7mm Mashburn Super Magnum

[joelkdouglas]

I saw this on the Nosler site today:

http://www.28nosler.com/#introduction

Brass wouldn't need forming...but it's not cheap! At least it's good brass.

 

[FOTIS]

viewtopic.php?f=4&t=29854

 

[SJB358]

Yeah, I saw that. Should be about the same in powder capacity and 300 Win cases are easier to come by. I'm always skittish of buying things where only 1 maker builds brass. I know Nosler isn't going away but I'm leery of it nonetheless.

I don't think a 3.34" COAL is going to really let the 28 Nosler strut it's stuff. It leaves very little slack to adjust bullet position. Not sure what length Noslers M48 has for a mag box. If it's in the 3.6 range that would seem to work decent.

Either way, I'm running the Mashburn for now. I guess if I ever wear this barrel out I could do a 28 Nosler in about 10 years!!! HAHAHAHAHAHA

 

[muleman]

Scotty,
The Mashburn is a super cool round! It should run between the RUM and the STW. I think your next one should be the 404 Jeffry or maybe the 275 Rigby. I'm hoping you did it on a Win 70?

I'm building my 28 Nosler on a Win 70 RUM action so my box is already 3.6+ and I'll throat it to take advantage of it. I'm looking forward to slinging 175gr ABLRs at 3150+.

 

[SJB358]

Scott your 28 Nosler will whoop some butt! Wow, 175's at that speed would negate owning much else for western hunting. That is just awesome.

Thanks for the drawing. I'll save that to my files. Can't wait to get this rifle back and yes, it's a Model 70. Is there any other kind? :grin:

 

[BobT]

Missed this one somehow! I have been playing with the 7mm Mashburn for a couple of years now, you will like it! I have hit a couple of snags along the way but they were brass quality issues and my chronograph dying. I don't have much for velocities yet but I was averaging 3227 with the 160 Sierra from a 24" barrel. If I can help let me know.

 

[SJB358]

Missed this one somehow! I have been playing with the 7mm Mashburn for a couple of years now, you will like it! I have hit a couple of snags along the way but they were brass quality issues and my chronograph dying. I don't have much for velocities yet but I was averaging 3227 with the 160 Sierra from a 24" barrel. If I can help let me know.

Bob, you have already helped! I would love any of your load data that you would care to share. Should have the rifle within a few weeks. I haven't decided on brass yet, so if you could let me know what you had that wasn't very good, that would be good to know as well.

I am hoping for 3200 with 160's and a comfortable over 3000 with 175's. The rifle is being chambered for a 160 AB at 3.603". I figure it'll work well once it's seated .030" off the rifling. All the other bullets I use should fall somewhere in there as well.

Again, thank you for anything you can pass my way. Scotty

 

[BobT]

Scotty,
The brass I had trouble with is Winchester, newer stuff, the primer pockets were shallow. To size for the initial fire form I run new unlubed Winchester cases into the full length sizer, load and shoot them. With new WW Super brass, trimmed to 2.600" (trim length is 2.625 I believe) and sized in the Mashburn FL die H20 capacity is 84 grains, with the same case fire formed in the Mashburn chamber is 90 grains H20. I trimmed my cases a little short because that is where they all cleaned up.
I think you should hit your numbers pretty easily form the limited data I have. The Mashburn seems to mirror the STW with 2 inches less barrel.
I will dig out my data but you probably already have it, mine came straight from a Bob Hagel article in either Rifle or Handloader magazine.
My reamer is a PTG, print #15106 except it has a short throat (.090) and I'll use a seperate throating reamer to lengthen it as I need to.
My test platform is a Stevens 200, I always use a Stevens or Savage for my initial testing of a new wild cat just because it is so easy to change things around then I have a good fire form barrel without wearing out a custom tube.
I got in a couple hundred 175 grain LRAB's in today and am anxious to try them out.

