US869 in 7mm RM

[Joec7651]

I think I’m going to crack open an 8lb jug of US869 I bought a couple years ago. I want to work on heavies in a 26” 1:8 barrel. It’s not as long as a bench barrel but should be long enough to begin getting benefits from the slow powder. Do any of you have any experience using it with heavy projectiles, 175gr and up? Maybe 160’s but not sure they are heavy enough. My Hodgdon manual shows pretty good velocity with Hornady 162’s. H says it’s fairly temp stable but I have read otherwise. I’m not concerned much about whether it is or not.

I’ll be focusing on 175gr and up though. I would like to try it with the Berger 195gr EOL hunting bullet if I could find any in stock, 180’s would be fine too. If anyone knows of them in stock anywhere pass it on if it won’t cut into where you get them. I’ve got 175gr ELD-X, and Partitions. Along with 160gr Partitions and Hornady 162gr btsp’s. Thanks in advance.

 

[SJB358]

I’d think it should work for the heavies in the 7 Rem. I used to use a lot of H870 in my old 7 Rem Mag. 869 is slow stuff but I’d assume you should get some good speed from it if you can get enough in the case.

Shoot me a reminder as I might have some 195 EOLs on my shelf I’d probably let go. Probably 80 or so in the box if I had to guess.

 

[str8meat]

Current load 7 rem mag 2950 FPS max magazine length 1 in 9 twist Remington cdl factory barrel

 

[jimbires]

it's going to be hard to get enough in the case , max pressure is at 112.5% case fill .


if you want to run 195's in the 7 rem mag N570 , RL33 , retumbo , would be better choices , if you can find them .

 

[Joec7651]

it's going to be hard to get enough in the case , max pressure is at 112.5% case fill .


if you want to run 195's in the 7 rem mag N570 , RL33 , retumbo , would be better choices , if you can find them .

They may be better but I have 8lbs US869 on the shelf. Or, maybe it’s time for a 27 Nosler. Lol

 

[Joec7651]

If they can get 113% load density with it in a 28 Nosler then I can make 112.5% happen in a 7RM case. I’ll use once fired cases, as long as pressure doesn’t rear it’s head I’ll be ok I think. If I could get it to 2800 I’d be very happy. May have to use a different powder to get it though. That is if I can get there. Time will tell.

 

[jimbires]

Joe , 2800 FPS is about at the top for velocity , in the 26" bbl .

Cartridge : 7 mm Rem. Mag.(SAAMI)
Bullet : .284, 195, Berger ElHunt G7 #28550
Useable Case Capaci: 68.686 grain H2O = 4.460 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon US 869

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 90 60.72 2143 1989 28334 9127 79.3 1.905
-18.0 92 62.23 2206 2107 30474 9500 81.1 1.848
-16.0 95 63.75 2270 2231 32797 9870 82.8 1.794
-14.0 97 65.27 2334 2360 35324 10233 84.5 1.741
-12.0 99 66.79 2400 2494 38076 10589 86.1 1.686
-10.0 101 68.31 2466 2634 41081 10935 87.7 1.626
-08.0 104 69.82 2533 2779 44367 11270 89.1 1.568
-06.0 106 71.34 2601 2930 47967 11591 90.6 1.511
-04.0 108 72.86 2670 3087 51919 11897 91.9 1.456 ! Near Maximum !
-02.0 110 74.38 2740 3250 56270 12185 93.2 1.404 ! Near Maximum !
+00.0 113 75.90 2810 3419 61071 12454 94.3 1.352 !DANGEROUS LOAD-DO NOT USE!
+02.0 115 77.41 2881 3594 66387 12700 95.4 1.303 !DANGEROUS LOAD-DO NOT USE!
+04.0 117 78.93 2953 3775 72275 12921 96.4 1.255 !DANGEROUS LOAD-DO NOT USE!
+06.0 119 80.45 3025 3962 78791 13115 97.3 1.208 !DANGEROUS LOAD-DO NOT USE!
+08.0 122 81.97 3098 4156 86053 13280 98.0 1.163 !DANGEROUS LOAD-DO NOT USE!
+10.0 124 83.49 3172 4356 94182 13411 98.7 1.119 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 113 75.90 2985 3858 75842 12621 99.1 1.236 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 113 75.90 2587 2898 48158 11594 85.3 1.502

 

[SJB358]

Those 195’s at 2800 will float though. Don’t need crazy speeds when the BC is up in that realm. Man, that would be a wicked cool combo if it works. Chances are you can seat that bullet out a bunch if you have the mag space.

