Savage BRX

[Stella]

Great way to spend the afternoon. After enjoying the time we've spent shooting the fly Dad and I have finally decided to start building a heavy gun (that will probably be lighter than our light gun).  We asked Russel Le Maitre to source a barrel and chamber it in 6 BRX as we have been more than happy with the results we were achieving with the 6 BR and if it could shoot even half as good we'd be ecstatic.  

A BIG thank you to Micheal Bell who not only hydro-formed the cases for us but also spent a length of time on the telephone providing us a place to start regarding load development. As per Micheal's recommendations we threw 32.4 and 32.6 of 2208 into the cases and headed out to the range this arvo. I know it's early yet BUT it's showing just as much if not more promise than the 6 BR. Now we can't wait to take it to Wagga!!

[Stuart Pethy]

nice work Stella
you will love the BRX and Belly is a top bloke for helping ya out, he also gave me alot of info when i built mine,
yeah i'm running 32.4gr in mine with 105gr hybrids , cant wait to see what you settle on when your load testing is completed
cheers
Pethy

[Stella]

Hi Stuart !

We were going to use the 107 SMK's as we have had a lot of luck with them in the 6BR but Dad couldn't get any. As it turned out we have 500 105 Hybrids on their way so I'm glad to see they have been working for you. Dad is asking if you Jump them or Jam them? And hopefully we will get to meet you in Western Australia next year as I'm trying to convince Dad to go!

[Stuart Pethy]

i jump them .008 , they liked .004 off to .012 off so i went for the middle to give myself some play room and the fact all 5 went into 1 hole at 200m , the wind pushed them wide but they opened up once i got to .016 off




and i hope to have a date soon for the fly nationals next year over here

cheers

[Stella]

Thanks Stuart

Tried the Berger Hybrids today, 34.2 - 34.6  Jumped .015,  34.6 showed the most promise, we'll try .008 next. The lapua's are looking good, only tried the one load 32.4 jumped .005 probably shoot them in our next club fly match.

[Peter Cross]

Chronograph-ed a few loads today with the Berger Hybrids and 2208

32.4 = 2927
32.6  = 2942  

However this isn't that much faster than our 6br  load with 107 smk's and 30.1 of 2208,  we are getting around 2890. I though with 2942  are we really taking advantage of the extra "power" of the BRX ?

Today I tried 32.9  & 33.1 yielding  2980 & 3000,  this is probably more the velocity I would have expected from this cartridge,  accuracy with the 33.1 was a little better in vertical than the 32.6 loads I have tested.  There certainly wasn't any sign's  of pressure.  What sort of velocity are others who are shooting the BRX obtaining ?  I have read that the BRX's  best accuracy is around the 3020 to 3080 fps though I do realise all rifles are different.  

Thanks

[Michael Bell]

Hi Peter,
Having shot the BRX for the last 6 or so years in both light & heavy categories I'll weigh in on this.

Like you, I've asked myself many times about the value of shooting an improved case at unimproved velocities.
There are many things to consider when thinking about muscle velocity. Bullet brand & weight, powder type & powder lot & barrel length to name a few.

Every one of the half dozen 6 BRX barrels I've used in competition was finished at 27 -28 inches & was most accurate  between 2980 & 3030 fps using 103 grain mollied copperheads & 2208 powder. Mollied 105 grain Bergers were also accurate  between 2980 & 3000 fps in a couple of these barrels with 2208.

In the early days I used 2206H to good effect with naked bullets but needed to run the 103's a little slower at about 2940 or so.

In high pressure testing I have run up to 3100 fps but this was absolute top end with no margin of error & was hammering the cases.
It's likely that every 1" of barrel length will equal up to about 20 fps in difference meaning that a 26 " barrel will run a bit slower than a 27" etc & different lots of powder can also quite easily make 20 fps of difference....so...there's a bit to consider.

I've used a variety of barrel brands & I reckon they were all within about 15 fps of each other when loaded with identical recipes & factoring in the small differences in barrel length.

Every barrel, with one exception, was capable of scoring 250 plus if the conditions were right when loaded to the previously mentioned velocities.

Peter, if you have a 28" barrel I would be using the 2980 muzzle velocity as a starting point when using 2208 but if you need to go 20-30 fps either side of this mark to get premium accuracy then I would take it.

Regards,
Belly

[Peter Cross]

G'day Belly

I was hoping you would weigh in on this.  From what I have read everyone seems to talk about 3 "nodes" for the  BRX.  The lower being around the velocities achieved with 32.4-.6, the high getting up around the 3080 fps. I'm not at all interested in this one, as you have mentioned it really seems to knock the cases and the barrel around.  From what I have been able to find, the middle node seems to be a good compromise between good barrel life, accuracy and it takes advantage of the extra speed you can achieve with an improved cartridge over the standard 6BR.   I think you hit the nail on the head, if I can achieve a consistent velocity between 2985 - 3000,  I think this thing should shoot pretty good.  Now that raises another question. What is considered the max extreme spread you should be trying to achieve over a 5-10 shot group. I realise 5 fps would be fantastic and maybe achievable but is that realistic or would 15 fps be what you would want to achieve?

Thanks

[Michael Bell]

  I might get myself into warm water over this one but in my opinion, (which is based on my observations of a few years while shooting regularly over a chronograph), the importance of ES is a bit overstated. At least as far as shooting 6mm 105 grn bullets from a BRX case to distances of 500 meters or LESS is concerned.

  I won't argue with the 1000 yard & F-Class shooters who seem to place a high degree of importance on ES as these guys know a lot more about that distance & also a lot more about the heavier 7mm & 30 cal projectiles  (that are often used ) than I do, but for Fly Shooting with the 6mm bullets we use I would suggest that a recipe that groups in that 1 " or under area at 300 meters is the thing to aim for.

 My experience has been that if a certain load regularly shoots groups to this size in moderate conditions then the ES will look after itself & will more than likely be in the 10 - 25 range.

  In the target you have posted it looks like you have 3 into about .75" with the fastest shot of 3033 fps printing higher & expanding your group to about 1.2" or so. Even though your ES is quite high at a touch over 50 the group is still ok.

  If you regularly have a shot jumping high perhaps just tweek the charge in .1 grn increments or adjust the seating depth by 3-4 thou in or out but it really looks like you're well on the way to getting it tuned to match level.

Regards,
Belly

[Stuart Pethy]

my 6BRX in a 30inch 1;7.5 twist kreiger barrel using 32.4gr 2208 with naked 105gr hybrids gives me spot on 300ofps, i checked speeds after my load testing and this is what i got


with load testing at 300m i had 2 nodes , 32.3gr to 32.5gr and 33.5gr to 33.7gr (last shot i hit low as i rushed it)
i thought the 33.5-.7gr node was going to be to hard on my brass so i went with lower node
and the speeds are above  so i stayed there


the barrel has now done 1100 rounds and i have only been changing my seating depth to follow the lands, pulled this out on the weekend in some tricky winds so its still shooting ok

i did have some better vertical ones but wind killed me haha

but from what i have read around the 3000fps give or take 20fps is where most shoot them

[Peter Cross]

Thanks Belly & Stuart.  

We think we have this thing shooting pretty good & we are  looking forward to shooting it under match conditions in Wagga. I would like one more day at the range without all this wind we are currently getting just to fine tune it, but if we don't I won't be that disappointing shooting the load we have developed  so far.

Thanks again.

[Stella]

Looks like our quest is over.  We won't be able to blame the gun now! This group has less vertical than we have ever shot with the 6 BR at 300m. Thanks again Micheal and Stuart we're looking forward to shooting with you guys soon