Best powder choice for velocity in short barrel 6BRX & 95gr VLD?

[Fordnutter]

Hi Guys,
I've just rechambered my 6BR to BRX in search of a little more speed from my light weight long range varminter (short 24" barrel). In the previous 6BR guise I were getting 2,780fps with the Berger 95gr VLD with 29.8gr Varget before hitting high pressures. I tried reloader 15 & gained 20fps but I couldn't get a load anywhere near as accurate as I did with the Varget. I've now just about fireformed all my new 200 pieces of brass so the question is - If I'm looking for maximum speed in the 6BRX with the 95gr VLD are there any other powders to consider apart from Varget or Reloader 15? Constructor is having some great results with V550 but also like him it is very hard to find, any other powders worth trying?

 

[Erik Cortina]

This is the information that QuickLOAD gave me. These are in order of highest speed to lowest. These are near max loads, start low and work up!


Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Alliant Reloader-17 101.9 38.6 2.50 3156 98.2 58000 10239 1.080 ! Near Maximum !
Winchester 760 100.7 38.4 2.49 3147 96.8 58000 10244 1.092 ! Near Maximum !
Vihtavuori N550 103.1 38.0 2.46 3143 98.8 58000 10125 1.101 ! Near Maximum !
Ramshot BigGame 98.9 36.9 2.39 3128 99.6 58000 9707 1.096 ! Near Maximum !
Hodgdon H4350 105.0 37.7 2.44 3117 97.6 55944 10080 1.101 ! Near Maximum !
Hodgdon H414 97.9 37.6 2.44 3117 96.7 58000 10055 1.104 ! Near Maximum !
IMR 4895 95.3 34.4 2.23 3111 99.7 58000 9585 1.108 ! Near Maximum !
Ramshot Hunter 105.0 39.1 2.54 3104 97.0 54921 10169 1.115 ! Near Maximum !
Hodgdon BL-C2 91.0 35.8 2.32 3099 100.0 58000 9375 1.110 ! Near Maximum !
Alliant Reloder-15 96.1 34.7 2.25 3099 99.4 58000 9523 1.108 ! Near Maximum !

 

[Fordnutter]

X3m Hunter - Thank you for that. It is greatly appreciated - I wondered about reloader 17 & Winchester 760. I'll give those ago & see what works best ;D

 

[RonAKA]

Hodgdon Hybrid 100V?

 

[Erik Cortina]

Hodgdon Hybrid 100V?

Too slow, it takes 113.3% fill ratio to reach max speed. At 100% fill ratio you can only achieve 2750 fps.

 

[RonAKA]

Hodgdon Hybrid 100V?

Too slow, it takes 113.3% fill ratio to reach max speed. At 100% fill ratio you can only achieve 2750 fps.

Interesting as Hodgdon rates Hybrid 100V as being faster than N550.

http://www.hodgdon.com/PDF/Burn%20Rate%20Chart-2010.pdf

 

[Fordnutter]

Interestingly enough a local f class shooter uses w760 powder in his 6brx with quite good results. You don't hear of anyone using Winchester powders for 6br or brx on this forum.

 

[constructor]

I am going to give N540 and 4007SC a try this next week.

 

[limbic]

wow that is alot of N550 to pack in that case. 32.5 gets me 2950 in a 27.5" tube. I couldn't imagine another 5.5 grains. Especially not getting it too hot and tearing up the brass. I realize it is a 95g projectile and all.

 

[MarkS]

Fordnutter,

I punched my first BR 25" to BRX. It was running 2790' as 6br with 105 Berger with 30.5gr of Varget. With a load of 33.5 gr Varget with a 105 gr, I was getting 3000 f/s. This load is warm in my gun, work up to that. I have shot them all, Varget and RL15 are the best, in a 6BRX.

Mark Schronce

 

[alf]

If I'm looking for maximum speed in the 6BRX with the 95gr VLD are there any other powders to consider apart from Varget or Reloader 15?

No.

I've got a 22" 8 twist Rock barrel in 6 Dasher that I run the 95 VLD's in at 3075 with Varget. Brass life should be forever at that speed. If it won't shoot with Varger or R-15, you probably have other issues.

 

[Moderator]

Ford,

I don't know why you were pressuring out with the 95 VLD. On Tuesday we shot the 95gr VLD from 6BR with CCI 450s, 31.3 grains of Varget. MV was ~ 3055 fps and there was no ejector mark. Bullets were seated about .012" into lands, in a 3-groove 27" PacNor barrel (which has shallow lands).

Overall length was 2.366" measured base of case to tip of bullet.

