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Post by kmshooter on Oct 31, 2016 17:56:55 GMT -8
looking to build a lightweight AR 20 practical. (Already have a Balios-lite receiver set on its way.) I have emailed BHW and got this as a response "14.5 pencil profile is 1.35 lbs. The slim Mid profile weighs 1.7 lbs, if you chose a slim carbine it saves .10 lbs"
My plan was to get the 14.5" pin and weld a Silencerco ASR break to get it to 16". (Don't want to get in trouble with them Feds)
To give you a little back ground on why I am looking at this length and caliber is first off I handload (9mm, .223, 6.5 Grendel, 6.5 WSM, and 338 Lapua) and coyote call here and there and hike a far bit to get away from the normal places people call. I understand the profile doesn't have an effect on accuracy nor does length, but length does effect Velocity and that's a big reason to go to this cartridge. I am wanting a lightweight rifle that shoots flat (as flat as can be had) out to 400-600 yards that doesn't take a lot of case prep or powder, that's why this cartridge intrigues me! Also wanting to run a suppressor on it (I know lightweight build to gain weight of a suppressor... But I'm willing to gain weight for the things I believe make it better, so where I can skimp on weight I'd like to)
So back to the question am I losing all the gains this cartridge has to offer by shortening the barrel and suppressing it?
Thanks for all knowledgable help.
P.s. If this is in the wrong spot I'm sorry
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Post by GLSHOOTER on Oct 31, 2016 19:04:17 GMT -8
Welcome to the board. The 20 is s great choice but running a 14h tube is like dropping a four cylinder in a Corvette. It'll get there but it's SLOW. The 20P lives on speed. You will leave about 350 FPS on the table if you go down. The energy and speed loss will cut down reliability on 350-400 yard coyotes and you can probably cross off those uber-long 600 yard pokes. The little guys just don't carry the mail that far out no matter what the speed. Even a 55 grain pumped up won't do it. Flatter than a 223 but still not enough to work with on anything bigger than a G-hog.
Suppression is fine but for me 20" would be the bare minimum. I would also recommend a standard weight barrel to hang a suppressor on. I shoot lots of 20's on PD's and the splat factor starts dropping at 400. I also shoot 24" to 26" barrels. I run them HARD in those chamberings and built a 20-250 for those 600 yard plus targets. Lots of horsepower but a blow torch on a barrel. I just wouldn't be comfortable shooting a 204 equivalent at those ranges.
Lots of opinions here so perhaps others will chime in with their take.
Greg
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Post by kmshooter on Oct 31, 2016 22:11:39 GMT -8
Well guess I can't have my cake and eat it too! I was hoping you would chime in Greg, as I have read lots of forums and you seem to be a major contributor to the replies, I like first hand knowledge! So thank you. Now that you have talked me into a 22/24 in. barrel (BHW is currently not offering 26" online) for the 20 practical, you said minimum contour, for a suppressor, would be a "standard weight" just to clarify but not disagree I don't plan on shooting any more than 5 shots at a time with this particular rifle, wish our PD's wasn't on the "not so" Endangered species list.
So knowing the barrel wouldn't see the high temp of more consistent firings would you still recommend the minimum standard weight??? I would rather this shoot amazing rather not good enough because I want to run a suppressor.
Second the the ranges was more to see what you recommend on this cartridge, I'm looking for a cartridge that I can do a Maximum Point Blank Range with and not have the hassle of hold over, yet not creating a "blow torch" on the barrel. (I have looked into the 6mm LBC as well and thought maybe get both) but like the Practical because it's just that, PRACTICAL, it can use 223 which I have plenty of. But also have enough Grendel brass as well,
Thanks again for the great info and steering me to the better choices for this build!!
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Post by GLSHOOTER on Nov 1, 2016 7:05:17 GMT -8
Well guess I can't have my cake and eat it too! I was hoping you would chime in Greg, as I have read lots of forums and you seem to be a major contributor to the replies, I like first hand knowledge! So thank you. Now that you have talked me into a 22/24 in. barrel (BHW is currently not offering 26" online) for the 20 practical, you said minimum contour, for a suppressor, would be a "standard weight" just to clarify but not disagree I don't plan on shooting any more than 5 shots at a time with this particular rifle, wish our PD's wasn't on the "not so" Endangered species list. So knowing the barrel wouldn't see the high temp of more consistent firings would you still recommend the minimum standard weight??? I would rather this shoot amazing rather not good enough because I want to run a suppressor. Second the the ranges was more to see what you recommend on this cartridge, I'm looking for a cartridge that I can do a Maximum Point Blank Range with and not have the hassle of hold over, yet not creating a "blow torch" on the barrel. (I have looked into the 6mm LBC as well and thought maybe get both) but like the Practical because it's just that, PRACTICAL, it can use 223 which I have plenty of. But also have enough Grendel brass as well, Thanks again for the great info and steering me to the better choices for this build!! BHW doesn't do 26" tubes on AR's as the demand is so low and those little holes are hard to drill. They do 26" bolt gun barrels but in an AR you are also looking at dwell time in teh barrel and a few other issues like extensions etc. sucking up some of the stock. I recommend the standard because hanging a weight on a light barrel can interfere with the harmonics to some extent IMHO. Lightweights work fine for the rates you are shooting at but sometimes more is better. The Practical will probably do anything you need. If you wanted to step up to a 243 LBC you will pick up bullet weight but not get quite as flat on the trajectory as the 20. Speed is nice for that. It's a different critter than the little guy. I have to flip a coin on which of the two I like best. Greg |
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Post by mrdakota8 on Apr 4, 2018 1:02:44 GMT -8
New g on the forum here...
I have a 22" SS P3 barrel my AR I'm playing with quickload software and I would like to know the cross sectional area of this barrel.
Thanks,
Keith
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Post by GLSHOOTER on Apr 4, 2018 7:11:38 GMT -8
New g on the forum here... I have a 22" SS P3 barrel my AR I'm playing with quickload software and I would like to know the cross sectional area of this barrel. Thanks, Keith The figure used as the default on the 204 Ruger works for me. You'll find that the pressures are a tad lower because of the poly rifling but that one is almost impossible to calculate unless you are on the Big Bang Theory. On the plus side the speeds tend to be higher. Remember that QL is just a model and IS NOT designed as a loading recommendation tool. I use it all the time and it does yield decent SWAG's in most cases but no guarantees. The tip off is look at the + and - numbers on a given powder and see the huge differences in pressures based on potential lot to lot variants. Do not fall into the trap of deciding what your load SHOULD be and start tweaking numbers to get the pressures you want via burning rates. Several idiots on the 'net do this routinely and others wonder why they can't get the same results claimed by them. Worse yet they will run a QL chart and put it out like it's the Goslpel. Lots of ruined brass and frustration out there over that. Greg |
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