Balancing ejection angle

[Roslyn]

Shooting a JP 14 inch .223 Wylde upper with JP factory BCG, sitting on an Anvil Arms lower with a SpringCo Standard Power buffer spring, Fiocchi 55 gr factory rounds. Alternating between P-Mags and C-Products mags.

Rifle shoots tight, groups more or less at .75 MOA at 100 yards when my fundamentals are good. So, happy days, except....

The spent rounds eject at 2 o'clock. Same whether P-Mags or C-Products mags. Brass isn't really beat up, occasional and slight ejector swipes on the brass, but nothing that would prevent reloading them.

Have a little downtime this week, so the OCD in me has me thinking: Hmm... how to move those ejections to 3-4 o'clock?

If I don't want to mess with the gas block, question is whether a heavier buffer spring might solve this non-problem.

Thoughts?

 

[Coyote Kev]

Shooting a JP 14 inch .223 Wylde upper with JP factory BCG, sitting on an Anvil Arms lower with a SpringCo Standard Power buffer spring, Fiocchi 55 gr factory rounds. Alternating between P-Mags and C-Products mags.

Rifle shoots tight, groups more or less at .75 MOA at 100 yards when my fundamentals are good. So, happy days, except....

The spent rounds eject at 2 o'clock. Same whether P-Mags or C-Products mags. Brass isn't really beat up, occasional and slight ejector swipes on the brass, but nothing that would prevent reloading them.

Have a little downtime this week, so the OCD in me has me thinking: Hmm... how to move those ejections to 3-4 o'clock?

If I don't want to mess with the gas block, question is whether a heavier buffer spring might solve this non-problem.

Thoughts?

Why not an adjustable gas block? Takes 10 min to put one on. They arnt that Spendy. $90 Or so. That would give you ability to tweak it perfectly to any load or temperature.

 

[Badfinger]

If it ain't broke ...........

 

[SupressYourself]

I don't think a buffer spring will help. You need a bit less gas. Your options are: adjustable gas block, or adjustable gas key. The key is cheaper, but I prefer to limit gas at the block instead of the BCG.

 

[MSTN]

If the rifle has a 14.5" barrel, the chances are good that it has a pinned and welded muzzle device to make it a 16+" (non-NFA) rifle. If that's the case, changing out the gas block becomes a major PITA.

As mentioned previously, a heavier buffer, and/or stiffer recoil spring, are simple enough to try.

 

[Push]

Shooting a JP 14 inch .223 Wylde upper with JP factory BCG, sitting on an Anvil Arms lower with a SpringCo Standard Power buffer spring, Fiocchi 55 gr factory rounds. Alternating between P-Mags and C-Products mags.

Rifle shoots tight, groups more or less at .75 MOA at 100 yards when my fundamentals are good. So, happy days, except....

The spent rounds eject at 2 o'clock. Same whether P-Mags or C-Products mags. Brass isn't really beat up, occasional and slight ejector swipes on the brass, but nothing that would prevent reloading them.

Have a little downtime this week, so the OCD in me has me thinking: Hmm... how to move those ejections to 3-4 o'clock?

If I don't want to mess with the gas block, question is whether a heavier buffer spring might solve this non-problem.

Thoughts?

Does it not have an adjustable gas block? It’s a JP, didn’t even know they sold a rifle with a non-adjustable gas block.

 

[Roslyn]

It does have an adjustable gas block. But the gas block is adjusted for a different round, a hand load, and buried under the hand guard. I just didn't want to have to mess with it. Which led to what else I might try to adjust the ejection angle.

 

[Push]

It does have an adjustable gas block. But the gas block is adjusted for a different round, a hand load, and buried under the hand guard. I just didn't want to have to mess with it. Which led to what else I might try to adjust the ejection angle.

Personally I would prefer to keep the reciprocating mass low, so I would try a gutted buffer with your hand load and turn the gas down a little. Use the standard buffer with your fiocchi rounds and see what happens.

 

[rxer311]

As another poster said, if it works, don't mess with it. Since you have the adjustable gas block, just use that to dial back the gas a bit. Other than that you are left with a stiffer spring or heavier buffer.

But really, 2 o'clock ejection isn't anything to worry about. 3 of 4 of my AR's eject at 2. I could get a heavier buffer...

 

[Jsp556]

If you change the spring rate or bcg/buffer mass, won’t you have to readjust for your hand load that the agb is set for?

 

[rxer311]

If you change the spring rate or bcg/buffer mass, won’t you have to readjust for your hand load that the agb is set for?

Yes. But you can't have it both ways.

 

[Roslyn]

Bingo. I was hoping a heavier spring, or buffer, might be sufficient to get the ejection angle where my OCD wants it, since it happens to be simpler to get at than the gas block key, given the configuration of the hand guard. As rxer311 points out, this is hardly a crisis, and the rifle shoots tight, with a commercial load no less.

This whole question has come up on other threads, namely: is there a way to predict the proper buffer weight and spring tension for a given load, so the brass ejects "correctly" and doesn't get all beat up. Has to be a balance between gas pressure, buffer weight and spring somewhere, which led to my original post. JP makes a configurable buffer in its silent captured spring set up, add weight or subtract weight, which I suppose is the direction I would have to go to really figure this out.

 

[rxer311]

The easiest way to "fix" it is to have a carbine, h1, h2, and h3 buffer in your spare parts bag. At the range you can swap it out easily.

The balance has to do with gas port size, dwell time, and reciprocating weight.

 

[rxer311]

And if adding a can, backpressure adds another dynamic.

 

[MtnCreek]

Any input on this:

556, 16" mid gas, Geissle gas block, M16 BCG, PSA carbine tube and spring. All unsuppressed. Std carbine, H1 and H2 all eject at 2:00 and hold open on empty. I just put a nice pile of brass in the yard using three weight buffers. No difference in ejection angle?

65 Grendel, 12" carbine gas, Geissle gas block, bootleg adj M16 weight BCG, PSA carbine tube and spring. All unsuppressed. Ejection with carrier opened all the way ranged from 4:00 to 4:30. Carrier turned down one notch ejected closer to 3:00. H2 would catch some on the cartridge when trying to pick up a rd. H1 and Carbine functioned. I really couldn't tell a difference in ejection.

 

[rxer311]

5.56....what does your brass deflector look like? Could be bouncing off that.

Don't have experience with the gender but if u are running an adjustable carrier then you should not need to mess with buffer weights.

Bottom line, if it functions leave it alone. If ejection was straight forward at 1 then I would run a heavier buffer and call it a day.

 

[MtnCreek]

556, I'll have to check. Son is banging away with it at the moment.

Grendel, heavy brass mark on deflector and brass looks a little beat up, regardless of any adjustments.

 

[MtnCreek]

Hopefully I'm adding to discussion and not hyjacking... let me know and I'll bow out.

 

[MtnCreek]

556, surprisingly no marks on deflector.

 

[rxer311]

There goes my theory. If your son was banging away on it, I wouldn't worry about it.