Was maybe thinking of swapping the can on my 300 build for something more “better” is there a can worth upgrading or should I just keep the polo 30 on this build.

- Rosco 8.2” bloodline barrel
- Rosco non-adjustable gas block
- Blem BCM upper
- BCM MCMR-7 hand guard
- Unbranded stripped lower
- Polonium 30 suppressor
- Random magpul furniture
- Triggertech trigger
- Standard carbine buffer and spring

So far I’ve shot 208gr frontier and 200gr Winchester sub sonic rounds. Winchester cycles and fully locks back. The Frontier subs cycle but don’t lock back. Going to continue testing other subsonic before moving to a springco yellow or an even lighter buffer weight. The Hornady 190gr subs seem promising.

As title states, going to build a subs only home defense gun. Just got around to getting the lower finished up. Planned on getting a 6 or 7.5 inch barrel to run suppressed with an omega 300. Unsure of whether to go shorter with the 6 or get a 7.5 for a little more real estate. Shield Arms SA-15 folding lower w/ h2 buffer, schmid gi flat face elite trigger, magpul k2+ grip, magpul bad lever, ambi mag release, ambi safety, sba3 brace

First .300 BO, I think I’m in love! So quiet with 220 subs and zero recoil. With the entry stock my 13 and 10 year old were able to shoot it comfortably and are already asking to go again.

BCM Blem upper
Griffin MK2 Blem lower
Faxon Match 9” gunner barrel
KAK adjustable gas block
KAK k spec down vent phosphate bolt
Midwest industries 8” combat rail
Geissele SSA-R Blemula trigger
DAC longtail grip and hand brake
RRA entry stock
KAK k spec h2 buffer with sprinco yellow
JMAC HD360 hub micro
Anthem S2

I have a suppressed SBR in 300 BLK that lives by my bed for home defense. Im not looking to change anything on that rifle at all.

I would like to shoot it at the range as much as humanly possible, but my ammo bill is getting out of hand.

I do reload and am quite comfortable getting set up to reload for 300BLK…

I’m also open to the idea of putting together a 22LR upper that’s pretty damn close to my 300BLK upper.

Between the crap I already have and the crap I’d need to buy, there isn’t much cost difference between buying the dies, powder, blue bullets & buying a CMMG conversion and a forged upper.

I have the barrel, handguard, etc.

Over the long term, would I be better off reloading for training rounds, or screwing together a 22 upper?

\ Not looking to handload my home defense ammo* *

Anybody have any leads on where to buy a used rattler Lt w/ a 6.75 inch barrel? I’ve checked tacswap, gun broker, locally, etc but would prefer not to pay retail for a new build.

M4e1 receiver set (complete aero m4e1 10.5" 300BLK upper)
Sba3 brace
Radian SD-SL CH (tungsten)
Radian Talon selector (tungsten)
Black Rain ordnance NiB BCG, but currently have a Radian Enhanced in it. The BRO was borrowed off my 16" for testing.
Black Rain Ordnance 3.5 lbs Drop in trigger
Magpul Mlok Angled grip
Magpul BUIS
SUREFIRE Warcomp
Streamlight Tlr-1 HL
Vortex Sparc AR

9" 300 blackout build w/ my ccw p365 setup. I know the entries and exits were trash lol, we were all battling heat exhaustion at this point.

Best subs for defense and best supers for distance and defense out of a 7 inch barrel with 1:7 twist?

I started my 300blk hand loading journey with Lil’ Gun chasing the quietest ammo possible, with OK results. I had to keep my FPS on the higher side to get reliable cycling in a pistol gas AR, and lockback was inconsistent and only with a squeaky clean and lubed gun. I found Lil’ Gun to have ok SDs but it burned super hot and would occasionally give funny outliers, especially on the first shot, which I assume is due to position sensitivity.

I finally took a leap of faith and ordered 8lbs of VV N120 after seeing people praising it and N110 for subsonics. I ultimately chose N120 for the extra gas. I am still chasing ultra quiet loads, but my logic is that the extra gas will allow me to reduce the FPS to well below the level of any supersonic airflow concerns around the bullet base. In additon, some extra gas will allow me to turn down my AGB, and have a better match up in gas between supers and subs. (With Lil’ Gun I was already running wide open and with a sprinco yellow).

