Mag length heavy AR15 bullets/loads

[Trevor300wsm]

Needing some opinions here. I do not have a lot of experience loading for AR's. I'm a 99% bolt gun shooter. My partner and I have a team match next month we are competing in. I'll be on a gas gun while he's on the bolt gun. I will have to shoot some decent distance and given the area, I'm expecting a lot of wind.

I'd like to shoot the heaviest, highest ballistic cof bullet I can while still being Pmag friendly. I have a 18" Specialized Dynamics built AR with a 1:8tw barrel. I know I can stabilize up to a 80gr, but I don't know which ones I can safely stuff in a Pmag.

Any advice on heavy bullet/powder combos would be appreciated. I'd like to run atleast a 70gr or higher bullet. I have plenty of varget and can get some CEF and a few other powders.

****Anyone shot the Berger 75gr VLD?

 

[Thebelly]

I've had very good luck with the Hornady 75gr BTHP.

I'm still doing load development on it for my gun.

 

[Litshoot]

From high power matches I've had many a friend running 77 sierras mag length put to 600yds with varget. I'm not sure the charge but they were competitive
Seth

 

[lancetkenyon]

I run 69 SMKs out of mine at mag length and still get 3033fps with a 24" barrel.

I know it does not quite meet your criteria, but I am sure a 70gr. would not be any different.

 

[Guest]

Myself and a friend were running WOA 16" SS Match 1:7 barrels last weekend with IMI 5.56 77gr OTM LR Mod 1 out to 800yds. We were making consistent hits on a 12" steel plate at 800. I shot a sub moa 5 shot group at 500yds as well.

I decided to work up my own load this week to test at distance. I'm currently getting excellent accuracy with the following load:

1xLC brass
77smk
CCI #400
23.5gr 8208 xbr
COAL 2.255

 

[FCS]

Myself and a friend were running WOA 16" SS Match 1:7 barrels last weekend with IMI 5.56 77gr OTM LR Mod 1 out to 800yds. We were making consistent hits on a 12" steel plate at 800. I shot a sub moa 5 shot group at 500yds as well.

I decided to work up my own load this week to test at distance. I'm currently getting excellent accuracy with the following load:

1xLC brass
77smk
CCI #400
23.5gr 8208 xbr
COAL 2.255

OP, I'd sub in a 77 Berger OTM, optimize charge for your chamber / barrel but this is your 90% solution for parameters as you originally defined.

 

[lennyo3034]

If you don't have a lot of time for load development. Try some factory Black Hills 77gr TMK (Tipped match king). It has a BC of .420, significantly higher than 77gr SMK.

 

[MLC]

I'd vote for the 75 Hornady BTHP as well.
I don't have experience with the Berger FCS mentioned but know for sure the Hornady works well, has a better BC than the 77 Sierra or Nosler and costs almost half what the Berger costs.
I've shot a lot of the Hornady 75's over RE15 in LC brass and couldn't be happier.
1/9, 1/7.7, 1/7 twist rifles all shot them well.
Varget is an excellent powder as well, it's just harder to get at times.

 

[MLC]

If you don't have a lot of time for load development. Try some factory Black Hills 77gr TMK (Tipped match king). It has a BC of .420, significantly higher than 77gr SMK.

That's kind of a big deal.
I like the way Sierra is thinking.

 

[B4forever]

I'm getting great results with the following load out of an 18" Noveske 1/7 barrel.
-LC brass
-Nosler CC 77gr
-23.6 gr TAC
-CCI #41 primer

This load prints 1/2moa consistently and works well in all weather conditions.

 

[JLR]

77gr SMK and 24.5gr of TAC

 

[Steel head]

I've had very good luck with the Hornady 75gr BTHP.

I'm still doing load development on it for my gun.

I'll second the 75bthp's.
My SPR loves them and the price is decent.
77smk's are another option.

 

[Trevor300wsm]

Thanks for all the replie folks. Much appreciated.

 

[Greg Langelius *]

My generic 223 accuracy load is HDY 75gr HPBT Match, mag length, PPU brass, CCI BR-4 and 23.7gr of Varget.

Shoots very close to peak accuracy potential in my 24" Stag Model 6, CMMG 16 Bull Wasp, is my match load developed for my Savage 11VT 223, and doesn't do too badly in my Mossberg MVP Predator 5.56 20".

The differences in accuracy seem to have more to do with the specific platforms' capabilities than to the load itself.

