My 358/25 WSSM Project

[kludge]

It's official. I've started a 358/25 WSSM project. I started talking to a deer hunting buddy at work and he said, "Let's do it." So I guess that's actually two rifle projects.

Today I received my reloading dies... in fact it was finding out that Redding has started making a "standard" custom die set for this wildcat that pushed me over the edge.

The Redding dies are called 358/25 WSSM and are part number 80739. (3-die set also available.) A couple e-mails later and I had their reamer print in my inbox. They have been very helpful and responsive, and since the dies are "in stock" I don't have to wait for 16 weeks getting custom dies; I'll be experimenting by the end of July! (When the barrels are done) (OK the dies are not really "in stock" - they are backordered, at least direct, and I got them through Sinclair International.)

Coincidentally, Dave Manson who has very helpful and has answered a multitude of my questions... his name was on the reamer print. So I ordered one.

I've been playing the last few weeks with a few different parent cases, making sketches and seeing what difficulties would be found forming brass. It was obvious when I started measuring water capacities that we would be on the verge "hot-rodding" some of these cases, and decided that the 25 WSSM could get us there with less pucker factor.

This design uses standard 25 WSSM headspace gauges. The brass is necked up in two steps (30 cal then 35 cal) and the tapered expanders are included with the dies. The brass will require just a bit of trimming to length, neck turning and annealing. The parent case starts with a neck thickness of 0.020" and after expanding is ~0.017" (not counting the "donut"). This turns out to be incompatible with the dies, so turning to 0.015" or maybe 0.014" will be needed. (Fortunately we have a nice set of gauges at work, and I measured the inside dimensions of the dies as soon as they showed up.)

A Savage 11 FNCS in 7mm WSM will be the donor. I picked it up on Friday. A small miracle occured... my somewhat crudely formed dummy loads (made before I got the dies) fed nicely from the magazine without any help. (WARNING: WSSM cartridges will fit and presumeably can be fired in WSM chambers.)

So let's see... I have a gun, brass (Winchester), bullets (180gr and 200gr to start), dies, a Forster neck turning tool (Note: the .35 caliber neck turning pilot does not have a built-in stop, that's going to be fun ), reamer is on order... so now I just need to decide on a twist rate and order barrels...

 

[42769vette]

keep us posted

 

[mwilson]

i to have a 358 started. 358 idc. apparently there are alot of 358 s with different names that use 25wssm headspace gauges. i have everything but the dies. have had a barrel for a month. sinarms over on the savagearms website chambered a adams and bennet midway barrel for me. 175.00 plus shipping. i to started out with a wsm savage and it feed fine. since i do not have dies i fire formed mine when i got the barrel. i annealed the brass first then used unique pistol powder and cornmeal. they came out fine. now to get the dies.

 

[kludge]

A quick update after running a few pieces of brass through these new dies... These dies are "new"; they aren't in Redding's catalog yet.

Redding Offers 358/25 WSSM Reloading Dies

Redding tech support told me they were "in stock" but as mentioned that "stock" was intended for a retailer. The lady I talked to at Redding said that backorders are 16 weeks out and the ones they have ready have (had) someone's name on them - Graf and Sons.

When I called Graf's they didn't have any idea about it; it wasn't in the system yet and didn't show any dates for arrival.

When I got back in touch with tech support, he told me to call Sinclair's. I had to ask for them (not listed in their catalog), and wait until their stock came in - but they did show that they were coming; they had them on order but they hadn't arrived yet. The order number for Sinclair's is 75-80739 and they are $180. The date they gave me was 4-25, but I guess they came in early.

Redding also has a 3-die set #84739, which has a bushing die included. FYI, the shell holder is not included. Redding #6 or Lee #5 is needed.

Now, as for the dies, you'll be interested in the numbers I measured at work - the seater die has a 0.391" neck - which means you'll have to do some neck turning if you want to seat bullets. I had to call Dave Manson back and change my reamer order when I found this out. The sizer die has a 0.379" neck and a 0.356" expander... a bit too small if you ask me, but the guy at Redding tech support said this was their normal size. The 30 cal expander included measures 0.3065". Both expaders are the tapered type.

At any rate, my brass is springing back to ~0.354" to ~0.355", and seating bullets is going to be difficult... or impossible.

I have an expander from a .350 Rem Mag from a Lee Die that measures right at 0.357" - right about where it should be. After I run them over this a .355" (9mm) pistol bullet is a tight slip fit.

I'm going to anneal a few of these cases again now that I've done the neck turning and run them through the expander again and see what I get. In fact it may be better to anneal between the 30 cal expander and the 35 cal expander to release some of the tension in the brass.

If the 0.357" expander doesn't work I'm probably going to have to call Redding and get an expander made with a larger diameter.

