300BlkTalk

I am new to this cartridge. Having purchased several Wilson Combat barrels in the past with good success in .223, I elected to try your 300 BLK, 16", carbine gas system barrel for my next project gun. I checked the gas port diameter at .106" as received from your factory.

Loaded rounds with 3 different bullet weights all using H110 power. All were supersonic loads at about 90% of max charge per Hodgdon's manual. Thought I'd try the Ares Defense gas piston conversion to see how it worked. It didn't. Short stroked every round. Bolt unlocked but rechambered the spent case with no rounds being ejected from the gun. Converted it back to DI gas system.

Back to the DI gas system, things improved somewhat. I now got 100% ejection of the spent cases but would only strip and chamber next round 4 times in 80 rounds fired. Generally, the bolt would close on an empty chamber. Bolt never locked back after last round or when single loaded. I am using a BCG that has about 500 rounds on it (gas rings are broken in), gas key is tight on the carrier, I have a good fit between the OD of the gas tube and the ID of the gas key, Yankee Hill lo-prof gas block fits nicely on the barrel OD, gas tube to gas block fit is snug with no significant leakage, gas port aligns with GB properly, and BCG is sloppy wet with Mobil 1. I tried a wide variety of mags, same results.

I am contemplating enlarging the gas port in the barrel some to see if I get more energetic cycling. What do you folks think about that? Any suggestions on gas port size?

What weight buffer are you using?

Hi there. I would think you may want to check your buffer assembly and see how far away from the standard milspec carbine spring and buffer you are.

Generally it seems that with what you have already tried and still having problems with supersonics then the port size is not the issue either the buffer assembly setup or the gasblock and tube alignment are the problem. With that said many seem to like to drill their port out to .120-.125 so that subs cycle with much more ease.

So, to reiterate. The port size should not be causing your supers to fail. Good luck with the troubleshooting

QuietMike wrote:What weight buffer are you using?

I forgot to mention that this rifle does have a collapsible carbine-type stock. While I have not weighed the buffer, it is unmarked on the face so I presume it is standard carbine as is the buffer spring.

tallburnedmidget wrote:Hi there. I would think you may want to check your buffer assembly and see how far away from the standard milspec carbine spring and buffer you are.

Generally it seems that with what you have already tried and still having problems with supersonics then the port size is not the issue either the buffer assembly setup or the gasblock and tube alignment are the problem. With that said many seem to like to drill their port out to .120-.125 so that subs cycle with much more ease.

So, to reiterate. The port size should not be causing your supers to fail. Good luck with the troubleshooting

Thanks for your comments. I have REALLY checked the gas system over thoroughly. GB fit and GP alignment are perfect. The YHM GB hole measures .156 and as stated above, the port is currently .106 as received from Wilson.

May have to try a completely different lower with this upper. Perhaps I'll try a rifle stocked lower to see what happend. I will save the gas port drilling as a last resort.

russ4777 wrote:

tallburnedmidget wrote:Hi there. I would think you may want to check your buffer assembly and see how far away from the standard milspec carbine spring and buffer you are.

Generally it seems that with what you have already tried and still having problems with supersonics then the port size is not the issue either the buffer assembly setup or the gasblock and tube alignment are the problem. With that said many seem to like to drill their port out to .120-.125 so that subs cycle with much more ease.

So, to reiterate. The port size should not be causing your supers to fail. Good luck with the troubleshooting

Thanks for your comments. I have REALLY checked the gas system over thoroughly. GB fit and GP alignment are perfect. The YHM GB hole is over .125 and as stated above, the port is currently .106 as received from Wilson.

May have to trys a completely different lower with this upper. Perhaps I'll try a rifle stocked lower to see what happend. I will save the gas port drilling as a last resort.

Switching to a different lower and checking your spring and buffer weight and such should give you a little more insight on what may be happening and is simple to do if you have the parts. Report back with what you find

Well I finally got my rifle to run perfectly. Again, 16", 1 in 8" twist, carbine gas system.

1. Enlarged gas port from Wilson's 0.106" up to 0.120"
2. Checked the ID of all my carbine gas tubes and found the largest ID of six of them to be 0.120". Installed that one in the rifle.
3. Took one coil out of the buffer spring. It is now at the minimum specified length of 10".
4. Buffer is standard carbine at 2.9 oz.

Went to the range today and with three different bullet weights (125, 147, & 168) all with IMR 4227 powder the rifle cycled perfectly. Bolt locked back on every empty mag. All were supersonic loads at about 90 to 95% of maximum recommended. Recoil was very mild. I don't think it is one bit overgassed as some say with a gas port this size.

I am now going to go back up to the faster burning H110 and see how things cycle. The 300 BLK is an interesting round but a little fussy.

I'm happy now.

Well Bar None Tomahawk! If everyone with a 16" carbine gas barrel just did that first step we would have about 10% less posts. It's really not that fussy if you stick to the extremes in bullets. It excels with 110s, 125s, and 220 plus.

russ4777 wrote:Well I finally got my rifle to run perfectly. Again, 16", 1 in 8" twist, carbine gas system.

1. Enlarged gas port from Wilson's 0.106" up to 0.120"
2. Checked the ID of all my carbine gas tubes and found the largest ID of six of them to be 0.120". Installed that one in the rifle.
3. Took one coil out of the buffer spring. It is now at the minimum specified length of 10".
4. Buffer is standard carbine at 2.9 oz.

Went to the range today and with three different bullet weights (125, 147, & 168) all with IMR 4227 powder the rifle cycled perfectly. Bolt locked back on every empty mag. All were supersonic loads at about 90 to 95% of maximum recommended. Recoil was very mild. I don't think it is one bit overgassed as some say with a gas port this size.

I am now going to go back up to the faster burning H110 and see how things cycle. The 300 BLK is an interesting round but a little fussy.

I'm happy now.

I too have a Wilson Combat barrel,Recon.I had cycling issue's as well.It's been awhile but I believe the gas port was .094",if my memory is good.None the less after talking on this site I decided to open it up.Again,if I remember right it was to .116".The gun has never malfunctioned since and shoot's sub MOA with 125SST's and TNT's,which is what I run in that rig,proven deer slayer.Maybe I could have changed something else to fix it but the bigger gas port worked fine for me."You can't over gas a 300BLK"is what they told me here.I'am a Wilson Combat fan have a stealth and a CQB pistol,great shooter's from a company with great service.

I also have a Wilson Combat barrel. I will take a look at the sizing. I have chalked it up to being how dirty the ammo is that I am shooting. I have just been using CLP, but it does seem like such a huge difference vs 5.56.

I have been shooting Freedom Munitions and Gorilla Ammo and have found that the DIRTIEST stuff is the supersonic Freedom Ammo, and it drives cycling issues without a healthy amount of CLP. Never used CLP while firing with the 5.56 before or in the military - just for cleaning.