.002 bump variation and giraud trimmer?? Solved! Thanks!!

[mustang-cars]

Forster F/L sizing die
Prime 3x fired brass
6.5CM
I’ve recently switch to a Giraud trimmer. I’m getting variations in trim length of .003
I knew before purchasing the Giraud that my trim length would vary because of the shoulder bump variations I have. I have an ES of .002 in my shoulder bump. I annealed before sizing last time and still encountered the variations. I’ve also switched from an RCBS RC to a Forster CO-AX and didn’t see any improvement. I’m uding Imperial lube and letting the press rest at the top of sizing. I’ve tried a few different things to no avail. This is the first time I’ve used the Giraud. I was using a LE Wilson before. I know I need to shoot them to see if it’s really effecting my load but what is everyone’s opinion on the .003 trim length/.002 shoulder bump variations really effecting things? Is it worth obsessing over getting the consistency? Seems like nothing I do fixes the consistency in shoulder bump.

 

[LawnMM]

I don't think it's going to make any difference in accuracy. Having said that, do you have a horizontal ring on the cases after trimming and twisting?

When I bought a 6x47L shell holder it was a touch tight and gave me trim length issues because some of the cases were sticking in the holder at different depths.

Giraud said send him 3 fired cases and the holder and he opened it up a touch and sent it back, all free. No issues since.

 

[mustang-cars]

I don't think it's going to make any difference in accuracy. Having said that, do you have a horizontal ring on the cases after trimming and twisting?

When I bought a 6x47L shell holder it was a touch tight and gave me trim length issues because some of the cases were sticking in the holder at different depths.

Giraud said send him 3 fired cases and the holder and he opened it up a touch and sent it back, all free. No issues since.

I do have a horizontal ring after trimming and twisting all around the shoulder about were the datum line would be.

 

[flyright]

Imperial gave me fits with inconsistent shoulder bumps. Switched to One Shot and it got better but then started using the lanolin/alcohol home brew and bumps are easily within .001 - more like .0005. My trim lengths directly corresponded.

 

[FLIGHT762]

Imperial gave me fits with inconsistent shoulder bumps. Switched to One Shot and it got better but then started using the lanolin/alcohol home brew and bumps are easily within .001 - more like .0005. My trim lengths directly corresponded.

Using the correct amount of lube has everything to do with consistent shoulder bumps. I've done a lot of experimenting around and discovered this a few years ago. Not using enough lube will cause shoulder bumps to go all over the place.

I'm a fan of the alcohol lanolin when sizing bulk amounts of brass.

 

[KZP]

My Giraud also gives slightly different trim lengths for my 308, but more like 0.002 difference at most. I marked some of the cases that were different to see if shots would land oddly when fired. I couldn't see any difference in how they shoot compared to cases that were spot on in case length.

 

[mustang-cars]

Using the correct amount of lube has everything to do with consistent shoulder bumps. I've done a lot of experimenting around and discovered this a few years ago. Not using enough lube will cause shoulder bumps to go all over the place.

I'm a fan of the alcohol lanolin when sizing bulk amounts of brass.

Yeah going to try the alcohol/lanolin lube. Ordered everything I need just a few minutes ago.

 

[Deleted member 113831]

The thing that makes the most difference in shoulder bumps is uniform annealing of the shoulders. I have the Giraud Tri-Way trimmers for 223 and 308 and use them for bulk brass. If I truly want all my brass the same length I use the Lee trimmer. It is the only relatively fast way I've found to cut every case exactly the same.

 

[Codiekfx400]

Hornady one shot works great for me. Make sure to shake the can for at least 60 seconds then spray the cases then wait 5 minutes. Otherwise you will get a stuck case.

 

[ZiaHunter]

The Giraud trimmer indexes off the shoulder of the case and will trim the necks with little or no variation if you apply consistent tension and turn the case while trimming. I prefer the case holders that are not spring loaded since they seem to work better in IMHO. Most likely the difference in length you are experiencing is in the body of the case. Improper lubing and/or inconsistent brass hardness is usually the culprit. Insufficient lube especially at the base of the case will cause the the case to drag in the die slightly stretching the case as it is drawn from the die.

