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Lowering ES and SD on BRX Loads

rcw3

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I am currently doing load work ups with one of my BRX barrels and the ES and SD chrono numbers with individually weighed charges are bigger than I am used to seeing with Reloader 15 and the Berger 105 VLD's with CCI #450 primers. I have not done a lot of chrono work with this barrel but other powders with this combo show low ES and SD numbers, but with RL 15, ES ranges (depending on the amount of powder in the load) between 25 - 40 and the SD 8 - 14. The RL 15 loading shoots well so any ideas how one can tighten up the ES and SD numbers?

Robert
 
Try Wolf Primers........I shoot a BRX with Varget, 105's,Lapua Brass, and Russian Primers. My ES and SD holds steady about 15 ES and and 7 SD runing 3030 fps. German Salazar has an article comparing primers and the effects on ES and SD and group sizes. Check it out. http://riflemansjournal.blogspot.com/2009/06/primers-small-rifle-primer-study.html
2 cents.....
 
brxbrad said:
Try Wolf Primers........I shoot a BRX with Varget, 105's,Lapua Brass, and Russian Primers. My ES and SD holds steady about 15 ES and and 7 SD runing 3030 fps. German Salazar has an article comparing primers and the effects on ES and SD and group sizes. Check it out. http://riflemansjournal.blogspot.com/2009/06/primers-small-rifle-primer-study.html
2 cents.....

It's funny because with other powders my ES and SD are right with your numbers, but not with RL15. Time to play more with the chrono and other primers and see if I can get the numbers tighter, or else I will need to switch powders.

Thanks for the input.

Robert
 
Problem solved - electronic scale went on the fritz right before it froze up permanently this afternoon. Pulled out back up scale, weighed new charges, went to range a second time, ES and SD numbers are excellent.

BR-4 Primers were the best
#450's next
Wolf SRM's last

Robert
 
rcw3 said:
Problem solved - electronic scale went on the fritz right before it froze up permanently this afternoon. Pulled out back up scale, weighed new charges, went to range a second time, ES and SD numbers are excellent.

BR-4 Primers were the best
#450's next
Wolf SRM's last

Robert

Robert,

how often do we this tale of woe on electronic scales these days? It's almost a standard excuse for poor F Class match performance now!

Anyway ..... what I really wanted to know was did the three primers produce any great difference in the average MVs, ES and SD values aside? I've found in my 90gn .223 Rem loads that the PMC version of the Russian / Wolf SRM and CCI-450 produce very similar results, but the CCI-BR4, or at least the lot that I have, produces around 40 fps more MV and appears to be 'too hot' for this cartridge and 24-25gn weight charges of VarGet and Re15. Reducing charges slightly to match the other two primers' MV performance didn't restore their groups sizes or ES/SDs.

Conversely, I've generally found the BR4 to give better results in 6.5X47L and 6BR with their larger charges.
 
Robert,
I am glad you figured it out, I am with Laurie on electronic scales. I am about to box them all up and go back to a 1010. I got very good #'s out of 205m, 450's, and br4's didn't see a lot of difference ES and SD from any of those, what I found to make the biggest difference was seating depth. I didn't shoot the Bergers but the 107 SMK's definitely made a difference in #'s where they were seated. I am using Varget and RL-15 and seeing the same #'s basically as brxbrad.
Wayne.

P.S you should receive $ for dies Mon or Tue, I enjoyed our chat on the phone.
 
Laurie

The BRX loads were all 32.5 gr. of RL15 (double weighed with back up scale) with Berger 105 VLD's Lot #1415 (plain thick jacket version before change to larger meplat with no moly or other coating) jumping .040" and fired through a 30" Brux 1:8" twist barrel:

CCI BR-4's - Mean Velocity 2955, ES 10, SD 4
CCI 450's - Mean Velocity 2953, ES 14, SD 6
Wolf SRM's - Mean Velocity 2957, ES 27, SD 11

I will be using either the BR-4's or the #450's. The Wolf primers also seat hard because they are a little oversize in diameter.

Robert
 
Laurie,
It's a neat little cartridge, do you have one yet? if not you better get one and burn the courses up over there with it. I think it is every bit as good as a dasher, time will tell I guess. I guess I have read you fellas like the big 7mm's to fight the wind with, I understand that. What kind of weather have been having the last few weeks or so? still windy and rainy here, NW USA.
Wayne.
 
