Can't seem to put too much powder in this load??????

[amlevin]

Went out Friday to shoot some .223 ammo I loaded using 2000-MR and 77 gr Nosler Custom Competition bullets.

Didn't have much to work with for starting data as Alliant only shows a single load for 77 gr bullet in .223 with this powder. 25.2 gr and nothing else.

To be a good reloader I backed off to 24 gr and then loaded 9 more "steps" in .3 gr increments. Shot everything at 200 yards from a 26", 1:7, 3 groove barrel bolt action. Chamber was cut using a 5.56mm NATO custom reamer ground for bolt action rifles using this cartridge. Throated using a dummy case just like the ones used in this "workup".

Cases = Lapua Match and bullets seated out to the lands (2.040" at the ogive). Pressure ring right at the neck/shoulder junction.

First group I stopped after 3 shots as the primers were domed up, not even enough pressure to push the m against the bolt face. Second the same. When I hit th 25.2 gr mark I started to get a nice group going but not as small as I wanted (of course). Primers were at least starting to hit the bolt face with some authority but not evenly, giving me the feeling that pressures were not even. Shooting without the chrono that day so no speeds to rely on, just observation.

I kept shooting, right up on past the Alliant load and didn't see any sign of pressure. All primers had plenty of radius on the edge, no cratering at the firing pin hole, no ejector marks, bolt lift nice and easy and case extraction as easy as pie. My last load was 26.5 gr of the 2000-MR and it was still about 1/16" below the case wall/shoulder junction. In short, far less than a full case. Groups were starting to close up again after the fairly nice group with the 25.2 gr load and primer's started to appear more uniform than with the lighter loads.

Now the question(s):

With a cartridge that is showing absolutely beginnings of pressure, and more room for powder before even getting close to compressing the load how far would one go with this powder? This rifle has been throated for the heavier .223 bullets and the base is just above the shoulder/case wall junction when touching the lands.

Does anyone else have experience with the Alliant Power Pro 2000MR? If so, what have you found to be the upper limits for charge weight and what speeds can I expect when I finally run these loads over the chronograph.

Is there any better information available than what Alliant is publishing. Find it strange that they would publish only a single charge weight.

 

[pacificman]

Don't mean to waist your time as I don't have any experience with 2000-MR but when using other Alliant powders I have noticed that they seem to be on the conservative side with the use of their listed loadings. At least that is my experience using at least 4 other powders they make.
Seems I have loading info for everything but 2000-MR. I have info for "power pro varmint" ...I'm thinking that is not the same? ???

 

[pauls]

I first started using 2000-MR when I purchased a 16.5" Remington AAC-SD in .223. I am using 69 grain Sierra MK's, loaded to an overall length of 2.30" ( typical long throated Remington ). LC brass, Tula SRM primers. The load is 28.5 grains loaded through a long drop tube ( worked up to in .2 grain increments ) and gives me 2926 fps in that 16.5" barrel ( suppressed ). Still no high pressure signs. Thought about trying to bump it up enough to get 3000 fps out of it, but it shoots into 1 tiny little hole at 100 yards. Went 10/10 on a 12" steel plate at 800 yards off a bipod with it back in the fall. I like it enough that I bought 8, one pound cans of it ( couldn't find any 8 pounders ).

 

[mic2377]

My experience has mirrored yours - I didn't think I was able to get enough powder into the case to go seriously over pressure. Of course my max is different due to mag-length constraints.

I was shooting Hornady 75 HPBT's, loaded to mag length (2.260), in FC brass, and CCI-400 primers. I have developed AR loads using CCI-400's before to use them as a "fuse" as they will occasionally pierce when my 75 HPBT/Varget loads got too hot. I got up to 26.0 gr of 2000 MR before I was running out of case, with ZERO pressure signs observed on case and some expected primer flattening. 25.2 gr shot the best anyways so I left it there. This was out of an 18" AR-15 with a 1/8 twist medium heavy Nordic barrel.

2000 MR is a strange powder and I don't think you are getting way out of the ballpark if loading longer. When I had stopped, I for sure had 100%+ case fill at that length/charge.

 

[Laurie]

Throating and resulting max. COAL is a major factor in this cartridge. There is a big difference in pressures between heavy bullet ammo loaded for a throat needing the standard SAAMI 2.26" COAL and one that runs with bullets 0.2" further out.

Using QuickLOAD to demonstrate with the default case internal volume, 24.0gn Alliant Re15 (my version lacks 2000-MR) 77gn Sierra MK at 2.26 COAL calculates 61,052 psi PMax. Increase COAL to 2.46" (with the proviso that the jump remains constant) drops the calculated peak pressure to 51,327 psi.

