Forums46
Topics538,021
Posts9,731,919
Members87,055
|
Most Online25,604 Feb 12th, 2024
|
|
|
223 subsonic that cycles an AR- AR helped needed
#5571059
01/29/15 05:49 PM
|
Joined: Sep 2009
Posts: 18,954
ChadTRG42
OP
THF Celebrity
|
OP
THF Celebrity
Joined: Sep 2009
Posts: 18,954 |
I need some help guys! I know ammo very well, but I don't know the inner workings of an AR as well, like some of you do. I began working on my 223 subs that will cycle an AR. I am working with some custom 87 grain and 94 grain flat base, HP bullets that will stabilize in a 1:8" or 1:7" twist, 16" barrel. I have a working subsonic load with both bullets in a standard M4 type, 16" barrel shooting suppressed. My problem is this. When I get down to the speed I need, I can not get the bolt carrier to fully cycle the next round. It will eject the spent case, but the bolt will not lock back on an empty magazine. When I get my speed up just above 1100 fps (supersonic speed), it will cycle and the bolt will lock back on an empty mag. So, I am almost there. What are some options I can do to help aid the cycling? My goal is to have a subsonic round to sell to any and all shooters who have an AR-15 with 16" barrel and a 1:8" or 1:7" twist barrel shooting suppressed. So, my solution needs to be simple and easily available to all shooters. The idea of changing out the bolt carrier and gas block and such is not an option. I am leaning towards playing with the buffer spring and/or buffer. I need to find a reduced spring that I can try. I have also thought about cutting a few coils off the standard buffer spring to see if this helps. Any ideas?
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5571069
01/29/15 05:54 PM
|
Joined: Dec 2008
Posts: 22,630
Cast
THF Celebrity
|
THF Celebrity
Joined: Dec 2008
Posts: 22,630 |
Send me a few rounds to try in my custom gun with a JP captive spring set. That spring set is very nice.
Cast I have a short attention spa
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5571095
01/29/15 06:03 PM
|
Joined: Sep 2005
Posts: 2,015
Furb
Veteran Tracker
|
Veteran Tracker
Joined: Sep 2005
Posts: 2,015 |
Buddy of mine's 300BLK would not cycle subs, cut about three coils off his buffer spring, ran fine, I'd try that first, Buffer Springs are cheap.
HHUUMMMM, what to write, what to write, I got nothing.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5571157
01/29/15 06:36 PM
|
Joined: Jun 2005
Posts: 2,481
BCJ
Veteran Tracker
|
Veteran Tracker
Joined: Jun 2005
Posts: 2,481 |
Chad, What buffer are you currently using? The CAR buffer is 3.0 oz; if you have an H buffer of heavier change it to a CAR buffer.
The problem you are going to run into is that different manufacturers have different size gas ports and compensate for over gassing with heavier buffers; while others optimize the port size to run with a CAR buffer. Once you get the load to work in your rifle you might want to try other brands of factory rifle to see if they run better/worse so you can let customers know the parameters to be successful.
My piston rifles run everything with just a CAR buffer, including all the under powered Russian stuff.
A lot of the market base for sub rounds that cycle are going to be the SBR guys; in general most SBR barrels are over gassed which should help you out.
Last edited by BCJ; 01/29/15 06:42 PM.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5572439
01/30/15 05:02 AM
|
Joined: Mar 2008
Posts: 838
stxhunter
Tracker
|
Tracker
Joined: Mar 2008
Posts: 838 |
I would say the only other thing you can do is change the buffer/spring or enlarge the gas port, of those two you said you don't want to mess with the gas port so that option is out.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5575770
02/01/15 02:46 AM
|
Joined: May 2010
Posts: 2,972
HuntTXhogs
Veteran Tracker
|
Veteran Tracker
Joined: May 2010
Posts: 2,972 |
I put a ARES Armor low friction BCG in my AR recently to get it to cycle easier and a Damage Industries spring....
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5579859
02/03/15 02:26 PM
|
Joined: Feb 2011
Posts: 1,009
THEBBC
Pro Tracker
|
Pro Tracker
Joined: Feb 2011
Posts: 1,009 |
Chad, Have you tried going to a lower mass buffer?
