300blk sizing issue (forster die problem?)


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0hw0rd
June 18, 2012, 10:10 PM
Greetings-
I recently picked up a new 300blk Forster full length bench rest sizing die, as I was unhappy with the lee sizing die I have been using the last six months or so. After trimming the Forster sized brass down to .360, I noticed the necks look much shorter than those from the lee die AND the primed AAC factory brass I picked up when it was first released. I checked many pieces, multiple times, and also ensured the sizing die was correctly setup. What's up with the massive difference in shoulder height/neck length (Forster on left, AAC factory on right)?

I have never seen such a large difference between sizing dies, prior to this. Thank you in advanced for your help....as always, I really appreciated it!

http://img513.imageshack.us/img513/2926/photo1lz.jpg

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ranger335v
June 19, 2012, 08:22 AM
What your photo shows is a difference in the shoulders and that indicates a difference in HOW the sizers were set up rather than a difference in the dies themselves. Sizer dies are occasionally slightly off in some dimension but that's really rare. It's really not rare for the user to fail to set a sizer correctly tho; I wonder what method of die set up you follow? This is the second sizer in sequence you've tried?

243winxb
June 19, 2012, 09:39 AM
The primed AAC factory brass may need to be fire formed. Do both fit into the chamber of the firearm?

cfullgraf
June 19, 2012, 10:24 AM
My 300 Blk cases look similar to the photo except the difference in shoulder position is not noticeable to the naked eye with my cases.

The unfired factory case has a rounded shoulder much like the factory case in the photo, the fired and resized case's shoulder is more pronounced as in the photo.

Measuring with my Sinclair Bump Gauge, the factory shoulder position is 0.005" to 0.008" shorter than the fired/resized case. I do not have a 300 Blk insert for the Sinclair gauge, it is one for 30-06 family of cases, so with the slightly different shoulder shapes with my 300 Blk cases, the contact point in the gauge may add to the variance.

The actual measurement number is not relevant to any other similar measurement or design number due to the nature of the gauge. The gauge is meant to measure differences, or comparisons.

My current sizing die is a Redding but I also have a Hornady. I did not see any difference in sizing between the two but I never measured the shoulder position with the Hornady resized cases. My die is set to contact the shell holder.

As already mentioned, maybe the Forester die is not set correctly. Or, if the die was properly set-up, maybe the chamber is out of spec.

0hw0rd
June 19, 2012, 11:37 AM
Thanks for the quick replies. The Forster die is touching the shell plate, so it's not a matter of it being up too high. I've never had this happen with any other sizing dies, Forster included. I've checked and rechecked the die setup.

0hw0rd
June 19, 2012, 11:42 AM
The primed AAC factory brass may need to be fire formed. Do both fit into the chamber of the firearm?
Yes, both fit into the chamber with no problem. The lee sizing die I have puts out brass like the factory primed.

cfullgraf
June 19, 2012, 11:46 AM
I do not have any un-resized fired cases at present to see if my chamber is long. I will have to check that next time I get the 300 Blackout.

243winxb
June 19, 2012, 12:22 PM
Control how much you bump the shoulder when sizing. In other words, back out the Lee FL die. I had a 7mmTCU die set that would crush the shoulder if set that the FL die contacted the shell holder. Factory new dies made by T/C. When you form the case, the die must push the shoulder back more than a standard FL die. This is because of spring back of the brass. Instead of buying/needing 2 dies, a form die & FL die, a die is made that will do both. But turning the die down into the press to much will bump the shoulder to much. The Lee die was a special run made for Midwayusa, Lee does not stock the die, last time i looked.

243winxb
June 19, 2012, 12:33 PM
SAAMI set a standard in 1-17-11 for the 300 AAC Blackout. When it was a wildcat, different measurement?? Just a guess. SAAMI Drawings- http://www.saami.org/PubResources/CC_Drawings/Rifle/300%20AAC%20Blackout.pdf Light loads may not expand the brass fully on firing. May take 3 firings or more to blow the shoulder forward???

0hw0rd
June 19, 2012, 02:50 PM
The issue is the short neck from the Forster die, not the longer necks from the factory primed and lee die. The factory primed and lee brass are both the same size as all of my factory 300blk rounds.

243winxb
June 19, 2012, 06:13 PM
If the empty brass on the left, sized in the Forster die will not chamber = bad die. This would be with no expander used to size, because the neck may have to be outside neck turned.

Nikdfish
June 19, 2012, 07:58 PM
Looks like you need either a shorter die or thinner shell holder - either could correct the error ...

I would expect that Forster would make it right. Have you sent them a copy of that picture?

Nick

Walkalong
June 19, 2012, 09:24 PM
My .300 Blackout barrel and my Hornady dies arrived today. I am looking forward to loading for it. I bought a box of Rem 115 Gr and a box of PNW 147 Gr to get some factory velocities in my barrel, and have some brass to do load testing. I will make my own brass from .223 after that.

It will be interesting to see a sized case with these dies. I should find out this weekend. The shoulder in the die is sharp, not rounded.

cfullgraf
June 19, 2012, 10:56 PM
My .300 Blackout barrel and my Hornady dies arrived today.

Have fun with the new gear.

cfullgraf
June 19, 2012, 10:58 PM
...because the neck may have to be outside neck turned.

Not required with 300 Blackout cases made from 223 Remington.

0hw0rd
June 20, 2012, 12:24 AM
Nikdfish - I ordered a new one from them today and am calling tomorrow to discuss my current die with them and the .308 neck turning pilot as well. If they replace it great, but I plan on shooting a bunch this weekend, so I wanted to get a replacement to use while they are sorting out what to do with the defective one.

