I'm going to pick up a pound of either for loading heavier bullets in the .458, I notice that there is a lot more loads with IMR then H.

Is one preferred over the other? From reading the description on the website, they seem to mention large calibers more in the IMR 4198 description.

I'm planning on using the powder for heavier gr Boolits. Specifically a 340gr PC'ed, GC'ed NOE cast Boolit.

Thanks, Dave

So, from what I am learning as far as the .458 goes, I think that IMR is going to work better with a "mid wieght" 340 gr boolit. Like I said above, I see way more loads in 350gr weight using IMR.

I guess a pound of both for more testing then.

Lil’gun and h110 meter better... I have had great success with Lil’gun in 500gr so I plan to try in lighter bullets. IMR 4198, not so much.

I have a 100 or so of My NOE 340gr HP cast, PC'ed, GC'ed, sized to .459, 50 cases sized, flared, primed. Going to work up a load with W296, see what happens, if it doesn't look promising, I'll try some IMR 4198.

Here is a cut and paste from a thread I have over at the SOCOM forum. Found about 10 different loads, from some people I think know what they are doing, so use their data and work up to it. Just some plinking rounds using up the Berry's 350gr plated I have.

Thanks for the replies.

I have been looking through the Load Data at the top of the Reloading section. I am going to be shooting My 340gr NOE cast lead bullet pretty much exclusively, but I have 3 or 4 different boxes of 50 in Hornady red tip, 350gr RN, some Berry's, just want to copy the info that is posted in there, and work up to some of those loads. Just a way to use up the various small lots of bullets I have. I had picked up a pound of H 4198, then saw that most of the info was IMR 4198. I'm in pretty tight with My local LGS, He will probably let me exchange it for some IMR, just bought it, did not open it. It just seems like there is a lot more data with IMR.

I am going to have 2 main loads, I scored a ton of the Nosler BT's, have a load pretty much dialed in with 300 MP, then My cast load, which will probably be H110, or one of the 4198's. Once I get My Hybrid out of jail, I may work up a 600gr load for subsonic, worry about that in 7 or 8 months.

I do not wanna have any more powders then I already have. One thing is that I read a lot about people using the 4198's for cast in a lot of calibers. I cast for .458, 300 BO, and I will play around with .223 at some point. Being alittle bit on the slower end is good for the cast loads, it sounds like.

So, I think I will pick IMR and start with it.

I guess just keep the H 4198, use it for something someday prolly, I hope My grandkids reload, I'm going to be leaving them enough for a few generations.

.458 SOCOM is going to be a SS, one at a time load for me, using the ChargeMaster, so not too much of an issue for me there.

I use the H4198 with 52/53 grain match bullets in .223. My bolt action loves it. 20.6 grains of H4198 produces 3177 fps from my 26" barrel.

Not every AR-15 will cycle this load, rifle gassed AR's need a lot of lube or need to be well broken in. Never had a problem with mid/carbine gassed AR's.

If you decide you don't like it in the big bore give it a try with 53 or lighter bullets in .223.

I did not care for how hot the barrel got when I used Lil'gun.  IMR4198 ran cooler, and had a softer recoil impulse.  Both were run behind Nosler 300gr MZBTs.

Noticed there isnt any book data for 300’s and Lil’gun anyway. I take breaks between mags and don’t do dumps. I also use a barrel fan. Hot in Texas!

I got a lot of unburnt powder with I4198... So, meh...

Interesting

I find it interesting I had the exact opposite situatiuon  IMR4198 no unburnt powder, lilgun i did.  I'm running a 16" barrel, 1:14, and a standard buffer

The lil'gun was used for a total of ~100 rounds and sold off.  I also tried it with some 350gr bullets less unburnt powder, but it was still there.  I'm thinking the difference is the opposite ends of the bullet weight spectrum.

I may have to try the I4198 with some 500s

OP PM’ed me asking if I load 458 socom on Dillon 1050. I don’t but do on my 550.

But I did look to see how I would do it... Havent fully tested but running by hand seems to work.