Type 7 Manufacturer/FFL Custom Builds/Gunsmith/Custom Ammo/Transfers www.titanweapons.comCheck out Titan Weapons for your next gun build. We offer small gun services to complete turn-key long range builds.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5579877
02/03/15 02:38 PM
|
Joined: Sep 2009
Posts: 18,954
ChadTRG42
OP
THF Celebrity
|
OP
THF Celebrity
Joined: Sep 2009
Posts: 18,954 |
That might be my next option. I am almost there getting it to cycle. I'm going to try an idea or two in the next day or two to see if I can get it to work. I'm shooting and testing on a mid length system. I'm fairly certain the pistol length system would cycle these rounds with a normal set-up. I need to refine and test (confirm) my load a little more before I know for sure. When I'm at a little over 1100 fps, it will cycle and lock the bolt back. So, I am almost there. After talking to some powder engineers and ballistic guys, I need to change up my primer I'm using. Every single part of this ammo is very sensitive to changes and I'm trying to get the recipe just right.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5579907
02/03/15 02:55 PM
|
Joined: Aug 2011
Posts: 13,415
jdk1985
THF Celebrity
|
THF Celebrity
Joined: Aug 2011
Posts: 13,415 |
What primer were you using, and what was suggested? What should the change be?
Instagram @justinkingwoodworking
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5586034
02/06/15 02:54 PM
|
Joined: Jun 2014
Posts: 329
bside
Bird Dog
|
Bird Dog
Joined: Jun 2014
Posts: 329 |
Chad,
If you're looking for this to be a commercial product, low mass buffers (/adjustable GBs) are probably not the ideal solution. What I would do is paint a straight line down your buffer spring and clip it one coil at a time. Note how many links it takes to get reliable action, and recommend to customers that they shorten up their spring accordingly. It's a cheap wear piece and is easy to change out. Alternatively, think about buying a bulk set of them, cut them yourself and offer the "subsonic-compatible" spring to your cusomers.
Edit -- You'll probably want to do this with more than one buffer weight.
Last edited by bside; 02/06/15 02:59 PM.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: jdk1985]
#5586756
02/06/15 09:48 PM
|
Joined: Nov 2007
Posts: 9,523
RiverRider
THF Trophy Hunter
|
THF Trophy Hunter
Joined: Nov 2007
Posts: 9,523 |
What primer were you using, and what was suggested? What should the change be? I'd like to hear a lot more about this myself.
"Arguing with you always makes me thirsty." -Augustus McRae
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: ChadTRG42]
#5587454
02/07/15 10:30 AM
|
Joined: Aug 2011
Posts: 1,682
cmorsch
Pro Tracker
|
Pro Tracker
Joined: Aug 2011
Posts: 1,682 |
Chad, you are going to have to use a light buffer/low mass bolt carrier group, or use a barrel with a oversized gas port which will result in the rifle being over-gassed when using supersonic rounds. If going to the over sized gas port, I would highly recommend using a adjustable gas block or adjustable piston system so you can limit the gas when not needed.
|
|
|
Re: 223 subsonic that cycles an AR- AR helped needed
[Re: cmorsch]
#5589091
02/08/15 06:24 PM
|
Joined: Sep 2009
Posts: 18,954
ChadTRG42
OP
THF Celebrity
|
OP
THF Celebrity
Joined: Sep 2009
Posts: 18,954 |
I've spoken to several ballistic engineers and powder engineers about this project, and I am getting really close to working it out. The primer part of it has been a real trick. I have learned more than I ever though about what causes certain reactions with primers and powders. I am still in the R&D side of things, so I don't have a lot of solid data yet. Just a lot of thoughts on what to try and experiment with. Chad, you are going to have to use a light buffer/low mass bolt carrier group, or use a barrel with a oversized gas port which will result in the rifle being over-gassed when using supersonic rounds. If going to the over sized gas port, I would highly recommend using a adjustable gas block or adjustable piston system so you can limit the gas when not needed. Hey Carl, for this project that's not an option. The buffer spring and/or the buffer would be the only 2 ways I can change to make it work.
|
|
|
Moderated by bigbob_ftw, CCBIRDDOGMAN, Chickenman, Derek, DeRico, Duck_Hunter, hetman, jeh7mmmag, JustWingem, kmon11, kry226, kwrhuntinglab, Payne, pertnear, rifleman, sig226fan (Rguns.com), Superduty, TreeBass, txcornhusker
|