Interestingly, I found out on 300blktalk, that the AAC primed brass was formed with shoulders that were too low (at least in earlier batches). A number of pieces had low enough shoulders that the primers were not being struck deep enough to fire...they were so shallow that they looked like normal firining pin marks you'd see in an AR when slamming the bolt It's unknown which batches had the issues, but I'm going to check all of mine to see if I was unlucky with my order.

Also - if you bought ammo from the smaller companies who loaded their ammo in the AAC primed brass, you should make sure you didn't get the bad batch(es), as some of them got their brass from the same problem lots.

0hw0rd
June 20, 2012, 12:28 AM
My .300 Blackout barrel and my Hornady dies arrived today. I am looking forward to loading for it. I bought a box of Rem 115 Gr and a box of PNW 147 Gr to get some factory velocities in my barrel, and have some brass to do load testing. I will make my own brass from .223 after that.

It will be interesting to see a sized case with these dies. I should find out this weekend. The shoulder in the die is sharp, not rounded.
If you can find them, check out the Barnes 110gr black tips. They feed extremely well and are very nice bullets. Guys are having great results hunting large hogs with them, and ate loving the bullets. They're sold out almost everywhere right now, but you can find them loaded in the Barnes 300blk vor-tex ammo, which are also great to shoot.

cfullgraf
June 20, 2012, 04:19 PM
Attached is a photo of some of my 300 Blackout cases at various stages.

From left to right

New R-P 300 Blackout case, unfired.
Reformed R-P 223 Remington case, fired and resized
Reformed R-P 223 Reminton case, fired, but not resized
R-P 300 Blackout case, fired, but not resized.

Resizing die is a Redding set to touch the shell holder.

The necks are nominally the same length unlike the OP's original photo

hentown
June 20, 2012, 07:10 PM
Something's bad wrong with the OP's brass. Looks like the Forester die is out-of-spec???

Walkalong
June 22, 2012, 09:18 PM
I put everything together today. I shot 5 rounds of RP 115 Gr FMJ (http://www.midwayusa.com/product/547535/remington-umc-ammunition-300-aac-blackout-762x35mm-115-grain-full-metal-jacket-box-of-20) and 5 rounds of PNW Arms 147 Gr FMJ (http://www.midwayusa.com/product/528716/pnw-arms-ammunition-300-aac-blackout-147-grain-full-metal-jacket-bi-metal-boat-tail-box-of-20). The recoil was similar but the recoil impulse with the 47 Gr stuff was much shorter. I fired both with no muzzle devise, since it came in after I went to the range. The RP Averaged 2285 FPS & the PNW Averaged 1981 FPS. The ES for the RP was 47 and the ES for the PNW was 27. It was 98 Degrees with 34% humidity. (Hot) It is over gassed for both these loads, but OK. It is an AR Stoner Ultra-Lite barrel (http://www.midwayusa.com/Find?dimensionids=4294846020&statuses=Available&statuses=In+Stock&statuses=Backorder+OK&statuses=Special+Order&statuses=Not+Available&statuses=No+Backorder&statuses=Coming+Soon&statuses=Other&minPrice=&maxPrice=&sortBy=1&itemsPerPage=20&PreviousCategoryDimensionId=15264&promotionId=&userSearchQuery=). About like a pencil barrel .223. Maybe a bit heavier.

http://www.thehighroad.org/attachment.php?attachmentid=166777&d=1340414127

Walkalong
June 22, 2012, 09:21 PM
Here are a couple of brass pics. The ones on the outside are Once Fired and tumbled about an hour. The one in the middle has been sized with the Hornady FL sizer. I bumped the shoulder about .004.

http://www.thehighroad.org/attachment.php?attachmentid=166780&stc=1&d=1340414448
http://www.thehighroad.org/attachment.php?attachmentid=166781&stc=1&d=1340414469

cfullgraf
June 23, 2012, 07:17 AM
I put everything together today. I shot 5 rounds of RP 115 Gr FMJ (http://www.midwayusa.com/product/547535/remington-umc-ammunition-300-aac-blackout-762x35mm-115-grain-full-metal-jacket-box-of-20) and 5 rounds of PNW Arms 147 Gr FMJ (http://www.midwayusa.com/product/528716/pnw-arms-ammunition-300-aac-blackout-147-grain-full-metal-jacket-bi-metal-boat-tail-box-of-20). The recoil was similar but the recoil impulse with the 47 Gr stuff was much shorter. I fired both with no muzzle devise, since it came in after I went to the range. The RP Averaged 2285 FPS & the PNW Averaged 1981 FPS. The ES for the RP was 47 and the ES for the PNW was 27. It was 98 Degrees with 34% humidity. (Hot) It is over gassed for both these loads, but OK. It is an AR Stoner Ultra-Lite barrel (http://www.midwayusa.com/Find?dimensionids=4294846020&statuses=Available&statuses=In+Stock&statuses=Backorder+OK&statuses=Special+Order&statuses=Not+Available&statuses=No+Backorder&statuses=Coming+Soon&statuses=Other&minPrice=&maxPrice=&sortBy=1&itemsPerPage=20&PreviousCategoryDimensionId=15264&promotionId=&userSearchQuery=). About like a pencil barrel .223. Maybe a bit heavier.

http://www.thehighroad.org/attachment.php?attachmentid=166777&d=1340414127

Nice upper. What sights will you be using?

Azsapper
July 2, 2012, 09:29 PM
I just received the Forster bench rest set and on the first case, which had been previously sized in a Lee 300 AAC die, jammed. Contacting Forster as I tore the die up trying to get the case out. It seems as if the case mouth is jamming on the die where the shoulder is created. Once i got the expander out, I couldn't t even press a sized case into the die? Not sure if its me or the die. Never had this type of problem with Lee or RCBS dies.

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