7mm Wby and RL-22 - how many grains?

[Dr. Vette]

I'm getting ready to try some RL-22 in addition to the H-1000 I've been testing. However, once I got done following the numbers in the Nosler manual I then found conflicting information.

Nosler lists 64.5 to 68.5 grains of RL-22 with the 160gr AccuBond:
http://www.nosler.com/Reloading-Data/7m ... rains.aspx

However the Alliant site lists one load at 70 grains and the Barnes data goes from 69 to 73 grains:
http://www.barnesbullets.com/wp-content ... numWeb.pdf

I've got loads from 64 up to 70 grains loaded now at every 0.5 grains. I can keep going to 73 but that's another 6 rounds and I'm not sure it's needed. Should I do it and just resign myself to spending an hour shooting the RL-22 as I march from 64 up to 73 grains? Or do others have experience showing that the true max load is probably "X" and that's where I should look. Currently the 70.0 load is not compressed and looks to be 95% or so. The 64 grain load just looked pathetic. :mrgreen:

If the max is really 73 or so then I would pull some of my lower charge loads and reassemble them as higher charged loads.

Thanks for any input you may have.

Patrick

 

[boomer68]

Hi Patrick,

A little off topic, but have you tried Retumbo?

 

[Dr. Vette]

Nope. One thing at a time.

Given that I did not get much velocity increase from 74 to 76 grains of H-1000 I opted to try a faster powder first.

 

[DrMike]

Patrick,

First, it isn't necessary to go in 0.5 grain increments. As you near the peak of the velocity curve, the slower powders become increasingly inefficient. In your rifle, 1.5 grain increments will likely tell you all you need to know. Second, the various sites list pressure tested data given specific conditions. Your velocities (and maximum charge) will vary depending upon lot-to-lot variation in components, chamber dimensions, etc. This data generated by QuickLoad will give you a relative idea of powders on which you should focus in order to achieve the velocity you are seeking:

Cartridge : 7 mm Weath. Mag.
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 77.642 grain H2O = 5.041 cm³
Cartridge O.A.L. L6: 3.360 inch = 85.34 mm
Barrel Length : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 55839 psi, or 385 MPa
or a maximum loading ratio or filling of 110 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