 

[Joec7651]

Thanks Jim, I really appreciate you taking the time to run it through Quickload. I’m not sure if I’ll be able to get to 2800 or not, but I think I’ll be able to get close. As far as magazine length I can seat them to 3.390” and have .010” left for small variations. So I can seat somewhat longer than SAAMI length.

Which brings me to a question……..some people see a 195gr bullet from a 7mm Rem Mag at 2800 fps and ask why settle for such a slow round. A slow Laod?! It’s a 200 grain bullet at 2800 fps! That’s what a 300 H&H will do with a 200gr load. If a 180gr bullet at 2700 fps from a 30-06 is enough for elk and moose, why is an essentially 200gr bullet(with much better SD and BC) scoffed at from a 7RM at 2800 fps. Has long range magnumitis made people so daft as they actually believe the BS? LOL.

Anyway, again Jim thank you very much. I’ll just have to see what it will do. The barrel seems to be on the fast side velocity wise so we will se.

 

[SJB358]

I don’t look at it like that at all.

I used the Hornady 212 ELD at 2700 to great effect on a bull at just about 400 last fall. It worked so well I questioned why I have other stuff.

That 195 at 2800 is straight poison, start speed ain’t high but it won’t take many 100’s of yards for that bullet to pass everything while probably keeping the edge in drift, FPS and even energy if that matters to you. And oh by the way, since you aren’t starting them at warp speed they act real well up close as well as far.

 

[Joec7651]

I agree completely. I wasn’t directing the question towards anyone here on our forum. It was more of a general question brought about by a couple “experts” at a LGS. I should have been more clear on that.

When I hear statements like “why would you want a load that slow from a magnum” makes me discount anything they say from that point forward. Or past for that matter. That’s why I called it magnumitis. LOL.

When I heard them say it I laughed before I could stop myself.

 

[jimbires]

all you can do is try it . I don't have any 195 Bergers , I'm not sure how the on game performance is . be sure the hollow point hole is open . be sure your die doesn't distort the bullet at all , especially with this highly compressed load . double check your COAL the next day . I've had compressed loads push the bullets out a little after setting over night .

 

[SJB358]

all you can do is try it . I don't have any 195 Bergers , I'm not sure how the on game performance is . be sure the hollow point hole is open . be sure your die doesn't distort the bullet at all , especially with this highly compressed load . double check your COAL the next day . I've had compressed loads push the bullets out a little after setting over night .

I'd bet if he can stretch it out a 1/10 and not be jamming the lands he will gain a little space there. I know that bullet shot amazing for me at nearly 3K in my Mashburn, but I never messed with them too much. I think I shot 16 of them.

 

[Joec7651]

My primary seating die is a Redding Competition Seating Die. I have their VLD stem in the micrometer which is profiled for Berger’s. It works just as well for ELD-X and standard bullets. I think the Berger will do fine. I’m not going to over complicate it. Prep the brass, prime it, charge it, seat the bullet to mag length, and work up till I can’t fit any more in the case or get pressure. Then Shazam! Dead critters.

Berger 180 VLD hunting bullets shoot well so maybe the 195’s will too. If it doesn’t shoot well it wouldn’t be the first, but it will be enjoyable finding out. It will have to shoot awfully tight to beat out my 308 and 270. It’s the journey, not the destination.

 

[jimbires]

I'll be real interested in your results . good , bad , or ugly , please post them up . I shoot bergers in two rifles . one rifle likes them jam into the rifling so much I can't eject a unfired round without the bullet getting stuck in the barrel . the other rifle likes a jump , I forget how much .

