Ejection

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Ejection

Postby Al in Mi » Sat Oct 01, 2016 12:04 pm

Crappy day here so did my annual tear down cleaning on my stock 16" Bushy upper this morning. Just did a couple mag dumps for function and noticed everything ejects at 1:00 now, even my 300gr 1680 loads that use to just sorta dump out of this gun, eject at 1:00. No feed issues, bolt locks back, just ejects forward now.

Everything I ever read about forward ejection was a sign of over gassed, and this gun has always ejected 4' at 4:00 sans that 1680 load.

Tomorrow I'll see what it does on paper, sure hope that did change!
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Re: Ejection

Postby Texas Sheepdawg » Sun Oct 02, 2016 8:16 am

You_Doodle_2016-10-02T14_16_05Z.jpg
You_Doodle_2016-10-02T14_16_05Z.jpg (236.4 KiB) Viewed 13244 times

For those of you who are new to this game, maybe this will help.
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Re: Ejection

Postby bushmeister » Mon Oct 03, 2016 4:51 pm

Good stuff!
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Re: Ejection

Postby Al in Mi » Sun Oct 09, 2016 5:58 am

Well she's just as accurate as she's ever been, but I'll have to look into a gas block or maybe I can drill and tap this one to make it adjustable.

Might be time to look back into Hoots cheap carrier weight system!
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Re: Ejection

Postby plant_one » Sun Oct 09, 2016 11:16 am

while hoot's system works pretty well - when you get into the upper end of the charge range with heavy's like the 300 xtp mag, all that extra mass coming back at ya really packs a wallop. Max charges of lil gun under them really puts some gusto into your shoulder. THey didnt shoot well out of my upper at just over 2000 FPS, so thankfully there's no need to abuse myself like that, but i'm gonna see about switching over to an AGB to tone them down a bit.


i would compare those loads to sitting behind a lightweight single shot 12 gauge with some brenneke 3" Magnum crush (their 1½ oz slug at 1600 fps).

next time i'm out i want to load a few up with similar charges and use a non-hoot-weighted carrier to see if theres a significant difference in feel, just for comparison.
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Re: Ejection

Postby Hoot » Tue Oct 11, 2016 11:52 am

Two things here worth mentioning.

Lil Gun is not the best choice for 300gr bullets, unless that's all you have (both ways).

The weighted carrier has zero effect upon Newton's 3rd law WRT recoil. Its main purpose is to slow the action down after that 3rd law has acted upon the shooter. That's not to say that perceived recoil stops after the bullet is up to speed or when the action cycles. There is a perceived recoil component that occurs as the bullet breaks seal with the muzzle as well as when the action cycles, but they are usually smaller in magnitude and/or shorter in duration. John Noonan's graphs show the different recoil components in relation to what time they occur.

In the case of the action cycling, an AGB can do wonders. IMHO, they are trickier to work with when you are shooting your own loads across a wide range of bullet weights and velocities. They are not a set-n-forget device. The CCWS is. We have come a long way in exploring and understanding the 450b since the CCWS was incorporated. Way back then, I don't recall reading of anyone having tried an AGB on their 450b.

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Re: Ejection

Postby plant_one » Tue Oct 11, 2016 2:01 pm

i agree on LG not being ideal for heavies - my chrono numbers show that clearly - but its what i was testing. my point was, my perceived recoil was significantly different on the upper vs the lower part of the charge range, likely due to velocity acheived by the BCG due to the difference in powder charge, and therefore port pressure and gas volume delivered back to the cycling BCG.

my next test with them will be running D063 (very close to 1680, just a RCH faster) and see how they do with that.


just out of curiousity what kind of velocity are you guy seeing accuracy with the 300's? my accuracy load with LG was around 1800, and at 2000 fps (max load) was closer to minute of microwave (and that was with a SD 19.8)
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Re: Ejection

Postby Al in Mi » Tue Oct 11, 2016 2:14 pm

I'll have to run them over the chrono, thought I had data on them but not where it's suppose to be!!!

I just had the target set out at 50yds and she's cutting holes. I set that gun up with a 1-4 Trijicon for in the woods, but next time out I'll see what my old eyes can do at 100. :(
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Re: Ejection

Postby Avenger10 » Wed Oct 12, 2016 3:30 pm

Al-

Don't sweat ejection angle. I can say without hesitation our bolts are the best money can buy.... period. We do not re-cut 5.56 bolts like "MOST" of our competitors do. Our bolts are purpose built from the best materials and heat treated to the most demanding specifications. We do not modify extractors either...ours are also purpose built for the specific caliber they are being used for. I say that so I can say this... we run our bolts 500-1000 pieces at at time for the .378, .441 and .473 families of cartridges and any given batch will eject from 2:00 to 5:00 on Texas Sheepdogs chart while the guns continue to shoot MOA. I can put a 2:00 bolt in another gun and it shoots 5:00... so don't sweat the small stuff.

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Re: Ejection

Postby Al in Mi » Thu Oct 13, 2016 4:41 am

Thanks Bartt. I don't think I'm gonna mess with it at least for this fall.
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