30 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
ADI AR 2218 106.5 81.2 5.26 3141 96.9 55840 14764 1.275 ! Near Maximum !
Vihtavuori N570 102.6 77.4 5.02 3131 96.8 55840 14430 1.297 ! Near Maximum !
Alliant Reloder 33 102.4 80.6 5.22 3118 97.4 55840 14222 1.300 ! Near Maximum !
Alliant Reloder-50 109.4 84.7 5.49 3116 96.6 55840 14590 1.324 ! Near Maximum !
Hodgdon H870 109.0 80.6 5.22 3112 98.3 55840 13992 1.301 ! Near Maximum !
Hodgdon Retumbo 106.2 76.4 4.95 3105 100.0 55840 12796 1.289 ! Near Maximum !
Ramshot Magnum 96.4 73.9 4.79 3071 99.7 55840 12835 1.295 ! Near Maximum !
PB Clermont PCL 517 96.8 73.9 4.79 3070 99.7 55840 12825 1.295 ! Near Maximum !
SNPE Vectan SP 12 96.6 73.8 4.78 3069 99.7 55840 12797 1.296 ! Near Maximum !
Norma MRP 2 101.4 72.6 4.70 3067 99.6 55840 13005 1.313 ! Near Maximum !
Vihtavuori N560 93.4 68.3 4.43 3061 99.0 55840 12974 1.301 ! Near Maximum !
Alliant Reloder-25 99.2 70.6 4.58 3061 100.0 55840 12068 1.298 ! Near Maximum !
Norma MRP 91.7 68.5 4.44 3058 100.0 55840 12532 1.309 ! Near Maximum !
IMR 7828 SSC 92.6 68.0 4.41 3055 99.4 55840 12595 1.289 ! Near Maximum !
IMR 7828 97.8 68.0 4.41 3055 99.4 55840 12595 1.289 ! Near Maximum !
Accurate MAGPRO 93.9 71.4 4.63 3055 98.1 55840 13115 1.309 ! Near Maximum !
ADI AP 2214 97.7 72.6 4.70 3046 99.6 55840 12390 1.283 ! Near Maximum !
Hodgdon H1000 102.7 72.7 4.71 3044 99.6 55840 12356 1.284 ! Near Maximum !
ADI AR 2213 93.6 67.7 4.39 3043 99.3 55840 12491 1.285 ! Near Maximum !
Bofors RP5/NP ~approximation 93.7 67.8 4.39 3035 99.8 55840 12417 1.307 ! Near Maximum !
Raufoss RA15 93.7 67.8 4.39 3035 99.8 55840 12417 1.307 ! Near Maximum !
Alliant Reloder-22 93.7 67.8 4.39 3035 99.8 55840 12417 1.307 ! Near Maximum !
Winchester WXR 96.2 68.1 4.41 3034 99.8 55840 12437 1.308 ! Near Maximum !
Bofors 12,7mmRA NC1214 Lot20115087 109.1 82.6 5.35 3023 88.9 55840 13765 1.343 ! Near Maximum !
Vihtavuori 24N41 105.1 80.1 5.19 3017 91.1 55840 13030 1.290 ! Near Maximum !
Bofors RP5 NT ~approximation 97.1 70.9 4.59 3014 98.0 55840 12394 1.288 ! Near Maximum !
Rottweil R905 95.1 67.5 4.38 3009 99.0 55840 12211 1.306 ! Near Maximum !
ADI AR 2209 90.5 64.4 4.17 2999 99.7 55840 11799 1.292 ! Near Maximum !
Alliant Reloder-19 90.8 65.0 4.21 2995 99.8 55840 11840 1.300 ! Near Maximum !
Hodgdon US 869 110.0 83.9 5.43 2992 90.8 54655 13023 1.314 ! Near Maximum !
Bofors RP14 ~approximation 91.6 65.5 4.25 2989 99.8 55840 11764 1.301 ! Near Maximum !
Hodgdon 50BMG 110.0 79.9 5.18 2988 86.7 54454 13123 1.313 ! Near Maximum !
Hodgdon H4831 96.1 66.8 4.33 2979 98.8 55840 11803 1.297 ! Near Maximum !
Hodgdon H4831 SC 92.4 66.8 4.33 2979 98.8 55840 11803 1.297 ! Near Maximum !
Vihtavuori N170 105.4 74.6 4.83 2968 95.2 55840 12275 1.321 ! Near Maximum !
Somchem S385 91.1 65.9 4.27 2957 100.0 55840 11293 1.323 ! Near Maximum !
Winchester Supreme 780 90.1 68.0 4.41 2954 99.7 55840 11322 1.308 ! Near Maximum !
Rottweil R904 90.1 63.5 4.12 2951 99.2 55840 11340 1.299 ! Near Maximum !
Vihtavuori N165 96.1 68.0 4.41 2945 99.9 55840 11082 1.313 ! Near Maximum !
Lovex D100 102.6 79.0 5.12 2945 91.8 55840 12049 1.309 ! Near Maximum !
Accurate 3100 99.4 67.3 4.36 2940 100.0 55840 10939 1.342 ! Near Maximum !
Lovex S071 99.4 67.3 4.36 2940 100.0 55840 10939 1.342 ! Near Maximum !
IMR 4831 90.3 61.9 4.01 2938 100.0 55840 10635 1.326 ! Near Maximum !
Vihtavuori N160 96.2 66.0 4.28 2935 99.2 55840 11153 1.303 ! Near Maximum !

As you can see, there are a number of slower powders that will give you better case fill and somewhat more velocity than RL22 in your 7WBY. I would be inclined to consider IMR7828, IMR7828SSC, RL25, N560, Retumbo or N570 before I focused too intently on RL22 if velocity was my primary concern.