Accuracy? To be honest, it was better than anything this rifle has ever done. Our 3-shot measured groups at 200 yards were in the ones. Honest. I too was flabbergasted. One three-shot group measured .335" edge to edge at TWO HUNDRED.

It may be a perfect combo for this rifle which was throated for the 95s.

 

[distinguished]

X3M hunter, I am new to the 6BRX. The quick load data looks more like 6XC to me? Just want to be sure. Thanks.

 

[constructor]

X3M hunter, I am new to the 6BRX. The quick load data looks more like 6XC to me? Just want to be sure. Thanks.

This is my 6BRX- quickload results max psi set at 58800 -notice this is for an AR max OAL 2.3"
These are max loads, I found 37gr of N550 to be the max in most of my rifles so start at least 2gr lower.
Cartridge : 6 mm BRX
Bullet : .243, 95, Berger VLD
Cartridge O.A.L. L6: 2.300 inch or 58.42 mm
Barrel Length : 22.0 inch or 558.8 mm

Predicted Data for Indicated Charges of the Following Powders.

Matching Maximum Pressure: 58875 psi, or 405 MPa

or a maximum loading ratio or filling of 105 %

These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Ramshot Hunter 104.1 39.7 2.57 3105 97.1 58875 13225 1.029 ! Near Maximum !
Winchester 760 101.4 38.4 2.49 3096 96.2 58875 13084 1.032 ! Near Maximum !
Vihtavuori N550 103.8 38.0 2.46 3093 98.5 58875 12933 1.041 ! Near Maximum !
Ramshot BigGame 102.9 36.9 2.39 3080 99.4 58875 12379 1.036 ! Near Maximum !
SNPE Vectan SP 11 99.8 36.9 2.39 3079 99.4 58875 12364 1.036 ! Near Maximum !
IMR 4895 98.1 34.0 2.20 3070 100.0 58875 11560 1.023 ! Near Maximum !
Hodgdon H414 97.2 37.1 2.40 3065 96.9 58875 12675 1.044 ! Near Maximum !
Hodgdon BL-C2 91.6 35.8 2.32 3052 99.9 58875 11929 1.049 ! Near Maximum !
Norma 203B 97.3 34.9 2.26 3052 99.5 58875 12000 1.048 ! Near Maximum !
Raufoss RA11 96.8 34.7 2.25 3052 99.2 58875 12047 1.048 ! Near Maximum !
Bofors RP11 ~approximation 96.8 34.7 2.25 3052 99.2 58875 12047 1.048 ! Near Maximum !
Alliant Reloder-15 96.8 34.7 2.25 3052 99.2 58875 12047 1.048 ! Near Maximum !
Norma 203 old 99.0 35.9 2.32 3051 99.8 58875 11941 1.057 ! Near Maximum !
Winchester 748 89.1 34.4 2.23 3049 100.0 58875 11461 1.042 ! Near Maximum !
Hodgdon H4350 105.0 37.4 2.43 3045 96.8 55530 12750 1.051 ! Near Maximum !
Rottweil R903 104.2 35.9 2.33 3043 99.7 58875 11840 1.058 ! Near Maximum !
Hodgdon H380 98.2 35.9 2.33 3037 98.3 58875 12137 1.051 ! Near Maximum !
Norma URP 105.0 37.2 2.41 3037 98.1 55224 12590 1.065
IMR 4320 98.8 34.8 2.26 3037 99.4 58875 11628 1.033 ! Near Maximum !
Bofors RP19 ~approximation 105.0 37.2 2.41 3036 98.1 55169 12584 1.065
IMR 3031 96.5 32.3 2.10 3034 100.0 58875 10770 1.048 ! Near Maximum !
Somchem S355 101.0 35.4 2.30 3034 99.7 58875 11777 1.054 ! Near Maximum !
Norma 204 105.0 38.9 2.52 3030 93.3 57384 12665 1.041 ! Near Maximum !
PB Clermont PCL 516 94.5 36.1 2.34 3028 98.2 58875 11971 1.043 ! Near Maximum !
SNPE Vectan SP 9 94.3 34.9 2.26 3025 99.4 58875 11662 1.044 ! Near Maximum !
Accurate 4064 103.4 34.6 2.25 3023 100.0 58875 11153 1.079 ! Near Maximum !
Accurate 2520 93.8 34.7 2.25 3023 100.0 58875 11155 1.061 ! Near Maximum !
PB Clermont PCL 507 90.8 34.0 2.20 3017 99.9 58875 11337 1.047 ! Near Maximum !
Ramshot TAC 90.2 33.9 2.20 3016 99.9 58875 11309 1.047 ! Near Maximum !
Somchem S321 90.0 34.4 2.23 3015 100.0 58875 11376 1.053 ! Near Maximum !
Hodgdon H4895 99.3 34.4 2.23 3015 100.0 58875 11038 1.039 ! Near Maximum !
Somchem S341 93.6 35.7 2.31 3010 99.4 58875 11423 1.045 ! Near Maximum !
Hodgdon VARGET 99.2 34.4 2.23 3009 99.0 58875 11522 1.040 ! Near Maximum !
ADI AR 2208 98.9 34.4 2.23 3009 99.0 58875 11522 1.040 ! Near Maximum !
Vihtavuori N530 90.0 32.4 2.10 3007 99.9 58875 11119 1.047 ! Near Maximum !
IMR 4064 99.9 33.8 2.19 3002 99.2 58875 11316 1.045 ! Near Maximum !