1. The case feed plate would likely be large pistol. If it doesn’t work as stock, try the washer that comes with it to raise up the plate. I haven’t tested fully (cause my two hoppers are full). I did note the case fits in the grooves.

2. The case feed tube works fine. I was afraid such a fat case would need a wider tube like 45-70 with that wide rim.

2. case feed funnel: Case fits in yellow but it needs to be shortened maybe 1/8” or so. Case mouth hits it during exit. I load for a dozen or so calibers. None of my others work at all. Maybe call Dillon and see if there is anything like it. Or just get an extra yellow and shave it down.

3. Plate would be same as 308/45. Same pins too.

4. The powder funnel is specific for 458 socom. Don’t cheap out and try 45acp one. Tried it on 550. Bad move.

5. Powder die is the extra large die. Case is too fat.

Anyway.. If anyone gets a chance to try this, let us know. If my presses were busy, I would try.

Thanks DJ,

I will try to run with the LP shellplate with washer first, that is already set up from 300 BO, standard CF tube, I will need to order the yellow adapter and a X-large plunger. I can test the casefeed and tube now, I am in the process of switching over to my processing toolhead to catch up with 18 months worth of range pick up and other misc. brass I have collected.

As I think about it, I was just wanting to use the S 1050 to de-prime, re-size. But, I could very easily use the Dillon AT 500 powder die with the funnel to reload. That much less handling of cases, just drop powder and hand feed the bullet while cranking.

I'll call Dillon back tomorrow and see what they say, maybe get a different tech guy this time.

I'm going to try the W-296 load I made up, but have read that people say it has to be up there in charge weight before accuracy was met. Worth a shot.

Finally got them made up the other night.




The most expensive bag of brass I have ever bought, but got a really great deal on, so I popped for it.

Try the large plunger first. It seems to work. Without cycling a few with the 308 plate, it’s hard to tell.

Edit: those are some pretty rounds. I have been focused on my 500gr cast loads but will try the light loads again soon. My suppressor just came out of jail.

Thank You.

I will, I guess the largest I would have will be in the .45 conversion kit. I just put a SiCo Hybrid in jail a month ago.

The Large casefeed plunger is a NO Go. bummer to, that is the expensive part.

45 doesnt use the large one, does it? Case seems to fit well in my plunger for 44mag/45 colt. Thought that was the “large”. Will check later.

I just called Dillon, the .45 ACP uses the medium plunger. I must have got what was in the conversion kit boxes mixed up, I need to go out there later and look.

But then I go to Dillon's site and look in the caliber conversion chart, and it says it uses the LARGE plunger?  I

But, according to Dillon, the yellow adapter,Large plunger, and part# 21440 powder funnel are all that is necessary to piece it together.

OK, I do not know what is going on, but Dillon told me that .45 ACP uses the medium plunger, their chart says it is large. My caliber conversion came with a large, and it does not fit SOCOM, IDK.

Best as I can tell, this what would be needed to run .458 SOCOM on the S 1050.



I dunno, maybe djryan can check and see if maybe his plunger  is a XL.

I dunno, maybe mine is bent?

Ok. You are right, need XL..

The case fits in a large (top down) but it doesnt fit to the right so it can’t exit into next station. If you bend it, maybe. Sorry bout that. Wish I had an XL to try.

No problem, kind of find it funny Dillon's site say Large for .45, my CC came with large, but the phone techy swore that .45 uses a medium.

Anyhow, anyone in the future can see the Dillon numbers to get what they need.

I'll order the stuff someday, just not now. Would be nice, could de-prime .45, .308, .458 by just swapping out casefeed adapters and plungers, shell plates.

Two lots of the same powder from long ago.

Each manufacturer now has powder manufactured to match 'Their' lot.

Regarding H vs I... I wonder if one will eventually be dropped like H4227. Hodgdon still doesn’t have any Socom loads. Kind of odd as I consider them one of the best to keep up.

I am really surprised as to how little info there is in print.

458 SOCOM is still a wildcat round.  SAMMI has not picked it up as a board member has a competing cartridge.  This conflict of interest has prevented the  458 from being brought up.

