Will unfired brass change accuracy/grouping?

[jdefranc938]

Just bought my .204 77 MK II over the summer and I've been workin here and there tryin to get a load that is very consistent. Right now, I'm getting 2 shots that are in the same hole or close to it and the 1st shot is usually thrown a bit (1/2"-3/4"). I'm just gonna clean the barrel and make sure it's not an error on my part. But what I have noticed is that the grouping changes DRASTICLY when I shoot a group with fired brass and when I shoot a group with the new, unfired brass. Have any of you ever come across this problem? I realize that the only likely solution is to fire all the brass. However this is really not feasible due to the shortage in primers and powder and I need to load about 2000 rounds for a prairie dog hunt. Any help will be greatly appreciated!

[Jim White]

In lieu of firing that many rounds, I would (as a minimum) full-length size the brass. This corrects a lot of manufacturing defects (tweaked shouders, bent necks etc...). If time allows, I would uniform the primer pockets, chafmber the case mouths and deburr the primer flash holes. Its a nusance but will pay dividends and you only have to do it once.

Jim

[jdefranc938]

Thanks for the info!
I have resized all the cases with the RCBS dies. Is there something that I'm missing with the resizing process? As for the others, I am looking into those as well. When I chamber the newly loaded brass, it sometimes sticks and is hard to completely turn the bolt without a bit of "UMPH". Ejection of brass is not a problem.

[futuretrades]

When I chamber the newly loaded brass, it sometimes sticks and is hard to completely turn the bolt without a bit of "UMPH"

If this is brass that you have FL sized, sounds like you don't have the die adjusted right. FL die needs to be adjusted all the way down to and touching the shell holder with the ram all the up. then lower the ram and turn the die down 1/4 turn, and you should be good to go.

as for new brass, i started using a suggestion from RIO, and that is to just neck size the brass, chamfer the necks, uniform primer pockets and go ahead and reload them to shoot at the rodents you are shooting. this eliminates wasting your precious components. Besides, they won't know what went on with your brass! and you will, have fire formed brass when you want to check loads, shoot targets, or even shoot some more varmints!

[jdefranc938]

If this is brass that you have FL sized, sounds like you don't have the die adjusted right. FL die needs to be adjusted all the way down to and touching the shell holder with the ram all the up. then lower the ram and turn the die down 1/4 turn, and you should be good to go.

Yep, I have the resizer die 1/4 turn past the shell holder and I have the decapping pin down just enough to pop the spent primer out. Is there anything else I'm not adjusting?

[jo191145]

jd

First off, Stop firing 3 rd groups with a 204. You'll chase your tail forever.
Is flyer shot #1 out of a clean barrel? You can always expect that to go out of the group. Not always but usually. Same with a cold barrel, 1st shot can fly.
Is shot #1 flying out of the group after firing a group with a different/lighter powder charge? Very common for the first shot to follow the fouling condition of the previous group. Hence the need to dispense with 3 shot groups.
I always discount the first shot in a group whenever any of the above conditions are present. Pay attention to the last four shots. Thats where your info starts, not ends, but starts.

Your FL sizer should not be adjusted to the instructions but according to headspace of your rifle. In your case it does not seem to matter as the die (most likely) is not setting the shoulders back enough.
Assuming at 2000pcs of brass your using either Win or Rem brass.
Do they chamber straight out of the bag with no problems? Assuming the necks are somewhat round of course.
If they chamber out of the bag but not after FL sizing your die is oversized. Not the first RCBS FL die this has happened too.
Brass that chambers hard can shoot to a different point of Impact (POI) than brass that chambers easily too.

First make sure you apply even pressure to your press when sizing. You said sized brass "sometimes" is sticky. This should mean the die is close to the proper setting. Perhaps your not bottoming out the press handle enough on some of the cases.
Try resizing some of the sticky ones making sure to bottom out the press handle hard. Still no good?
Try screwing the die in another quarter turn. Still no good?
Two options left. Return the die or stone a little off the bottom of the die or shellholder top. Your choice.
Or for the ime being just let the expander ball run through the necks to iron out the wrinkles without letting any sizing take place

New brass usually does not shoot the same as once fired.
Lets quess and say your happier with the groups out of fresh brass as opposed to second fired FL brass.
I'll bet you can feel different seating depth tensions between the two. Therein lies the answer.

[jdefranc938]

jd

I kinda felt the same way about doing the 3 shot groups. I was just trying to conserve components until I had something that I seemed to like. Ya, the first shot is always the flyer and it was out of a cold, uncleaned barrel. All are charged with the same load of powder, primer, brass (winchester) and bullet. Is ther anywhere on here or the ne I can find a nice little tutorial on figuring out headspacing? From what i've been seeing in my own and what I've been reading from all you guys, it seems that is where the majority of my problem is. But the sizer die hasn't been loose and is in the same position for each shell, so I'm still not sure y some are easy to chamber and others aren't. Must be variations in the brass, but I thought that resizing would take out as much of that as possible to make them uniform. I really do appreciate all the input. Please don't give up on me!

[BabaOriley]

I bought one of these before I ever loaded my first .204 cartridge. I have used it to check tolerances but never had anything I FL sized measure outside spec using a Hornady die. Using the gauge would make it more clear if there's something wrong. Seems more simple than chambering one every time you want to check.