 

[Fordnutter]

Thanks for all the help guys. I'd love to try the N550 ifI could actually get my hands on some & know I could continue to get a regular supply. W760 powder is quite common here in NZ so will try some loads to see how well it shoots. I'm not unhappy with the performance of Varget & berger VLD combo as It shoots in the two's but I would like some more velocity. It will be interesting to see what velocity, ES & SD I get with W760. It may be a weekend or two before I get a chance but will keep you posted. I just love to fiddle :

 

[constructor]

One other thing about QLs results, I am using a PacNor 8 twist 3 groove on this particular rifle 22" long. The velocity I get here at 4800 ft elev is 3075 with 36gr N550 and apx 3200fps with 37gr. It could be the altitude helping my velocity because when I shoot at my cabin (9800ft) the velocity is faster.
We are experimenting with high groove to land ratios 70:30 and higher with 5 grooves, the barrels produce as much as 100fps more than other barrels from the same maker so I expect Bartleins .436 5 groove barrel to produce more velocity than this PacNor and it may allow us to reach the next node without pushing the pressure so high. If you are wondering about life with thin lands we may have lost 6-7% but are now nitro-carburizing the barrels which greatly improves the life of the barrel.

 

[Fordnutter]

I managed to get to the range for a quick ladder test with W760 powder & 95gr Berger VLD in my 24" trueflight barreled 6BRX. Started out low & worked up in .3gr increments hitting a sudden velocity spike at 36.9gr (2,975fps) then 37.2gr giving sticky bolt lift (3,000fps). When I get a chance I'll go back & accuracy test 36.6 to 36.8gr, everything went into one ragged hole at 100yds. For a comparison I'll need to try reloader 15 & varget again but so far from the original 6br chamber we have gone from 2,780fps with Varget to 2,975fps with W760 in the 6BRX chamber. Not the 3150fps I were hoping for (I must have a slow barrel) but still a 195fps gain from the previous 6BR chambering.

 

[Fordnutter]

As an afterthought my testing (& most my shooting) is done at near sea level. What velocity increase would one expect if the same load was shot at a much higher altitude?

 

[constructor]

Not much change, I go to Texas elev 120ft a few times a year to hunt hogs and vels are within 40ft and some times higher than what I get here at 4800ft. Now my cabin at 9800ft is a different story I see more gain.

Update on velocity, all max loads in my 8 twist 3 groove pacnor barrel so start lower.


105gr Amax, 22" barrel, CCI450 primers
N540-34gr=3009fps
RE17-37gr=3087fps
N550-36.5gr=3085fps
4007SSC-36gr=3087fps

95SMK
35.5 N540=3179
37 RE17=3100 max load due to compression---Is this the same as ADI AR2209?
37 N550=3180
36gr Varget=3209

Earlier Varget had given what I thought was high pressure signs but I started again and was able to get to 36gr before primer cratering. The difference could be the land to groove ratio of the rifling, these PacNors are around 40:60, land:groove. Have you tried IMR 4007SSC,
H414(ball) or Norma 204? 37gr of stick powder is close to max fill. The CCI 450 primers give me 40-50fps more than BRs.

On another note I broke 3300fps with a 105Amax from a 26" barrel 6x47 lapua and stopped because of max compression not pressure, again N550. There is a node around 3250.

 

[constructor]

6BRX AR15 quick function test video using factory PRI 6.8 15rnd mags just to show it does work and work well.
95gr SMK at 3180 fps from a 22" barrel.
This is not a BRAT or Oly system.


http://www.youtube.com/watch?v=je3ulQuG3S0