I am considering using Norma MRP for a load in my 30Gibbs, but case space could be an issue. Is this a granular or ball powder, and does anybody know how many grains there are per cubic centimeter, and/or whether it is denser than IMR4350 (if so by what percentage?)?

Deke,
Norma MRP is a stick powder (cylindrical granules) that is very similar to RL-22.

In fact, RL-22 is the leftovers from MRP. They sweep up the spilled or rejected MRP and put it in batches of RL-22 that are shipped to Alliant for packaging and labeling as RL-22.

Really, MRP and RL-22 are supposed to be the same thing. Just like ADI2209 and H4350 are the same thing.

As RIP has said, it is an extruded "stick" powder, and is very similar to Reloder 22 (if not the "same").

RSY

Despite RIPs peculiar affection for Merkel actions (that’s a joke RIP ), he’s right… Art Alphin FWIW confirms that the two are the same in his manual “Any Shot You Want.â€

BUT – for safety's sake - do your own homework when developing your loads.

Deke,

MRP was reviewed in the Dec 2004 Handloader Propellant Profiles by R.H VanDenburg Jr. He reports nitroglycerin content at 11.5% (on the high side); energy content of 3,831 J/g; and bulk density of 920 g/L.

Nominal kernel dimensions: length 1.5 mm, diameter 1.0 mm, perforation of .15 mm and a web thickness of .425 mm. English units are .059", .039" .006" and .017" respectively.

.30-'06 data shows 180 gr/57.6 gr/WLR primer/2,558 fps and 2,563 fps with the Fed 215 primer.

MRP is dense, so I don't think you will run out of room before pressure tops out. I have used it for years, and I like the powder. My only problem with it has been availability, which is way better now.

jim

If I did my math/conversions correctly, 1Gram=15.432Grains, 1Liter=1000Cucm, meaning that the volume of 1Grain of MRP has a volume of .0704Cucm. I believe 1Grain of RL22 has a volume of .0697Cucm, which if the energy of MRP & RL22 are equal, RL22 should be a SLIGHTLY better choice for a limited volume situation...... I guess if anyone knows the weight/volume and energy content of RL22 we could make this comparison easier . Both of these are the powders I am considering for this load.

Deke.

I used MRP for years. Since it was getting so hard to find I switched to RL22. While it is close I never found it to be exactly the same as MRP.

Gentlemen

MRP is my favourite powder for almost any caliber....

Reloader, RWS, Rauforss, Norma and a few other powders are made by Eurenco Bofors. Vihtavuori is also a part of the Eurenco family.

Foreign powders are almost impossible find but we are doing pretty good anyhow

Cheers
/ JOHAN

I used Norma MRP in my larger calibers for quite a few years and really like it. It was called Norma-205 then. It's since changed names, but I don't think the powder was altered, just the name. Best wishes.

Cal - Montreal

FYI: Another MRP/RE-22 "twin" is Winchester WXR. Made by Bofors, as well.

RSY

All so close...

Faster
*195 MRP
196 N-560
*197 RL-22
198 S-385
199 TU-8000
*200 WXR
201 N-165
202 IMR-7828
203 H-1000
204 AR-2217
*205 MRP-2
206 S-371
*207 WMR
Slower

quote:

Originally posted by ricciardelli:
All so close...

Faster
*195 MRP
196 N-560
*197 RL-22
198 S-385
199 TU-8000
*200 WXR
201 N-165
202 IMR-7828
203 H-1000
204 AR-2217
*205 MRP-2
206 S-371
*207 WMR
Slower

Supposedly MRP-2 is RE-25 in disguise (or, vice versa). Anyone verify?

RSY

Faster
*205 MRP-2
206 S-371
207 WMR
208 N-170
209 Retumbo
210 H-870
211 AR-2214
*212 RL-25
Slower

I've used MRP, MRP-2, VVN560, Re22, Re25, IMR7828ssc, and Retumbo extensivelly in a variety of calibers (i.e., 257 AI, 25-06 AI, 280 AI, 30-06 AI, and 300 WM).

I can't find a commercial source for MRP or MRP-2 at present - can any of you?

VVN560, MRP, and Re22 are essentially the same powders producing about the same velocities with nearly the same powder charges and with essentially identical case pressure signs and predictions from QuickLoad. IMR7828ssc (also long cut) is, likewise, a very near twin to this group.