 

[Jimbeaux82]

I have a bit of data here that might be of help as I have done quite a bit of experimenting with RL22 in my 7 Wea. As stated before , my rifle is a MkV with a 24" barrel. I have worked up loads with the 162 SST, 160 NAB and 160 TSX. All groups are 3 shot groups, as follows:

162 SST, 3.400 OAL

71 grs 3006 fps 1.5" group
72 grs 3026 fps .75" group
73 grs 3050 fps 1" group
74 grs 3167 fps 3" group - too hot, badly flattened primers

160 NAB, 3.294" OAL

71 grs 2950 fps .75" group
72 grs 2985 fps no grp size recorded ???
73 grs 3050 fps .5" group
74 grs 3150 fps no grp size recorded, too hot - badly flattened primers

160 TSX, 3.200 OAL

69 grs 2963 fps 1" group
70 grs 2960 fps .5" group
71 grs 3007 fps no grp size recorded, max load

I thought I had found the right combo at 73 grs with either the 162 SST or the 160 gr NAB so loaded up a bunch. Then last season when sighting in (10 Oct 11, 80 deg afternoon) I blew a case with this load with a 160 NAB. Since I had loaded this batch with a Lyman 1200 scale/electronic dispenser, I decided to pull all the bullets and check for powder load variations. After pulling about 100 loads, the powder charge was very consistent (to my pleasant surprise) between 72.9 and 73.1 grs so that was not the problem. In any event, I reloaded the ammo with a reduced charge of 71.0 grs and that will be my new hunting load. Last month, I went back to the range to recheck sightin and I got 2985 fps with this load but 1.5" groups. Not sure what happened on the group size.

Anyway, these were my results and any suggestions from your side would be appreciated as well.

Jimbeaux

 

[Dr. Vette]

I note that QL also lists about 68 grains as a max load. I've read that QL underestimates for the Weatherby as it doesn't take into account the freebore. Any truth to that? In any even it's nowhere near 73.

I'm going by the 0.5 gr from 64.5 to 68.5 (the Nosler listed extremes) to see if I can find any accuracy node. I'm new at this and so far somewhat disappointed in my results. Since no one here in town reloads with the level of precision I'm trying to maintain (at least no one I've yet met) I'm mostly flying blind and doing internet searches as well as e-mailing and posting.

I chose RL-22 as it is allegedly close to Norma's MRP which is also allegedly factory fill for Weatherby ammo. As the rifle shot factory 160gr Accubonds at about an inch I was hoping to meet or exceed that by handloading it. And, it has been recommended to me several times.

Make sense?

If I can find an accurate, repeatable load with one of these two powders I'll go for it for this year's hunts. I prefer accuracy over speed as I can always adjust the dial to account for more drop. :shock:

 

[SJB358]

I am with Mike. RL22 has worked really for me in the 7RM in the past, and works really well in the 7WSM, but if I were doing the loads all over again, I would try RL25. Seems like case fill is about perfect and has the ability to run the 160's to the optimum speeds with acceptable pressures.

Saying that, RL22 is darned good in the 7RM and I can't see it being a bad powder at all in your WBY.

Cartridge : 7 mm Weath. Mag.
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 77.642 grain H2O = 5.041 cm³
Cartridge O.A.L. L6: 3.360 inch = 85.34 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-22

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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

-10.0 88 63.90 2868 2923 46712 11909 98.8 1.421
-09.0 89 64.61 2899 2985 48261 12014 99.1 1.399
-08.0 90 65.32 2929 3049 49859 12114 99.3 1.378
-07.0 91 66.03 2960 3113 51507 12208 99.5 1.357
-06.0 92 66.74 2990 3177 53209 12297 99.6 1.337
-05.0 93 67.45 3021 3242 54965 12380 99.8 1.317
-04.0 94 68.16 3051 3307 56778 12456 99.9 1.297 ! Near Maximum !
-03.0 95 68.87 3081 3372 58649 12527 99.9 1.278 ! Near Maximum !
-02.0 96 69.58 3111 3438 60582 12592 100.0 1.259 ! Near Maximum !
-01.0 97 70.29 3140 3503 62577 12650 100.0 1.241 ! Near Maximum !
+00.0 98 71.00 3170 3570 64637 12705 100.0 1.223 !DANGEROUS LOAD-DO NOT USE!
+01.0 99 71.71 3199 3636 66766 12759 100.0 1.205 !DANGEROUS LOAD-DO NOT USE!
+02.0 100 72.42 3228 3703 68965 12813 100.0 1.188 !DANGEROUS LOAD-DO NOT USE!
+03.0 101 73.13 3258 3770 71237 12865 100.0 1.171 !DANGEROUS LOAD-DO NOT USE!
+04.0 102 73.84 3287 3838 73586 12916 100.0 1.154 !DANGEROUS LOAD-DO NOT USE!
+05.0 103 74.55 3315 3905 76014 12967 100.0 1.137 !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 71.00 3287 3839 77322 12250 100.0 1.134 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 98 71.00 2994 3185 52115 12911 97.6 1.342