 

[SJB358]

Bob, great info buddy. I borrowed a reamer that was made by JGS. We shall see what it does soon I think. It was throated longer for the 160 AB, but it should work out decently will all similar 160-175 grain bullets.

That is almost exactly what I was looking for when you mentioned matching the 7STW with less barrel. Didn't understand how it would come close till I started seating bullets and the light bulb went off.

Pretty sure if it comes out good, I'll take it to Wyoming this Fall and see how it works. I don't expect any surprises since the rifle shot very well as a 7mm Rem Mag, so I am hoping it continues to deliver the goods..

 

[mrandrew]

Cool round Scotty, like some of you I read about the Mashburn in Hagel's writings as a young guy and was intrigued. With those long 175 gr Partition's he got exceptional penetration on big moose and also took one of the most beautiful caribou I have ever seen with a 160 gr PT.

As a side note I find the 6.5mm Saum very interesting, I do wonder if the data was pressure tested how much lower the reported speeds would be.

Yup, I've read the same stuff Gerry. I haven't really decided which bullet to start with to be totally honest. A 160 at 3200 seems really good to me. 300 yard zero, 7-9" low at 400 and 18-24" low at 500. That's pretty good stuff in the high country if you ask me. I have a huge pile of red tipped 160 ABs so they might get the nod. Not sure there is a bad choice in the mix. I really liked what I saw from the 150 Swift too. It's got good BC and it should be able to be launched pretty hard. I like the bullet a bunch as well.

I also have a 7mm mashburn. Mine is an old reamed out Remington 700 adl. It is even bedded and floated in the factory Remington stock.

Favorite loads are...
norma mrp
120 tsx 3500 fps
140 tsx 3320
150 swift scirroco 3180

imr 7828
150 ballistic tip 3220

My rifle hasn't given me the screaming velocities that are often talked about when the mashburn is mentioned. In fact I think that when comparing my gun to the 7mm weatherby my gun may take a second seat. For example my gun runs at max when loaded with 71 grains of 7828 and a 150 ballistic tip. The hodgdon website says that a 7mm weatherby can go to 72 grains of powder.

I won't knock the mashburn because I have only played with this particular gun and because the accuracy of the round seems to be quite acceptable. For instance my gun shoots 1.5 inches at 200 yards all the way from 69.5 to 71 grains of 7828. Brass can be a pain to keep sorted into lengths that are about the same although a company named quality cartridge company has also started making runs of new 7mm mashburn brass although the price of 2.50 a case seems realllllllllllllllllllllllllyyyyyyyyyyyyyyyyyyyyy steep.

 

[IdahoCTD]

Weatherby cases usually have a ton of freebore so if one shoots more powder than yours that is easily explainable. The freebore basically acts like it has more case capacity. If your barrel is only 24" long like most of the old 700 7rm's were then your velocity is acceptable IMO. With the heavier bullets a slower powder would give you more velocity. I shoot H-1000 in my 7-300wm's with 162's at 3260 in a 27" barrel and 3290 in a 28" barrel. Your 150gr load is close to those velocities with a shorter barrel and a faster powder.

 

[mrandrew]

problem with the mashburn is that guys say that it shoots 3250 with a 160 in a 24 inch barrel....I haven't seen that yet.......

 

[SJB358]

Thank you for the info Mrandrew. Even 3200 with the 150's is pretty danged good. I am looking forward to the working with the rifle some. Being an old rechambered Winchester, I am not expecting miracles but I think it should be fun.

What kind of COAL's are you using with your loads?

 

[mrandrew]

I think that my gun is throated for a 175 grain Partition to 3.565. Most of my stuff is loaded to 3.4 something which is where I found the best accuracy. One of my best loads out of my 24 inch barrel is that 120 grain barnes in a federal case with a federal large rifle match magnum primer. buzzes out at 3500. That's about 75 fps short of what a 7mm weatherby is supposed to push that bullet.