Re25 is very much like Retumbo and MRP-2, although I don't think the latter two have quite the energy content as Re25. Re25 in my experience is the BEST slow burner, high-performance powder on the market - especially for the 300 WM, 280 AI, and 25-06 AI. If I can't pack enough Re25 in the case to reach 65,000 psi, I switch to Re22, 7828ssc, or VN560, all of which seem about the same in performance. 7828ssc can give quite high load densities.

I don't like H870 - too much blast - and it's dirty! I haven't tried H50BMG (ADI2218). Do you guys have any experience? - but I'm worried about too much blast again.

HunterJim,

I too have worked up some good loads using MRP for my 6.5x55 and 300 H&H. But the last Norma powder I bought was from Graf & Sons and they have since discontinued carrying it. I had planned to try to switch my loads for MRP over to RE22 as I too had heard they were ballistic twins.

Do you have a source of MRP that you can pass along? I'd sure like to keep on using it and I'm down to my last pound.

Thanks,
Brian

I looked long and hard fro MRP over the course of the last three months. I was unable to find any in the US. None of the wholesalers carry it anymore. I'm willing to buy from a retailer or a private party if anybody has anny to sell. jorge

quote:

Originally posted by Deke:
I am considering using Norma MRP for a load in my 30Gibbs, but case space could be an issue. Is this a granular or ball powder, and does anybody know how many grains there are per cubic centimeter, and/or whether it is denser than IMR4350 (if so by what percentage?)?

I found Norma N205, and later, MRP which replaced it, had a burning rate about the same as old-time surplus H4831, BUT was more dense and had smaller grains. Thus, I could use heavy charges of it in little cases, like the 7X57mm, which I could not do with H4831 because the little cases just would not hold enough to give decent velocities. However, both N205 and MRP, and now RE22, allow one to get enough into the 7X57mm and similar cartridges to produce results which are pretty eye-opening. The same should prove true in the .30 Gibbs. These powders are not quite as compact as a ball powder, but are close!!

However, for optimum performance in the 7mm Rem. Mag. with 175-grain bullets, I have found RE22 to be a tad on the FAST side. I had to go to IMR 7828 for the 7Mag with heavy bullets, in order to get the velocities I wanted without excessive pressures.

quote:

Originally posted by jorge:
I looked long and hard fro MRP over the course of the last three months. I was unable to find any in the US. None of the wholesalers carry it anymore. I'm willing to buy from a retailer or a private party if anybody has anny to sell. jorge

This is the same damn thing that has happened to me on several occasions with Norma powders-just about the time I got a real good load developed, the sob's stopped importing it!!

Also, Hodgdon dropped a real good one, H205, and it was the ONLY powder that let me get 2600 FPS with 200-grain Noslers out of my 8X60RS SXS double with acceptable pressures. Now I use RE22 in the 8X60, and get 2400 instead - accurate, yes. But 200 FPS slower!!

El D, you should try RE25 or Retumbo in your 7mm Mag. You might like the results.

quote:

Originally posted by Ackley Improved User:
El D, you should try RE25 or Retumbo in your 7mm Mag. You might like the results.

Thanks! I will! I think I'll also try VV560 or a similar VV powder - I have been hesitant to try any of these "exotics" because I was afraid that as soon as I found a good load, the stuff would disappear from the dealers' shelves, as has Norma at least twice in the past 40 years.....

Well I loaded up some 168TSX and 180XLCBT pills w/RL22 in the Gibbs and was quite pleased. The 168's hit max @ 3050fps which was 50fps faster than RL15. The 180's hit max @ 2948fps which was 63fps faster than my H414 load. Looks like I will stick w/the 180's if they shoot 1.25MOA or better (they shot 1.00MOA or better w/the H414 which was a temp sens pwdr).

Deke.

Deke, how do you decide a load is "max?" How long is your barrel? Regards and happy shooting, AIU

AIU,

Judging by your handle, I (like you probably have), have played a fair amount with hand loading and believe I am a good "technical" handloader. Since I mentioned the Gibbs I will address it in particular.