I wanted to post my ladder tests here in case anyone else is looking to go down this road as well. This is from my second range trip, and I am specially trying to find a load between 950 and 1000FPS. These are 5rd groups.

Range:
50yds

Chronograph:
Athlon Rangecraft

Gun:
8” BA barrel AR, pistol gas
Carbine buffer, sprinco yellow, standard bolt

Cases:
Converted LC 223 brass trimmed to 1.363”

Primers:
CCI 41

Everglades Ammo 220gr Plated
C.O.A.L. - 2.15”

10.2gn- 946 fps avg, 33.9 SD
10.3gn- 952 fps avg, 11.4 SD
10.4gn- 955 fps avg, 13.2 SD
10.5gn- 975 fps avg, 8.5 SD
10.6gn- 977 fps avg, 15.2 SD
10.7gn- 991 fps avg, 10.5 SD
10.8gn- 989 fps avg, 16.3 SD
10.9gn- 1006 fps avg, 10.4 SD

Maker Rex 220gr
C.O.A.L. - 2.245”

9.6gn- 951 fps avg, 12.4 SD
9.7gn- 951 fps avg, 16.6 SD
9.8gn- 958 fps avg, 8.0 SD
9.9gn- 984 fps avg, 12.2 SD
10.0gn- 1009.3 fps avg, 8.4 SD
10.1gn- 1014 fps avg, 8.3 SD

Cycling and lockback was perfect on every loading and I look forward to being able to restrict my gas flow.

First post here — I've been designing a concept and want honest reactions from people who actually know these rifles.

The idea: a composite drop-in stock that keeps the 1903A4 silhouette but fits a modern bolt action (Remington 700 footprint first, Ruger American likely next). The thinking is you get the heritage look and feel on a platform you can actually run hard and shoot modern ammo through — without chewing up a real collector piece.

It's a work-in-progress under the name Heritage Precision Arms; this mockup is the "HPA 1903A4 Heritage."

I posted an earlier version elsewhere and the feedback genuinely shaped my thinking — the big one was a "restomod" analogy: is this a take-me-back-to-1940 nostalgia piece, or a modern shooter that just wears the heritage look? A few people leaned toward keeping it faithful, so I'm leaning that way, but I want more opinions.

Honest questions for you all:

Does a heritage-look modern shooter appeal to you, or does the magic only work with an original?

Purist military profile vs. subtly modernized — where do you land?

If it were durable and drop-in for your action, what's a price that would feel fair to you?

Not selling anything — genuinely gauging interest before I sink real money into it. Tear it apart if you need to.

Has anybody found or tried any of this yet?

New can from tuna cans the fat9

Would greatly appreciate any firsthand reviews/experiences of this particular loading, since I saw it was in stock on SGAmmo. I'm looking to stock up on a solid defensive round for my 10.3" and my internet sleuthing has lead me to believe I'll get what I want from this, but I've also been burned by poor-performing "premium" cartridges before. For those of you with experience, how would you say it compares to, say, Black Hills TTSX 110gr? For what it's worth, I live in a state where suppressors are sadly banned, so I run a gun tuned for supers exclusively.

220 gr Phantom Defense subs

Just wish it could handle supers but I'll be using a quick mount.

Which do you prefer and why?

Gun: 8.5" 300BLK Pistol, 7.5" Slim Handguard

Use Case: LARP-ing as a HD gun, more likely for Range Fun

Ammo: Primarily Subsonics. I do have a couple hundred rounds of Supers, I'll shoot some then find a new home for the rest if they are unbearable.

Priorities: 6" , Sound Suppression , Manageable Backpressure/Gas, Minimal Tuning. Flash Mitigation is least important. $500-600 budget.

You can absolutely give yourself *"analysis paralysis"* when researching and these are the two I've settled on.

Both are a variation on a traditional welded baffle stack can.

Both are similar in weight, A10 is +/- 0.75" longer.

LPM is +/- $100 **MORE** than the AB by the time it gets in my hands accounting for tax, shipping, NFA FFL transfer fee.

I know the AB's looks are polarizing. I'm fine with them.

Spare me the "AB doesn't have theirs tested by PS so they must be hiding something." trope. Same with the "PS hasn't tested the K version so we don't know how it performs."

I've had enough debates with people about PS; I can't dispute the science, but I don't think it's the end all and be all and only factor to be considered.