300 Blackout Sinclair slotted Guage Question or am I being paranoid? *picture heavy*

[fullretard]

All,
I first ask for your patience then ask for you help.
I have an AR in 300 blackout.I am reloading some 2x fired (once as 223/556 once as 300blk) cases. I think I might be paranoid as it took me forever to fix a stuck case issue in my 223/556 AR.

I full length resized with my hornady 300 blackout die and also backed out the neck on my RCBS small base 223 die and ran it through that as well.
I take both my LE Wilson case gauge and my sheridan engineering slotted case gauge.

I then seat a CCI400 small rifle primer and load 17 grains of h110
http://sierrabullets.files.wordpress.com/2013/07/300-aac-blackout.pdf

my intention is loading 5 rounds in .1 intervals between 17 and 18.1 using 125 SMK HP
I intended to load 60 rounds but I stopped, because of something curious

It is under length

But it won't go flush in my Sinclair slotted case guage

Of Course it seats great in the LE Wilson gauge. I had issues with the LE Wilson gauge causing stuck cases in my 223 AR 15, which is why I have both an RCBS small base die and a set of sheridan engineering slotted gauges

I plan to buy an extra firing pin at the next gun show so I can grind it down so I can cycle rounds through an AR to check.

Am I being overly paranoid? I just don't want to comeback from the range pissed off about a stuck case.

I have 5 rounds loaded.
Should I carry on?
Am I overly paranoid?

As bugs would say I am a maroon, so clue me in guys!

 

[rjacobs]

What brand of brass are you converting? There are a lot of brands that have thick case walls that end up being thick necks when converted and they do exactly what your loaded rounds are doing in your slotted case gauge. There is a big thread over on 300blktalk with all the good and bad brands of brass to use. There is a reason I only use LC brass because it has zero issues with thick necks once converted.

Wilson gauges have their place, but they ARE NOT a loaded round gauge since the ONLY thing they measure is headspace and to a lesser degree trim length. They are bigger in almost every dimension than the min SAAMI spec. The Sheridan gauges are cut to min SAAMI chamber spec. If your brass passes that gauge it will function in every rifle(save for any that have tighter than SAAMI spec chambers like some CMMG chambers).

I would check the thread on 300blktalk and see if the brass you are converting is on the bad list. If your brass is passing the Sheridan gauge unloaded, then thick necks is what I suspect.

If you can measure the brass thickness of your necks that would help. Also the neck size of your loaded round. You can compare these to the SAAMI print out and see where your dimensions are off.

 

[FNARSHOOTER]

Check your neck thickness .Hard to tell in photo but it seem to be hanging up on the neck .If it fits the Sinclair gauge before you load the bullet its either neck thickness or crimp. What Brass are you using ? 300 blk forum has full specs and a list of brass that is GTG and some that needs necks turned.

 

[shoot4fun]

It appears to me that the last pic shows the neck too thick once the bullet is seated.

 

[fullretard]

Logic would dictate that it is neck thickness of the case.
I have the el cheapo harbor freight saw, but my current reloads were made from brass that was previously cut and sized.
I have had good luck with Freedom Munitions brass, which is reman but shot great.

I have half a dozen fired cases from factory 300 brass, but I was saving those for subsonics.

I will bounce out to the 300 black forum, but out of all the forums this one seems to have the most participation.

I have loaded 6 rounds same issue.
FC 12 223 rem x 3
LC 12 natocross
FC 09
Speer 12 223 Rem

Assumptions being the MOTHER of all fuckups
I assumed if I had no issues running reman 300 rounds that I could reload them.

 

[TRD1911]

Here is a link to the thread on 300BLK forum that was mentioned earlier - 300BlkTalk ? View topic - STICKY - Good/Bad brass list converting 5.56->300blk

A lot of good information in there

 

[fullretard]

Very polite way of saying RTFM
this is my first attempt at reloading this caliber, and it looks like I have join that forum instead of just lurking.

I'll reload the few factory cases this weekend to verify for my own sanity.


Sent from my iPhone using Tapatalk

 

[fullretard]

One thought if it was loaded once, why can't it be loaded again?


Sent from my iPhone using Tapatalk

 

[rjacobs]

If you are using factory 300BLK brass and coming up with this issue as well as your converted then another theory is that your Hornady 300BLK size die might not be right. I dont know if it was Hornady, but I remember reading a year or 2 ago that somebody put out some out of spec dies. Or the Hornady dies are 300 Whisper(small differences, but differences none the less) but remarked as 300BLK. I think I remember reading something about the Hornady dies.

Ive converted thousands upon thousands of LC brass into 300BLK using a Whidden trim/form die and finishing in a Forster full length die with zero issues reported.

300BLKTalk is a VERY active forum with guys that have reloaded and shot thousands upon thousands of rounds of 300BLK. I think myself am somewhere in the 10k rounds of 300BLK loaded and shot and I have converted closing in on 50k pieces of brass. I know there are guys over there that have loaded and shot way more than me.

 

[Splat]

If you are using factory 300BLK brass and coming up with this issue as well as your converted then another theory is that your Hornady 300BLK size die might not be right. I dont know if it was Hornady, but I remember reading a year or 2 ago that somebody put out some out of spec dies. Or the Hornady dies are 300 Whisper(small differences, but differences none the less) but remarked as 300BLK. I think I remember reading something about the Hornady dies.

Ive converted thousands upon thousands of LC brass into 300BLK using a Whidden trim/form die and finishing in a Forster full length die with zero issues reported.

300BLKTalk is a VERY active forum with guys that have reloaded and shot thousands upon thousands of rounds of 300BLK. I think myself am somewhere in the 10k rounds of 300BLK loaded and shot and I have converted closing in on 50k pieces of brass. I know there are guys over there that have loaded and shot way more than me.

What is your process? I also use a a trim/form die (Redding) with LC 12 before trimming with the Harbor Freight. I then run it through a Forster FL die and make final trim.

 

[Splat]

FullTard. Have you tried chambering the rounds in your rifle?

 

[fullretard]

I had the rounds to an coal of 2.24 and had the issue so I shortened them to more closely match the Sierra PDF

Everything chambers....
The difference between whisper and blackout is similar to 223/556

Now time for more coffee
Again I think I am just being paranoid, but I wanted to check.


Sent from my iPhone using Tapatalk

 

[rjacobs]

Just remember that the Sheridan gauge is TIGHT. Most chambers in my experience are a lot looser than min spec.

 

[rjacobs]

What is your process? I also use a a trim/form die (Redding) with LC 12 before trimming with the Harbor Freight. I then run it through a Forster FL die and make final trim.

I do this on the side so not to give all my process away but I am single pass forming and final trimming. Punch primer, swage, form and trim, final size in a Forster FL size die. Produces killer brass.