That's too bad. Seems like more then a few people are building/buying them.

So, in the last few days of searching, and finding confusing data, I have begun working up a chart of info I have found. These are to be loads that are for the more common bullets/powders People will find. I got some more work to do to it, then I'd like to post it and have people take a look.

I've been digging through the .458SOCOM forum and following links, comparing peoples loads to known info to try to make a pretty realistic load chart for a person starting out to load for their SOCOM. I find lots of good loads, but they are spread here and there, then there is some differing info on some of the more popular loads.

So, anyone who has a pet load that they do not see listed once I post it, or if you see something wrong let Me know please. I can then add or alter the info as needed. I am basically stating Minimum load, maximum load of safe loads from "Trusted Sources".

My version of a cliff notes to starting out loading for .458 SOCOM. All this will be posted to reduce 10% and work up.

Gimmee a day or two, and I'll have it posted.

Thanks, Dave

I finally got out to the range Yesterday. Got some good info.

I will tell you that it was a very good lesson in powders. Testing the difference between W296 and IMR 4198, really shows a person the difference in speed.

I will NOT be loading much more with W 296 in .458 SOCOM. IMR 4198 is much more enjoyable to shoot.

I will keep some of the W 296, 300gr HP's around to let people feel the power of .458 SOCOM. But I was very pleasantly surprised with the accuracy of the NOE 340gr with all loads, especially with IMR 4198.

I'll post the results when I get time to download the chrono and pictures.

Great to know Dave. Looking forward to results.

Would be great to see 296 vs 4198.

Haven’t tried h110 yet but maybe will soon.

My 500gr NOE mold was fantastic too in terms of accuracy- although it still runs too close to transonic. I am going to attempt to reduce again.

I have that NOE .45/70 350gr mould I am going to sell, I may then buy the 500gr for subs some day.

So, I will post up the results from my trip to the range. I learned an awful lot about reloading the .458 SOCOM while putting these loads together. There is an awful lot of knowledge and information over at the .458 SOCOM forums, not a lot of activity, but a lot of info in the forums, you just got to dig back and read, alot.

Several different things going on, I will need to do more work to get things dialed in. I did a large amount of reading, trial and error, tore apart more then a few rounds too.

The main bullet I was working with, the NOE HTC459-354-FN-BU5 RG4 cavity GC A thread from over at the the 458 SOCOM forum I have, Thread, several people gave some good advice and or Intel.

1) The .458 SOCOM has a very short, tight chamber. I was loading according to the Tromix case gauge, not OAL. It seems to be way more sensitive to PC'ed bullets. I was trying to load them out to 2.140", which is well short of the CG put in the moulds for the .45/70 guy's. But with the PC, I ended up loading them in to 2.100", which is basically the CG. I ordered some Hi-Tek coating to try out someday, just a small package, I wanna try to load some with the same powder charge, but one PC'ed, seated to 2.100"and one Hi-Tek coated, seated to 2.140". See what accuracy/velocity differences will be. Intel6 posted a good pic of this in the other thread.

2) I think most all the data I am posting is kind of flawed to an extent, so read it with that in mind. I was expanding the cases with an NOE .460" x .456" Exp. Plug, that fits in a LEE universal expander die. I had sized and gas checked all of the bullets to .459". I took all the previously expanded, primed cases, and dropped all the charge weights for the W296 ladder test. As I was seating the bullets, it just felt like I was having to use way too much force to seat them. I measured the bullets right at .459", and the case mouths at .456" with just enough flare to set the bullet in nice and square. Using the Forster CO-AX to do all of this. IDK, just felt like an awful lot more force required to seat them, then the Hornady 300gr HP, and Berry's 350gr plated, which those cases were sized the same as the cast NOE Boolits. I also think there was some OAL variance due to the PC, which may have been a bit splotchy, need to shake the bullets better next time.

I have since purchased a .461" x .457" Exp. Plug, .462" x .458" Exp. Plug and a .458" Bushing for the sizing die. For 20 some bucks, it will be interesting to me to experiment with it.

Anyhow, on to some results. I put a different scope on for load development, so I had to zero it with some of the Berry's 350gr plated with 28.0 gr of Lil' Gun. The 3 that are touching are the first three shots, then I started to dial in. The group down in the bottom right is the Hornady 300 gr HP with 34.0gr W2-296.



After shooting 30 or so rounds of the Lil' Gun and W-296 loads, I was starting to wish I had put a better stock on then the Magpul MOE. I think I will snag the STR with the LimbSaver pad before the next outing.

As I started in on the W-296 load with the NOE bullet, I was starting to flinch alittle. I will not be using W-296/H110 anymore. The recoil was just violent, and it was just climbing as the charge went up. I hadn't been to the range since January I think, and I was starting to feel it.

The first set.


Then something interesting started to happen, never seen it before. But between 33.0gr to 34.2gr, I think that the powder kind of "maxed" out. Not a lot of FPS gain, but it started chewing up the brass. I had been seeing the occasional marks, but attributed it to excessive head space from the brass being new? Maybe.*I another Hypothesis on that also*


I did not shoot the last charge weight, as at 34.2gr it chewed up 3 of the 5 cases, and I had had enough.

It's late, I've done as much mousing and typing for today, as I want.

I need to finish the data for the IMR 4198, so I can post it. But I will tell you it was so much softer shooting, that is where I will look in the future. Less recoil, good accuracy, I didn't spend too much time working it up, just 3 rounds each at 34.0, 34.5, 35.0, 35.5gr, and I think there is much more to get out of it.

I hope this is not too much for one post.

So, here is the results from the IMR 4198/ NOE 340gr test. I liked this much better as it was much softer to shoot, while still having good accuracy. I only loaded a limited amount, as that was all I had left from the batch of cases I had prepared ahead of time. I figured I would just load them up and shoot them, then I can measure this brass to figure out what the headspace on this rifle is, try to bump it back until it just fits the case gauge. I know some of the brass was oversized, due to the way it fit the Tromix case gauge.

Now I have enough fired brass to de-prime, wet tumble, and re-size.

I only loaded up 3 each of 34.0, 34.5, 35.0, 35.5gr,  as that was all the prepped brass. I want to do this over, but go up to maybe 37.0gr? I'll have to look again, but These cast PC'ed, GC'ed Boolits seemed to do just fine up around 1800-1900 FPS. All the cases from this test were perfect, no marks of any kind.



As you can see, I think it was just starting to get going at 35.0, 35.5gr, FPS was only low 1600's, so I will push this one a little harder, see what happens.

5 rounds 100 yards
458 Socom with 4x Leupold
325 gr GC bullet from an Accurate mold
27.5 gr Lil’ Gun

Untitled by Adam C, on Flickr" />

Missed this thread apparetly....

I have had bad luck with lots of powders in 458... My go to has become RL-7 for three reasons; it's stable, it produces good velocities without flattening primers, and it burns more completely and cleanly than others.

I DO NOT like Lil-Gun in that cartridge. It gives some pretty wild swings in pressures from the visible signs. I would be careful of some of the loads shown out there too. They are WAYYYY too hot in my barrel at starting.

Small ball powders seem to give incomplete burn too. I'm not sure if the primers just aren't hot enough or what's going on?

I went out for a shoot with some local ArfCommer's, decided to take the .458 out.

I had several different batches of prepped cases from different aborted loads. So I just loaded them with some Hornady 300gr HP's and 34.0gr of W-296. 100 yards with a 10" steel gong, was able to hit dead center with all the loads. Some cases were expanded .455", some were .456", some had been loaded and pulled. All shot the same POI. Was quite happy that the 100 yard grouping was so good, had only shot at 50 yards previously.

Also loaded some with the NOE PC'ed bullet with 33.0gr of W-296, virtually same impact and felt recoil.

Time to de-cap and wet tumble some cases and get them prepped for more of the NOE cast bullet with IMR 4198 testing.

I would get unburned powder shooting 300gr bullets using h-4198.

I’ll save it for heavier loads.

While Lil Gun has hissy fits, it still produces great velocities.

PS- Black powder coated bullets look purdy with nickel plated brass.