Having Some Chambering Issues

[xer0]

Got a buddy with a .300 Whisper that needed some rounds made as a favor. As I'm such a nice guy, I figured why not try out my first wildcat for my friends benefit. I recently ordered a M1S upper anyway and figured that I might as well get myself set up for reloading once it comes... in 20-24 weeks...

Anyway, I used 556/.223 once fired brass and used a Redding Full length sizing die with the decaping rod assembly removed to form, then cut to 1.350" and reamed and chamfered, then resized again in the dies before charging and seating. It turned out that there was a lot of tension in the chamber. I remeasured the rounds I loaded and they all came within .01 - .005" below sierra's rendition of factory spec on all measurements.

It turns out that a buddy of his built his rifle... I was initially thinking that it wasnt headspaced properly and even filed down my shellplate a bit to lower the shoulder on the brass to no avail. After blackening a dummy round (just lead and brass) with a parafin candle, I chambered it to find that the headspacing was just fine but it seems like the body of the brass is binding. Pix are attached.

I was really hoping to figure something out on my end to custom make a cartridge for this particular rifle but im about ready to have him send it back to his builder for some refinishing. Any thoughts?

[Pnutz]

Your not Alone. I had all kinds of cambering problems when I got my 300/221.

USING ONLY LC BRASS fixed my cambering problems.

If that still doesn't fix it. Try running the 300/221 formed LC case through a .223 Small base die. ( I haven't had to do this ).

If that doesn't work You can try trimming the LC Case down a bit more to 1.340 - 1.335

Good Luck!

[xer0]

Pnutz,

I already tried shaving a piece of brass down to 1.320 and didnt have any luck. As you can see from the pix however, it doesnt look like overall case length is the issue. I'll give it a go with different headstamps.

[Rikky Lee]

Try different brass - why not 221 Fireball? It looks like a very tight chamber and a small base die could help too.

[TCCrewchief76]

Your cast lead bullet might be making contact with the throat and preventing chambering. Take a permanent marker and scribe from around the case mouth to the ogive of the bullet to see if it is engraving when chambered. When my Whisper barrel comes in, I'll be shooting the RCBS 308-200-SIL bullet cast of wheelweight at 215 grains. I'll let you know how it turns out.

Kevin

[xer0]

I measured some of the brass I made up from misc. once fired .223 to have a range from 0.373 all the way out to 0.377 for the max diameter of the case.

Just in case, however, I did scribe the bullet with a permanent marker and didnt find any engravings... Im thinking that Rikky Lee figured this one out; the chamber is just very very very tight. I dont have any 221 fireball brass on hand and i have an abundance of .223/556 brass available. Im thinkng that the small base die might be a good step to get these all uniform. Does anyone have any preferred manufacturer?

Thanks everyone for your help with this!