 

[mustang-cars]

I wanted to say thanks to those who suggested lube maybe the problem and especially those who said the lanolin/alcohol was the ticket. I got all of my supplies in today to make my home brew. Used a 10:1 alcohol/lanolin mixture. Completely solved my shoulder bump inconsistencies. I’m down to .0005 ES and subsequently .001 ES in trim lengths.

 

[JWG284]

What is the alcohol/lanolin process?

 

[KZP]

What is the alcohol/lanolin process?

One method is to mix up the ratio that works for you, spray your brass inside a ziplock bag, shake it up a bit, spread them out on a paper towel until the alcohol dries and you are good to start sizing.

I couldn't get it to work for me without excessive force required to resize. I tried a couple ratios and eventually got a stuck case, so I gave up messing with it. It seems to work for others somehow.

 

[Bradu]

I use the Dillon case lube spray which is the alcohol and lanolin mix. I stand the cases up in a shallow box so I get a little lube in the neck, then I tip the box so they are laying down. Give it a few sprays, roll the cases around and spray a couple more times. Let it dry for a few minutes and you'e ready to size. I do about 50 cases at a time.

 

[Bradu]

Before I started standing them up I would use imperial sizing lube every so often on the inside of the case neck but that gave me up to .004" variance in headspace. I had much better luck with the method listed above

 

[spife7980]

What is the alcohol/lanolin process?

Usually 10:1 alcohol to lanolin.
http://www.65guys.com/brass-case-resizing-lube/

I use an old cardboard shoe box currently, I used to ziploc but I like this better. I stand all the cases up on end and give two spritzes into the necks and then dump them in the side for 4-6 more sprays. Shake em around to evenly coat and then let dry. What’s nice about the cardboard is it seems to soak up any excess but also gets saturated, it’s a bit like a lube pad after a few sessions once it’s seasoned.

 

[JWG284]

Good deal. Thanks. I’m ordering the stuff now.

Usually 10:1 alcohol to lanolin.
http://www.65guys.com/brass-case-resizing-lube/

I use an old cardboard shoe box currently, I used to ziploc but I like this better. I stand all the cases up on end and give two spritzes into the necks and then dump them in the side for 4-6 more sprays. Shake em around to evenly coat and then let dry. What’s nice about the cardboard is it seems to soak up any excess but also gets saturated, it’s a bit like a lube pad after a few sessions once it’s seasoned.

 

[mustang-cars]

I used a plastic tub. Stood them up and sprayed the necks and then rolled them around like the 6.5 guys video. The cases sized the easiest of all the lubes I’ve used so far to include Imperial sizing wax. It was pretty easy with the wax but was inconsistent. The lanolin is extremely smooth and consistent. Sizing is a joy now.

 

[whatsupdoc]

The lanolin alcohol works great just put them in a plastic pan spray 3 shots while swirling the cases around with your hand for a few seconds.
I do the inside of the necks with a brush. You wait till the alcohol flashes and then you have just the lanolin on the cases.
I found trying to spray into the necks only makes you apply excessive lanolin/alcohol. You only need a little and if you are wiping it off you are using too much.

 

[bobke]

I’ve been down this path, to a degree, but opted to stick with a thin coat of Imperial, and also use their dry neck lube. Found that pulling an unlubed button back through the neck, even if carbide, created enough drag to affect consistent shoulder dimensions. Proper initial die setup, especially locking down a die ring and setting decapping stem in place will hit runout. All the above, and a CoAx, fixed most all of issues. Very consistent heat and timing during annealing another positive contributor to consistency.

 

[flyright]

10/1 works great - just spritz at a 45 degree angle on both sides, roll them around in it a bit and wait 5 minutes. Sizing will be smooooth including inside of necks. Best method I've found for consistent sizing.

 

[bobke]

To be clear, since absence of any lube in neck or exterior case body is desired net result, is everyone here running through another cleaning process, or wiping any excess off, to include ID of neck?

 

[mustang-cars]

I just tumblr them again for about 10 minutes in untreated corn cob

 

[flyright]

I use rice but yep - 15-20 minute tumble.

 

[Chris399]

I use the alcohol/lanolin mixture as well. I spray in a plastic tub, sit 5 minutes, neck size then full length size. It is effortless, with both neck and shoulder bump. Well under 0.001 on the shoulder measurement.

I finish with ultrasonic cleaning at 55 Deg. C.