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18 VS 22 Barrel Advice - Printable Version +- 6.5 Grendel Forum (https://65grendel.com) +-- Forum: 6.5 GRENDEL DISCUSSION FORUMS (https://65grendel.com/forumdisplay.php?fid=3) +--- Forum: 6.5 Grendel Build-It-Yourself & Custom Builds (https://65grendel.com/forumdisplay.php?fid=9) +--- Thread: 18 VS 22 Barrel Advice (/showthread.php?tid=20358) |
18 VS 22 Barrel Advice - TwoStrokeTyrant - 01-07-2020 I am planning a build using JP Enterprises upper, bolt, bcg, and of course, barrel. However I am torn between the 18 inch and 22 inch barrel lengths. I was initially gonna go 22 to get the most out of it but I am not convinced the added size/weight will really be worth the performance gains. It will primarily be a range/hunting gun within 500 yards but I would still like to have 1000 yard capability if I ever get the chance to take it out that far. So what would be the better choice? PS: I am wanting consistent sub-moa capabilities out to 500 yards 18 VS 22 Barrel Advice - VASCAR2 - 01-07-2020 A Friend has an 18 inch barrel he was shooting at 950 yards and getting consistent hits in the Ft Campbell area of Kentucky. The main issue he encountered was not enough elevation on his scope. I put 20 MOA mounts on my 6.5 Grendel rifles because at my elevation above sea level my scopes max out around 800 yards. I have one Aadmount 30 MM mount and several Warne one piece 20 MOA mounts. A Friend and I chronographed several loads with a Magnettospeed chronograph on 16, 18, 20 and 24 inch AR-15 6.5 Grendels. Here is a list of the tested ammo by average velocity for each barrel length. 120 Grain HP BT PPU 16" 2392 18" 2455 20" 2480 24" 2559 110 grain FMJ PPU 16" 2510 18" 2570 20" 2614 24" 2683 123 grain A-Max Hornady 16" 2419 18" 2464 20" 2505 24" 2568 123 Grain SST Hornady 16" 2430 18" 2493 20" 2511 24" 2583 Hand Load 123 Grain Nosler CC, 31.0 grains CFE223, CCI 450 16" 2449 18" 2471 20" 2526 24" 2619 100 Grain FMJ Wolf 16" 2507 18" 2571 20" 2615 24" 2695 Hand Load 107 Grain SMK 28.5 IMR8208XBR, CCI 41 Hornady cases. 20" 2658 24" 2729 Here is the difference between the 18” barrel compared to the shorter 16” barrel which was slower with every load. 120 grain PPU HP BT 63 FPS difference 110 grain PPU FMJ 60 FPS difference 123 grain A-Max 45 FPS difference 123 grain SST 63 FPS difference Hand load 123 grain Nosler CC 27 FPS difference Wolf 100 grain FMJ Steel cased 64 FPS difference Difference between 20” and 18” barrel 6.5 Grendel 120 grain PPU HP BT 25 FPS difference 110 grain PPU FMJ 44 FPS 123 grain A-Max 41 FPS difference 123 grain SST 18 FPS Hand load 123 grain Nosler CC 55 FPS difference Wolf 100 grain FMJ Steel Cased 44 FPS difference 18 VS 22 Barrel Advice - FLshooter - 01-07-2020 I always get the heaviest,longest barrel that I can shoot for what I am using it for. PS if you are wanting sub moa capabilities at 500 yrds,call Mark at precision.I am sure he will give you the same advice I gave you.And he will probably recommend a Krieger or Bartlein 24 inch heavy barrel.I have the Bartlein.It does sub moa at 600. 18 VS 22 Barrel Advice - Wethepeople - 02-06-2020 Kind of an old thread but thought I'd share my thought process when making a decision to buy my JP barrel. My use is pretty much the same as the OP's. Unless I have some messed up inputs in the ballistic calculator, should be close. Used 123gr SST, G1 BC .510 with a hopeful 2450 fps intial velocity. Input a 90deg 5mph wind velocity at avg atmospheric conditions here at 4600 ft altitude. Shooting angle 0. -403.05 " bullet drop at 1000 yds. 38.49 moa or 11.2 mils come up. 40" Wind drift or 3.84moa/1.12 mils TOF 1.68 seconds. 