cant make heads or tails of shoulder bumping

[Tonmarchelli]

Hey guys,

I want to get into bumping the shoulders of my 300WM to preserve brass life and not FL size them each time I load them. I understand the concept of shoulder bumping and why it preserves the brass. but what I cant find out is what die to use. Ive got a set of RCBS and hornady dies (both FL sizers) but ive read I need to get a neck sizer, or neck bushing die. another person has told me that in order to bump just the shoulder back I need to have a custom die made.

basically what im looking for is what die i need to bump back just the shoulder (neck too if necessary) and how to adjust said die. I like redding products and plan to go that way but again, dont know which die to get.

Thanks for the help.

 

[Layton]

Isthis what you're looking for?

L

 

[milo 2.0]

Hey guys,

I want to get into bumping the shoulders of my 300WM to preserve brass life and not FL size them each time I load them. I understand the concept of shoulder bumping and why it preserves the brass. but what I cant find out is what die to use. Ive got a set of RCBS and hornady dies (both FL sizers) but ive read I need to get a neck sizer, or neck bushing die. another person has told me that in order to bump just the shoulder back I need to have a custom die made.

basically what im looking for is what die i need to bump back just the shoulder (neck too if necessary) and how to adjust said die. I like redding products and plan to go that way but again, dont know which die to get.

Thanks for the help.

Tom,
Bumping the shoulder really means fl sizing, you're constricting the case vertically or shoulder to case head. I suppose in fl sizing you're constricting the diameter of the case also, but this isn't what causes problems in brass. You have to resize the neck either way each time.
I think this shoulder bump die concept is BS. Either die you mention that you have will serve you well. My advice is to quit reading! There are more gadget whores out there buying needless shit than I care to mention.

The way to set up a die, bump or fl is to take a good supply of fired brass, 100 or so, set your rifle on a table and start feeding them into the gun, find your five hardest chambering pieces. Now back the die out of the lock ring slightly, run a couple cases into the die, wipe them off and try chamber them, still tuff, turn die downward 1/16 of a turn, re-lube and try again, then try chamber them again. Just keep doing this till they feed ever so NICELY, you can get a feel for sloppy over sized cases. Then size all the cases, about 70% of the cases wont even get a shoulder bump, and they wont till they need it, now your die is set for the life of the barrel.
It's in your head you need this bump die, so if you're like me you'll own it shortly, but?? I don't find the need for headspace gauges either.
Whether you bump the shoulder .001", or .0025", who cares as long as the cases feed without oversizing. The only place you need to know that number is on a gun forum, and you can post up, "I bump my shoulders .001556", err! err! err!, BIG FUCKING DEAL.
I've loaded for 30 years and only ever had one case head separation, and that was from a grossly oversized chamber.

 

[Temp9]

Milo,

I agree with most of what you say. I will disagree on your point about not needing headspace gauges, though. Okay, well, I suppose you don't NEED them, but for people like me who think in numbers, it's a huge benefit. Plus, I don't have to get out my rifle and start dicking with tight fitting brass all the time. I know my 6XC gets bumped to 1.4920" and I can adjust my dies to bump to there whether it's Norma, Hornady, or Winchester brass, and regardless of whether or not it was annealed recently, or if I somehow lose the adjustment on my dies completely. Again, without the need for chambering and bumping a bit more and chamber and bumping....

And I've gotten incipient case head separations in .223 Rem after 3 firings at .004" bump. Now I know to bump less than that. Maybe I just have bad luck or run hotter loads.

 

[1SMALLJOHNSON]

Well..... It's not hard to set up any FL die to bump the shoulder. You just got to have some patience, and understand the concept. Me personally, I also use a bushing to size the neck, all while I'm bumping the shoulder.

I think Milo has a good "cheap bastard" method to set up your FL die. I say cheap bastard, b/c I'm in that club too. However, I did splurge and buy the Lock-n-load "headspace" gadget, and I use it religiously.

A piece of scotch tape mic' s right about 0.0045". If you can set up your FL die such that a piece of fired then lubed (important, when you're looking for consistent sizing) then "bumped" brass "goes" with no tape on the case base, then "NO-GO's" when you put a piece of tape on the base, you've got a good measurement.

Please keep in mind that as you deviate from consistent lubrication on the sizing step, you will find variation in your sized brass.

You can set up your RCBS or Hornady dies to perform this function, just fine.

Might want to get a permanent marker and "paint" the shoulder area of your brass you're using to set up the die. As you approach the correct die setting, you will see "witness marks" on the brass, at the shoulder/body junction. This way, you know you're approaching the "tickle point".

Best of luck!

