Reloading 270 WSM

[Joe C.]

Just asking those that have worked with them. Are they super sensitive to pressure? I know you have to keep an eye on it no matter the round, but my Model 70 in 270 WSM seems extremely sensitive. For example, I’ll be at a mid book load, add .5 grain and them the bolt is very hard to lift. Cases look fine until the hard bolt lift. Rifle has been cleaned and borescoped with nothing abnormal. Bullet isn’t jammed into the rifling. Is the 270 WSM just more temperamental than I’m used too? Also I’m going to quit being lazy and do load work up over a chronograph. This is my first time working with a WSM.

I’ve got a great load with RL23 and 130gr Partitions. The loads I’m working on now is Staball HD with 130gr Partitions, and 145gr ELDX with RL26 and Staball HD. I also plan on starting working up an E-Tip load.

Edit: also with it being a short mag does it take smaller powder increases to get magnum performance, as apposed to what full length case magnums require?

 

[Blkram]

I have not handloaded for my current rifle (LH Browning X Bolt All Weather 23" barrel) in 270 WSM as yet. The factory ammo tried to date is not showing any pressure signs and producing good performance (Nosler 140 gr AccuBond at 3073 fps and producing 0.565" 3 shot groups at 100 yards. Federal 140 gr Trophy Bonded Tip at 3156 fps and producing 0.396" 3 shot groups at 100 yards.
And unfortunately, I do not have my data from handloading for my first rifle in this cartridge (Rem 700 B&C Edition 26" barrel) anymore, and can only recall that I was loading with the 140 gr AccuBond great accuracy (approx. 1/2" groups at 100 yards), but velocity was about 200 fps slower than expected.
I think that I was using Re-22, using data from Nosler's Reloading Guide, up to max listed. And I did not have the rifle long enough to see if velocity improved after shooting a couple hundred more rounds through it. I did not have any pressure issues in that rifle.

Dr Mike has done a lot more loading with various bullets and powders for his 270 WSM (Model 70 FWT), and would be a better reference for you. If I recall correctly, his rifle's preferred load was with the 130 gr E-Tip. He also has done a lot of handloading with all of the WSM cartridges, and can give you a better assessment of common issues with the WSMs.

Your pressure issue could be a headspace issue (I had one with my 300 WSM; I only have these two WSM), or a chamber issue. A gunsmith may be able to assess and let you know.
Have you measured the fired cases to check dimensions? Might verify if there is a potential chamber issue.

 

[Joe C.]

Thanks for the response. My next step was going to get a Forster Go/No Go gauge, because the chamber feels snug when closing. What’s on more set. Lol
I have also had to pay close attention to the OAL gauge, because book OAL’s have been long when chambered.

 

[DrMike]

The WSM cartridges are not overly sensitive. I treat them as I would any longer cartridge.

 

[Joe C.]

Thanks Mike for the input. My RL23 load with Partitions is great. It’s an upper load I think, as it has 66gr of RL23 and a 130gr Partition. As far as the other testing I’ve done proves the rifle much more sensetive to powder charges than book manuals say it should be. ….".i do have resistance closing the bolt on new brass. Just enough to notice. I’m seriously contemplating getting a Go-No Go gauge. Will be taking my chrono from now of with this one. Chamber and bore looked fine with a scope. I’ll try bumping the shoulder back with the help of my headspace gauges.

Edit…Fired cases holds 83.6 grains of water as apposed to 79.1 in GRT.

 

[sako2]

Joe i worked up a load for a friends 270 wsm. It relly liked Magpro.

 

[Joe C.]

I’ll figure it out. As far as suitable powders on hand go it’s Staball 6.6, IMR4831, IMR7828SSC, RL22, RL23, RL25, RL26, Staball HD. So I should be able to find something it likes. I think the Staball 6.5 will be too fast to use but included it anyway. The shorter fat case seems to give a more efficient powder burn.