 

[SJB358]

Patrick, looking at QL with a max of 65,000PSI, I would feel pretty comfortable working up to 70-71 grains, if you come up on it slowly. Maybe load some of 67, 68.5, 70 AND then 71.. Out of those 4 charges, you should see if anything has any potential in your rifle.

I would bet something out of those will show you how much to pursue it. Chances are, something will perk for you. As I said before, I love RL22 in my 7WSM. It is fast and accurate, but it is a touch smaller than your Wby.

The freebore is a wild card, but working up slowly should net you what your looking for.

 

[Jimbeaux82]

I have tried RL 25 as well and was not too happy with the results

162 SST

73 grs 2980 fps
74 grs 2975 fps
75 grs 2980 fps - blown case

as you can see, I could not get even close to the velocities that I got with RL 22 which was a disappointment. No increase in velocity at all from 73-75 grs.

Also, before you think I am a reckless reloader showing 2 blown cases, these are the only 2 blown cases I have ever experienced in 20 years of reloading over 20 calibers.

Jimbeaux

 

[Jimbeaux82]

Dr Vette,

what was the velocity of the factory 160 NAB loads? They list them at 3050 fps, which is considerably less than the listed 3200 fps for the 160 NPT loads? NAB's must have a much harder jacket generating more pressure than the Partitions.

 

[SJB358]

Dr Vette,

what was the velocity of the factory 160 NAB loads? They list them at 3050 fps, which is considerably less than the listed 3200 fps for the 160 NPT loads? NAB's must have a much harder jacket generating more pressure than the Partitions.

I have found the opposite in my loading Jim. I actually usually require more of the same powder to push AB's to the same speed than PT's. Granted, that is just in my little corner of the world, but it has been fairly the same across the board on a few different cartridges.

 

[Dr. Vette]

I did not get the velocity of the factory loads. I was just seeing if they would even shoot well in this rifle, and they did. They shot well in another almost identical 7mm Wby also, and may end up being default ammo for one of them this year.

 

[Jimbeaux82]

I like to get Weatherby factory loads and shoot them in my rifle and see what velocities I get, and use that as a general guide for what velocity I try to get close to. I would never try to exceed any of the Weatherby factory velocities. For instance, in my rifle, the Weatherby 154 gr Hornady clocks 3170 fps in my 24" tube where the listed velocity is 3260 fps in a 26" tube. So my goal is around 3150 fps with 150 gr loads with appropriate powders. That is why I am curious about actual 160 NAB factory load velocities.

 

[Dr. Vette]

I can easily enough run one through and report back.

 

[Jimbeaux82]

That would be great. Does your rifle have a 24 or 26" tube?

 

[DrMike]

I note that QL also lists about 68 grains as a max load. I've read that QL underestimates for the Weatherby as it doesn't take into account the freebore. Any truth to that? In any even it's nowhere near 73.

QL projects for the parameters given. The default parameters are SAAMI or CIP. Pressure limits are pressure limits, regardless of freebore. However, the data is only as good as what is put in. Dr. Broemel plugs in burn rates from samples of propellants sent to him, and plugs in data for bullets from the samples sent to him. Thus, if manufacturers alter their product, the result will vary. This is the reason you always work up from a safe point. You can become very precise with QL if you measure your case volume and account for the temperature. As it is, it is very accurate, even on Weatherbys. I've worked up loads on a good number of Weatherby rifles, and QL was right in line with what I observed.

 

[Dr. Vette]

Thanks Dr Mike.
I changed my loads to every 1.0 grains from 64 up to 73 now. I left a few of the XX.5 loads together in case I want to check them out, but will just disassemble them if I don't use them.

Jim, 26 inch barrel, stainless rifle.