View Full Version : Load Request - .357 Magnum 170gr LSWC "Keith"
Load Request - .357 Magnum 170gr LSWC "Keith"
I'm looking for load data for a 4" S&W using a 170gr Keith style 170gr LSWC.
I don't have and 'Magnum' powder yet but have been looking at purchasing some 2400, H110, or Lil Gun for this load.
I would like to start somewhat below max load and work up from there...so H110 concerns me a little.
You didn't mention what model 4" S&W you're going to be shooting. A 'K' frame will not take the punishment over the long term that a 'L' frame will.
I've never loaded a 170 grain SWC but for many years have been loading a 162 grain Lachmiller mould SWC and a Lyman 358156 mould with gas checks.
Depending on velocities you're aiming for Unique, 2400 and H-110 may fit your needs, (the H110 can be problematic if you're not very comfortable with loading). Lil Gun is a newer powder, (for me at least) and I have no experience with it at all.
Lyman manual has the best loading information for lead bullets and starting with their mid loads should give you a safe and comfortable starting point.
Sooner or later Fred will pop up here... he's pretty much a walking book of knowledge when it comes to different powders. Word on the street is he's an heir to the Dupont Powder manufacturing fortune.
of your powder choices I prefer 2400. h110 to me is too narrow of a window for loading. I prefer the flexibility of 2400. I also prefer alliant powders, to be honest. Between Bullseye, Power Pistol, and 2400 I can load every handgun round that I need to.
I run 13.5grns. WW296 (same exact powder as H110) w/180grn. lead bullets as my standard .357 load. Accurate, power to spare, and lethal it's a great GP magnum reload from soup-to-nuts.
Being you're shooting 170s I don't see any problem in using the same powder charge. Drop it a grain and a half and work up.
I have some data that may help you. This 173 gr Keith bullet is very hard and cast by Beartooth Bullets.
First is the milder of the two. It has 8.5gr of Longshot in it. Out of my 4" GP-100 it gives 1,230 fps. I loaded hotter and milder and thought this the most practical load with this powder.
Second is the faster of the two. It has 14.5gr of AA9 powder. Out of my 4" GP-100 it gives 1,305 fps. Again, this is my favorite load out of the 8 different AA9 loads I tried. I would not shoot this out of any J or K frame Smith or clone.
All loads are with Federal standard primers. Cases are Starline. The GP has the cylinder throats opened up to .359 and the bore is firelapped. In other words, my loads may or may not be safe in your gun. All cautions apply.
I used to load the Keith bullet (mine were 168 grains) with 10 grains of Blue Dot and a CCI 500 standard small pistol primer. This is a max load in the Lyman manual (all 3 I own, even the 49th) but showed no signs of high pressure in my 4" S&W 686 or 2 different GP100's.
For pure fps, this load from a 4" tube is only a few fps slower than a max charge of H110 and does it with a lot less flame and concussion.
I used this load to shoot IMSHA with until I stepped up to a T/C Contender. It knocked the 200 yard rams very well.
The following is the only chronograph data that I have for this type of cast bullet...
168g LSWC Ideal# 358 429 <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:place w:st="on"><st1:State w:st="on">COL</st1:State></st1:place>: 1.590” in .357 Magnum brass
Shot in a Ruger GP-100 Revolver 6” Barrel CCI 550
11.8g 473AA 1160 1130 1136 1155 1192 1185 Avg: 1160 PF: 195
Best I can tell, 473AA is close to Unique in appearance and load data. I came across bulk amounts of this powder and have worked up loads with it. It has given me very consistent velocities especially in 9x19
2400 will give you about 1340 fps with 12.1 grns. That would be considered a max load.
If 1150 fps or so is sufficient for you use Bullseye (6.2 grn), Unique (6.8 gr) or Herco (7.0). Another good bet with the 170 grn is Blue Dot. 1300 fps with 9.7 grains.
These velocities are with a 5 1/2" bbl.
H110 is a powder I've used in the 357 for quite a while, especially with 158 grn bullets. But please load with care with H110!
Lil Gun works well with 158 grn as well as 170 and even 180 grn. but, once again, in longer barrels, like 8" or so.
As always, watch your minimum OAL and work up to these EXCEPT
with H110 (and W296) the general recommendation is to NOT reduce a listed load by more than 3% as it may cause inconsistent and incomplete ignition. IAW....stuck bullet in the bbl.
Go by the book with H110!
Hope this helps.
I cast my own Keith SWC, which is 175 grains ready to load. The load I use most is 8 grains of SR-4756 in a .38 Special case. This load should only be used in .357 guns, as it is a heavy load. Out of my 5 inch Model 27, it goes around 1140 fps, is quite accurate for me and very economical for being such a stout load.
Stepping up, I also load around 14 grains of 2400 in a Magnum case, with the bullet crimped short to facilitate use in my short-cylindered N frame. With this load, I get around 1350 fps, good for long range shooting.
Both of these loads carry the usual disclaimer that I worked up to them and am not respnsible of you blow off your face, hands, genitalia, etc. while using them.
I'm loading 162gr Lyman to 950 FPS in 357 using 5.5 gr of Unique.
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