 

[DrMike]

Cartridge          : .270 WSM
Bullet             : .277, 130, Nosler PART SP 16322
Useable Case Capaci: 73.934 grain H2O = 4.800 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length      : 24.0 inch = 609.6 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 64000 psi, or 441 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 !

19 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
---------------------------------  -----------------------------------------------------------------
Alliant Reloder-26 *C               98.5     72.1     4.67    3372   100.0    64000   13905   1.113  ! Near Maximum !
Alliant Reloder-25 *C              107.5     72.9     4.72    3357   100.0    64000   13542   1.097  ! Near Maximum !
Alliant Reloder-22 *C              101.7     70.0     4.54    3328    99.6    64000   13932   1.105  ! Near Maximum !
Alliant Reloder-33 *C              110.0     81.3     5.27    3311    95.1    59030   15349   1.140  ! Near Maximum !
Alliant Reloder-16 *C *T            94.4     62.6     4.06    3299   100.0    64000   12533   1.094  ! Near Maximum !
Alliant Reloder-19 *C               98.7     67.3     4.36    3287    99.5    64000   13316   1.099  ! Near Maximum !
Alliant Reloder-23 *C *T           103.3     68.9     4.46    3282   100.0    64000   12438   1.112  ! Near Maximum !

Looks as if you have a good range of Alliant powders that will work for you.

 

[DrMike]

Cartridge          : .270 WSM
Bullet             : .277, 130, Nosler PART SP 16322
Useable Case Capaci: 73.934 grain H2O = 4.800 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Winchester 6,5 StaBall *T*C

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   85    62.46   2896    2421   45456  10811     99.9    1.289
-09.0   86    63.15   2925    2470   46969  10880    100.0    1.269
-08.0   87    63.85   2954    2520   48534  10944    100.0    1.250
-07.0   88    64.54   2983    2569   50152  11003    100.0    1.232
-06.0   89    65.24   3012    2619   51827  11062    100.0    1.214
-05.0   90    65.93   3041    2669   53555  11120    100.0    1.196
-04.0   91    66.62   3069    2720   55353  11178    100.0    1.178  ! Near Maximum !
-03.0   92    67.32   3098    2770   57208  11234    100.0    1.161  ! Near Maximum !
-02.0   93    68.01   3126    2821   59122  11290    100.0    1.144  ! Near Maximum !
-01.0   94    68.71   3154    2872   61094  11345    100.0    1.128  ! Near Maximum !
+00.0   95    69.40   3182    2923   63129  11399    100.0    1.111  ! Near Maximum !
+01.0   96    70.09   3210    2975   65234  11452    100.0    1.096  !DANGEROUS LOAD-DO NOT USE!
+02.0   97    70.79   3238    3027   67410  11505    100.0    1.080  !DANGEROUS LOAD-DO NOT USE!
+03.0   97    71.48   3266    3079   69660  11556    100.0    1.065  !DANGEROUS LOAD-DO NOT USE!
+04.0   98    72.18   3293    3131   71989  11607    100.0    1.050  !DANGEROUS LOAD-DO NOT USE!
+05.0   99    72.87   3321    3184   74399  11656    100.0    1.035  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba     95    69.40   3236    3022   68971  11226    100.0    1.072  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     95    69.40   3117    2804   57269  11608    100.0    1.157  ! Near Maximum !

You can make Staball 6.5 work for you as well.

 

[Joe C.]

Thank you Mike. I appreciate it more than you can imagine. Thank you.

I'm below the max's you show above so that makes me feel better. I've been lackadaisical to this point and haven't taken my chrono with me. It goes with me from know on. I prefer using the chrono results over eyeballing the fired case alone.

 

[Joe C.]

I'm starting ladders for two loads for this weekend.
1. 270 WSM, 145GR eldx, with RL26
2. Is the 130gr E-Tip, with Staball HD.
3 130gr Partition, with Staball HD

I figure the 145gr ELDX will be a nice deer load, and the E-Tip and the Partition will be the anything that walks load...............and for the record Spring can get here anytime now.

