Hornady AMAX 208gr loads?

[Sami]

I've tried H110 with this bullet, even at supersonics it will not cycle. I can't find AA1680 or N110 locally but I might be able to locate RL7 which I read that would cycle with this bullet. Anyone have any loads for this combo or possibly N530 or Ramshot TAC?

I found this for 220gr and N530 (which should be similar to TAC):

http://www.reloadersnest.com/detail.asp?CaliberID=135&Powder=Vihtavuori+N530&LoadID=11345

If I were to try this on 208gr bullet, I probably should start higher, right? 16gr still should be able to fit into the case. I might be better off just copying what others have already shot but if I can establish safe guidelines on where to start, I would not mind experimenting myself.

[TCCrewchief76]

We need to know where your gas port is and what size it has been drilled to. We also need to know what your barrel length is. 1680 and similar are good for carbine length gas systems (16" barrels), and the 2400 burn rate powders are good for subsonic with large gas port holes in the pistol position. Just need a little more load info to help you out.

Kevin

[Sami]

SI defense 16" 300 Fireball barrel with pistol length gas port location. Gas block is from a 16" .223 upper.

http://shop.si-defense.com/SI_Defense_16_300_Fireball_Barrel_p/si%20ar15-b-300f-16.htm

[TCCrewchief76]

Still need the port size. Try the largest drill bit shank that will fit the port hole.

[Sami]

I am waiting on confirmation from SI before I take it off. Should I be looking at increasing the size and go with an adjustable block?

[Sami]

Reply from SI:

.056" on the pistol location. It may have to be enlarged with ammunition types such as subsonics or the use of suppressors. An adjustable gas block is highly recommended.

[TCCrewchief76]

I am waiting on confirmation from SI before I take it off. Should I be looking at increasing the size and go with an adjustable block?

Uh, yeah. Mines over twice that size at .118". Cycles the subs just fine with 8 grains of 2400.

Kevin

[Sami]

Uh, yeah. Mines over twice that size at .118". Cycles the subs just fine with 8 grains of 2400.

Kevin

Seems like I will need to disassemble it and put it on the drill press then. Any recommendations for a low profile adjustable gas block, or should I first see if size increase will do the trick alone?

[TCCrewchief76]

Your block should be fine. You will need a good drill press, and a bunch of incrementally larger drill bits. You need to drill that port in as small of an increment as possible to lessen the possibility of burrs inside the barrel. I would actually recommend sending it off to Spook here on the forum for that. I've had two barrels built by him, and can't recommend him highly enough.

Kevin

[Sami]

I already got it done. Started with one that actually fit in and worked my way up from there to 2.8mm (7/64). It's back up assembled and ready to go testing as soon as I reload some more ammo.

Thank you for your help, much appreciated!

[TCCrewchief76]

No problem. Be aware that your bolt is going to see a LOT more gas volume, and that supersonic rounds are going to be a bit rougher on your weapon. The gas port specs you now have are ideal for subs...

Now go have fun,

Kevin

[Sami]

The whole thing made me reorganize my garage, much nicer now for reloading and wife should be happy as well. I think I figured out the gas block now, I guess research would have been in order earlier but glad I got it done now. I'm new to AR's so I thought the block was the one restricting the airflow, not the hole. Now that I have ideal flow for subsonics, I would have to get an adjustable block to restrict the airflow IF I wanted to shoot large amounts of supersonics. I think I'll manage for now since I built this just for subsonics.

For supersonics I have plans for bolt guns in 22-250, .308 and/or 6.5x55. Of course AR10 in .308 wouldn't be bad idea, unless you ask the wife... :)

Now I just have to set the drill press back into neck turning setup as the SI Defense uses 1.40" length with 0.01" neck diameter. By far the most time consuming task in forming brass from .223, that's why I had to use the drill press. Lathe might be a "must" purchase now so I can thread my own barrels too. :nanabang:

[Sami]

208gr A-Max, 10.7gr of H110 seemed to cycle without a problem and it sounded like subsonic. However, due to increased gas flow the case ruptured and left the neck on the chamber. I got it out and now I have a cast of the chamber which I will be using as reference. Looks like I neck turned a bit too much into the shoulder which caused the rupture. Live and learn, thank god!

[Retooferab]

Here is a sub load that I am playing with. This info is for the first five shots that I shot with it.



Barrel length 10.5
Port position..... pistol
Bullet type.... AMAX
Bullet weight... 208
Powder... N110..... 8.0gns 2.16oal
Velocity... 1028
Standard Deviation
Extreme Spread... 20
Accuacy.... 3/4"
temperaure... 48
altitude... 300
wind.... calm

[Alleycat]

I run 8.2 gr of VV N110
OAL of 2.234
11 inch barrel
Blackout chamber
Cyclone suppressor
V = 1050 to 1060
I've never shot them out of my 16 inch gun.

[Retooferab]

The way I came up with this load I was running 8.6 of N110 with 220smk and getting about 1035 avg. With a 2.09 oal. I just guessed that about 8gns would be close to 1030 and left my dies set at 2.09 for the SMKs. When I seated the amax they came in at 2.145 I shot them and they seem to be doing great. I hope to do more testing this week.

[Dacapster]

Any other powder loads for the subs in 208?

[Retooferab]

I am going to try some AA9 when I get a chance. I also have some 1680 but it sounds kind of loud to me. The AA9 should take even less powder than the N110 so it should be quieter.

[Rancid Coolaid]

Sami,

I've had no end of problems with H110, it seems to be very temp and position (in the case) sensitive.

I chased stringing problems in a 16" bolt gun for a good 6 months before realizing H110 just plain sucks for relatively precise shooting.

Some will disagree, probably, but that's my note of disdain for H110.
My best luck has been with #9 and lil gun.

[Sami]

Unfortunately local powder selection isn't that great. I did pick up a jug of 2400 to try a different powder. Have not been able to find 1680 or N110 anywhere so far.

[martineta]

I can't speak to using H110 for subsonic but I can for Supersonic. The guy that turned me on to the 300 Whisper is a friend from Paraguay where I have a hunting lodge. I took Marco a 300 Whisper barrel in 2000. It was a 10 inch barrel made by JD Jones. Marco was always a good shot. After he got his new whisper barrel he started winning every silhouette competition he entered. The only Powder he uses is H110. He has been the national champion Silhouette shooter 3 times since 2000. I have since taken many 300 whisper barrels to other guys in our shooting club there. Marco made me promise not to take anybody dies as he has a nice side hussle selling his reloads to the other guys in the club. 18.5 gr H110 does the trick. Its what I shoot now. For subs I do use 10.5 grs of N110. Point of impact is dead on same as supersonic at 25 yds., 2 inches low at 50 yds., and 11 inches low at 100 yds when the encore has been sighted in with 150 gr ballistic tips for 100 yds.

[alorton]

I've had pretty good luck with 2400. I use 8.5gr of 2400 with 240gr SMK's and 8.0gr of 2400 with 208 AMAX's, both right at 1030fps.

ETA: 10.5" bbl