.40 smith and wesson problems

[stacks04]

hey guys, i have bought the rcbs .40 dies, i wanted lee because i like there stuff, and the instruction that comes with it, but cant find em. so far after using the rcbs i like them better. they are easier to use imo and easier to fine tune.

okay, the issue i am facing now is i have about 1000 once fired casings i shot at the range, all factory ammo, either rem, winchester. i am going through and sizing them, and depriming them trying to set up my dies. after sizing and depriming only, i am able to take a winchester 165 grain fmj bullet and slide it right into the case. no flare, and minimal pressure, i mean so little that trying to get a measurement in the dial caliper cant be done because the thumb wheel over powers the resistance and pushes the bullet in more.

none of the specs for the case in the hornady reloading guide 7th edition match the cases i have. the case length is supposed to be .850, i consistantly get .841. the case head is supposed to be .423, i have .418. the only thing that matches is the case base it is .424.

not sure where my problem lies, i assume it is not the dies, i also thought that the brass would be good, but maybe not. please help me figure this out. thanks guys.

 

[SL1]

It sounds like you have a bad sizing die. It's function is to reduce the case mouth to LESS THAN .002" BELOW bullet diameter, so that the expander plug can bring it back up to about 0.002" below bullet diameter and leae you with a tight bullet grip.

Are you using a carbide die? If not, I may have some more questions for you to figure out what is happening. But, the carbide insert should be making your case small enough everywhere it touches the case, so die adjustment should not be your problem with one of those.

It sounds like your brass is not being sized at all. Does it seem any different than an unsized case?

One thing that comes to mind is that RCBS sometimes puts a decapping pin attachment on its expander plugs as well as the stem for their sizing dies. No chance you decapped with the expander die instead of the sizer die, is there?

SL1

 

[stacks04]

the cases i size are coming out uniformed shape atleast. not sure size wise, i will have to check it out tonight. it is very tight fit once i get the case to the die, i have to use some pressure on the press handle to go in and out. it is definately the sizing die though, the flare die only has the round nose flare inside. and yes they are carbide.

 

[SL1]

OK, try measuring the bullets. They should be 0.400" or larger by maybe 0.0005".

Also, measure the diameter INSIDE of the case mouth.

Those two things should tell us what is happening.

SL1

 

[stacks04]

winchester 165 grain truncated fmj are measuring at .399 .400 that i have in front of me. the 2 cases i have here are reading the exact same. same caliper and verified with 2 others. maybe the sizing die is bad.

 

[SL1]

Well, .399" seems pretty small for a .40 S&W bullet, but .400" seems really too large for a sized .40 S&W case.

I just measured mine, sized with a .40 S&W/10mm Auto Redding die, and got:

once-fired, unsized = 0.399" - 0.403" (out-of-round from ejection)
sized = 0.396"-0.397"
expanded = 0.3975" - 0.380"

It is hard to accurately measure inside diameters with calipers. But, my plated .4005" bullets are a slip fit in unsized cases and are held tightly by sized and expanded cases.

From what you have provided, I think you have a sizing die problem.

Call RCBS. They have a really good reputation for providing quick and satisfactory customer service to correct problems like this.

 

[stacks04]

can you check your outside diameter of the sized case also, the 2 i have here are both reading exactly the same at .4195. i will call them and see what they think. thanks for your help. i feel better knowing it wasnt me doing something wrong in the infancy of my reloading.

 

[SL1]

OD on my sized but not expanded Winchester case is 0.4195" - .4120"

Since you have the same dimension, I am now wondering about your brass thickness at the case mouth. My Winchester case measures 0.010" - 0.0115" (mostly 0.011"). Since you said you also have Remington cases, I measured case mouth wall thickness for one of those too, and got the same as the Winchester. Neither of my cases are nickle plated.

If your case mouth thhickness is not thinner than mine by at least a thousandth, I don't understand how we can be getting different IDs and the same ODs on a sized case.

So, I would not be surprised for you to find that your case mouths are on the order of 0.009" to 0.010", which could cause your case ID to be something like .002" larger than mine when only sized.

I am also having a hard time making my case ID plus twice my case thickness EXACTLY equal my case OD. I keep coming up a little short on the sum, by maybe 0.001". I think that is coming from two problems. One is that measuring with calipers causes errors in the ten-thousandths range that can add-up to 0.001" when you are using a combination of 4 measurements. The other problem is that it is very difficult to get a good ID measurement with calipers.

So, I think the case mouth thickness measurement is the most telling here.

Please let me know what you find-out.

I may be away from my computer in a little while, so don't think I am ignoring you. I will check in later, if I leave before I see your case mouth measurements.

SL1

 

[SL1]

Another check to make

While we are groping for answers, try pushing your expander plug into the mouth of your sized case. Do it by hand and see if it is as loose or looser than your bullets. It should be looser if your bullets are not under-size, because your expander should be about 0.002" smaller than your bullet.