Glad to hear you solved your problem. I had problems with pierced primers when using the BR4's. A friend gave me 300 russians and I gave them a try, took them to a match and had great results. I haven't had any more piercing and haven't seen any pressure signs. Good luck and shoot small.

Brad
 
Hate to spend the money but I have had my fill of less expensive electronic scales, so it looks like a higher end scale this time (Sartorius). I guess I should be fair, the prior scale did weigh out many thousands of rounds of ammo and recently, due to the storms, our electric has been bobbing all over the place, off and on every other day, power spikes, etc. - kind of wrecks havoc on electronic stuff.

Robert
 
brxbrad said:
Glad to hear you solved your problem. I had problems with pierced primers when using the BR4's. A friend gave me 300 russians and I gave them a try, took them to a match and had great results. I haven't had any more piercing and haven't seen any pressure signs. Good luck and shoot small.

Brad

Brad

With AR-15 cartridges and smaller cartridges in general, the Wolf SRM's have been good, but with this set up, for some reason, they did not do as well as the BR-4's or the #450's, so I have to go with what's working. Thanks for your help!

Robert
 
bozo699 said:
Laurie,
It's a neat little cartridge, do you have one yet? if not you better get one and burn the courses up over there with it. I think it is every bit as good as a dasher, time will tell I guess. I guess I have read you fellas like the big 7mm's to fight the wind with, I understand that. What kind of weather have been having the last few weeks or so? still windy and rainy here, NW USA.
Wayne.


Wayne,

I've plumped for the BR-DX version and a 1-10" twist barrel for my 500-600yd Light Gun replacement barrel. We're waiting on the reamer from PT&G throated for the 88gn Berger HBC-FB. Thought I'd try a lighter bullet at higher MVs this time around.

The rifle currently has a (shot-out) Border 1-8" and was originally built for F Class in 6mm Norma BR / 105s in the early days of F Class when there were more than a few 6BRs being used here. It has done very well indeed over a 4,500 round barrel life, and was still competitive in 600yd bench rest with getting on for 2,000 rounds down it. For longer range BR, I have a 6XC wearing a Bartlein 1-8" which I've not got sorted yet - too many rifles, not enough time so far.

F Class wise, I'm an F/TR competitor at national GB level these days, and Open in club competitions, the latter alternating between .308W (soon to be 6.5X47L) and 6.5X55mm rifles at the moment. (Don't ask!) 7mm rifles are a bit too rich fare for me, although I fancy having a go with a short .280AI based on Lapua .30-06 brass at some point. My 'league F/TR' rifle is a Savage based .223 Rem shooting 90gn Berger VLDs at 2,850 fps and I'm doing very well with it. Your F/TR team guys will see it in early July at Blair Atholl in the annual Scottish Rifle Meeting where I'll take part in a Scotland v USA F/TR team shoot at 900, 1,000, and 1,100yd.

Weather here? We've had a strange mix. After the coldest winter in around 30 years, we had an abnormally warm early spring, and over most of the UK, it has been near drought conditions for the last 3 months. The English grain harvest will be maybe 15% down on normal and food prices will rise we're told. Three weeks ago the weather broke and it's been cool, slightly damp and very windy ever since. Both F Class league rounds to date had difficult, windy conditions, the first (our sole 'short-range' national league match at 500 and 600yd) won by Ian Boxall shooting a 6mm Crusader cal Surgeon and beating all the sevens despite some very tricky winds on Day 2, the second at Blair by the standard 7mm short magnum. The top handful of shooters used 7mm/300WSM, 7mm SAUM and .284 Shehane - take your pick! The only time we see sixes in F Open at this level is the annual F Class European championships that see several European entrants use them. A lot of our top 'Open' guys such as the F Class world champion Gary Costello are very fond of the sixes though and had an unofficial 6mm F Class league series last winter that I think may become a fixture, maybe even 'official'.

Robert,

Changing subject to electronic scales, I came to this conclusion too last autumn and bought an Acculab VIC123. I really need it for the .223 Rem ammo as plus or minus 0.15gn is too coarse in the little cartridge with 0.1gn = 10 fps. I've not regretted the purchase.

