I'm brand new to this forum; just registered.

I just paired a new Anderson 80%er and radical firearms 458 socom upper. Took it to the range this past Wednesday to zero the iron sights. I had black butterfly 306 gr CTX Migration #1 and Xcaliber 300 gr Hornady JHP. I had SERIOUS FTF/FTE issues with the CTX rounds but no problems with the JHPs. I was using metal mags from calegalmags.com that are specifically made for the 458, as well as a metal mag that radical sent me with the upper that is also specific to the 458. I have a milspec M4 buffer tube, spring and buffer with a Hera CQR buttstock. I cleaned and oiled the new upper before going to the range. Any idea what is happening here? Thanks.

When you manually cycle the rounds do you get any marks in the bullet? Might be too long.  Also if they are not sized properly it can cause them to stick in the chamber.  Another thing is unburned powder in the chamber.  

Do you have a cut away chamber gauge?   They can help imensly.  There have been other reports of radical chambers not cycling in the 458socom.   They use a reverse engineered reamer that may not be to true spec.

Get on the 458socomforums.com. There is a lot of great info and help there.

First problem is the Radical chamber.  They are not true to spec but rather the bastardized PTG chamber. Then there has been a problem with Black Butterfly ammo in some chambers, being as mentioned, too long and hitting the rifling.  In correct chambers the BB ammo is fine because it is set up using correct spec chamber gauges but all bets are off with non-spec PTG chambers.

Solution, don't use ammo your rifle doesn't like, see if Radical will give you a refund and buy a correctly chambered upper, or call TROMIX and see if he can rechamber your barrel with the correct chambering reamer.  If your barrel has the QPQ/melonite treatement then I'm not sure rechambering is an option.

What ^^^ Big-Bore said.....

You don't have to be a member to read the posts.

I dont see marks on the round or case when manually cycling or after firing. Since the JHP from Xcaliber works well i think im gonna do what big bore said (which is what i was thinking already) and just use ammo it likes. Seems easier than trying to get a refund or trying to get tromix to fix it. All good ideas though. Thanks.

Heading back to the range tomorrow.  Have another box of the BB so i will see what happens. If it doesn't work then i just won't buy more.

Tell us what happened at the range>>>>???

Thx.

I bought a radical barrel and bolt off the EE here and had the same problems OP described.  When I measured the bolt face it was undersized.  Some quick work on a late to open it up to spec and it runs like a dream now.  I'm running the Rainier 350 FP at 1.970" OAL. Much longer and they won't function.