 

[SJB358]

Got ya, I am having mine chambered so a 160 AB loaded to 3.603" is AT the rifling. I figured once I get the required jump into the rifling, I should be in great shape as far as OAL.

Great info. Found a cartridge on QL called the 7mm Boo Boo that seems to be close if not nearly identical to the Mashburn, so it gives me something to play with while I wait.

Great info though MrAndrew. I appreciate it all. Scotty

 

[mrandrew]

what does it say about the boo boo as far as max loads with a 150,160, or 175 grain.

 

[SJB358]

This is what I am looking at.

Cartridge : 7 mm BooBoo
Bullet : .284, 150, Nosler BalTip 28150
Useable Case Capaci: 83.541 grain H2O = 5.424 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-25

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 81 62.40 2575 2209 32072 12260 96.7 1.559
-18.0 84 63.96 2641 2323 34314 12589 97.7 1.520
-16.0 86 65.52 2707 2440 36718 12890 98.5 1.482
-14.0 88 67.08 2772 2560 39294 13160 99.1 1.433
-12.0 90 68.64 2837 2681 42056 13397 99.6 1.388
-10.0 92 70.20 2901 2804 45018 13599 99.9 1.344
-08.0 94 71.76 2965 2928 48201 13764 100.0 1.301
-06.0 96 73.32 3028 3054 51620 13905 100.0 1.261
-04.0 98 74.88 3090 3180 55296 14042 100.0 1.221 ! Near Maximum !
-02.0 100 76.44 3152 3308 59252 14175 100.0 1.184 ! Near Maximum !
+00.0 102 78.00 3212 3437 63475 14304 100.0 1.148 ! Near Maximum !
+02.0 104 79.56 3273 3567 67984 14428 100.0 1.113 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 81.12 3332 3699 72813 14548 100.0 1.079 !DANGEROUS LOAD-DO NOT USE!
+06.0 108 82.68 3392 3832 77988 14663 100.0 1.047 !DANGEROUS LOAD-DO NOT USE!
+08.0 110 84.24 3451 3966 83541 14773 100.0 1.016 !DANGEROUS LOAD-DO NOT USE!
+10.0 112 85.80 3510 4103 89506 14877 100.0 0.986 !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 102 78.00 3332 3697 77495 13829 100.0 1.058 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 102 78.00 3029 3057 50278 14850 99.3 1.267


Cartridge : 7 mm BooBoo
Bullet : .284, 150, Nosler BalTip 28150
Useable Case Capaci: 83.541 grain H2O = 5.424 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : IMR 7828 SSC

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 76 60.00 2546 2159 32214 11884 90.5 1.547
-18.0 78 61.50 2612 2272 34415 12280 91.9 1.508
-16.0 80 63.00 2678 2388 36771 12661 93.1 1.471
-14.0 82 64.50 2744 2508 39288 13026 94.3 1.423
-12.0 83 66.00 2810 2630 41979 13373 95.4 1.378
-10.0 85 67.50 2876 2755 44860 13700 96.4 1.335
-08.0 87 69.00 2942 2884 47944 14004 97.3 1.294
-06.0 89 70.50 3008 3014 51248 14285 98.0 1.254
-04.0 91 72.00 3074 3147 54792 14539 98.7 1.216
-02.0 93 73.50 3140 3283 58593 14767 99.2 1.179 ! Near Maximum !
+00.0 95 75.00 3205 3421 62651 14965 99.6 1.143 ! Near Maximum !
+02.0 97 76.50 3269 3560 66976 15133 99.8 1.109 !DANGEROUS LOAD-DO NOT USE!
+04.0 99 78.00 3334 3701 71606 15270 100.0 1.075 !DANGEROUS LOAD-DO NOT USE!
+06.0 101 79.50 3397 3844 76568 15375 100.0 1.043 !DANGEROUS LOAD-DO NOT USE!
+08.0 102 81.00 3461 3989 81890 15469 100.0 1.013 !DANGEROUS LOAD-DO NOT USE!
+10.0 104 82.50 3523 4134 87606 15558 100.0 0.983 !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 95 75.00 3348 3733 75489 14445 100.0 1.055 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 75.00 3001 3000 50454 14726 94.6 1.257


