Shoulder bumping technique

[Apnea]

I'm new to reloading and would like some advice on shoulder bumping. What I'm noticing is that on the first pass through my FL sizing die the case lengthens of course, and after a couple more strokes the shoulder is back about a half of a thousandth (or not at all), and sometimes further passes will get me about 0.0015 or maybe 0.002, which is what I'm trying to obtain. Adjusting the die less than a tenth of a turn deeper gets me too far, sometimes 0.0035 or more. I can't seem to find the middle ground that gets me 1.2-2 thousandths on the first pass. First time the ram comes down (full stroke) there is a gap between the die and shell holder about the size of a sheet of paper, and second or third the die touches. With no case, the die touches. Appropriate "cam-over" at the end of the stroke. I attribute what I'm seeing to some slop in the press, not sure if I should change anything.

What would you do? Does it sound like I need to work on getting better adjustment or is this acceptable technique?

Equipment:
RCBS Summit press, bolted solidly
RCBS FL sizing dies & shellholder
Measuring shoulder with Larry Willis digital headspace gauge (confirmed my technique with them, measurements are consistent and repeatable)
Norma 6.5 Creedmoor brass, once fired, deprimed and cleaned, lubed

 

[jimbires]

I see you are trying to get set up on once fired brass . one of your problems is this brass is not fully expanded yet . I'll neck size only a few pieces of brass until it gets a little tight to chamber , then I'll set up my die to bump the shoulder about .002" on this fully expanded brass . I could never get repeatable shoulder bumps when I had a gap between my die and shellholder . I use the redding competition shellholder sets . this really helped my shoulder bump consistency .

Competition Shellholder Sets - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

Reloading equipment for rifles, handguns, pistols, revolvers, custom dies, bullet casting equipment, powder measuring and weighing equipment, bullet seating dies

www.redding-reloading.com

 

[Apnea]

I see you are trying to get set up on once fired brass . one of your problems is this brass is not fully expanded yet . I'll neck size only a few pieces of brass until it gets a little tight to chamber , then I'll set up my die to bump the shoulder about .002" on this fully expanded brass . I could never get repeatable shoulder bumps when I had a gap between my die and shellholder . I use the redding competition shellholder sets . this really helped my shoulder bump consistency .

Competition Shellholder Sets - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

Reloading equipment for rifles, handguns, pistols, revolvers, custom dies, bullet casting equipment, powder measuring and weighing equipment, bullet seating dies

www.redding-reloading.com

 

[Apnea]

Oh I see, that makes sense, and would explain why there's some inconsistency in this measurement amongst fired cases.

Is it reasonable to just not worry about the shoulder until I can start to detect it on closing the bolt?

Thanks.

 

[fmuguira]

Yup. That's how I do it. Then only bump it back a couple thousandths so the bolt closes good and you re back in business

 

[jimbires]

Oh I see, that makes sense, and would explain why there's some inconsistency in this measurement amongst fired cases.

Is it reasonable to just not worry about the shoulder until I can start to detect it on closing the bolt?

Thanks.

yes , when you can feel it being a little tight when closing the bolt . that is when you can get your die set up on fully expanded brass .

 

[jimbires]

the case lube you use can contribute to this also . if it's not slippy enough you will get inconsistent shoulder bumps . the lube allows the brass to go in the die without added friction . if the lube is not doing it's job it will help cause varying shoulder bumps . I went full circle here . I started with a lube pad. after trying a few different lubes , I'm back to the lube pad .

 

[Deputy819]

I started with a lube pad. after trying a few different lubes , I'm back to the lube pad .

Hey Jim! Was wondering if you had tried Hornady One Shot and experienced the varying shoulder bump issues with it as well?

 

[Mram10us]

just a couple pointers that help me.
1. make sure you let the lube dry for a bit. Don't spray and size or you get stuck brass
2. let the brass sit in the die for 5 seconds (vary time on what works for you) to let brass conform better
just things that help me, but not gospel. Good luck

 

[Capt RB]

I started with lee resizing lube in 1977. I've tried Imperial, Hornady one shot, RCBS spray and the old squeeze tube. I still have more than 3/4s of these 2. I've stuck cases with everything but the Lee. All were stuck due to too little lube, not necessarily the lube itself but the application.
With using the lee I reapply lube to the pad every 30 cases and clean the pad with Starret oil in an aerosol can once a week. The cases stay very consistent this way. You can go further than 30 without sticking but you can feel the difference in the press handle.

 

[L.Sherm]

Annealing your brass will help with consistency also.

 

[jimbires]

Hey Jim! Was wondering if you had tried Hornady One Shot and experienced the varying shoulder bump issues with it as well?

Hi Buddy , I did use one shot for a while when it first came out . I also gave the Lyman spray a try . I liked one shot better than the Lyman spray . when using the spray lubes , I had more sizing effort , more stuck cases , and more variance in shoulder bumps .

 

[Deputy819]

and more variance in shoulder bumps

Gotcha. I haven't really noticed an increase in required sizing effort or had any stuck cases, but I do see some unexplainable shoulder variance from time to time during the sizing operation (even with annealing after every firing). Wouldn't hurt a thing to give another method a try and see what happens.....especially now that I have to spend a little more time 'indoors'.

 

[Tiny Tim]

I see you are trying to get set up on once fired brass . one of your problems is this brass is not fully expanded yet . I'll neck size only a few pieces of brass until it gets a little tight to chamber , then I'll set up my die to bump the shoulder about .002" on this fully expanded brass . I could never get repeatable shoulder bumps when I had a gap between my die and shellholder . I use the redding competition shellholder sets . this really helped my shoulder bump consistency .

Competition Shellholder Sets - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

Reloading equipment for rifles, handguns, pistols, revolvers, custom dies, bullet casting equipment, powder measuring and weighing equipment, bullet seating dies

www.redding-reloading.com

Sound advice here. You cannot get consistent results without camming over the press. The competition shell holders work great. Also per above quote, if your case is not fully expanded and not touching the chamber shoulder, you are chasing a "floating"target. If your loads are not heavy enough, it may take several loads to get to this point. Some loads I shoot could be neck sized and chamber fine for several reloads before needing the shoulders set back. Again, When you get to this point, consistency is king. Same type and amount of lube, same amount of time at the top of the stroke, and consistent annealing is also of great value.