low fps cast from BO pistol

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popper

Well-Known Member
Yup. The 145 sounded like a roman candle shot. KVP comp reduces (perceived) noise a bit. Don't know about flash. Went from 5# loaded pistol to 6# now. Not minute of bunny but think I can get the second shot at moving hog @ 50 ok. Kinda neat hearing that thunk-whack. Barrel is slick & clean, need to clean the comp, looks pretty dirty. So basically, semi-auto 357 (short) rifle.
Oh, Ed was shooting 299, 155 and a 125 SP I didn't recognize with Rx7 prob. ~ 1800 fps so I'm knowing where mine hit @ 100 now and don't have to carry another rifle to the range.
 
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popper

Well-Known Member
Looked inside the KVP comp, kinda dirty with a few lead specks. Need to remove it to swab the barrel. Cleaned the BCG in kerosine/US cleaner - really DIRTY! No fire, did just OK but kerosine is nice and black. Softened it up pretty good. Hadn't cleaned it in prob a yr. Swab barrel with Ed's red, few speckles, mostly black residue. Now to find a 5/8x24 nut to cut and use as thread chaser. Carbine threads are buggered a bit, never could put a protector on it - how it got out of QC that way?
 
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popper

Well-Known Member
Ran ~100rnds through the BO pistol playing 50 yd 'whack-a-mole' pig hunting practice. Closest I can get to moving target. Ripped a few rims off with the hot carbine loads. Not DRT shots (but decent hits) random mag loads of 145 & 170gr PB - POI was the same. Took home the 30rnd 308W pmag somebody left and it's a BIG sucker.
 
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popper

Well-Known Member
Cleaned to BO pistol this morning. just one tiny blob of lead near the chamber probably due to shaved PC left in the LG when seating. Shot probably 50 rnds before yesterday which added another 75, mostly GC & some PB. Some crud in the bore but extension was full of chunks (not lead)! Bolt was normal dirty. Loads been running 13-1400 fps, cfe pistol and 2400. Running H2 buffer and adj. gas block, ejection @ 3 olock. Entire fired case is dirty not just the neck. Thinking port is too close to chamber. Pressure is good to open bolt but occurs too early so lots of blowback. I'll try Rx7 & 4227 to see if powder makes a big difference.
 
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popper

Well-Known Member
Mind got spinning a bit yesterday. Figured the bore volume increases linear 15%/inch (1.5%/0.1")- for any bore dia. So when pressure curve drops below that 15% decrease, powder burn is over. From flash of short 223 barrel, combustion temp. is 4-5k F (yellowish). Dang, might need to get QL even though most of the data base is irrelevent for me. Or a pressure trace rig?
 
CWLONGSHOT

CWLONGSHOT

Well-Known Member
QL helps allot, but gospel it is not.
Like all Computer related things its as accurate as the information it knows.

CW
 
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popper

Well-Known Member
Kinda always thought a cartridge is designed for a purpose, fired at near max fps. Got into 'bunny' loads where we are pretty much left on our own. Pistol powders work OK, burn complete fast on one side. Other side, make a smaller case, just $$. QL seems to be the only way to 'experiment' without wasting a lot of lead. Getting interested in 'fill %' and effect. Not much real data out there, mostly just a dab of Unique.
edit: IMHO one of the reasons the BO or derivatives has been so popular. No, not a 30/30 or 308 but can be pretty decent for HD/truck gun or 100yd deer/pig. Tin can, bunny, squirrel, just drop a light load in and done. Hog or deer, drop a hot load in and go for it. Got a can, drop in the heavy. Versatility!! Now if the load books carried tabulation of 'good' lite loads !!
 
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Ian

Ian

Notorious member
Popper, you of all people would get your money's worth out of QL, even if you only load for three rifles and a handgun.

The BLK was enginerded by AAC to do two things interchangeably: 125-ish bullets at 55Kpsi and 220 grain bullets at 1050 fps, with no adjustments to the system. M4 barrel with gas port at the carbine position if I remember right, some of this is fuzzy now. The Honey Badger notwithstanding (integrally suppressed, not sure where or how big is the gas port), this is doable with a suppressor. Carbine gas position (7") makes subs iffy locking the bolt on last round without suppressor but can make gas hole .120" and still not overpressure with supers. If pistol gas (4") then it will always be overgassed and out of time. 10.5" barrel lessens the dwell time and harsh ejection on pistol gas, less than 9" of barrel is too little dwell even with pistol but with any pistol length gas system the extraction cycle begins too soon. Nature if tue beast, best we can do for pistol systems is tune the gas down for supers.
 
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popper

Well-Known Member
Yea, almost tempted, had the CC out yesterday, but I can get a lot of powder and lead for 150$. Don't think I could afford the liability ins. if I wrote a reduced load book.
My carbine cycles factory subs/supers no problem. Pistol gas was for subs and my port is OK but seems like delay is the problem - pressure is right, bolt speed is right, just timing allows early open and some performance loss. I've seen the curlyQ gas tubes to solve the problem but no room under the H.G. so basically searching for a powder that will burn good but slower. Or just put up with the crud.
 
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CWLONGSHOT

CWLONGSHOT

Well-Known Member
This is where I am.
I have a "few" BO's

I have t been a sub man. Not owning a moderator...

But.... my endevors with the Legend and subs are causeing me to look again at the BO. Im having a ball with 270g subs!!

Plus, the 311284 HP I bought here. :)

Im seriously considering making one of my Barrels Sub spec. (Drilling the port.)

Of coarse could do so AND add a adj block.

I havent had big problems but have had better results from Bolts ans SS with subs then MSR's.
CW
 
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