First of all I have a commercial mauser action (very strong that will vent gases safely through the mag box if I ever get to that point which I have once and God forbidding won't do on a regular basis) with a 24" sporter barrel that I consider on the thick side. Secondly, when playing with a wildcat (I also have a 3030AI), I research/read and talk to others as much as possible, know where the max loads probably are, then take things methodically slow. With my Gibbs in my Mauser setup, I have pushed hard enough to loosen pockets and blow a primer (once! ), I have carefully observed cases to that point and noted that with my prefered brass (R-P .280Rem), I get extractor marks on the head 1-2gr prior to the stretched primer pocket or blown primer situation. I back off .5-1gr from where I get ANY extractor marks and call that max for this rifle. I also track my progress along the way with my chrony and by taking pressure ring measurements in once-twice fired brass. My safe max PR for my chamber is .4705"-.4707" and have found the extr marks show up slightly @ around .4710". I have tested case life at this max and found that I get 10+ firings with the primer pocket still holding the primer okay and no other type of case failure.

With my 3030AI in my 1938 Marlin w/24" barrel, it is knowing where the max loads probably are, and then monitoring my chrony and PRE with once-twice fired brass since it does not show visible signs on the case and primers like the higher pressure cartridges do.

How about you, how do you determine max, and what wildcats do you play with?

Deke.

I shoot as many of my own designed wildcats as factory. When I'm working up a load I will mic each case head before and after firing. If I get .0005" expansion I call that max and back off a touch.

Some interesting info here as well.

http://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf

Deke, your experience is exactly mine, but I don't mic the case heads - I follow extracter marks, primer pocket loosening with a hand primer (poor-man's case head mic), and use Quick Load to estimate internal pressures.

Like you, I'll workup a new load by increasing powder charge in 0.5 gram increments until I get "significant" primer pocket loosening or extractor markes (~65 to 70,000 psi). This usually occurs 1 or 2 grains before a blown primer (~75 to 80,000 psi). I like to get ~5 reloading from a case before the primer pocket gets too lose to use - that is, if I can push the primer back out of the case by hand, I discard the case. Cases act as my "copper" crusher (i.e., "brass" crusher), and they are cheap and expendable.

I have custom made guns with after-market barrels and trued bolt actions. I like using the slowest burning powders possible for my maximum hunting loads - especially, Re22, Re25, Retumbo, IMR7828, and Vn560.

Re25 has been my work horse. In fact, with 70 grs. of Re25 behind a 180 gr. NBT, I'm getting 3100 fps (Oehler 3 screen spaced at 4 ft.) with a 26" barrel in a 30-06 Ackley Improved - awesome - AND, at ~65,000 psi with no pressure signs. How does that Gibbs perform? At ~65,000 psi I'm getting 3200 fps with Re22 with a 165 gr. NBT.

quote:

I used MRP for years. Since it was getting so hard to find I switched to RL22. While it is close I never found it to be exactly the same as MRP.

RL 22 is close, but no cigar.

RL 22 will not duplicate the same MV @ the same pressure when "pushing the envelope".

Pressure will "max out" with RL 22 before MRP

Vv N560 is a great HE powder, but it will get into high pressure sooner than RL22.

I wish I could find some MRP!!!

AIU,

Sounds like your pressure detection methods are very similar to mine. That 26" barrel is pushing your performance beyond mine. My Gibbs shoulder was held back .05" so I can fire 06 factory ammo, but using the Gibbs profile still nets a tad more case volume and with the shallower shoulder slope I believe offers better feeding. Using tougher bullets that produce more pressure than the BT's is also slowing me down a bit, but I don't mind the tradeoff (especially when my 180Barnes load equals the published Winchester ballistics for a 300WinMag using 180gr failsafes). Never thought of RL25, maybe that is next....

Deke.

BTW, is RL25 denser than RL22, and if so by what percentage (if someone could fill a case with each and weigh, I would appreciate it). Approx how much more powder (%) does it take for RL25 to equal RL22 so I will know if a gain in velocity is likley? My RL22/180XLCBT load is compressed so it might not be better.

Deke.

Deke, I went to the bench and took out a 30-06 AI Winchester Super-X case and tapped in the following powders, filling the case to the absolute top (or brim) each time. This is how much of each I could get in:

Retumbo - 71.0 grs.
Re22 - 72.0 grs.
MRP - 72.2 grs.
Re25 - 73.0 grs.
7828ssc - 74.2 grs.
7828(std) - 69.4 grs.
VVn560 - 75.3 grs.