1324 fps at 1000 yds. Looks very doable from 18" barrel based on VASCAR2s post. So I bought the 18" barrel. Plenty of elevation, 17mils, on my optic. Someone could sanity check these estimates. No range time on my barrel yet to compare to actual DOPE. This bullet starts exceeding velocity of my 18" WOA .223 Wylde barrel shooting 77gr OTM pills beginning at approximately 975 yards. That rifle is very consistent at 1000 yds under the same conditions. Requires 9 mils elevation dialed. 18 VS 22 Barrel Advice - LRRPF52 - 02-09-2020 If you're at 4600ft elevation, the 18" is more than plenty in my experience. 123gr SST isn't a .510 BC as stated, but was found to be more like .462 G1 region. If you want to shoot more TGT shooting with it using a bullet that also doubles as a hunting bullet, you can also try the Sierra TMKs and TGKs, Berger hunting VLDs, or Hornady 123gr ELD-Ms. 18 VS 22 Barrel Advice - nuthead - 02-11-2020 ive been using a 0.239 G7 bc for the 123gr amax.... its spot on out to 500m for all temps and air densities (I use a 0.8fps/ degree celcius for MV variation with 8208) havent pushed it any further only because you cant really use it for hunting past 400m or so 18 VS 22 Barrel Advice - Harpoon1 - 02-11-2020 I?m rarely happy with a ?one size, do it all? gun. End up compromising on everything and inevitably wishing I hadn?t. There?s ?hunting?, and then there?s ?hunting?. Riding a four-wheeler up to your blind and sitting there all day, is one thing. Throwing a gun over your shoulder and ?still? hunting up and down through the mountains for days on end is another. Just saying....... 18? is slightly better for hunting, the 22? is slightly better for the range. Hunting season is couple of months long, you can go to the range year round. What?s more important to you? 18 VS 22 Barrel Advice - Wethepeople - 02-23-2020 Hey 52, do you have the actual G7 BC for the 123 SST? I can only find the published data as you pointed out. Thanks, Jeff. 18 VS 22 Barrel Advice - CJW - 02-24-2020 Interesting post Vascar 18 VS 22 Barrel Advice - LRRPF52 - 02-24-2020 Wethepeople Wrote:Hey 52, do you have the actual G7 BC for the 123 SST? I can only find the published data as you pointed out. Thanks, Jeff. The main reason we would be using a G7 BC is for beyond 600yds, and I'm not sure the 123gr SST would be the bullet for beyond 600yd shooting unless that's all you have.
18 VS 22 Barrel Advice - Wethepeople - 02-26-2020 Thanks. Yep, I know. Just looking to update my list of G7 BC's from a more reliable source than manufacturer published data. I use Litz's custom drag profile data from his second addition book or those added since then on AB library.. I couldn't find 123gr sst G7 data from AB but have found .232 as opposed to the .230 you show since I posted the question. Close enough for now. My new rifle doesn't like the 123 sst so far, at least in the Hdy factory loads. So far, 120 gr. hpbt in the PPU blue box, 123 eld m Hdy and 130gr Berger in FGM loads are shooting best. I haven't been rolling my own loads yet as I only have 60 rounds thru the new pipe. Just getting some early velocity data for each of those factory loads this far. Will be working our LRP public range days this coming Thurs. and Sun., so should get some good trigger time and more baseline DOPE for those 3 bullets. I'm really enjoying my Grendels soft shooting characteristics. Can only go 400m at home so looking forward to getting on the LRP range in a couple days. Lots of different bullets yet to be tried. |