SL1

 

[SL1]

Die ID

Stacks04,

One more thing to try. The ID of my carbide die body (carbide insert) is 0.416" and VERY uniform. You should compare that to your die. Remember, there is a slight taper to the insert, so take the decapping stem out and measure it all the way up inside where the insert ends.

I checked my sized brass again and there are some places where it gets down to almost 0.418" OD, but others where it is still 0.020". Those little buggers are springy, and not completely round after the die lets them go. That is making our brass measurements somewhat hard to compare.

That is why I suggested going directly to the die measurement to determine if it is the problem or not.

SL1

 

[stacks04]

okay, the die measurment will happen tonight once i get home, my brass i have here the case thickness is measuring very thin, 1/8 from the top it measures .006 and .007. down near the base it gets substantially thicker at .030 and can see the gap in the caliper jaws. i am thinking i have some bad brass. but i am also concerned because it is all once fired stuff if the manufacturers are cutting costs? i will measure my die tonight and get back to you on that. thanks again for your help. the much thinner brass will definately cause the issue i am having.

 

[SL1]

Wow, that is REALLY thin brass! Are the Winchester and Remington cases BOTH that thin, or is it just one brand?

What ammo did the thin cases come from? (I don't want to buy any of it.)

SL1

 

[stacks04]

from what i gathered online, the headstamp is r-p. and i guess it is from the remington umc stuff. i have used alot of it along with the wwb. i have to start the sorting process tonight. thanks again for your help.

 

[SL1]

Big Safety Problem

Stacks,

Glad to help.

You have stumbled onto a really significant safety problem. If manufacturers are making thinner brass to keep-costs-down/increase-profits, they are making a trap for reloaders who use progressive presses to reload auto-loader cartridges.

A thin case mixed into a batch of good cases makes a a round that will let the bullet push all the way back into the case to the powder, and maybe even compress the powder a little. Even a moderate load can skyrocket pressure when a bullet pushes back that far.

SO, PLEASE POST WHAT HEADSTAMPS YOU FIND WITH THIN WALLS. And, if possible, please post what ammo it was loaded (e.g., UMC, WWB, etc.).

That info could save some of us major grief.

SL1

 

[bullspotter]

I had this exact same problem with my 40 brass and carbide rcbs dies, got new dies after lots of greif trying to get good reloads, the dies were over sized, not making the brass small enough to get good bullet tension, the R-P brass i had in my mixed lot of brass were the thinnest side walls. I had range pickups from my area, and 2 lots of mixed brass i bought online, from 2 dif states, and a box of remington shells i bought early this year, all thinner walled, at about .009-.010. never seen one over .011. The winchester, blazer and cci brass i have all run about .011-..012, some at .013 thick. They were alot better with tension on my 1st set of dies, but still not good enough, after getting a new size die, im getting great BT with all my brass, even the R-P. But on my thinner walled brass, i only reload it 2 times and thats all, The thinner brass seems to get what apear to be stress cracks, stretch marks near the base, after just a few reloadings, Yeah im shooting a glock, 2nd gen 22, their not bulged real bad either, but you can tell the thinner brass is getting worked harder. my winchester brass seems to hold up better for more reloadings, so now thats what i look for is the winchester. I also had a guy from a shooting club tell me that using regular reloading die on 40 that is failry streched out from lose chambers will case the case to push down and in, making the dia small and the length shorter, and the little extra brass that pushes down ends up at the bottem of the case where a rcbs die wont keep it at the same dia, causing a slightly larger dia at the base, thus causing jams in tighter cambers, also wears the brass out faster, He said the 40 brass needs to be roll sized. I think lubing the cases will help this as it dosent push down as hard during the sizeing operation. Now i dont have any proof or data for this myself. But i can see and under stand what hes talking about.

 

[SL1]

Walls in the 0.009" to 0.010" range are not unheard of before.

But, walls in the 0.006" to 0.007" are REALLY thin. Have you ever heard of THOSE before? Even a properly dimensioned sizing die would not be adequate for them.

SL1

 

[bullspotter]

Walls in the 0.009" to 0.010" range are not unheard of before.

But, walls in the 0.006" to 0.007" are REALLY thin. Have you ever heard of THOSE before? Even a properly dimensioned sizing die would not be adequate for them.

SL1



I agree, thats pritty thin, I havent seen any that thin, yet. But on average my rp brass is the thinnest ive come across.

 

[stacks04]

i went to the local gun shop and bought some brand new winchester cases and they are around .010. i think it is a compiled problem of the thin wall and a thin bullet. i measured most of the 165 gr winchester i have and they are consistantly .399. i will buy more bullets and figure it out. the brand new winchester is okay though.

 

[BHP9]

Load 1 round up and see if you can pull the bullet out by hand.

Initially you have only sized the brass, you can't say that the sizing die has a problem until the round is loaded.

 

[stacks04]

i unless the powder and primer shrink the case i wont waste my time setting up the power measure and loading a round. i have made a couple dummy rounds and can pull the bullet out even after i crimped them. and i mean i crimped the crap out of a few to make my point. and they wont hold.