Belted Magnum questions for you guys....

[AtownBcat]

Today I have had to throw away(in the bucket for recycling), 150 pieces of RWS Brass. It had all buldged at the area right above the belt to .512-.514, new brass is .507.(Using the blade or knife portion of my calipers right under the belt.) I had been having trouble with a sticky bolt, but not heavy from the bottom but almost stuck at the very end of the bolt lift. My brass had only been fired 3 times. I believe this was caused because of a couple things.
1. My load is on the warm side 77.7 retumbo 210/208 burger/Amax both shot great. CCI Mag Primer. Neither bullet actually touching the lands. The primers are pretty flat but I didnt have loose pockets and there was no ejector mark.
2. I have been pushing my shoulder back way to far. According to my new(and bad ass) headspace guage that I got from Innovative Technologies, I have been pushing the shoulder back .0075. This was happening because I was trying to get my redding body die as low as possible to get as close to the belt as possible. I also bought a special collet die for belted magnums from Innovative Technologies, but the max that can be saved is .511 and all my brass was past that point.

So I need to buy new brass and start over so I wanted to see what you guys with belted magnums are doing about this issue. What brass seems to hold up the best for you? I thought RWS because of the thickness would have been the toughfest and maybe it is but I was over working it.(I was shocked to learn the first time you shoot virgin brass it as .020 clearance at the shoulder)I know Lapua isnt doing 300WM any more...

 

[hoguer]

Re: Belted Magnum questions for you guys....

nosler custom brass. only way to go

 

[aloreman]

Re: Belted Magnum questions for you guys....

larry willis collet body die

 

[tcmajor]

Re: Belted Magnum questions for you guys....

Hey, give this guy a look. I get over 10 loads from my winchester 300wm brass loading 208 AMAX with RL-22. I use the collet resizing die when I start getting stiff bolt lift (3-4) loadings. Run them through the collet die/ neck size and good to go.

http://www.larrywillis.com/

 

[Cigarcop]

Re: Belted Magnum questions for you guys....

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DFCMAJOR</div><div class="ubbcode-body">Hey, give this guy a look. I get over 10 loads from my winchester 300wm brass loading 208 AMAX with RL-22. I use the collet resizing die when I start getting stiff bolt lift (3-4) loadings. Run them through the collet die/ neck size and good to go.

http://www.larrywillis.com/ </div></div>

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AtownBcat</div><div class="ubbcode-body"> I also bought a special collet die for belted magnums from Innovative Technologies, but the max that can be saved is .511 and all my brass was past that point.
</div></div>

He has the collet die

 

[glock24]

Re: Belted Magnum questions for you guys....

I'm using my Larry Willis die EVERY TIME with my 7mmRM Norma brass. No problems after 6 firings.

My load isn't as warm as yours however; 75g Retumbo under a 162g A-Max

 

[Cigarcop]

Re: Belted Magnum questions for you guys....

I agree the brass is toast because of how and what you have been doing to it.

Start over with new brass not pushing the shoulder back farther than is needed. Use the Collet die to achieve the sizing near the belt. You can spin that FL Sizing die as far down as you want but camming the press isn't gonna help you as you've already found out.

 

[Squid284]

Re: Belted Magnum questions for you guys....

Some dies like Redding are "tighter" than others on the body near the head/belt and better push it back to where it should be. I've found that Redding type S bushing dies and comp shellholders are superb for controlling shoulder bump, neck tension and properly sizing the body down the entire length. I haven't needed a second body die.

Right above the belt is where the case tends to thin out. This is where the case stretches to headspace off the shoulder during firing (think case-head separation) and less material in this area of the case therefore causes more deflection/yeilding. In my opinion, this is what causes the bulging. Pushing back the shoulder .007" everytime accelerates the stretching/thinning and reduces case life. Cut one or two of the cases in half (one of the ones you were going to toss anyways) and see how bad the thinning is, you can also use a paper clip or RCBS casemaster gage.