0.003" of neck tension is too much - I'll be shaving bullets. 0.001" or 0.0015" would be nice.

I shouldn't jump to conclusions too quickly though, I need to get this brass back to work and get a more accurate measure of them... I'm not trusting my calipers at home to be 100% accurate, especially for inside mesurements, but I do trust them to be consistent.

 

[fireball168]

And to think, somebody already did all this work three years ago to save you the hassle.

Hard to believe.

 

[kludge]

My barrel arrived!

I just finished bore sighting the finished rifle a couple hours ago. I also had to do some inletting of the stock. The barrel is from McGowen, and the finish matches the receiver perfectly. It's 22", with a 1:14" twist, and a Savage Magnum taper. I don't have an accurate scale at home but it looks like it's right about 8 pounds. Scope is a Redfield 3-9x40mm.

Now to get loading!

Here it is...

 

[mwilson]

took mine to the range the last 3 weeks to work on loads. think i have settled on blc-2 and 225 sierra game kings so far. would shoot 3 shots into groups under 1" but the next 2 would open up to about 2". tried some magnum primers with the same powder charge (50 grains) and it seems to like them.

 

[kludge]

It won't be long now...

A few dummy rounds, to get all my dimensions finalized (.357 Mag for scale)...

And some brass ready to go. My final measurements on my actual lot of new brass showed a case capacity equal to the .358 Winchester. My prototype case measurements with once fired factory .25 WSSM had thicker case walls and a case capacity between .35 Rem and .358 Win. IOW, know your brass.

 

[451_Detonics]

I neck up the Winchester .348 brass up to .458 for my 450 Alaskan. I anneal before expending by setting the cases in water up to the shoulder and using a propane torch. When the brass starts to glow (I do this in dim lighting) I knock it over into the water. My expander die is a single two step die and I have never lost a case doing this nor have I had a problen with spring back. I will admit I have gotten lazy of late now that the brass is available pre-formed with the correct headstamp from Quality Cartridge...lol.

 

[kludge]

Since I made the post in April, I did some more prototype cases to figure out a good process before starting in on my new batch of brass.

Annealing is *required* even if using new brass. After going from .25 caliber to .35 caliber the brass is far too hard. If you are starting with previously fired .25 WSSM, then I suspect that annealing could be necessary for the first expansion to .30 caliber. In the 25 new cases I formed, I expanded without annelaing to .30 caliber, then to .35 caliber, annealed, and ran it through the sizing die once more. I did not lose any cases, but I suspect that I would have an easier time of it by annealing before expanding to .35 caliber.

Just for fun, and to confirm my annealing process, I ran a twice fired .308 case into a .35 caliber expander, and it readily split. The next .308 case, with the same two firings, was annealed first, and then expanded to .35 caliber quite nicely. I suspect that my batch of new brass was without question properly annealed at the Winchester factory, or I would not have been so lucky.

To anneal I heat the brass, turning it in the flame with an electric screwdriver, and drop it into the water when it turns light blue. I drop it into water to keep the heat from conducting to the case head, not to "quench" it as is done for steel. The brass needs to be hard enough to give proper neck tension and also so that it will spring back after being fired enough to release from the chamber wall. On the other hand if the neck gets to hot (turns red), the necks will be too soft, may not have enough neck tension and and fired cases may stick in the chamber.

The best article I've found on the subject --> The Art and Science of Annealing

Even after annealing I have found that the expander in the Redding die is still just too small. It measures 0.3533". I am going to write them again on this subject. I am not able to get the brass over the mandrel on my neck turning tool. The mandrel measures 0.3547". Besides, even without neck turning 0.004 to 0.005" of neck tension is just too much. To compensate I've borrowed the expander from a Lee die set in .350 Rem Mag, put it in a Lee Decapping Die, from which I had to cut 1/2" off the bottom to get the short brass up far enough into the die to expand it just a hair more. Then I can get the brass onto the mandrel to turn the necks. I'll probably cut another 1/4" or so off the Decapping Die for a more comfortable reach for the .350 Rem Mag decapper/expander. I didn't measure the Lee expander with the micrometer before I installed it, but the calipers gave me 0.357". With a bit of spring back I'll get a more comfortable 0.002" to 0.003" of neck tension.

 

[kludge]

WARNING: The load data presented below appears to be safe in my rifle and my chamber, using my lots of components and my loading dies. Neither I nor INGO make any claims of safety or suitability for use in any conceivable application.


Finally yesterday I was able to go to the range and spent a few hours developing load #1.

Load #1 is a Hornady 180gr SSP Interlock and Hodgdon Benchmark. Readings are at 15ft from the muzzle.