Laurie,
York, England
 
Hardrock,

I shoot 33.2 Varget, Lapua Brass, Tula SRM Primers, 105 VLD Targets, Jumped .030. I'm runnng 3030fps with 15 fps ES and 7 SD. I have a 26" barrel, 1-8 twist with a old Savage 110 action. It shoots on average in the high 190's at 600 and low to mid 190's at 1000. It's a great gun.
 
I have been shooting 33g RL15 br primers 105JLK jamed .05 3028mv 28in barrel. So our loads are real close. Can't shot your scores though. Still learning
Thanks for the info.
Gary
 
Some good loading data coming out of this thread too - thanks guys!

Interesting to see brxbrad jumping the VLD's .030". I was a "died in the wool" VLD jammer until just recently when one of my BRX die customers (who shoots very well indeed) indicated he was jumping his VLD's quite a distance, and then I looked at Mike Davis' website and saw that one of Sam Hall's records were shot with him jumping the VLD's .040". The first time I tried out jumping VLD's, a jump of .040" shot real well, but .070" did not do so well and jamming in that barrel shot well but yielded and occasional flyer (which I cannot accept).

The purpose of my chrono testing noted on my initial posting on this thread was to see what the VLD's were doing at a .040" jump.

I am still a little hesitant jumping VLD's, but I am getting over it fast as I see how well they are currently shooting with that jump.

Robert
 
The purpose of my chrono testing noted on my initial posting on this thread was to see what the VLD's were doing at a .040" jump.

I am still a little hesitant jumping VLD's, but I am getting over it fast as I see how well they are currently shooting with that jump. [rcw3]

Robert,
yes, it's a real challenge to one's experiences, maybe prejudices, isn't it? A step that I've not yet heard of people making over here. It's one of those things I have on my list to play with - trying VLDs in the lands then again 20, 40, and 60 or 70 thou' out. It'll probably be in .308 Win with Bergers as I have a choice of 175, 190 and 210gn VLDs to experiment with.

If jump works, there is a real advantage for F Class and sling shooters that doesn't apply to bench rest - the ability / need to unload a live round mid shoot on the RCO's orders if required without leaving a jammed bullet in the leade and an action full of powder. Many people won't use VLDs for this reason (amongst others).

When I get the BR-DX going, I'll try the 88s with their aggressive secant form front ends both 'in' and jumped on the basis of these BRX reports and let you know how I make out. So, please Mr Kiff, where is the reamer ordered last October?
 
I usually have problems with ES/SD when I have less than optimum case preperation. I also question my chrony. It has been giving questionable readings for the last few months.
105 scenars
33.8g vv550
BR-4
2.810 (.020 in the lands)

Occasionally I get ES in the 11-15 range and occasionally it is in the 20 range. I've shot this load for the past 3 Fclass matches and I can honestly say I don't have a doubt in the world about this setup. Pretty strong words coming from a guy who changes his load 4-6x a year!

I can't ever get varget to shoot well which is frustrating. I guess I need more jump with the bullets.
 
Just to chime in with what little I think I've learned about the 6BRX, since it's beginning several months ago/ 430 rounds fired. 33 grs. of Varget with the ever reliable, old fashioned 107 SMK, BR4 primers, has been settled on as my standard. I say "old fashioned" since contrary to the VLD's that I found to be so critical on seating depth, the SMK's just seem to shoot at any reasonable seating depth. And I'm not burning up valuable barrel life experimenting with trying to find that magical depth. Have some RL-15, but keep hearing about how dirty it is, and carbon buildup is one area I try to avoid, so will stay with Varget. I have one box of Lapua now that is on it's 21 st. loading and the cases are as new. No sign of neck splits developing and primer pockets are tight. Brass has been forming perfectly by just loading up to 6BR combinations, with a .010" jam and shoot 'em. No big deal, as I was concerned about at the beginning. The BRX is fighting the wind better than my 6BR's with 8 twists (also) and the same 107 SMK. Longest distance I've been able to use has been our match's that are fired out to 500 meters, and the BRX has done very well. ;) Note to Robert: Great Redding BRX FL bushing die: It's working as expected. Thanks again. fds ps: my chronographed velocities are averaging 2930 with a 26" Krieger .237" bore.
 

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