Cartridge : 7 mm BooBoo
Bullet : .284, 150, Nosler BalTip 28150
Useable Case Capaci: 83.541 grain H2O = 5.424 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon Retumbo

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 87 67.20 2540 2150 30635 12610 93.7 1.583
-18.0 89 68.88 2612 2273 32867 13028 95.2 1.541
-16.0 91 70.56 2684 2400 35273 13414 96.5 1.500
-14.0 93 72.24 2757 2531 37870 13764 97.6 1.456
-12.0 95 73.92 2829 2666 40670 14075 98.5 1.406
-10.0 98 75.60 2901 2803 43701 14343 99.2 1.358
-08.0 100 77.28 2973 2944 46977 14566 99.7 1.312
-06.0 102 78.96 3044 3086 50526 14740 100.0 1.267
-04.0 104 80.64 3115 3231 54370 14866 100.0 1.224
-02.0 106 82.32 3184 3377 58549 14977 100.0 1.183 ! Near Maximum !
+00.0 108 84.00 3253 3525 63092 15083 100.0 1.143 ! Near Maximum !
+02.0 111 85.68 3322 3675 68038 15183 100.0 1.104 !DANGEROUS LOAD-DO NOT USE!
+04.0 113 87.36 3390 3827 73432 15277 100.0 1.067 !DANGEROUS LOAD-DO NOT USE!
+06.0 115 89.04 3457 3980 79329 15365 100.0 1.032 !DANGEROUS LOAD-DO NOT USE!
+08.0 117 90.72 3524 4136 85786 15445 100.0 0.997 !DANGEROUS LOAD-DO NOT USE!
+10.0 119 92.40 3591 4295 92870 15519 100.0 0.964 !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 108 84.00 3396 3842 78966 14493 100.0 1.046 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 84.00 3032 3062 49795 15535 98.1 1.270



Here is some looks with the 160's.


Cartridge : 7 mm BooBoo
Bullet : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 83.776 grain H2O = 5.439 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon Retumbo

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 86 66.40 2492 2206 31132 12799 95.2 1.617
-18.0 88 68.06 2561 2330 33383 13190 96.5 1.574
-16.0 90 69.72 2630 2457 35807 13547 97.6 1.533
-14.0 92 71.38 2699 2588 38418 13867 98.5 1.486
-12.0 94 73.04 2767 2721 41233 14147 99.2 1.435
-10.0 96 74.70 2836 2857 44272 14383 99.7 1.387
-08.0 98 76.36 2904 2996 47553 14573 99.9 1.340
-06.0 100 78.02 2971 3136 51101 14716 100.0 1.295
-04.0 103 79.68 3038 3278 54941 14844 100.0 1.252
-02.0 105 81.34 3103 3421 59104 14967 100.0 1.211 ! Near Maximum !
+00.0 107 83.00 3168 3566 63622 15084 100.0 1.171 ! Near Maximum !
+02.0 109 84.66 3233 3713 68530 15196 100.0 1.132 !DANGEROUS LOAD-DO NOT USE!
+04.0 111 86.32 3297 3862 73872 15302 100.0 1.095 !DANGEROUS LOAD-DO NOT USE!
+06.0 113 87.98 3361 4013 79699 15402 100.0 1.059 !DANGEROUS LOAD-DO NOT USE!
+08.0 115 89.64 3424 4166 86025 15496 100.0 1.024 !DANGEROUS LOAD-DO NOT USE!
+10.0 118 91.30 3488 4321 92891 15583 100.0 0.991 !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 107 83.00 3300 3869 79428 14522 100.0 1.072 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 107 83.00 2964 3122 50102 15658 98.8 1.300