 

[Joec7651]

Worked up charge weights for Berger 180gr Hybrids. Both rifles are shooting 79gr of US 869 without pressure signs and well enough to start changing seating depths. The max for both turned out to be within a half grain of each other so I took the lower charge of 81.3 grains as max for both. Not sure about velocities yet but they shoot well. I have the rounds for the Remington seated to Mag length 3.350” at .060” off. The rounds for the TC Compass II are a little short of Mag length of 3.460” which are .015” off the lands. Now I’ll start adjusting the seating depth to see what each rifle likes. The Remington has a rifling twist of 1:8, and the Compass has a 1:9. I’ll post photos when I get them nailed down.

 

[SJB358]

Joe, I just remembered I have some bullets on my counter for you. Hopefully I will get them out to you this weekend.

 

[Joec7651]

One thing that concerns me is that the loads are far above what Jim’s Quickload information shows they should be with 195’s. These are 180 Hybrids but there is quite a bit of difference in manufacturers recommendations. I went with the 180’s because the 195’s would need to be seated past the ogive to fit I’m the magazine of my 1:8 twist rifle. The 180’s will work in both rifles, one with 1:9, and the other rifled 1:8.

I’m not getting any signs of excess pressure, but could they look ok and still be over pressure? Hodgdon shows a max of 77gr with a 175gr Partition, and my Lyman manual shows 79gr as max. I’m .045” over SAAMI COAL in one and .165” over in the other. Bullets in both loads are coated with HBN.

They chamber fine with only neck sizing. No heavy bolt lift. Primers look good. Cases only stretched .002-.003” from the 2.490” trimmed length. I haven’t run them over my Magnetospeed yet but will during the next range session.

Are over pressure situations less visible with very slow powders? Is it possible I’m not over pressure? Am I right to wonder, or am I trying to find a problem where none exists? I don’t want to over stress my rifles and cause damage to them, myself, or others near me.

 

[SJB358]

Joe, without a chrono you're just guessing. Let the chrono tell you where you are at.

Typically if everything is functioning nicely and you're getting 5 or more loads per case, your chrono isn't showing insanely higher than book speeds you're okay.

Hope that helps. Each and every rifle acts different and the 180 Berger has much less bearing surface so it'll be faster than a PT or similar.

 

[jimbires]

Joe , here is a 180 hybrid data . there is a lot of tweeking that needs to be done to quickload , before you call it absolute . these are just quick and dirty info that should keep you out of trouble . like Scotty said , chrony info will tell us a lot . it sounds like you're getting something promising worked up . thanks for the update .

this is SAMMI COAL

Cartridge : 7 mm Rem. Mag.(SAAMI)
Bullet : .284, 180, Berger Hy Tgt G7 #28407
Useable Case Capaci: 70.939 grain H2O = 4.606 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon US 869

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 91 63.20 2214 1960 28072 9210 77.6 1.845
-18.0 93 64.78 2280 2078 30209 9598 79.4 1.792
-16.0 95 66.36 2347 2201 32530 9983 81.2 1.740
-14.0 98 67.94 2415 2331 35062 10363 82.9 1.687
-12.0 100 69.52 2484 2466 37824 10736 84.6 1.635
-10.0 102 71.10 2554 2606 40841 11100 86.3 1.575
-08.0 104 72.68 2625 2753 44146 11453 87.8 1.518
-06.0 107 74.26 2696 2906 47773 11793 89.3 1.462
-04.0 109 75.84 2769 3065 51761 12118 90.8 1.408
-02.0 111 77.42 2843 3230 56159 12425 92.1 1.357 ! Near Maximum !
+00.0 113 79.00 2917 3402 61022 12711 93.4 1.306 !DANGEROUS LOAD-DO NOT USE!
+02.0 116 80.58 2993 3580 66419 12976 94.6 1.257 !DANGEROUS LOAD-DO NOT USE!
+04.0 118 82.16 3069 3765 72424 13215 95.7 1.210 !DANGEROUS LOAD-DO NOT USE!
+06.0 120 83.74 3146 3957 79117 13425 96.6 1.164 !DANGEROUS LOAD-DO NOT USE!
+08.0 122 85.32 3224 4156 86580 13605 97.5 1.119 !DANGEROUS LOAD-DO NOT USE!
+10.0 125 86.90 3303 4362 94961 13751 98.3 1.076 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 113 79.00 3106 3855 75918 12975 98.7 1.193 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 113 79.00 2681 2872 48176 11749 84.0 1.451