

Thank you Powermac, the information on the difference between the VV N1xx and N5xx series is helpful.

 

[milo 2.0]

Thank you Powermac, the information on the difference between the VV N1xx and N5xx series is helpful.

He may be right on the temp issue, what he didn't tell you is the Horsepower difference. 500 series powders rock! You'll gain velocity over other powders, it's quite amazing. But you pay for it also!

 

[Glassaholic]

He may be right on the temp issue, what he didn't tell you is the Horsepower difference. 500 series powders rock! You'll gain velocity over other powders, it's quite amazing. But you pay for it also!

What kind of velocity difference? 50-100fps or more are we talking? When you say "pay for it" are you referring to the pocket book or the life of the case or something else.

 

[milo 2.0]

What kind of velocity difference? 50-100fps or more are we talking? When you say "pay for it" are you referring to the pocket book or the life of the case or something else.

Price. Velocity must vary per?

 

[Powermac]

To quote myself :
The advantage of course is the extra velocity you normally gain, but depending on where you live the temp sensitivity can become bothersome

Is what i said so i did not leave it out, but maybe i did not elaborate enough, as yes indeed the N5xx series gives you extra velocity compared to a N1xx powder of similar burn rate.
The 500 series is slightly more dense, and with the extra energy the Nitro adds to the powder it is quite logical that it's capable of producing a higher velocity.
The same tendency you will see in fx a 284 if you change from H4831sc to RL 17.

To give you a exact number is quite impossible as there is too many variations in play. First off different calibers and bullet weights reacts differently with different powders, there is barrel harmonics that comes into play. Different receivers, chambers etc makes some rifles react to chamber pressure differently.
Case capacity is different from mfg to mfg. And you have lot to lot variations in powders.

There are people that claims the double based powders will increase throat wear though so it has a possible negative side effect.
Can neither confirm or deny that statement with any certainty. But if i remember correct Nitroglycerol has a higher combustion temperature then the single base powders, so it could theoretically increase wear on the throat.

The price is slightly higher yes, but worth it if you want the extra velocity, and overlook the downside to it.
Here the price difference is about 10 dollars pr jug of 2.2 lbs, but since a jug of the N1xx series costs 98 dollars already the price is really not much of a concern for me.
Powdervalley lists 1 lb of N150 and N550 with a 4 dollar price difference from what i could see.

Eventually for me it usually boils down to what load is the most accurate, velocity is not that much of a concern.
As long as my 7 RM keeps above 2900 fps with the bullets i use for hunting i am satisfied pretty much, as it means a 180 Berger hunting, and possibly the new 175 Accubond LR's can keep my countries silly energy demand(2600 J) for big game hunting, out to 500 meters witch is as far as I'm willing to shoot on any living animal in my normal weather conditions.
Shooting targets long range for me just means a bit more adjustment if the velocity for a load is low, witch certainly don't matter much.

A last thing to mention about VV powders are that they tend to produce lower ES/SD compared to Norma in my rifles.
And according to several sources, it does contain some sort of flash suppressing ingredient witch most other powders don't have, allegedly because they were used for military purposes, that's all i know about it though, so don't take my word for it.

 

[milo 2.0]

Sorry Powermac, I didn't read your whole post, nor was I pointing fingers. Just explaining the known gains of 500 series. Myself, have never opened a can of 100's. Your posts have been more than enlightening.