Slowing the cycle time of a direct impingement auto loader.

So..

I've been asked a question about getting brass to drop closer to the ejection port on an AR style rifle.

The fellow shoots commercial loads, but reloads too.

An adjustable gas block came to mind, but... nah.....

Weighted buffer is an option, but so is a weighted BCG. al. la. Tubbs device.
Tubb Precision AR-15 Carrier Weight System (CWS™) - YouTube.

Some Rifle length buffers have free weights inside, so it would actually be difficult to "calculate" just how much mass is shifted during the "bolt open" movement.

I can't yet get my head around the differences between increased inertia mass locations.

Your considerations are welcome...

CalG said:

So..

I've been asked a question about getting brass to drop closer to the ejection port on an AR style rifle.

The fellow shoots commercial loads, but reloads too.

An adjustable gas block came to mind, but... nah.....

Weighted buffer is an option, but so is a weighted BCG. al. la. Tubbs device.
Tubb Precision AR-15 Carrier Weight System (CWS™) - YouTube.

Some Rifle length buffers have free weights inside, so it would actually be difficult to "calculate" just how much mass is shifted during the "bolt open" movement.

I can't yet get my head around the differences between increased inertia mass locations.

Your considerations are welcome...

Click to expand...

Not a new need. Capture bag:

https://www.amazon.com/Caldwell-Resistant-Convenient-Picatinny-Collection/dp/B07FCRM3D9

If the intrusive annoyance and mass-shift are to be avoided, just adapt the concept of the initial deflector portion, let the brass fall clear, but not so far-off nor as randomized as to dispersal pattern. You do NOT want it TOO close so as to have some of it bounce BACK into the firing position. It tends to get bent when trod on.

Messing with the gas, mass, or any key part of the action OTHER than not ejecting AT All, and hand cycling it - is a waste of time.

If the brass is important for analysis, not just reload, it is simpler to only load one round at a time, modify nothing at all.

Too many other inter-related downsides to try to "adjust" ejected brass throw at the energy-input side.

Historically, arms that have NEEDED it, Military, usually (been done..) the whole port location and shape, ejector as well, were re-designed, relocated, reshaped.

It’s common and easy in NRA HP competition to trim the ejector pin back some to dump your brass in a nice little pile by your side. John Hollinger has the dimensions on his WOA page I believe it’s .020 thousands off. Don’t clip the spring it will cause malfunctions but trimming the pin works well and if you mess up, a new pin is about $1

akajun said:

It’s common and easy in NRA HP competition to trim the ejector pin back some to dump your brass in a nice little pile by your side. ..............

Click to expand...

Ding, ding, ding. THAT is the correct answer.

Did that to my match AR and, in the prone position, you could just about put your hat about 3' away in the 2:00 position and have all of it eject into the hat. Also eliminated the dents in the case from being slammed into the shell deflector.

Grind off one coil at a time and try it.

Steve

SteveF said:

Ding, ding, ding. THAT is the correct answer.

Grind off one coil at a time and try it.

Steve

Click to expand...

Spring coil reduction implied. AKAJUN suggests "don't clip the spring".

Oh my, what to go with.....

I guess there must be more than one way to skin a cat.

But really, I'm just going to print out Bill's (thermite) comments, give them to the guy, and have him walk away shaking his head and muttering expletives to himself about why the subject was ever brought up. Job DONE! ;-)

Yeah, he did say "pin" and not "spring". Pain meds make you miss things.

Everyone I've ever known to do this shortened the spring and it worked fine. Sure, don't "clip" it because that may leave a burr and is less precise than grinding it down.

Here is the tech bulletin from Armalite:

-------------

TECHNICAL NOTE 34, ADJUSTING THE EJECTION PATTERN OF THE AR-10® RIFLE



Purpose:

To advise owners and gunsmiths how to adjust the ejection pattern of the AR-10B™ series rifle.

