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They vary a bit but generally right around 2.065 to 2.067". I usually take an ogive reading on a handful and go from there.What is the coal on a factory Hornady sub-x ?
...FWIW, you are making too many changes with too many parts/components at one time. I recommend you start with one barrel, one BCG, one buffer/buffer spring and one bullet/powder combination to start. Also, do it without the suppressor until you get it running right. Adding the suppressor will increase the back-pressure, which you can adjust for with your adjustable gas-block as needed. Pistol length gas systems rarely, if ever, require increasing port enlarging, especially in 8" barrels.
In looking at the Faxon barrels, you can clearly see that the older one has really angular edges at the beginning of the chamber, less angular on the newer barrel. The Rainier barrel was much better, with smooth, slightly rounded appearing edge transitions. It is not absolutely necessary to use "300BLK specific" mags, normal .223/556 mags work. The only concern claimed about using 556 mags was the foremost internal rib, i.e., depending on the particular bullet used and it's ogive location, if seated out too far the rib would contact the ogive at a point greater than a location measuring 0.250" and cause the round to "toe-in" which could affect feeding. This is why it is recommended that bullet seating be to a depth where the rib contacts the portion of the bullet ogive that measures .250". In the early days of 300BLK, people removed some of the material at the top of the rib to mitigate this condition when using polymer mags, steel/aluminum mags were more problematic. Compare your Magpul 556 mags to your Magpul 300BLK mags, you will see the difference. Attached you will find info from AAC & R. Silvers, the developers of the AAC 300BLK cartridge. Remember, the 300BLK was designed to meet a DoD requirement to utilize standard STANAG 556 magazine.
FWIW, I've been using standard Magpul 556 mags (all gens), original Colt AR-15, multiple USGI and Lancer 556 mags for over 10 years with no problems or modifications with a multitude of .308 bullets in handloads for supers and commercial offerings. As suppressors are not legal in my locale, I've limited experience with subs but I've used subs in both commercial & handloads just to "test" in unsuppressed mode.
BTW, the GO/NOGO gauges aren't going to measure the freebore or "leades" on the barrels, just up to the neck/shoulder junction for determining headspace. The freebore is where the bullet ogive shape/measurement makes a difference and affects seating depth (and seating depth affects feeding).
Yep, familiar with it! I have their reloading app as well. Hodgdon also has data up on their reloading site. Here's a link but you'll need to put in the cartridge, bullet weight and powder....FWIW, heres the link to the Hornady site that lists their load data for the 190gn sub-X, albeit is for a 16" barrel...note the load length they use.
Thanks for that. I'm using CFE Black, for better or worse, in LC brass converted from 5.56 for the subs. I think I have a sweet super load for 110gr. VMAX bullets using H110 that I'll be doing a 10 cartridge test with today as proof of concept. Last time out I tested three different ladder loads, each with a different primer. Looks like CCI400 won over CCI41's and Tula small rifle primers (got those for subs really). But I had well under an MOA at 50 yards with the CCI 400 and CCI 41 primers.Here’s some data Seekins 8” and Omega can and Seekins AGB
Hornady 190 Sub-X
AA1680
Fed 205M
COL 1.345
COAL 2.140
BTO 1.625
12.4 gr 1094, 1083, 1064, 1057, 1063
12.5 gr 1119, 1115, 1096, 1106, 1086
12.6 gr 1106, 1116, 1132, 1107
25 yrds and EoTech sight fwiw
View attachment 7714005
I'm assuming, with a shorter barrel, I want a faster burning powder.
A few things. . .
Be careful with Lil' Gun. Tons of load data and discussion on the 300 blk forum. General consensus seems to be Lil' Gun gives best velocities (only by a little) but is extremely temperature sensitive. You do load workup in cool weather, then you take your handloads out in summer and get blown primers. Or do some quick shooting and get your chamber really hot, then a round sits in there for a minute before you shoot and boom. No personal experience with Lil Gun, but plenty of reports. Just be careful.
H110 is the bees knees for supers.
Stop banging your head into the wall and put an adjustable gas block on that barrel. Yeah, I know all the "USGI reliability" guys prefer a simple gas block and and a port that is an optimized compromise that will cycle most ammo most of the time. But this isn't the 1990s any more and [good] AGBs are just as reliable as simple gas blocks.
You are combining irrespective and regardless. Irregardless is not a word.
Good luck at the range
...even if your barrel is dimpled for the set screws, the uppper quarter of the gas block will be "pulled down" by tension against the upper half of the barrels circumference. Shoot enough supersonic ammo through it and a carbon seal will form eventually. Typically, the gas port hole on the gas block WILL be larger than the gas port hole in the barrel, this accommodates slight misalignments of the gas block or minute adjustments needed to ensure the gas tube alignment through the receiver and seating with gas key. If the gas block was a loose fit on the journal to begin with, polishing the journal didn't increase the friction fit. I'd be inclined to advise just shooting a bunch of supersonics to break it in well before starting your sub load development.So someone on the 300blk forum pointed out that the gas ring around the gas port is quite large. I have a "satin" finish on the barrel and it's basically a bead-blasted finish. Pointing this out, I took out my wide selection of micro-mesh (up to 8000 grit!) and worked on the gas block portion of the barrel. I also noticed the gas port had a bit of a raised lip. I knocked that down and smoothed out the finish.
I went back to the range after and things were improved. I was able to get the gas block to lock back with a number of different subsonic rounds. I had a completely different snafu which shut down my testing for the day so I'm not listing it as problem solved just yet.
One other point he brought up is it should be tough to fit the gas block onto the barrel. Even prior to knocking down the surface finish, it was effortless to get the gas block to slide on. I use the set screw version. Going to take calipers to the barrel and gas block to make sure they're in specification. Still a mystery as to why such a change vs. the 10.5" barrel though. Same gas block.
Yes that is the worlds worst chicken scratch. LolWTF is on that note pad? Some kind of Dan'l Boone kilt a bar scribblin's? LMAO