I just started a build on a lower that will be dedicated to .458 SOCOM.  This is my first .458 SOCOM, and was wondering if anyone knows of a reliable rifle length Spring and Buffer combo?  If you have experience with the .458 SOCOM, please give me your two cents.  The reason I ask is cause I run a Blue Sprinco Carbine spring with a DPMS heavy buffer on my 5.56 Carbine and have never had a malfunction (knock on wood) after 7000 plus rounds.  I got that combo from another post on here, and was hoping I could get some more good info for this new build.  Thanks.

I have extensive experience with the 458S and own 4.  This round was designed to run with STANDARD rifle and CAR buffers and springs.  Quite often when people try to get fancy they create jam-o-matics.  The SOCOM is NOT a 5.56 so forget what you know about them.  No midlength gas (stick with CAR gas) and no need for HBs and XP springs.

I ran a A2 spring and buffer from Bushmaster with my 458S with no issues other than it made my upper dentures(old school hockey fanatic,LOL) ting when fired, I tried a Wollf buffer spring and MGI rate reducer and that smoothed it out, I didnt have any issues running that combo as far as reliability was concerned.

I have a 50 beowulf & put an A2 buf & spring w/ no problems. Yes, it is designed, like the socom, to use car parts. The slightly heavier buff & spring slow it very little & it cycles flawlessly. Now, If one put a 6 oz buff & HEAVY spring I'll bet it would jam up. I only did it because I had the parts laying around AND I wanted an A2 stock on the heavy bugger instead of a car stock. If it ain't broke don't fix$ it.

You may find a few combos that will work for a while. But, it was designed to work with the standard spring.
As said before, if it ain't broke, don't fix it.

That is absolutely correct.  But as with anything, you can always find exceptions to the general rule.  You can make it run with odd-ball buffers and springs, and it will work with some loads, but IMO what good is a rifle if it will run with 300 gr. TTSX but jam every other round with a 500 gr. solid?  The standard buffers and springs, rifle or CAR, will run with any load you put through it.  That is not saying you cannot fine tune a particular load to give less recoil with a XP spring or HB, Endine... but if you find you need to switch loads do not be surprised if it becomes unreliable.  And for God's sake do not shoot yourself in the foot by getting a midlength gas.  Yes, you can make it run with midlength gas but you limit yourself to powders that do not give you the top velocities, and face the facts, the .458 SOCOM is no speed demon to begin with.  The ONLY reason Rock River produced the midlength, and they even said so on ARFCOM, is because so many 5.56 people thought that if it is good in the 5.56 then it must be equally good in the .458 SOCOM, and nothing could be further from the truth.  I have rifles in  barrel lengths from 13.5 to 20 inches and different gas lengths, including the midlength, and the midlength is by far the most finicky of the three lengths.  As to a rifle length gas system, if ANYONE tries to steer you toward a rifle length gas run away, run away VERY fast!
Since you are new, also, barrel length.  There is NOTHING to be gained by going over 16 inches.  As I said, 13.5 to 20 inches, same loads over the same chronograph on the same day and there is less than 50 fps difference between them.  All that extra 4 inches gives you is a longer sight radius if you are using it, and more stick to maneuver through the woods.  Don't think for a second that you are going to gain the often claimed 50 fps per inch by going to a longer pipe.  Not going to happen.  The faster powders that give you top speed give up all they have to give in about 14 inches of barrel, so even if you go SBR you lose nothing, and going longer than that only makes your life easier by not having to do a Form 1, but there will be no significant gain in velocity.

Sounds like I shot myself in the foot by getting the midlength as I was told it would have a higher velocity by the dealer I bought it from... Ive shot it very little because I just haven't had the time but Ive run 3 different loads with 3 different powders and other than the bolt not locking when empty, it has run fine from what I can tell.. If I could ever ... AND I MEAN EVER... get on the 458forum  it would sure make life easier...... Not trying to highjack the OP but I finally found a place to talk about this gun. Hope we can learn more about this round, I love it so far.. Just darned expensive to shoot buying others bullets instead of making my own!

Try Reloader #7. It will make the rifle function.  Too many people think the SOCOM is a bigger version of the 5.56.  Nothing could be further from the truth.  The guy who advised you to get the midlength has not the slightest clue what he is talking about in regards to the .458 SOCOM.  Sad, but true, there are a lot of salesmen that will tell you anything you want to hear to move product.  It needs a handgun or CAR length gas to maintain enough pressure from the fast burning powders to make it function.  Move the gas port out, pressures are falling off too quickly and that is why the bolt is not locking back.  I imagine you are using the powders that give the fastest velocities, like my personal favorite, H110, or Lil-Gun, 296... but with it out there at the midlength, Re #7 rules along with either H or IMR4198s.  You do not give up much velocity going to the the slower powders to make it work, but better to have a rifle that works than have another 50 fps or so, although, personally, I am a bit of a speed freak.  If it is short stroking to the point of not locking back it may well be on the verge of not picking up the next round too.  A temperature drop of 60 degrees, such as that load you worked up in the summer heat, now may not run worth a hoot in the deer stand at 25 degrees.
When it comes to the .224 bore versus the .458 bore, the .458 bore is not just twice as big, it is 4 1/4 times bigger in area, and that affects the way the gas will act tremendously.

Thanks everyone for your knowledge.  I ended up taking your advice Big Bore and just got the standard rifle buffer and a2 buffer spring.  Again, thanks I learned a lot.

That's might fault, sorry... too much "sightseeing" just recovered from a severe bout of intestinal crud courtesy of my most recent trip.  In any event, I believe you are now all set up on the forums!

LOL!! Thanks MARTY!!  Big Bore, I've found the 4198 loads for the midgas and very soon will be trying them out I hope...