Background:

ArmaLite® occasionally receives complaints that expended cartridges ejected from the AR-10® strike and damage the rifle’s upper receiver. The most common complaints are that the case spins and strikes either the case deflector or the front of the ejection port opening.

These ejection patterns are common to all AR-15/M16™ pattern rifles. They are more noticeable on the AR-10® because the heavier cartridge case mars the finish of the receiver easier.

The ejection pattern of a rifle is created by a complex interplay of the opening velocity of the carrier group, and the extractor, ejector and their springs. In general, the faster the carrier group opens, or the stronger the extractor and ejector springs, the farther toward 12:00 (looking down on the rifle) the case is ejected. The weaker the springs are, or the slower the carrier group opens, the farther toward 6:00 the case is ejected.

ArmaLite® seeks an ejection pattern between 1:00 and 3:00, and inspects for this characteristic during inspection. Obviously, the carrier’s opening velocity is subject to differences in ammunition. Springs can take a set over time, and the ejection pattern eventually shifts toward 5:00. This is normal, and readily adjusted by extractor spring replacement and ejector spring timing.

The extractor spring and plunger can be changed during routine cleaning. The ejector spring can be replaced if ejection is too far to the rear, or tuned by shortening it a coil at a time if ejection is too far to the front. Tuned ejector springs will be between a minimum of .950 and a maximum of 1.015 inch long.

As usual, selection of good ammunition minimizes complaints.

----------------

akajun said:

It’s common and easy in NRA HP competition to trim the ejector pin back some to dump your brass in a nice little pile by your side. John Hollinger has the dimensions on his WOA page I believe it’s .020 thousands off. Don’t clip the spring it will cause malfunctions but trimming the pin works well and if you mess up, a new pin is about $1

Click to expand...

Thanks for the reminder on the WOA pages. I had entirely forgotten about them.
And I just received a set of scope rings from them day before yesterday. ;;;;;;
(CRS, is setting ...)

I've ground the springs in all of mine, and never a malfunction related to ejection in over 20k rds.

Cut it back to where the ejector is flush with the face of the bolt. Or better, start a bit proud, maybe 1/32", and see what you get.

Huh? Who is this.
You can trim what ever part you like , I’ve trimmed springs before, I’ve also had them give me fits and sometimes no problem at all. Haven’t had an issue since I just trimmed the pin.
Plus Hollinger, I mean when you make your living at it, produce the best ar15 competition uppers, and have been on stage at Perry more times than most people have even shot at Perry, it pays to listen.

I've read....

That a properly shaped ejector head has a pronounced chamfer, and not a simple flat top.

Anything to that?

I never noticed I just broke/ deburred the edge of the ones I did

CalG said:

I've read....

That a properly shaped ejector head has a pronounced chamfer, and not a simple flat top.

Anything to that?

Click to expand...

In this case I'd go with - Over the last 60ish years 10s of millions of those ejector pins have been made to the same shape. Why would you think a different shape is better?

To those who will ask - Why doesn't that same logic apply to the spring? It's because in this case the ejector spring works perfectly fine and needs no modification. Unless you are a Highpower Rifle competitor who shoots on a firing line with people 6 feet apart and doesn't want to play the "who piece of brass is this?" game because of how far your brass went. Before I learned the "shorten the spring trick" I was coloring the base of my brass with a red marker to make it easier.

Ask far as Hollinger - I looked on the White Oak pages and if there is something there on shortening a firing pin instead of the spring I couldn't find it. Maybe David Tubb told him it wasn't the best idea.

Steve

Huh, I cant find it either, maybe it was one of his newsletters, IDk. Anyway here is a link to a big discussion about it on US rifleteams where the whole pin vs spring was hashed out.
Sign In - National Match Competition

This is why I like roller locked guns. There's no need to worry about collecting brass because most of the time it tears them open and dents the hell out of them anyways, and that's if you can find them some 30 odd feet away.