new gun... put it up for a yr, then got corbon 350 gr hp's and 405 sp's... put a millet reddot on it, and it shot the 405's better... used the 10 rd mag that came witht he gun... don't remember any feed issues... there were 3 of us shooting, and we passed it off after a couple shots... last week, getting ready for hogkillers dangerous water jug shoot, i put a scope on it... i've bought 6 boxes of corbon 405 gr sp's. 3 differnt lots, bought at 3 different times... bore sighted the rifle to get me on paper... shot 3 rds at 50 yds, 2 fed, 3rd hit the back of the barrel, never did feed... loaded another mag (new military 30 rd mag with green follower) with 4 rds, chambered 1 by hand with the t-handle... instead of the bolt release... it chambered, then the next 1 would not chamber... tried the handbump assist, all it did was jam it harder... hard to eject an unfired round... chambeered the next round witht he t-handle, fired, then jammed... looked at the feed lips of the mags, followers, tried differnt (new) mag... same issues... so we loaded an empty in the bottom of the mag, and it (at least) fed better... gun was sighted in, so i figured to quit for the day, and shoot at hogkillers.... next day loaded a mag with 3 rds, it fired 2, then jammed... 3rd was so stuck that it took 2 of us to get the t-handle to eject it... ramrod shot it, and it jammed afer 1 shot...its got feed issues, and maybe ammo issues... called and emailed RRA and they told me not to use the corbon 405's... they think its the bullet... i think it's something else.... before i ship the gun back, what can i check??? here's a quote from the email i got from RRA...""""" Jim, There is an issue with the 405gn rounds for the .458 due to the bullet shapehitting the rifling. You will want to use a different bullet size.""""... and RRA has links to corbon for the ammo.....

I would try some factory ammo with a different bullet. If the gun works then the e mail was correct.

If the rifle does not work with different bullets then I would send it back to RRA.

i have some 350 gr corbon left... ill try it .... the rifle did not want to group the 350's... about 5-6" at 50 yds... it would shoot the 405's into 1 hole.... i don't think the ogive of the bullet is an issue... some rounds feed, others don't...and there ought to be some freebore from the end of the chamber to the start of the rifling... RRA advertises that you can shoot from a 240 gr to a 600 gr...i've got a different action spring to install, i'll try that too...

Hey bud,

This is not a corbon issue, it is a RRA chamber issue. Some have sent them back to RRA to have fixed and others have sent them to Marty (Teppo Jutsu, creator of the .458 Socom). It is possible to polish the chamber yourself and it clears up the whole issue.

If yours is anything like mine, it functions great but when hunting if you chamber a round and don't fire it the only way to get it out is to beat the buttstock on the ground while pulling the charging handle.

I fixed mine with some polishing compound and a drill in 30 seconds.

Hope this helps.

Also, if you are having feeding issues try modifying the mags like suggested by RRA. Half moon cut up front, or try different mags altogether.

My RRA .458 SOCOM shoots and functions great. I did have an issue with some .350 grain Corbon ammo. That stuff was supper hot! The extractor was deforming the case heads badly. I now reload all of my SOCOM ammo and have no issues at all. It shoots very accurately.

I have built several of these and the mags are very critical to feeding; no matter what they say, all mags are not equal; make sure your feed lips allow the top round to feed up into the chamber without hitting the barrel extension, as much as possible. Bending the lips upward is the cure. Also, some lower receivers will seat mags slightly lower in the frame than others, so making the bullets point higher in the mag during feeding will insure good feeding. Tolerance build up; and those blunt bullets don't like to hit the back of the barrel extension. If you have a tight chamber, well, that is another issue... I use my own reamer and shoot Rem and Speer 400 grainers only. RRA throats, I don't know what their spec is. I have a .050 long leade with a 1.5 degree throat.

+1
A thorough cleaning and polish fixed the same problem for me. Chambers were fine except for the big 500Gn monolithic solids. I'm building a carbine off a RRA upper and a pistol that I have from Marty

quote:

Originally posted by kaizer27:
Hey bud,

This is not a corbon issue, it is a RRA chamber issue. Some have sent them back to RRA to have fixed and others have sent them to Marty (Teppo Jutsu, creator of the .458 Socom). It is possible to polish the chamber yourself and it clears up the whole issue.

If yours is anything like mine, it functions great but when hunting if you chamber a round and don't fire it the only way to get it out is to beat the buttstock on the ground while pulling the charging handle.

I fixed mine with some polishing compound and a drill in 30 seconds.

Hope this helps.

Also, if you are having feeding issues try modifying the mags like suggested by RRA. Half moon cut up front, or try different mags altogether.