Greg

 

[Trevor300wsm]

Thanks Greg

 

[Guest]

What kind of velocities are you guys getting with your 75/77gr match loads? Have you run them through the chrono?

I just started load development for a 5.56 match load and worked up an extremely accurate load as follows:

1xLC
77smk
CCI 400
23.5gr 8208 XBR
2.2595 COAL

Im only get 2556 with an SD 13 but .36-.50" accuracy.

Shooting IMI 5.56 77gr OTM LR MOD 1 out of the same gun Im getting 2672avg fps and can bang a 12" steel plate consistently at 800yds.

Looking for a load that gets same accuracy as my 8208xbr load but velocity in the 2650-2700 range for long range shooting.

I am shooting a WOA 16" SS Match 1:7 barrel.

 

[MLC]

Try Reloder 15.
Edited because the 77 apparently has a lot more bearing surface than the 75 bthp.

 

[Cornholeo]

16" Shilen 1:8
LC 1x
23.8gr XBR
77SMK
2.245COAL
2702 ave velocity
0.558 best I have been able to do accuracy wise.

 

[Guest]

16" Shilen 1:8
LC 1x
23.8gr XBR
77SMK
2.245COAL
2702 ave velocity
0.558 best I have been able to do accuracy wise.

Im really confused with your velocity #. I chrono this very load today along with 23.3 and 23.5 and all were under 2600 fps. Im using a WOA 16" SS 1:7

What primer are you using? 205M or BR4? I used 2.2595-2.260 coal. Maybe I need to try the 2.245 coal you used to bring up velocity but I didnt think that would give me a 75-100 fps velocity increase. Will try tomorrow along with a suggested Varget load.

 

[Cornholeo]

Using CCI#41 primers. I do not know where I read it on the hide but there was mention of accuracy increase as well as velocity increase going from 2.55 down to 2.45. I am new at the reloading bit but that is from to sessions on my Caldwell chrony, one a 5 shot avg of 2700.96 SD of 17.67 and one a 5 shot avg of 2704.20 SD of 24.19.

My 23.6gr XBR laod was only 4 shots today with avg of 2646.75 SD 19.75.

Hope this helps and again take it that I am new to the reloading business. I want to get the SD down on those and would love to get those smaller groups.

 

[kyle528]

Be careful when loading heavy bullets mag length as they tend to be long and will give some compressed loads...

 

[Trevor300wsm]

Ok guys I picked up some Sierra 77gr BTHP Match today along with some BL-C2. I already have plenty of Varget and I can get some XBR8208 & CFE. I have some LC brass coming in a day or two.

 

[mdavlee]

I use 69 grain smks with varget. 25.0 or 25.2 was the best load. 3" 5 shot groups at 400 yards if I did my part. Cci primer and set to mag length. This was out of a 16" bushmaster from 2002 era.

 

[Trevor300wsm]

Update
Well the Varget is a no-go. With the 77gr MK's I could only get about 2,550fps. That was with 24.5gr of varget. That was a pretty compressed charge. It crunched for a long time before the bullet seated. That was at a COAL of 2.245". That is just too slow for what im wanting. I need a fast, somewhat temp stable powder......any suggestions?

I'm going to try some 70gr VLD's also.

 

[Guest]

I just got back from the range and experienced the same issue with varget. Crunching when seating at 24.7gr and velociry 2539.

I am using 8208xbr right now, 23.8gr seated to 2.248 with 77smk which is extremely accurate and getting 2603. I have zero pressure signs so Im going to increase charge.

 

[-Nick-]

I've run 77 SMK factory loads out of an 18" 1:8 to 905yds reliably. The wind is going to hurt you some at those distances though. If you load 77 or 75 grainers I would make sure to crimp the bullet. We noticed on a few that the length although it would feed out of a mag fine was pushing some back into the case.

 

[FALex]

I've run 77 SMK factory loads out of an 18" 1:8 to 905yds reliably. The wind is going to hurt you some at those distances though. If you load 77 or 75 grainers I would make sure to crimp the bullet. We noticed on a few that the length although it would feed out of a mag fine was pushing some back into the case.

what powder are you running with your load? I just received an 18" 1:8 and looking to see what might work well. Thanks much.

 

[-Nick-]

what powder are you running with your load? I just received an 18" 1:8 and looking to see what might work well. Thanks much.

That was with Factory loads, but my reloads will be using Ramshot Tac and I should see 2740-2750 FPS. I know someone else running the same load on a 20" 1:8 getting 2775 FPS.

 

[lancetkenyon]

LC brass
25.0gr. Varget
CCI BR-4
69 SMK
3033fps
.204" 5 shot groups

Mag length, not sure on COAL.

24" barrel Bushmaster Varminter

 

[gasdoc09]

That's kind of a big deal.
I like the way Sierra is thinking.

I'd like it better if Sierra would sell those bullets to the public. Someday?

Until then I guess I'll just keep using the 75 A-Max.

 

[MLC]

In your AR?
Not that I disagree about them selling them to the public.

 

[-Nick-]

Honestly one of the best rounds out there that I wish I could buy separately... Speer 64 GDHP

 

[DavidAR10]

If your stick doesn't like 69 and/or 77gr FGMM...

If your stick STILL doesn't like anything on this page:

Shooters Pro Shop: Ammunition / Ammo

Then call up STAG ARMS for a MODEL 6.

Get rid of that nickel plated magpul crap and purchase

DH Tactical in a round count of your choice.


BTW, D&H/LaBelle... Do you speak it!!!

Best to you. Win it.

 

[damoncali]

I've had good luck with 77's over N540.

 

[sawman556]

75 BTHP
1x PSD
23 H335
#41
1.752
2.250
No crimp
2540FPS
14.5 1/7 Noveske Afghan
-1MOA NF 1-4x FC-2

 

[Douglas-001]

Well there are a whole lot of recipes there! SMK 77 with 24.1 RL15. Good luck and good shooting!

Doug

 

[JB02]

I need a fast, somewhat temp stable powder......any suggestions?

Power Pro 2000-MR. It's my go-to for heavy 308s and 223s when there is a need for speed. Using LC brass and a COL of 2.225" with Hornady's 75gr BTHP, I have gone up to 26.5gr with no pressure signs in my AR. Haven't had a chance to stretch it out to see how it performs at a distance or chrono it, but any accuracy load near this charge weight is supposed to ~ 2950 fps per Alliant's load data.

FWIW, during my OCW development, the most accurate load was 24.0gr. I'm able to put 10 shots inside a nickel at 50 yards using a 6x scope. I also tried 26.4gr, which wasn't as good (this is the max per Alliant's recipe), but using the 3% rule the high power node should be ~ 26.2gr.

 

[Trevor300wsm]

UPDATE:

I ordered some Berger 77gr OTM's and picked up a couple of pounds of 8208XBR. I found a very good load at 24gr. I did not try very many different loads. I'm running out of time as we leave next week and I just needed an accurate load with decent speed. With 24gr I could put 5 shots into one wallered out hole. Easily covered by a dime. For an AR15, that is very shocking to me, not to mention I'm not an AR shooter at all. I checked the speed with the Magnetospeed and a 10 shot avg was 2,733fps. That was good enough for me. I tested it out to 700yds and it did well. I'm gonna call it good for now.

Lake City brass (08)
Berger 77gr OTM
24.0gr 8208XBR
2.245" base to tip
1.841" base to ogive with a Hornady anvil in my calipers
2,733fps avg.

Thanks for the help guys.

 

[Guest]

UPDATE:

I ordered some Berger 77gr OTM's and picked up a couple of pounds of 8208XBR. I found a very good load at 24gr. I did not try very many different loads. I'm running out of time as we leave next week and I just needed an accurate load with decent speed. With 24gr I could put 5 shots into one wallered out hole. Easily covered by a dime. For an AR15, that is very shocking to me, not to mention I'm not an AR shooter at all. I checked the speed with the Magnetospeed and a 10 shot avg was 2,733fps. That was good enough for me. I tested it out to 700yds and it did well. I'm gonna call it good for now.

Lake City brass (08)
Berger 77gr OTM
24.0gr 8208XBR
2.245" base to tip
1.841" base to ogive with a Hornady anvil in my calipers
2,733fps avg.

Thanks for the help guys.

What size barrel were you shooting? What primers?

 

[Trevor300wsm]

What size barrel were you shooting? What primers?

18" with a 1:8tw AR15 made by Specialized Dynamics. Primers are CCi450's

 

[jLorenzo]

Working with Hornady 75gr BTHPs and RL15 has given me the best velocities. Tuning seating depth now, they seem to shoot better a little shorter than mag length. 18" WOA spr barrel. Will report seating depth results. Right around 24.1gr of RL15 seems to be a sweet spot, 24.3 gave good numbers but was a little harder on the brass than I like.
****whoops zombie thread