I started at 43.0gr of Benchmark, made careful measurements of the case head before and after, and worked up in 0.5gr increments to 46.0gr where I got flattening of the primer at 2498 fps, and strong recoil. I backed off 0.5gr so my MAX LOAD is 45.5gr of Benchmark with a COL of 2.343" (not seated to the cannelure, but 0.015" to 0.020" off the land in my chamber). I don't think 26.5gr would have fit without compression, but I wasn't tempted to compress Benchmark, which I think is toward the fast end of what this cartridge will be.

I shot 12 rounds total, and with 43.0gr velocity was just over 2300fps. I loaded 3 more with 45.5gr and average of four shots was 2461 fps. It's just a guess but it seemed like the best efficiency was at ~44.0gr at 2412fps; it took one grain to go from 2300 to 2400 and it took another 2 grains to get almost another 100fps, which was over max. I wish I could get my hands on a bottle of H4895 -- I think I can get another 100fps.

Shooting from a rest on a bench with nothing more than a t-shirt wasn't fun, even with a >8 pound rifle.

So far so good from the barrel. I imagine any of the loads will shoot cloverleafs at 50 yards. All the lower charges made one cloverleaf, all the upper charges made a cloverleaf ~1" to the right... very curious... I think I may have some more stock inletting to do...

If you have any insight on the right shift of the upper end loads, please chime in!

 

[mwilson]

i have been working with blc-2 and 225 grain sierra game kings for my 358 idc. so far my max load has been 51.0 grains at 2380 to 2400 fps

out of my 24" barrel. i am getting 5 shot groups a little over an inch at 100 yards also. i have not seen any pressure signs except the bolt lift seems to be stiff. from what i can seem to find it seems as some people think this is a trait of the short fat wssm case. so far the case life seems good as i have fired some of my brass 5 times at this load and so far all looks good. no loose primer pockets or brass stretching.

 

[kludge]

It must have a fairly high density though if you are fitting 51gr into the case. Is this a compressed load?

I have a box of 225gr SGK also. Your BL-C(2) load, from what I can tell, seems to be about all i would expect from a 225gr, and you're going to have a 40-60fps advantage over my 22" barrel.

Load #2 is going to be with 200gr FTX... probably won't take it past 2300fps simply because it was designed for the lower speeds of the 35 Rem. Well, I'll take up as far as I can just to see where it will go, but for a hunting load, I'll leave it at 2300fps. Should be able to get there with Benchmark.

My e-mails from Hornady say that the FTX was designed for a 1600fps to 2000fps impact velocity, but they also said the 180gr SSP Interlock and 200gr Interlock will do fine at the higher velocities. Factory .35 Rem FTX ammo is claimed to go 2225fps.

I like doing ballistic calculations for some reason, and a quick ballistic calulation says that the FTX will slow from 2300fps to 2225fps in about 25 yards, be +3" @ 100 yd, -3" @ 220 yd, -16" @ 300 yd, with 1000 ft*lb available out to 330 yards.

I can get the 225gr SGK for quite a bit less than the Hornadys so I'm leaning in that direction, and it has a good reputation too, so that will be load #3. But with the improved BC and still hoping for 2300fps, the trajectory will be just slightly flatter, +/- 2.8" at 100yd/220yds and -14.5" @ 300 yd w/ 1450 ft*lb.

Pushing the 225gr SGK up to your 2380 gives a +/-3" MPBR of 235 yards and a 200 yard zero, -12" @ 300 yd w/ 1565ft*lb... so in essense you have a 300 yard gun for about anything you want to hunt. Plus if you open up your MPBR window to +/-4" you have a 260 yards MPBR.

I have not used any BL-C(2) though I have been tempted to try it in .223 Rem. I have avoided purchasing BL-C(2) for this project simply because no one can seem to agree on where it is on the burn rate charts... some put it between Benchmark and H4895, some put it slower than Varget (like Hodgdon, who makes the stuff!), but if you're having good luck and no pressure signs, I'll pick some up if I find it first.

I know that burn rate is sometimes meaningless - and can vary quite a bit depending on what cartridge the powder is used in.

 

[mwilson]

the reason i may not be having any pressure problems may be the neck diameter. i believe the reamer for the idc is a little larger in diameter than the 35wssm by a few thousands. i am using 358bfg dies. when i run a case in the bfg die after firing it in the idc chamber the neck is not squeezed down enough to hold a bullet so i run the neck in my .357 mag die and it tightens it up enough to get good bullet tension. does not seem to hurt anything. brass life is good and groups are good enough. i have a luepold bdc scope on my rifle now and am trying to find a good zero for it. zeroed 2" high at 100 with the crosshairs. 200 yards with the first dot seem to be about 2" high also. 3rd dot at 300 yards is 5-6" high. am going to go back to dead on at 100 yards this weekend and try it again. blc 2 is compressed a little at 51.0 have loaded some at 51.5,52,52.5,53 to try also. even at 53 cases still are not full,close but not quite.