Since you are using a redding die already... and my 7RM RP brass after 8 firings measures .513"-.514" above the belt let me ask you these questions: Is it just the upper bolt lift that's sticky or does it take more effort to pull the bolt back and extract the case from the chamber? Is this a "factory" barrel/chamber? Do you see any drag lines running down the fired case or any other consistant marks on the body from case to case? The reason I ask is because I had what turned out to be a rough chamber on a rifle that had to be polished out by the gunsmith, after that the problems miraculously went away. Cost me like $40 but I was frustrated over the issue for a month or two before I took it in. I found that it normally occured after 2-3 reloads similar to your story but eventually it happened on new box ammo.

I would look to the chamber as the culprit, but it may be a combination of issues. Possibly the camming action of raising the bolt is sticky because it's fighting to pull the case out of the chamber? I would think an overpressure condition would make the bolt sticky during the whole range of bolt travel? If that makes any sense.

Try lubricating the bolt/lugs. Try cleaning the hell out of the chamber with a brush/solvent and see if that helps. Also (after cleaning) see if the phenomena happens again on both a fired and a FL sized case (no bullet/primer/powder). Anytime there is 77 grains of Retumbo, there will definetely be some fire forming going on. Can you reproduce the problem by firing brass reloaded 2-3 times with 72-73gr of Retumbo? Maybe this will shed some light on the issue.

 

[Casey Simpson]

Re: Belted Magnum questions for you guys....


Now. Where did you say you threw that 150 rds of RWS brass?

 

[AtownBcat]

Re: Belted Magnum questions for you guys....

Thanks for the posts and as noted I do have Larry's die I just called it by his company's name instead of his personal name.

Ok Squid, Here is the deal if the bolt lift was the face of a clock and closed was 5:00 and open was noon(not exact but you get the idea) there is no problem until you get to 1:00. Then you have to either wrap your thumb around the scope and pop it to noon and open or open and close it several times. Once at noon about half the time i need a little extra to extract the round. As a side note rubber mallets are not recomended...lol
Also this will not happen on factory ammo or my loads using virgin brass. It opens and extracts perfectly.

The barrel is a kreiger and they did the build also. I sent them the action and they did a level 2 truing and fit the barrel and all that. Not saying that it is not the chamber but this is no "factory" rifle.

 

[Casey Simpson]

Re: Belted Magnum questions for you guys....


<span style="font-size: 11pt">Your load is <span style="color: #CC0000">too hot</span>.

Other than why you are shooting<span style="color: #CC0000"> too hot</span> of a load and still wondering why problems have developed, there is nothing mysterious here. Having loaded multiple belted magnum cases multiple times using standard dies, no problems have developed for me setting back the shoulder @.005". Currently my primary shooter is 7 Rem Mag, WW cases, 175 grain bullet at 2950 in cooler atmospheres like now in Texas and Louisiana.

FYI. When I proclaim the load too hot, I mean for that chamber, ambient temperature and the other pertinent variables that affect chamber pressure. let off the gas. If you continue experiencing extraction problems upon firing reasonably charged rounds, you have a chamber or gun issue.

All guns benefit from polished chambers, bolt faces, and proper lubrication (grease).


</span>

 

[Jig Stick]

Re: Belted Magnum questions for you guys....

I'm using a Collet neck sizing die on my winmag cases. I've fired them 4 times with no changes in performance. I keep seeing posts regarding this Willis die for belted magnums, but I'm unsure how to encorporate it into my brass prep. My plan was to set my full length die up and use it after the 4th firing, and set it up to just bump the shoulder back 0.001 - 0.002. How would using the Willis die be better? I'm barely working my brass already

 

[Bigwheels]

Re: Belted Magnum questions for you guys....

I have been using the It collect die after every 3rd firing. Until I got an.S-die. Also I have had no problems resizing the belt area even @ .515". I have several hundred that are on their 8th firing now. My S-die sizes the belt back to .511-.512 by itself. They drop into the top of the It die every time.