H110 in an AR15? Bullet weights?

[Garrett]

I've been loading .300 Whisper in an SSK Contender for the past 5 or 6 years. Since I've been using it in a single-shot, I haven't really been concerned with how my loads would run in a gas-operated semi-auto.

I recently bought one of the Noveske .300/221 barrels for an AR15 and put it together last night. The barrel does have a 1:8 twist and the gas port is in the pistol position. Now I'm wondering if any of the loads I have already worked up will run it or not. I'd prefer to use some of the powders I have on hand before buying some different stuff.

I've got some ammo loaded using a 220 gr SMK and H110, that I'm thinking should do okay, although they might be supersonic. They were developed in a 10" barrel and the Noveske is a 16" barrel. I'm sure my AA#2 loads won't run.

What are some other good powders for a gas gun?

Also, I'm thinking of working up a cheap plinking load for this gun. How light can you go on the bullet weight and still get reliable functioning at subsonic velocities? Can you get surplus 147 gr. bullets to cycle? Any other inexpensive bullets to look at? I've got a few hundred 220 SMKs still, but it's nice to shoot on the cheap as well. I had worked up a great subsonic load using a 150 gr. bullet for the .30-30, but I doubt that one would cycle either.

[N310toN170]

I've had pretty good success with H110 in the AR's. It does however tend to be very temp sensitive either weather related or by rate of fire. VihtN110 moves from ball to extruded and tends not to be as fickle.

There seems to be a fine line between balancing bullet weight to charge weight and properly cycling. I've found that the lighter weights (110-125) take enough powder to cycle that it becomes violent and pressures can be borderline. Once you start to move to the heavier weights you get a bit better 'push off' and the actions cycle a bit nicer. Then you transition to sub and the cycling may fail to lock the action after the final round.

As for cost compares on the rounds...I've had pretty good luck with the Hornady InterLock lineup and then of course there's SMK in bulk for a little relief. Some of the InterLocks vary in shape enough that you can play with getting closer to the lands w/o exceeding mag length but I'm still working up conclusions on that one.

[Colohunter]

I have a M1S upper with the gas block in the carbine position, so I am not sure how much my info well help you with your pistol length system. I got H110 to work pretty well with 125gr Sierras at about 2200 fps, but with 220gr SMKs I could not get them to cycle at all.

I then tried AA2680 from some suggestions on this board. With 1680 I get 100% function with 220gr SMKs and about 90-95% function with Hornady 150gr FMJs. They don't lock the action back on the last round, but cycle between shots for the most part, the won't feed the next round every ten to fifteen rounds, mainly when it is cold out. Overall it is adequate for me for a cheap plinking round.

And I got 1000 150gr FMJs when I bought my Hornady LNL AP, so that makes for some really cheap shooting!:grin:

[TheAlmightyBob]

I would like to add my experience. I use H110 with bullet weights up to 150gr supersonics. But from starting at 147gr and up I use AA 1680 for subsonic loads. I also found temp problems with H110, but since I dont head out to play till its 60 degree's and up, I dont have a problem with it. I also found out that above 150gr, the 1680 give me more consistant velocities and much lower deviation numbers.

[markpurifoy]

I have a M1S upper with the gas block in the carbine position, so I am not sure how much my info well help you with your pistol length system. I got H110 to work pretty well with 125gr Sierras at about 2200 fps, but with 220gr SMKs I could not get them to cycle at all.

I then tried AA2680 from some suggestions on this board. With 1680 I get 100% function with 220gr SMKs and about 90-95% function with Hornady 150gr FMJs. They don't lock the action back on the last round, but cycle between shots for the most part, the won't feed the next round every ten to fifteen rounds, mainly when it is cold out. Overall it is adequate for me for a cheap plinking round.

And I got 1000 150gr FMJs when I bought my Hornady LNL AP, so that makes for some really cheap shooting!:grin:

I have a new model1 upper i'm having cycle problems.I loaded 240 gn MKBT by Sierra started with 8.4gr to 10.8 gn h110 and none cycled right the 10 .4 and 10.8 would sometime get the bolt back for enough to stove a round in chamber.

[Spook]

V V N 110 is good stuff. Lil Gun is good stuff.:smile: H-110 ..not so nice

I've heard good things about AA#9 and IMR sr4756. Check your gas port diameter as it will need to be .118 or so to get these powders to cycle the action

[N310toN170]

I'm going to have to second the earlier post... H110 and N110 work great with the lighter <168 gn loads. Once you get up heavier than 175 gn I moved over to AA1680. This got the M1S upper 16" to function pretty reliably (carbine gas port).

The Noveske was more forgiving with the gas port in the pistol position but had a much tighter chamber (whole 'nother issue).

[markpurifoy]

V V N 110 is good stuff. Lil Gun is good stuff.:smile: H-110 ..not so nice

I've heard good things about AA#9 and IMR sr4756. Check your gas port diameter as it will need to be .118 or so to get these powders to cycle the action

how do i check it and open it.never done this before.i loaded all kinds of stuff your years,but this 300 is something different.help.thanks

[markpurifoy]

Update call Model1sale talked to their 300 tech.Their sending me the 300 whisper sub sonic spring kit free of charge. cant wait to see if this fixes cycle problem..:uzi2: