GorillaTactical Posted February 5, 2011 Share Posted February 5, 2011 (edited) Chrono-ed my rifle today, and found that I was pushing a velocity much slower than I anticipated. My AR has a 16" barrel, is chambered in .223, and I fired several different ammo types. Only one brand (Monarch 55grn) was able to come in over 2800 fps @ 2830 on average. NOTE: I do run a JP adjustable gas block (idk if this would lower velocity if my adjustment is tightened down....doesn't make sense that it would, but I thought I'd mention it). Wolf/Brown Bear (55 grn) - 2700 Hornady Tap (60 grn) - 2575 (the box suggests that 2863fps should be the average velocity through a 16" barrel) PPU Match (69 grn) - 2500 Monarch Brass Cased (55 grn) - 2830 (I was able to shoot this @ 2-3" groups at 200) HotShot/PPU (55 grn) - 2750 Remington from the Green/White Box (55 grn) - 2700 Are these velocities typical??? I know the chrono was fine because I shot a buddy's rifle through it and it came in where expected (most ammo above 2800) Edited February 5, 2011 by GorillaTactical Link to comment Share on other sites More sharing options...
DocMedic Posted February 5, 2011 Share Posted February 5, 2011 More importantly does it group shots well? Link to comment Share on other sites More sharing options...
GorillaTactical Posted February 5, 2011 Author Share Posted February 5, 2011 (edited) More importantly does it group shots well? Yes......but a good amount of ammo's are not meeting power factor which is not ok.... Edited February 5, 2011 by GorillaTactical Link to comment Share on other sites More sharing options...
DocMedic Posted February 5, 2011 Share Posted February 5, 2011 Hmm, You said JP Gas block, so I'm guessing its a JP rifle? how many rounds have you shot through the barrel? Link to comment Share on other sites More sharing options...
mhearn Posted February 5, 2011 Share Posted February 5, 2011 (edited) My results 16" Sabre Mid legth Fed American Eagle 55 gr Velocity 2650 Fed XM 193 55 grn 3042 Bushmaster 16” Carbine Gas system Federal American Eagle .223 FMJBT Velocity 3050 Edited February 5, 2011 by mhearn Link to comment Share on other sites More sharing options...
00bullitt Posted February 5, 2011 Share Posted February 5, 2011 Those velocities are about the norm for a 16" barrel for factory ammo. An adjustable gas block will not have any negligible effect on velocity. Federal XM193 NATO spec ammo will run about 2900-3000 PMC Bronze shoots about 2650 out of my 16" gun and 55 gr. Rem/UMC runs about 2750 My 55 gr. hand loads run 2900 and my 69SMK load runs 2750. Link to comment Share on other sites More sharing options...
bigbrowndog Posted February 5, 2011 Share Posted February 5, 2011 I would say your results are pretty typical, first, most manufacturers velocities are optimistic and done thru 24" barrel rifles. second, a 16" gun can lose quite a bit of velocity. I don't think the gas block is the cause, do you have past results to compare to??? or are you simply going with what you thought it should be doing or what the manuf. said it should do?? trapr Link to comment Share on other sites More sharing options...
GorillaTactical Posted February 5, 2011 Author Share Posted February 5, 2011 (edited) I would say your results are pretty typical, first, most manufacturers velocities are optimistic and done thru 24" barrel rifles. second, a 16" gun can lose quite a bit of velocity. I don't think the gas block is the cause, do you have past results to compare to??? or are you simply going with what you thought it should be doing or what the manuf. said it should do?? trapr Going on what I thought it would be, this is my first time running my rifle through a chrono. I was under the impression that manufacturer specs were for a 20" barrel so that is where my mistake is. So, understanding that I can't handload yet (don't have the space), would you guys suggestion finding some hotter factory ammo such as the xm??? Or should I just go with the lower velocity and compensate for the bullet drop? *Thanks for the responses so far Edited February 5, 2011 by GorillaTactical Link to comment Share on other sites More sharing options...
00bullitt Posted February 5, 2011 Share Posted February 5, 2011 Find an ammo that reliably cycles the gun and gives acceptable accuracy. XM193 usually does both and has good velocity. Just remember it is designed to be shot out of a 5.56mm chamber. Shooting non SAAMI NATO spec ammo out of a .223 chamber could result in blown primers or possibly a separated case. Black Hills blue box 55 gr. usually produces great accuracy at about 2800fps from a 16" barrel Link to comment Share on other sites More sharing options...
CocoBolo Posted February 5, 2011 Share Posted February 5, 2011 Gorilla - Thanks for the post, I had not even thought about power factor. My 18" Sabre gets just under 3000 fps with the 55gr PMC Bronze and my twin reloads (they hit same poi) are 2918 which works out ot 160pf, 150 pf is the requirement right? My 69GR SMK's are 2682 or 180pf and when you shoot them you can tell they are a little stouter. Groups are tiny. I've tried higher velocity but the groups started spreading. Not sure which ones are going to the Texas 2-Gun yet, still want to do some testing out to 400 yards or more. Link to comment Share on other sites More sharing options...
esskay Posted February 5, 2011 Share Posted February 5, 2011 Couple more data points for factory ammo from a recent session with my 16" uppers. AE223 - avg 2920 fps PMC Bronze 223 - avg 2775 fps Link to comment Share on other sites More sharing options...
Graham Smith Posted February 5, 2011 Share Posted February 5, 2011 I may be wrong, but I don't think that you are seeing unreasonable results for a 16" barrel. That length is more typical for a 5.56 while I think that most .223 ammo is rated based on a 20" or 24" barrel. 5.56 ammo is often hotter (higher pressure) than .223 as well. For a 16" barrel, you are going to need to find a load that uses a fairly fast powder for it all to burn in the barrel. Link to comment Share on other sites More sharing options...
GorillaTactical Posted February 5, 2011 Author Share Posted February 5, 2011 Hmm, You said JP Gas block, so I'm guessing its a JP rifle? how many rounds have you shot through the barrel? Not a JP, custom build...has approx 2000 rounds through it Black Hills blue box 55 gr. usually produces great accuracy at about 2800fps from a 16" barrel Thanks for the suggestion 00, will pick some up and try it out Gorilla - Thanks for the post, I had not even thought about power factor. My 18" Sabre gets just under 3000 fps with the 55gr PMC Bronze and my twin reloads (they hit same poi) are 2918 which works out ot 160pf, 150 pf is the requirement right? My 69GR SMK's are 2682 or 180pf and when you shoot them you can tell they are a little stouter. Groups are tiny. I've tried higher velocity but the groups started spreading. Not sure which ones are going to the Texas 2-Gun yet, still want to do some testing out to 400 yards or more. 150 is minimum pf for rifle. make sure you do your LR testing b4 the T2G Link to comment Share on other sites More sharing options...
HRider Posted February 6, 2011 Share Posted February 6, 2011 I chronoed 2913fps with PMC Bronze 55gr out of a 20" 1/7 a few weeks ago. That seems right in line with what everybody else is saying. Hurley Link to comment Share on other sites More sharing options...
CDPMatt Posted February 6, 2011 Share Posted February 6, 2011 I just chronoed my 16" M&P 15 last week using Academy steel cased Monarch 55gr.... Avg Velocity: 2909 Avg PF: 159.9 Link to comment Share on other sites More sharing options...
GorillaTactical Posted February 7, 2011 Author Share Posted February 7, 2011 Here's a question for yall.......I shot this the day of the massive snow when it was approx 30 degrees out...would the change in temp have effected my velocity? Today I rechronoed it and it came in at 2960 with the Monarch ammo which had averaged 2830 last week. Same box, same set up, etc etc etc. My group was also impacting way high...approx 8" high at 100 yards... Link to comment Share on other sites More sharing options...
bigbrowndog Posted February 7, 2011 Share Posted February 7, 2011 yes cold will affect velocity Trapr Link to comment Share on other sites More sharing options...
strat81 Posted February 8, 2011 Share Posted February 8, 2011 Temperature can affect velocity, particularly with the cheaper powders used in cheaper ammo. Some powders are reputed to be less temperature-sensitive than others. If you start reloading, you might want to use those temperature-insensitive powders (the new IMR 8208XBR comes to mind). Link to comment Share on other sites More sharing options...
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