Cartridge : 7 mm BooBoo
Bullet : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 83.776 grain H2O = 5.439 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H1000

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 83 63.20 2444 2122 31281 11776 91.3 1.604
-18.0 85 64.78 2510 2238 33496 12174 92.7 1.562
-16.0 87 66.36 2576 2358 35877 12554 94.1 1.521
-14.0 89 67.94 2643 2482 38435 12914 95.3 1.473
-12.0 91 69.52 2710 2609 41187 13250 96.4 1.425
-10.0 93 71.10 2777 2739 44150 13560 97.3 1.378
-08.0 95 72.68 2844 2873 47343 13843 98.2 1.333
-06.0 97 74.26 2911 3010 50788 14095 98.8 1.289
-04.0 99 75.84 2977 3149 54508 14314 99.3 1.247
-02.0 101 77.42 3044 3291 58531 14499 99.7 1.206 ! Near Maximum !
+00.0 103 79.00 3110 3436 62886 14647 99.9 1.167 ! Near Maximum !
+02.0 105 80.58 3175 3583 67610 14757 100.0 1.129 !DANGEROUS LOAD-DO NOT USE!
+04.0 108 82.16 3241 3731 72740 14848 100.0 1.092 !DANGEROUS LOAD-DO NOT USE!
+06.0 110 83.74 3305 3882 78322 14933 100.0 1.057 !DANGEROUS LOAD-DO NOT USE!
+08.0 112 85.32 3370 4034 84407 15011 100.0 1.023 !DANGEROUS LOAD-DO NOT USE!
+10.0 114 86.90 3434 4189 91012 15083 100.0 0.990 !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 103 79.00 3247 3745 76859 14060 100.0 1.075 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 79.00 2908 3004 50573 14606 95.8 1.286


Cartridge : 7 mm BooBoo
Bullet : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 83.776 grain H2O = 5.439 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-25

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 80 61.60 2519 2254 32575 12345 97.7 1.592
-18.0 82 63.14 2581 2368 34836 12652 98.5 1.553
-16.0 84 64.68 2644 2484 37257 12929 99.2 1.514
-14.0 86 66.22 2706 2602 39849 13174 99.6 1.464
-12.0 88 67.76 2768 2722 42625 13386 99.9 1.418
-10.0 90 69.30 2829 2843 45602 13563 100.0 1.374
-08.0 92 70.84 2889 2965 48792 13716 100.0 1.331
-06.0 94 72.38 2948 3089 52215 13866 100.0 1.290
-04.0 96 73.92 3007 3213 55876 14012 100.0 1.250 ! Near Maximum !
-02.0 98 75.46 3065 3338 59761 14154 100.0 1.213 ! Near Maximum !
+00.0 100 77.00 3123 3465 63904 14292 100.0 1.176 ! Near Maximum !
+02.0 102 78.54 3180 3593 68326 14426 100.0 1.142 !DANGEROUS LOAD-DO NOT USE!
+04.0 104 80.08 3237 3722 73050 14555 100.0 1.108 !DANGEROUS LOAD-DO NOT USE!
+06.0 106 81.62 3293 3853 78100 14680 100.0 1.076 !DANGEROUS LOAD-DO NOT USE!
+08.0 108 83.16 3349 3985 83504 14800 100.0 1.044 !DANGEROUS LOAD-DO NOT USE!
+10.0 110 84.70 3405 4119 89292 14915 100.0 1.014 !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 100 77.00 3233 3713 77642 13839 100.0 1.087 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 77.00 2955 3102 50629 14888 99.7 1.298


Cartridge : 7 mm BooBoo
Bullet : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 83.776 grain H2O = 5.439 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-33