 

[milo 2.0]

Temp,
Well I guess we see I have an opinion! My statement is, once you have the die set, for the same press, same gun, etc.., you never have to readjust, as long as you tighten the die in the press the same way each time, eliminated with a Forster coax of course.
I can see where the tool would come in handy, but your separation incident was in essence, your fault. Setting dies according to manufacturer's directions can be quite misleading also. I worked with a guy who got into reloading, one morning in the office, I listened to 7 different opinions on how to set the sizer die, Oh My God. 2 busted decapping rods later, we stopped by his house on the way to the field, fifteen minutes of common sense instruction and he was up and running for that rifle. Whether he retained any of it, I'm not sure!!

 

[milo 2.0]

Well..... It's not hard to set up any FL die to bump the shoulder. You just got to have some patience, and understand the concept. Me personally, I also use a bushing to size the neck, all while I'm bumping the shoulder.

I think Milo has a good "cheap bastard" method to set up your FL die. I say cheap bastard, b/c I'm in that club too. However, I did splurge and buy the Lock-n-load "headspace" gadget, and I use it religiously.

A piece of scotch tape mic' s right about 0.045". If you can set up your FL die such that a piece of fired then lubed (important, when you're looking for consistent sizing) then "bumped" brass "goes" with no tape on the case base, then "NO-GO's" when you put a piece of tape on the base, you've got a good measurement.

Please keep in mind that as you deviate from consistent lubrication on the sizing step, you will find variation in your sized brass.

You can set up your RCBS or Hornady dies to perform this function, just fine.

Might want to get a permanent marker and "paint" the shoulder area of your brass you're using to set up the die. As you approach the correct die setting, you will see "witness marks" on the brass, at the shoulder/body junction. This way, you know you're approaching the "tickle point".

Best of luck!

Johnson, By the way, I love your name!
I'm cheap by no means, I have more gear than most, it's just how I choose to spend my money. I really want a case concentricity gauge, but every time I put one in the cart I think of sleepless nights trying to figure out how to straighten out a problem that really doesn't exist.

Good idea on the soot trick, or marker though!

 

[1SMALLJOHNSON]

I assure you sir, I meant no offense.

 

[Prairie Wolf]

Well..... It's not hard to set up any FL die to bump the shoulder. You just got to have some patience, and understand the concept. Me personally, I also use a bushing to size the neck, all while I'm bumping the shoulder.

I think Milo has a good "cheap bastard" method to set up your FL die. I say cheap bastard, b/c I'm in that club too. However, I did splurge and buy the Lock-n-load "headspace" gadget, and I use it religiously.

A piece of scotch tape mic' s right about 0.045". If you can set up your FL die such that a piece of fired then lubed (important, when you're looking for consistent sizing) then "bumped" brass "goes" with no tape on the case base, then "NO-GO's" when you put a piece of tape on the base, you've got a good measurement.

Please keep in mind that as you deviate from consistent lubrication on the sizing step, you will find variation in your sized brass.

You can set up your RCBS or Hornady dies to perform this function, just fine.

Might want to get a permanent marker and "paint" the shoulder area of your brass you're using to set up the die. As you approach the correct die setting, you will see "witness marks" on the brass, at the shoulder/body junction. This way, you know you're approaching the "tickle point".

Best of luck!

I read an article by ML McPherson in Varmint hunter about this.

The whole point of shoulder bumping is not brass life, it is keeping headspace to a minimum for better accuracy. The gist of his article was that if your shellholder isn't bottoming out, your press will flex enough (believe it or not) to cause your headspace to vary. You might have one round that actually needs to be cammed into the chamber and one that is perfect fit and they wont shoot the same. In theory.

I was reminded of this by your comment about lube for consistent sizing. Brass hardness also has an effect but I suppose one can anneal.

Anyway, solutions are:
1. Redding competition shellholder. You select the shellholder that provides the exact headspace you need, and set up so the shell holder makes contact.
2. The forster die linked above.
3. if you have a savage rifle you can adjust the headspace to match your die using a F.L. resized piece of brass and a shim of the correct thickness (like the aforementioned piece of tape) as a headspace guage. I had thought the headspace you wanted was less than the .045 mentioned but I don't really remember.

That reminds me I need to renew my subscription to Varmint Hunter.

 

[turbo54]

Milo is correct in his procedure, though I'd like to point out 2 things:

1. $35 on the headspace measuring tool is money well spent. While not needed when making ammo for a rifle YOU possess, it is needed to make good ammo that WILL fit any SAAMI compliant rifle.

2. I've found it is helpful to only size any given piece ofbrass ONCE while setting the die. If you size one and it doesn't fit right, set that piece aside and grab another fired case. You want the sizer to get it right on its FIRST pass. Don't know why it does something slightly different on its 2nd, 3rd, or 4th trip into the die, but I've found it does.

 

[milo 2.0]

I assure you sir, I meant no offense.

None taken bro! After re-reading, I do sound like a chinsey fuck.

 

[1SMALLJOHNSON]

Holy Cripe! I screwed up! Scotch tape is NOT 0.045"!!!! It's 0.0045" That's 4 and a half thousandths. Sorry!