Best Way To Setup Die For .001 Shoulder Bump

waynewjw

waynewjw

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I’m reloading for a .243 Precision and only want to setback 1/1000ths without, hopefully, a ton of to and fro on the die. I have Lee and Hornady Custom Grade die sets, the Lee die is what I’ve used consistently for reloading .243 for my other rifles. Do I insert shell in die, raise ram and screw die down until it touches the case or do I raise ram and place nickel on it and then screw down die or.....what do you guys suggest?
 
Wow! Is likely over my head, but how I would go about it.

That "nickel" thing - creates a repeatable gap between shell holder and die bottom - you can get about exact same next time by using same coin - is almost a "must" if using dies like RCBS to seat bullets - else they will also roll crimp that bullet. For "sizing" die - if using a FL die - that would minimize or eliminate any body sizing - might be what you want. It would also eliminate any neck sizing for that thickness - just ahead of the shoulder junction - some might find that desirable to "re-align" that cartridge in that chamber?

Might need to count or measure your threads - often is 7/8" x 14 tpi on a die body. So a full rotation would be 1/14 of an inch = .0714###" per full rotation. If you wanted .001 "bump" after contact - that would mean 1/71.4### rotation of that die body into the press. That amounts to a smidgeon more than 5 degrees. Maybe you can figure out how to measure that accurately??

It shows on my shooting that I am not nearly so precise - if the fired round will re-chamber, then I size down the neck to hold a bullet and consider that "good enough" - if the fired shell is too snug to re-chamber, then I would screw the die down to contact. Give it a slight turn more - and then try in the rifle's chamber, until the bolt closes to my satisfaction. If making up casings that might be used in multiple rifles, I just Full Length re-size - shell holder top hard on bottom of the die.

Is sort of up to you to be able to show if it is worth what you propose or not - for you and your rifle - reasonable might be 3 or 4 x 5 shot groups at range of interest - can you demonstrate a difference on target or not? In my case, I can not - so either I am limiting factor, or my rifle - chamber - barrel is, or both. As a result, after trying most bench rest things like peeling case necks, "bumping" shoulders, and so on - I gave up on all of that - with my gear and my abilities, I could not show a statistically valid difference on targets to myself, so I just went with the "easy" way. Almost as a joke - I proved that I can shoot 1/4" groups at 100 yards with most of my rifles - by firing at least 10 times - is almost always 3 or 4 holes overlapping, but many more that are not close!!!

There is no doubt in my mind that there are shooters with skills beyond me, and who use rifles much finer than mine, who can demonstrate that some of those fine and esoteric things make a difference for them - sometimes a LARGE difference. But, I tend to have stayed with what I can show works for me and my gear - holes showing up on target usually a good sign - getting those holes closer and closer together requires multiple things - shooter competency, bedding, barrel quality, chambering, "jump" and a myriad other things, I think. I tend to view 3 or 5 shots at 100 yards into less than an inch as "success" with my hunting rifles - I suspect old guys like ChiChi Rodrigues shooting "two's" and "teens" with his stuff, would be pretty disappointed with my results.
 
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In my post I was thinking about FL sizing but in the case of the Lee die set I also have the collet die, which always seems to give me tribulations when setting up, I think because I’m likely screwing the collet down more than it should be.

I’m using Hornady headspace comparator gauge to get initial fire-formed setting of the case shoulder.
 
I am perhaps too old to change - my intention is to fit the brass case to my rifle's chamber - so I do not use intermediate measuring devices - the case fits snuggly or it doesn't - does not matter to me what value a measuring device gives me.
 
flyr said:
Redding Competition shell holders.
Click to expand...

Those will work.
I still prefer neck sizing, either Redding or Forster NS dies, not the bushing dies just the regular ones, I've always got way better results neck sizing then bumping, and it's ridiculously easier too.
 
Hitzy - I think your perspective is correct - is the results that you get that count - does not matter so much what others do, or say they do - you know what you did to get those results, or what you did not have to do to get them.
 
I’m using Hornady Comparator gauge. I’m shooting a Savage Axis II Precision .243 and have got into long range shooting. My previous rifle was a .243 Savage American which I sold when I acquired the Precision. I had 25 rounds that were sized for the Savage American. A week ago I took the Precision to the range to zero at 100 yds and after zeroing the rifle I tried three different handloads which were only 0.1 grain apart. So 1st 3 shots were ok but nothing to write home about, 0.49”. The next 3 shots were .218” and the final 3 shots were 0.192”. Holy crap! 1st time out and the rifle is a shooter but I think I got lucky with these reloads.