A quick look at the Alliant website confirms that COAL remains at 2.26" for its 77gn bullet data and 2000-MR. Powder and bullet manufacturers are in a real quandiary here as they must assume that some users are using industry standard throated rifles, but in reality most people will have more suitably set up rigs for this sort of bullet, in which case the data is potentially misleading. It is at least a 'right-side' failure (ie falls on the side of being cautious / safe.)

 

[amlevin]

Throating and resulting max. COAL is a major factor in this cartridge. There is a big difference in pressures between heavy bullet ammo loaded for a throat needing the standard SAAMI 2.26" COAL and one that runs with bullets 0.2" further out.





. It is at least a 'right-side' failure (ie falls on the side of being cautious / safe.)

Thanks for this. I'll proceed with my load work-UP with a little more confidence now. There's still a lot of room in the case based on my COAL so I'll just lessen my increments to .2 gr and proceed.

 

[fm1947]

Thanks for this. I'll proceed with my load work-UP with a little more confidence now. There's still a lot of room in the case based on my COAL so I'll just lessen my increments to .2 gr and proceed.

I go up in powder until I get heavy bolt lift , then I stop there

 

[SheepDog]

I go up in powder until I get heavy bolt lift , then I stop there

In my mind this advice (it is offered) is a dangerous condition. By the time bolt lift becomes heavy (considering a polished and clean chamber) the load is well past any tolerance in any accepted norm. I don't care if someone overloads his own ammunition but advising another to do so is beyond negligent.

My advice to anyone looking for load data is to get information from a reliable source such as a manufacturers web site or from a manual. Work up to the maximum listed load while watching for any sign of over-pressure. If you get signs of over-pressure stop and reduce the load. Always begin with the listed information for length, primer, case and bullet type, weight and manufacturer. Once you find an accurate load you can use seating depth to fine tune for accuracy while continuing to watch for those pesky pressure signs. The manuals list loads that have been measured for pressure and found to be safe. The maximum load may or may not be safe in your gun which is why we start low and work up to the maximum.

If, after shooting this load under a wide range of conditions and you feel you need to get more from it then you can go beyond what the book recommendations with the knowledge that you are entering an area that can destroy guns and injure or kill yourself and those around you at the shooting range.

 

[Ned Ludd]

FWIW - I know a few people that have used PP2000MR in F-TR loads with both .223 and .308. What I can tell you is that their charge weights in Lapua brass relative to powders like Varget or H4895 were much higher, in some instances as much as 2 to 4 gr more (total charge weight). The velocities they were able to achieve with PP2000MR seemed almost miraculous...so high, in fact, I'm not even going to say what they were getting. However, I can also tell you that several of these folks found out the hard way that when the daily high temps went from around 80 degrees to the mid 90s, they started blowing primers right and left. This powder is definitely more temperature-sensitive than something like Varget, so if you're going to shoot long strings on a very warm day, you'll want to adjust your charge weight accordingly.

To answer your question regarding pressure signs, the first thing I would ask is whether you did the testing in virgin brass. I can't tell from your OP and so thought this worth mentioning. If so, you may not be able to make much of the primers as "pressure signs". In virgin brass, the shoulder has not yet been pushed forward and so the case has a lot of room to move away from, and back toward, the bolt face during the combustion cycle. Once the brass has been fire formed and the shoulders sized back down by about .001" to .002", that amount of movement is no longer possible. Because of this issue, it is possible to get some pretty bad-looking primer effects when using virgin brass, that are actually a function of excessive headspace, rather than truly high pressure. So it can be very difficult to tell if you were using virgin brass.

Also, the case volume of fireformed and re-sized brass will be about halfway in-between that of virgin brass and fired, but not yet re-sized brass. In other words, you effectively gain some case volume with fireformed brass, as far as the apparent fill ratio of the cases goes. Virgin brass can look very full and/or behave as a compressed load with a charge weight that is, in fact, well under 100% fill ratio. If you haven't already, you might try some firedformed and re-sized brass and see how things look in that.

 

[USMCDOC]

Back when i was using 2000MR, i was using a Barnard action, with the 90 gr VLDs, my working load for that rifle was 27.2 grs.

 

[johnu]

A couple of years ago I was considering using MR-2000 in both M1 Garand and 7.62x54r loads (Finn M28 and Molot sniper - have not loaded it in .223.) There was little to no load data and it wasn't listed on burn rate charts - not even Alliant's! So I sent an email to Alliant and here was their response:

2000MR is very slightly slower burning than RL 15. Thanks for your note.

I'd say it's amongst the very slowest powders one would consider using in .223 (hot weather notwithstanding.)

John