 

[kludge]

My chamber neck measures 0.390" and loaded ammo measures 0.386" so the neck is a bit tight, but not benchrest tight. Fired cases measure 0.387" to 0.388". Also with my micrometer I'm keeping tabs on the case head diameter... before and after = 0.5500" so far. My throat lets me seat the bullets out a bit farther out than I though would be possible; the SGK for instance is seated so the base is just hair past the bottom of the neck, so I have the full case and the bullet is not taking away any of the case volume.

Thanks for the BL-C(2) info. It sounds like you are zeroing in on your load just fine!

 

[mwilson]

was reloading for my 358idc today and decided to see what the case capacity was with blc-2. reloaded some at 51.5 and 52 to try thursday. 1st pic is 53.0 grains to show the powder would not be compressed very much. next pics are the case full.

 

[rjhans53]

WARNING: The load data presented below appears to be safe in my rifle and my chamber, using my lots of components and my loading dies. Neither I nor INGO make any claims of safety or suitability for use in any conceivable application
For the record I'm talking about my 358 BFG's. Both rifle barrels a savage and a howa came from BFG, the howa was finished with a 358 bfg reamer. The hornady annealling set up works good. New brass necked to 7mm, annealled then to 30 then 35 not a split in the 80 I've done. With 200 horn Varget runs about 2375, 3031 gives me a hair over 2500 and I get over 2600 with 10x. No pressure signs on any of them. Recoil is right there with my 358 win but less than my 338 fed. Kludge your right there is a very fine line on the right neck thickness. I finally got my sinclair tool set and it's a tad bit thicker than Byran's at BFG (who has been a load of help in this "experiment"). I can't feel bfg brass slide over the expander at all but the neck holds the bullets well. Mine I can feel the expander on the way back out but it's so close to size that I don't lube the inside of necks.

 

[kludge]

WARNING: The load data presented below appears to be safe in my rifle and my chamber, using my lots of components and my loading dies. Neither I nor INGO make any claims of safety or suitability for use in any conceivable application.

Just thought I'd give you all an update... got to do some development yesterday with 225gr SGK and BL-C(2).

Barrel = 22", 1:14"
Powder = BL-C(2), Primer = CCI 200, COL = 2.363"
Start load = 44.8gr vel = 2168 fps (easy recoil BTW, and exceeds 220gr .35 Rem max load by ~300fps)
Max load = 50.5gr vel = 2388 fps, Muzzle Energy = 2849 ft*lb.
Calculated Drop @ 300yd = 34.27", +/-3" MPBR = 235yd w/200yd zero, -11.9" @ 300yd w/200yd zero.
Energy @ 200yd = 1955 ft*lb, Energy @ 300yd = 1606 ft*lb.

I settled on 50.5gr as my max load and COL of 2.363". The bolt got hard to lift when I went to 51.0gr., and on 3 shots velocity was a bit erratic (2518, 2394, 2383). I backed off to 50.7gr and the velocity was very stable (2386, 2390, 2391) and I got just over 1/2" group at 50yd, but on 2 of 3 the bolt was still hard to lift.

My chrony got an error on 2 of 4 at 50.5gr but average of two shots was 2388fps (2375 & 2401) from my 22" barrel, so I'm really satisfied with that. Now I can load a bunch and shoot some real groups and longer ranges.

mwilson: I can get 55.0gr of BL-C(2) level to the top. It looked like at 51.0gr I might be starting to get a bit of compression. BTW, thanks for the BL-C(2) recommendation, it worked out very well! Also my buddy found a can of IMR-4895 in his stash and gave it to me

Note to self: make a plexiglass box to hold the scale while loading at the range... hmmmm.... maybe I can just get a clear tub and put over the scale.

 

[mwilson]

glad the blc-2 is working for you. fireball is the one that told me about it. there maybe a little more speed in another powder but i am happy with 2400 fps and 1" groups. i just have to fiqure my leupold bdc scope out now. zero cross hairs at 100 yards and the first dot below cross hairs is about 2 " high a 200 yards. at 300 yards the second dot is about 7" high. need to play with the power ring at 300 and see if that changes anything. cant wait for deer season.

 

[kludge]

My buddy is getting some longer ranges set up so we can test the same thing. I have a duplex reticle.

Incidentally, I got an e-mail back from Sierra and the guy said that on deer, expansion gets a little rough below 1900fps with that bullet, so for me that would be ~240 yards. However on elk or other heavily bodies animal there would still be some expansion below that.