Seems to me you are the only that does this. I will not compress a powder due to the problems it can cause...... jim
Anyone Tried H4350 or N550 in a Straight 6BR Behind 105's?
- Thread starter HTSmith
- Start date
Seems to me you are the only that does this. I will not compress a powder due to the problems it can cause...... jim
urbanrifleman
Site $$ Sponsor
The only problems I ever experienced compressing powder was that it shot much more consistently.
R15 and varget in the 223 and the 55 grain bullet for example. Basically as much powder as it will hold and seat the bullet. Immune to all conditions. Pain the butt to load bulk but man does it shoot.
Unever pressure on the bullet, hard to hold seating depth, hard to load and it doesn't shoot as consistent as non compressed loads. what your referring to is an AR? sub .1 loads aren't going to happen, if you had one it would not repeat..... jim
There's compression and compression, of course. Mild compression never bothers me unduly, but there does come a point where COALs vary unless you're running with ferocious neck tension. This is with extruded powders. At one time - and still included in Norma's reloading manual - one was advised to avoid compressed loads with ball powders. Norma seems to be alone in this advice these days. Its reason is that compressing this type removes the already minimal gaps between powder kernels stopping the primer flame from penetrating the charge.
Many decades ago the H.P. White laboratory did tests on the the 30-06 and one of the commonly used slower burning IMR powders on this issue. Its findings were that simple compression within reason caused no pressure increase or other downsides, but that when 'extreme settling' methods were used, ie very, very long drop tubes and particularly vibratory settling to pack yet more into the case, charge ignition consistency deteriorated and ES/SDs rose sharply. ie same issue as over-compressing ball powders.
I have seen a near 3 ft drop tube used to get some unbelievably large charge of Viht N150 into the 'straight 6BR' under the Berger 105 VLD to attain the next highest node and produce Dasher MVs from a 30-inch barrel 'Heavy Gun'. This combination shot fantastic 1,000 yard groups for maybe 300-350 rounds then two things happened - brass life was terrible from the outset, but worse, when the barrel hit whatever that round count was, pressures went through the roof and the rifle's owner kept retiring from matches with blown primers and hard extraction. This continued for a while despite a continuing series of charge weight reductions until it got down to the usual N150 charge levels. I suspect the barrel was discarded early too (alongside the 3ft drop tube) as the rifle disappeared for several matches and reappeared the following season with a new barrel chambered for the BRA.
Many decades ago the H.P. White laboratory did tests on the the 30-06 and one of the commonly used slower burning IMR powders on this issue. Its findings were that simple compression within reason caused no pressure increase or other downsides, but that when 'extreme settling' methods were used, ie very, very long drop tubes and particularly vibratory settling to pack yet more into the case, charge ignition consistency deteriorated and ES/SDs rose sharply. ie same issue as over-compressing ball powders.
I have seen a near 3 ft drop tube used to get some unbelievably large charge of Viht N150 into the 'straight 6BR' under the Berger 105 VLD to attain the next highest node and produce Dasher MVs from a 30-inch barrel 'Heavy Gun'. This combination shot fantastic 1,000 yard groups for maybe 300-350 rounds then two things happened - brass life was terrible from the outset, but worse, when the barrel hit whatever that round count was, pressures went through the roof and the rifle's owner kept retiring from matches with blown primers and hard extraction. This continued for a while despite a continuing series of charge weight reductions until it got down to the usual N150 charge levels. I suspect the barrel was discarded early too (alongside the 3ft drop tube) as the rifle disappeared for several matches and reappeared the following season with a new barrel chambered for the BRA.
My 6BR barrel now has 2,400 rounds on it and still shot a 598 35x score at 600 yards 2 weeks ago. Look at the targets from my F class shoot shot with 34.6 grains of H4350, they show the SD at 13.8 and 17.4, a pretty stable load. I measured some leftover ammo from 2 weeks ago and the seating depth has not changed. I’m running .002 neck tension. Attached are some pictures of a 6BR case with 34.6 grains of H4350 right at the neck shoulder junction. This is not a compressed load. The brass has at least 10 firings on it and is doing fine. My drop tube is just under 6” long. It works well.I run 36,0 grs H4350 in a BRDX with 104 Bibs at 3015 fps,,
I know. it shoots good .
That maybe fine for F Class mid range SD of 1 or 2 would shoot smaller, in fact SD. doesn't enter the picture ES of single digits is what I seek. The records now at BR 600 are 5 shot groups in the .3 area 1" is quite common.....jim
Mulligan
Silver $$ Contributor
Jim,
I think those SD’s are measured at 600 yards by the electronic target system. With all the environmental variables effecting the bullets flight, I would think a SD of 15 out of a 20 shot string measured at 600 yards is pretty darn good.
CW
urbanrifleman
Site $$ Sponsor
Pssshhh... Whatever. No, it's not an "AR".
Yes I guess but again that is F class, you can not use electronic targets for bench rest because they are not accurate enough. SD's of 1 or 2 or less would be prefered at BR..... jim
Excuse me then a .223 kind of made me think that, maybe I should have said with a .223 repeatable sub .1 loads aren't going to happen... It was not designed for accuracy it was made to kill people.... jim
urbanrifleman
Site $$ Sponsor
Oh, give me a break.
Great information.
Are you still working with this combination?
Hmmmm a 4 year old thread. Probably a couple barrels since last post.
Frank
Frank
Why yes it is 4 years old...
Isn't that why the forum comes complete with a search engine?
If he's getting BRA speeds out of a straight 6 i want to know his thoughts about performance.
I have other viable powders "other than VARGET" to use including 8# of H4350.
wildcatter
Silver $$ Contributor
This is why I posted my thread on this topic, lot of incomplete old threads that don't answer anything, but lead to more questions! For the guy in 2018, hope someone told him to skip the drop tube, the only way I can make this powder work in my 6BR Norma is dumping by hand!
Find a fiberglass or carbon fiber arrow of the right diameter(most sport stores have an assortment of long arrow blanks), wrap electrical tape around on end until it makes a tight fit for your powder funnel, chamfer the other end so it fits over the mouth of your case. Build a simple stand to hold the drop tube vertical and your set.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.