Fast forward to yesterday, loaded 10 of each of the 0.1 grain difference, shoulder setback same as before. Well I was disappointed to say the least. I shot 4 groups of 5 shots. The results weren’t close to what happened the 1st time out. So it’s back to trying to find that perfect load, hence the initial post about setback 1/1000thou. I’m using a Hornady comparator gauge to measure fire formed and then the 1/1000thou shoulder bump.
 
Potashminer said:
Hitzy - I think your perspective is correct - is the results that you get that count - does not matter so much what others do, or say they do - you know what you did to get those results, or what you did not have to do to get them.
Click to expand...

Yeah, it may not work for everyone, but here are my results with my 6.5CM
First group on left is fireforming with 120gr PRVI, lousy bullets, rifle hates them.
Middle group is the 2 thou bump with 140's, not bad, not great.
Right group is Redding NS die, same load and bullet as the 2 thou bump, results were acceptable.
100m, the red circles are around 1/2", black is 3".
20200816-181204.jpg
 
waynewjw said:
I’m using Hornady Comparator gauge. I’m shooting a Savage Axis II Precision .243 and have got into long range shooting. My previous rifle was a .243 Savage American which I sold when I acquired the Precision. I had 25 rounds that were sized for the Savage American. A week ago I took the Precision to the range to zero at 100 yds and after zeroing the rifle I tried three different handloads which were only 0.1 grain apart. So 1st 3 shots were ok but nothing to write home about, 0.49”. The next 3 shots were .218” and the final 3 shots were 0.192”. Holy crap! 1st time out and the rifle is a shooter but I think I got lucky with these reloads.

Fast forward to yesterday, loaded 10 of each of the 0.1 grain difference, shoulder setback same as before. Well I was disappointed to say the least. I shot 4 groups of 5 shots. The results weren’t close to what happened the 1st time out. So it’s back to trying to find that perfect load, hence the initial post about setback 1/1000thou. I’m using a Hornady comparator gauge to measure fire formed and then the 1/1000thou shoulder bump.
Click to expand...
It is most likely more than a few other variables that have given you the mixed results- and it may NOT be in your hand loading.
Shooting form and wind are two big ones that many shooters tend to disregard when bench shooting- just saying as a competitor of well over 50 years .
I am not as good as I once was but I am as good once as I ever was!
Cat
 
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It's not likely detrimental to accuracy to bump the shoulder 2-3 thou, and a lot easier to measure with certainty. I wouldn't consider calipers any more accurate than plus or minus .001. If you are using a full length die and seeing the should bumped back .001 or even not moving, you are still likely bumping the shoulder back because the case elongates as the diameter is squeezed down by the die. So if you didn't reach the shoulder with the die, the shoulder measurement would grow, owing to case elongation.
 
waynewjw said:
Erik’s video is great. I never thought about doing it his way, but will get another set of callipers and see what results I get. I will also use both the Lee and Hornady dies and see which provides better consistent bump.
Click to expand...

I could not help but notice the calliper that he used - is not a $16.99 tool from NAPA or Canadian Tire. I suspect that a Mitutoyo like he is using is likely north of $C 200, these days.
 
Personally, I use something more like this.

I put the shell in a cartridge headspace gage that sits on the plate, then I compare the measurement from the gage to the base of the shell.

Measure the case both before and after resizing and adjust to get the target headspace.

This is much like the Cortina caliper thing in the video, but more accurate.

SG308WIN_1-600x600.jpg


s-l1600.jpg
 
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Maple57 said:
Personally, I use something more like this.

I put the shell in a cartridge headspace gage that sits on the plate, then I compare the measurement from the gage to the base of the shell.

Measure the case both befor and after resizing and udjust to get the target headspace.

This is much like the Cortina caliper thing in the video, but more accurate.

SG308WIN_1-600x600.jpg


s-l1600.jpg
Click to expand...

Thanks for posting that method. I'm going to give it a try next time.
 
The most important part in doing precise case sizing is the case lube. Use quality lubes and use enough to get consistent results.

Lee collet neck die, Redding body die has been my goto for all my rifles for many many years.

running a case into the body die a few times after turning 90degs can iron out any issues with press ram spring back. I do not like cam over presses... I want metal on metal.

As was said, fit the brass to the chamber regardless of what that number might be. A piece of masking tape on the head of the case makes for a very nice go/no go comparison. Will be around 2 to 3 thou when compressed.

I wouldn't go any tighter unless you have a perfectly trued up action and chamber.... and even then, fouling can cause a world of headaches.

Keep it simple...

Jerry
 
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