I too am sitting with batches of .204 brass all in differing ages and conditions. I have 1000 new brass prepped/primed/ready to load, and several other batches, one on their 3rd load. With this last batch I prepped, I did NOT uniform the primer pockets, because I felt on the first batch I did, I didn't get them as consistent as I would have liked. Often, the case would turn in my fingers when the cutter dug into the bottom corners of the primer pocket. With no way to hold the case anymore securely by the mouth end, I decided this time I'll leave them alone and see if it clears up any accuracy issues.

I would think case mouth tension would be the biggest difference in work hardened brass vs new brass. I've spent some time already looking at high volume annealing systems, thinking maybe I should anneal them after 3 firings instead of waiting to have half a batch of 1000 split on me someday. I don't think I'm loading them hot enough to do much damage quickly, but who knows. I'm also firing mine in an AR-15 exclusively, and the semi-auto trip through the gun may be harder on brass than any work hardening is. I'll probably keep loading a small batch several times here and see how long they last before putting down $200+ on an annealing machine.

Good luck, and let us know what you figure out...

[futuretrades]

one other suggestion here. if you have any more new brass, that you have not fl sized, try running them thru your rifle. my guess is that all of them will chamber with no problems. then go ahead and fl size the same brass and run it thru the rifle again. if you have no problems chambering again, you should be good to go. if you have problems after fl sizing, something is not tight or as jo191145 stated there is a problem with your die. at one time RCBS dies were some of the best on the market, but after they sold to another company, their quality has gone down hill since. if you return the die to them, send a note explaining your concerns with the die or dies. I think the company will replace the die without question. My experience with trying to call RCBS on the phone, they are almost impossible to get to talk to any one in their company.

[Jim White]

Folks,

I suggested FL sizing because of what I just went thru with 6mm brass for a rifle I just obtained a few months back. In my case, the virgin brassed had run outs any where from .000 to .015, most being in the .006 to the .009 range. At short distances that may not be seen but it would seem to me those at .006 and greater certainly narrows the accuracy window as the range increases, IMHO. Neck sizing didn't help my run out woe's, I tried. FWIW, the same occured with some 300 virgin 204 casses too. Afterwards, load them and go shoot/hunt/load test or what have you. Afterwards, neck sizing is OK.

As far as your dies, they have to be set up correctly. It sounds like (by your discription), they weren't sized enough. Also, there is a tool gage made by "Wilson" called a "cartridge case gage" that is a very valuable tool. Of course, the best way to go is to get a comparater (I believe Hornady makes them now) but mine was made by Stoney Point) along with the attachments, measure a fired case from your rifle and set the shoulders back say .003 and then test (with a blank case) to see if it functions.

HTH,

[jdefranc938]

Thanks again guys. I'll be headin back home in a couple days so I can try some of ur suggestions. Is there a tutorial anywhere online that I can learn more about headspacing? It's a new concept to me!

[Silverfox]

jdefranc938--There's a fellow by the name of German Salazar who is quite knowledgeable about many aspects of reloading and shooting and shares his knowledge through various articles he has written and posted at his Web site, "Rifleman's Journal."

http://riflemansjournal.blogspot.com/20 ... chive.html

If you go to the home page of the Web site you can click on the various months out on the right-hand side and read many other interesting articles he has written about Neck Tension, Bushing Dies, Seating Die runout, Process for Coating Bullets, etc., etc. It's a good site to visit if you are hungry for reloading information. Here's the link to the homepage:

http://www.riflemansjournal.blogspot.com/

[jdefranc938]

Well, from everything that has been said, is it a good possibility that my much enlarged group from firing brand new brass is from the headspacing? If I fire the exact same brass again that were previously unfired, i get an amazing group.

[Bunnybuster]

The rounds loaded with new/unfired brass may have more slop, if your chamber is on the large size, and this will have an effect on accuracy.

I shoot a Ruger No. 1, and neck size only. Brass that has been fired and then neck sized gets the group size down to about .375 with my rifle. I don’t normally full length size any case that has been fired in my rifles. But I load for only one rifle per caliber, so I don’t have all the issues about having to fit multiple chambers.

As to your having a stiff bolt on closing with your reloads, there are a couple of possibilities.

1. As others have said, the resizing die could be larger than your chamber, and causing problems. I'm not quite sure how this would happen, if your die is set up correctly. To resize cases dedicated to a specific rifle you want to remove the decapping pin / neck sizer rod from your die, and then run a fired case up the die with it set out a couple of turns so you are sure it won't hit the case. With the ram at full extension, adjust the die down onto the case just until it hits the shoulder of the case, and then go about a 16th of a turn further. This will set the shoulder back about 0.005-inches. Set the lock ring and retract the ram, and then reinstall the decapping pin / sizer assembly. If you want to get really accurate, you need to buy one of the "Bullet Comparator and Bushing Insert" sets, and a pair of calipers. Using the bushing for a 25-caliber bullet, you can get direct measurements on the shoulder of the fired 204 cases, and see how far you are pushing the shoulder back.

2. The next most probable thing that could cause a case to be stiff to load is that the case is over length, and hitting the end of the chamber throat. So use the new calipers to check the case length, and trim if necessary.

3. There is some possibility that the bullets are seated too far out and actually touching the lands. This is very unlikely with light bullets.

[MarineSniper]

just a quick reply to getting ahold of RCBS, i agree it is very difficult to contact them by phone but i have had great success using the email on thier site. They have always fixed or replaced any of my RCBS dies quickly and without charge. So if you need to contact RCBS use thier email feature it will save you alot of headaches...