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 83 70.40 2428 2094 29672 12731 84.0 1.660
-18.0 85 72.16 2501 2222 31943 13259 86.0 1.615
-16.0 87 73.92 2575 2356 34411 13775 87.8 1.571
-14.0 89 75.68 2651 2496 37092 14274 89.6 1.528
-12.0 91 77.44 2727 2641 40009 14754 91.2 1.471
-10.0 93 79.20 2803 2792 43189 15211 92.7 1.418
-08.0 95 80.96 2881 2949 46659 15641 94.1 1.366
-06.0 97 82.72 2959 3110 50450 16041 95.4 1.316
-04.0 100 84.48 3037 3277 54602 16407 96.5 1.268
-02.0 102 86.24 3116 3449 59134 16735 97.5 1.222 ! Near Maximum !
+00.0 104 88.00 3195 3626 64054 17023 98.3 1.177 ! Near Maximum !
+02.0 106 89.76 3274 3808 69426 17267 99.0 1.134 !DANGEROUS LOAD-DO NOT USE!
+04.0 108 91.52 3353 3994 75303 17464 99.5 1.092 !DANGEROUS LOAD-DO NOT USE!
+06.0 110 93.28 3432 4184 81747 17611 99.8 1.052 !DANGEROUS LOAD-DO NOT USE!
+08.0 112 95.04 3511 4379 88830 17704 100.0 1.013 !DANGEROUS LOAD-DO NOT USE!
+10.0 114 96.80 3589 4577 96637 17752 100.0 0.976 !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 104 88.00 3386 4072 80455 16583 100.0 1.069 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 104 88.00 2932 3055 49239 16230 90.6 1.320


And some 175's..

Cartridge : 7 mm BooBoo
Bullet : .284, 175, Nosler PART SP 35645
Useable Case Capaci: 82.339 grain H2O = 5.346 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-33

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 82 68.00 2350 2145 29951 12782 86.2 1.719
-18.0 84 69.70 2419 2274 32214 13286 88.0 1.673
-16.0 86 71.40 2489 2408 34667 13777 89.7 1.628
-14.0 88 73.10 2560 2547 37329 14250 91.3 1.581
-12.0 90 74.80 2632 2691 40221 14702 92.8 1.525
-10.0 92 76.50 2704 2840 43366 15131 94.1 1.470
-08.0 94 78.20 2776 2994 46792 15532 95.4 1.418
-06.0 96 79.90 2849 3153 50525 15903 96.5 1.367
-04.0 98 81.60 2922 3317 54561 16241 97.4 1.318
-02.0 100 83.30 2995 3485 58924 16542 98.3 1.272 ! Near Maximum !
+00.0 102 85.00 3068 3658 63663 16803 98.9 1.226 ! Near Maximum !
+02.0 104 86.70 3141 3834 68818 17023 99.4 1.183 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 88.40 3214 4015 74435 17197 99.8 1.141 !DANGEROUS LOAD-DO NOT USE!
+06.0 108 90.10 3287 4199 80567 17323 100.0 1.100 !DANGEROUS LOAD-DO NOT USE!
+08.0 110 91.80 3360 4386 87276 17403 100.0 1.061 !DANGEROUS LOAD-DO NOT USE!
+10.0 112 93.50 3432 4577 94634 17467 100.0 1.023 !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 102 85.00 3241 4083 79609 16262 100.0 1.115 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 102 85.00 2825 3102 48931 16194 92.0 1.374


Cartridge : 7 mm BooBoo
Bullet : .284, 175, Nosler PART SP 35645
Useable Case Capaci: 82.339 grain H2O = 5.346 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-25