 

[Blkram]

I am going to have to look closer at Re-26 for the 270 WSM with the 140 gr AB, 140 gr Trophy Bonded Tip and 136 gr Terminal Ascent bullets I have on hand, as I was just able to get another 5 lbs of this powder at a decent price.

 

[AFG270]

When I had my 270wsm it shot 130g Etips over RL26 best.

 

[Joe C.]

Joe i worked up a load for a friends 270 wsm. It relly liked Magpro.

Unfortunately Magpro is one that I dont have around

 

[DrMike]

Cartridge          : .270 WSM
Bullet             : .277, 145, Hornady ELD-X 27356
Useable Case Capaci: 71.184 grain H2O = 4.622 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-26 *C

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   87    61.38   2870    2653   43816  12756     99.8    1.385
-09.0   88    62.06   2903    2714   45440  12837     99.9    1.362
-08.0   89    62.74   2936    2775   47129  12909    100.0    1.339
-07.0   90    63.43   2968    2837   48877  12971    100.0    1.317
-06.0   91    64.11   3001    2899   50682  13030    100.0    1.295
-05.0   92    64.79   3033    2961   52548  13089    100.0    1.274
-04.0   93    65.47   3065    3024   54482  13146    100.0    1.253  ! Near Maximum !
-03.0   94    66.15   3096    3087   56486  13202    100.0    1.233  ! Near Maximum !
-02.0   95    66.84   3128    3150   58563  13257    100.0    1.213  ! Near Maximum !
-01.0   96    67.52   3159    3214   60718  13311    100.0    1.193  ! Near Maximum !
+00.0   97    68.20   3191    3277   62952  13364    100.0    1.174  ! Near Maximum !
+01.0   98    68.88   3222    3342   65270  13416    100.0    1.155  !DANGEROUS LOAD-DO NOT USE!
+02.0   99    69.56   3253    3406   67675  13467    100.0    1.137  !DANGEROUS LOAD-DO NOT USE!
+03.0  100    70.25   3284    3471   70171  13516    100.0    1.119  !DANGEROUS LOAD-DO NOT USE!
+04.0  101    70.93   3314    3537   72762  13564    100.0    1.101  !DANGEROUS LOAD-DO NOT USE!
+05.0  102    71.61   3345    3602   75454  13611    100.0    1.083  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba     97    68.20   3261    3423   70586  13088    100.0    1.121  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     97    68.20   3103    3100   55406  13701    100.0    1.236  ! Near Maximum !

Unfortunately, I don't have Staball HD in my data base.

 

[SJB358]

The WSM cartridges are not overly sensitive. I treat them as I would any longer cartridge.

Agreed. Check your resized dimensions of your cases. The 270 WSM has been one of my easiest to load for since I have started loading.

 

[Joe C.]

Thank you Mike for all the time you invested in the Quickloads. It’s greatly appreciated.

I’m also going to measure the fired headspace and compare it to the headspace of a sized case to see if they size or maybe need annealed.

 

[SJB358]

Thank you Mike for all the time you invested in the Quickloads. It’s greatly appreciated.

I’m also going to measure the fired headspace and compare it to the headspace of a sized case to see if they size or maybe need annealed.

Sometimes pressure signs aren't really pressure in my experience. If you can't feel the shoulder engaging a bit during final bolt turn down, I always worry a bit. Keep it the same throughout the brass life cycle and it makes "signs" easier to spot.

 

[Joe C.]

Thanks Scotty, I’ve been looking for a fully free close. Great insight, thanks.

 

[SJB358]

Thanks Scotty, I’ve been looking for a fully free close. Great insight, thanks.

That's the last thing I'd want myself. That just doesn't work out well for me. I'd rather feel the case the chamber, doesn't have to be much, but you should always feel case engagement, I know it's my thoughts, but I want as little case growth as possible along with max case alignment in the chamber. .002" is a solid place to be in my little bit of experience with the WSMs and about everything else with a shoulder Joe.