Obviously, Lapua, R-P, and recent Win cases will take less. I don't think the 7828ssc will compress well; the others compress quite well.

Regards and happy shooting - AIU

AIU,

Thanks for weighing those for me.

Looks like the vvn560 is a bit faster than the RL22 so I'm thinking I probably won't see a velocity gain with it. The 7828ssc looks like it could offer better velocities, but with it not compressing as well as RL22, I am probably looking at only 1.5gr more than the RL22 (currently have 67.0gr safe max w/180XLCBT), and I don't know if that much more is going to be worth it to me (lets say 15-25fps is worth it with a granular, 40-50fps is worth it with a ball). Also with the RL25 I could get 1gr more, but again I don't think that will give me a large enough velocity gain. What do you think?

Deke.

Deke, I would think in that 30 Gibbs you should be able to get 70 to 71 grs of Re25 (even more) and still compress the powder with no trouble - that is, the bullet will not push out over time. In my 30-06 AI, I've loaded up to 71.5 grs. of Re25 behind a 165 gr. NBT without difficulty. I would suggest behind that 180 grs. bullet (esp. a stiff solid Barnes bullet) you'll achieve maximum velocity with the least pressure with the Re25 (i.e., ~65,000 psi with ~3035 fps in a 24" barrel). In my 30-06 AI 67 grs. Re22 behind a 180 gr. bullet would be quite HOT. Also, don't give up on Vn560 and 7828ssc, you may get a "perfect" lot with the burn characteristics your looking for. They are worth a try, but I'd try only after I had worked with the Re25, which has been the BEST slow-burner I've encoutered - that is, velocity, accuracy, consistency, and low pressures. Regards and happy shooting, AIU

AIU,

Alright, I'm gonna try the RL25 (the prospects are too good to resist). I think you said you use quick load. If you wouldn't mind, could you work up a RL25 load that equals pressure of a 67grRL22 load w/Barnes 180XLCBT's in a 30Gibbs and/or 300RSAUM(found it to CLOSELY mirror my Gibbs, not sure which quickload will calc for) for an idea of when I will reach max?

Thanks for all your help,
Deke.

Deke, I'll run QL tonight - it has 30 Gibbs in the file. But, I need to know some things to fine tune the output (although in regards to you I know some of the answers already, but this is the info I need)

1. OAL of your 180 load - base to tip of bullet.
2. Bullet make and type (Barnes....?)
3. Barrel Length.
4. Your measured average muzzle velocity
(+/- high/low would be nice but not necessary)
5. grains and type powder (i.e., 67 grs. Re22)
6. Fired case volume (in grs. of water) filled to the absolute brim - otherwise I must use what QL provides for the 30 Gibbs.
7. How many grs. of Re22 you can get in a re-sized case, when tapped in and filled to the absolute top.

I can take care of the rest. Regards and happy shooting, AIU

Deke, FYI, when I "pack" the powder in, I use a long drop-tube funnel, which I purchased from Sinclair. I measure out each charge on my powder scale and tap the base of the case on the bench as I gradually feed the powder incrementally into the funnel. After this, I use a metalic spoon to tap the case directly, but gently, for 10-20 seconds. (Hornady must be using a similar technique to hyperfill their light-magnum ammo with slow-burning powder.) Finally, I compress the bullet on top of the tap-packed powder. You need a tight neck to hold the bullet, but with Re25, I've been able to compress successfully, even after all of the above packing. With this technique, you should be getting 3000 fps + velocities with 180 gr. bullets with your 30 Gibbs - easily. IMR7828ssc tap-packs extremely well (as does Vn560), hence you may not compress it as easily - it's already at high load density.

AIU,

Thanks a bunch. Will look for your info and hopefully load some up tonight.

1. 3.350"-3.400"
2. Barnes 180XLC Boat Tail
3. 24"
4. 2948fps using above and 67grRL22
5. 67grRL22
6. 72.4gr water
7. 68grRL22 (tapped when completly filled, some spills out, 68gr maybe a tad more remains.

Don't have a long tubed funnel, but have allways thought of getting one. I use my finger nails and thump/tap a dozen times or so to pack down powder. How much powder can you fill the case with before setting the bullet?