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 78 59.20 2416 2268 32489 12089 98.6 1.658
-18.0 80 60.68 2475 2380 34710 12365 99.2 1.617
-16.0 82 62.16 2533 2493 37082 12613 99.6 1.577
-14.0 84 63.64 2591 2608 39618 12830 99.9 1.527
-12.0 86 65.12 2648 2724 42329 13015 100.0 1.480
-10.0 88 66.60 2704 2841 45229 13178 100.0 1.434
-08.0 90 68.08 2760 2960 48333 13337 100.0 1.391
-06.0 92 69.56 2815 3079 51632 13493 100.0 1.349
-04.0 94 71.04 2869 3199 55122 13646 100.0 1.309
-02.0 96 72.52 2923 3321 58832 13794 100.0 1.270 ! Near Maximum !
+00.0 98 74.00 2977 3443 62779 13939 100.0 1.233 ! Near Maximum !
+02.0 100 75.48 3030 3567 66980 14081 100.0 1.198 !DANGEROUS LOAD-DO NOT USE!
+04.0 102 76.96 3082 3692 71453 14218 100.0 1.164 !DANGEROUS LOAD-DO NOT USE!
+06.0 104 78.44 3135 3818 76220 14351 100.0 1.131 !DANGEROUS LOAD-DO NOT USE!
+08.0 106 79.92 3187 3946 81304 14479 100.0 1.099 !DANGEROUS LOAD-DO NOT USE!
+10.0 108 81.40 3239 4076 86731 14604 100.0 1.068 !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 98 74.00 3076 3678 75976 13513 100.0 1.141 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 98 74.00 2824 3100 49811 14542 99.9 1.359


Cartridge : 7 mm BooBoo
Bullet : .284, 175, Nosler PART SP 35645
Useable Case Capaci: 82.339 grain H2O = 5.346 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H1000

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 82 61.60 2381 2202 32239 11851 93.5 1.648
-18.0 84 63.14 2443 2320 34513 12221 94.7 1.606
-16.0 86 64.68 2506 2441 36954 12571 95.9 1.563
-14.0 88 66.22 2570 2566 39575 12898 96.9 1.509
-12.0 90 67.76 2633 2693 42391 13200 97.8 1.460
-10.0 92 69.30 2696 2824 45413 13475 98.5 1.412
-08.0 94 70.84 2759 2958 48683 13720 99.1 1.367
-06.0 96 72.38 2822 3094 52197 13935 99.5 1.322
-04.0 98 73.92 2884 3232 55989 14115 99.8 1.280 ! Near Maximum !
-02.0 101 75.46 2946 3372 60083 14262 100.0 1.239 ! Near Maximum !
+00.0 103 77.00 3008 3515 64512 14376 100.0 1.199 !DANGEROUS LOAD-DO NOT USE!
+02.0 105 78.54 3069 3659 69308 14482 100.0 1.161 !DANGEROUS LOAD-DO NOT USE!
+04.0 107 80.08 3129 3805 74508 14582 100.0 1.124 !DANGEROUS LOAD-DO NOT USE!
+06.0 109 81.62 3189 3953 80121 14677 100.0 1.088 !DANGEROUS LOAD-DO NOT USE!
+08.0 111 83.16 3249 4103 86193 14765 100.0 1.054 !DANGEROUS LOAD-DO NOT USE!
+10.0 113 84.70 3309 4255 92781 14847 100.0 1.021 !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 103 77.00 3129 3804 78596 13818 100.0 1.107 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 77.00 2825 3101 51786 14590 97.2 1.320


Cartridge : 7 mm BooBoo
Bullet : .284, 175, Nosler PART SP 35645
Useable Case Capaci: 82.339 grain H2O = 5.346 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon Retumbo