Deke.

Deke, putting your parameters into the computer and running QL, the following predictions spit out. Please keep in mind, that QL uses "average" powder parameters as provided by the manufacturers, and there are significant lot-to-lot variations that cannot be easily accounted for. That withstanding, here it is.

QL predicts a pressure of 69,912 psi and 3050 fps, when using 67 grs. of Re22 behind a 180 Barnes XLC-BT. BUT, 62,319 psi is predicted when Re22 is used to push the same bullet at 2948 fps. Thus, you're likely operating closer to 62,000 than 70,000 - that is, given your measured velocity. You have a relatively slow lot of Re22 - that's good!

Now, given that Barnes 180 XLC-BT, what powders will give you the best overall performance, when operating pressure is limited to 65,000 psi. They are:

MRP 66.6 grs. ~3022 fps
Re25 70.5 grs. ~3018 fps
N560 66.2 grs. ~3001 fps
Re22 65.7 grs. ~2985 fps
7828ssc 65.4 grs. ~2975 fps

BUT, if you're willing to switch to a different bullet - e.g., 180 Nosler BT (I've killed many elk with this bullet, and they drop in their tracks. But, you may prefer the Nosler Accubond which gives similar performance) - you'll achieve the following performance, and you'll be at ~65,000 psi.

MRP 68.3 grs. ~3050 fps
Re25 69.9 grs. ~3043 fps
N560 67.8 grs. ~3031 fps
Re22 67.3 grs. ~3014 fps
7828ssc 67.0 grs. ~3004 fps

Finally, with 67 grs. of Re22 and a 180 gr. NBT, QL predicts a velocity of 2998 fps and a psi of 63,778. At the same PSI (63,766) Re25 (69.6 grs) will give you 3027 fps.

But, there is no real need to switch bullets, because the Barnes XLC-BT has a higher BC (.552) vs the NBT (.507) and by 200 yds. the Barnes bullet is going slightly faster than the NBT and at 600 yds. the Barnes bullets has ~100 ft.lbs more energy - their trajectories are essentially identical.

Remember, these are all predictions, but amazingly close to reality, when checked. Proceed with caution and workup from below - but, you know all about this.

Regards and happy shooting, AIU

AIU,

I got 70gr of RL25 in the case tapping each 1/3 as it went in. With a little luck I will try them (67gr-70gr) out tomorrow and let you know how it goes.

The Partition is an excellent bullet and if I was going to use one load for Elk and Deer it would be the bullet of choice (still not impressed with the new bonded bullets for Elk). This load is strictly for Elk and I like its ability to penetrate giving me the best chance of two holes, not to mention the high BC.

Thanks Again,
Deke.

There's a lot of real good info in this thread!!

Well it looks like the RL25 performed significantly less than the RL22 (go figure.... ). I stopped @ 69.5gr to save bullets where I got 2794fps and a PR of .0002" below max. Based on steady velocity increases and their corresponding PR's, I roughly calculated that I would reach max safe @ 70-70.5gr and a velocity of approx 2820-2835fps which is a far cry from the 2948fps I got with 67grRL22 which I am very happy with (equals the published ballistics for Winchester Factory 300WinMag180Failsafes). Now to play with OAL to get it accurate enough, but will have to wait a couple months while I finish some 7-08 load development for silhouettes and hopefully pronghorn & mule deer.

Deke.

Deke, that's weird - not c/w my experience with Re25, nor that predicted by QL. You may have a very slow lot of Re25, and I a relatively fast lot. I have a 300 WM (26" barrel), and with 83 grs. of Re25 and 180 gr. NBTs, I average 3275 fps. Alliant claims that 82.3 grs of Re25 (24" barrel) will drive 180 spitzer bullets to 3176 fps. With 70 grs. of Re25 in my 30-06 AI (26" barrel) I get 3100 fps consistently. I use a Oehler 3-screen chronograph with 4 ft. spacing.

But, if your Re22 is working to your satisfaction and you have confidence in it, why change. But, you may want to try some Vn560 - who knows, you may fall in love. Also, have you tried the Lost River Ballistics J36 180 solids - they claim a BC of .672!

Regards and safe/happy shooting, AIU