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 84 64.00 2402 2242 31207 12660 96.6 1.678
-18.0 86 65.60 2467 2364 33429 13013 97.7 1.635
-16.0 88 67.20 2531 2489 35818 13332 98.6 1.592
-14.0 90 68.80 2595 2617 38385 13614 99.2 1.543
-12.0 92 70.40 2659 2748 41150 13856 99.7 1.492
-10.0 94 72.00 2723 2880 44126 14056 99.9 1.443
-08.0 96 73.60 2785 3015 47334 14213 100.0 1.396
-06.0 99 75.20 2847 3150 50795 14355 100.0 1.350
-04.0 101 76.80 2909 3287 54532 14492 100.0 1.306
-02.0 103 78.40 2969 3426 58571 14625 100.0 1.264 ! Near Maximum !
+00.0 105 80.00 3029 3566 62943 14752 100.0 1.223 ! Near Maximum !
+02.0 107 81.60 3089 3708 67680 14875 100.0 1.184 !DANGEROUS LOAD-DO NOT USE!
+04.0 109 83.20 3149 3852 72821 14992 100.0 1.146 !DANGEROUS LOAD-DO NOT USE!
+06.0 111 84.80 3208 3998 78357 15104 100.0 1.110 !DANGEROUS LOAD-DO NOT USE!
+08.0 113 86.40 3266 4146 84333 15209 100.0 1.075 !DANGEROUS LOAD-DO NOT USE!
+10.0 115 88.00 3325 4296 90799 15308 100.0 1.041 !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 105 80.00 3149 3853 78313 14223 100.0 1.122 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 80.00 2845 3145 49495 15397 99.4 1.356


Cartridge : 7 mm BooBoo
Bullet : .284, 175, Nosler PART SP 35645
Useable Case Capaci: 82.339 grain H2O = 5.346 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : IMR 7828 SSC

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 74 57.60 2417 2269 33512 12051 93.8 1.628
-18.0 76 59.04 2477 2384 35772 12412 95.0 1.587
-16.0 78 60.48 2537 2501 38182 12756 96.0 1.542
-14.0 79 61.92 2597 2620 40754 13081 96.9 1.495
-12.0 81 63.36 2657 2742 43497 13385 97.7 1.449
-10.0 83 64.80 2716 2867 46427 13668 98.4 1.405
-08.0 85 66.24 2776 2994 49552 13927 98.9 1.362
-06.0 87 67.68 2835 3122 52857 14161 99.4 1.322
-04.0 89 69.12 2893 3253 56362 14368 99.7 1.282 ! Near Maximum !
-02.0 91 70.56 2951 3385 60092 14548 99.9 1.245 ! Near Maximum !
+00.0 92 72.00 3009 3519 64064 14699 100.0 1.208 ! Near Maximum !
+02.0 94 73.44 3066 3654 68295 14828 100.0 1.173 !DANGEROUS LOAD-DO NOT USE!
+04.0 96 74.88 3123 3790 72806 14951 100.0 1.140 !DANGEROUS LOAD-DO NOT USE!
+06.0 98 76.32 3179 3927 77619 15070 100.0 1.107 !DANGEROUS LOAD-DO NOT USE!
+08.0 100 77.76 3235 4066 82759 15185 100.0 1.076 !DANGEROUS LOAD-DO NOT USE!
+10.0 102 79.20 3290 4207 88254 15294 100.0 1.045 !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 92 72.00 3126 3797 76626 14153 100.0 1.119 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 92 72.00 2836 3125 51709 14816 97.0 1.326


So, MrAndrew, you would be a better guide since you are shooting the Mashburn, but how do the numbers compare?

The Boo Boo is a reformed 8x68S, but case capacities look pretty similar to what I am seeing with reformed 300 Win Mag.

 

[DrMike]

Yeah, but what a terrible thing to do to an 8X68S case! That hurts! Still, not everyone has a 7mm Mashburn Super Magnum. :wink:

 

[SJB358]

I was thinking the same Mike. Those 8x68S cases are tough to come by. Seems like a very neat cartridge, despite the name....

 

[BobT]

Looks like the Boo Boo has a little less capacity than the Mashburn, the numbers still look pretty good though.
I got interested in this cartridge when Warren Page's rifles came up for auction a few years ago, Mr. Page was very fond of the Mashburn and is reported to have taken over 700 head of game all over the world with "Ole Betsy". I intend to give it a workout when the weather improves a little.