Double base powders who has tried them for FTR?

[Pommy Chris]

I avoided them due to the temp variable issues but looking at the numbers unless bullets are left in the sun it should not be a real issue. Friend gave me a half tub of n550 and I made up a few loads to see how it shot and the groups were amazing the worst was good the best was stunning at 200 yards. The difference between the lightest and hottest group was half a grain so why are we avoiding these powders?
I read that the average (not the best) temp issue was one Fahrenheit per one foot per second. In Aus unless you leave your bullets in the sun this relates to about 15 feet per second at worst and decent double base will be a lot better so what is the issue?
n550 is not available so will be trying a few powders, they are not perfect but cant see any other way to shoot an 09 and get velocity.
Any thoughts?
Chris

[jasmay]

VV powders are great, I have used N150 & 550, but what's the point now when they are no longer available in Australia?

If you want velocity in a .308, use 2208 or 2206H.

Unless you are adapt with a tuner, I would stay away from powders that are sensitive. My preferred powder from VV was N150 for this reason.

[Pommy Chris]

I know the n550 is not available just tried it to see if double base worked and it does for sure. There are loads of double base options too which is what I am looking at. I know abvout the temp sensitivity, but most are like 15 fps for Aus conditions ie 15 to 30 degrees at most and most double base react to heat to 1 degree Fahrenheit per one foot per second. IMO if you go out of the node with 10 or so foot per second you are in the wrong node anyway. Of course keep bullets out of the sun..
Only reason giving this legs so to speak (double base) is my tests so far gave amazing groups over three loads over half a grain (all groups amazing), all three would have been good to shoot. From a barrel that would not shoot heavies with any load of adi..
I might be chasing my tail but IMO what we need is an 09 powder (slow) for most barrels to shoot 200 and above but finer so not so compressed (this powder does not exist in single base). Answer might be double base??.. If you can control the heat issues for what they are..
Chris

[Brad Y]

Just not worth it if you can’t reliably get it. Used rl19 in 284 shehane and it was too fickle. In 308 as Jason says, use 2208 or 2206h. Adi powders consistently win around the world... sometimes there’s no need to re invent the wheel

[Pommy Chris]

Just not worth it if you can’t reliably get it. Used rl19 in 284 shehane and it was too fickle. In 308 as Jason says, use 2208 or 2206h. Adi powders consistently win around the world... sometimes there’s no need to re invent the wheel

Not reinventing the wheel, 2206 is too fast 08 only works with some barrels with 215's as really it is too fast for them and adi dont do a fine powder that is the speed of 2209. I have some great 215 barrels but I have many that wont work with 215's. The powders I am trying are easy to get, tried win 760 and rel 17 today with great results on using a barrel that just would not shoot 215's at all with adi. Going to try testing at distance next and then try warming the bullets and comparing. I try even with adi to keep bullets a constant temperature so this warming I would not allow normally with adi anyway. Will post some pics when I have a minute..
Chris

[Pommy Chris]

How do you link a pic here?
Chris.

[jasmay]

Chris, I have been saying for years that 215’s are in the outer limit for .308’s and accurate shooting, there is reasons for this that I’m not going to divulge publicly but I’m sure I’ve discussed them with you.

This is the reason I have zoned in a settled on 200’s in a permanent basis.

The other thing I would say you should re-check is your figures on how temp effects velocity, I think your figures are very conservative.

[Gyro]

Yes lads surely there's a point where the gun upset gets too hard to deal with ? Is Derek Rogers using them ?

Guess I'm going off topic, ignore if so.

[Pommy Chris]

Tested today at 600 yards, 60 with 6 X's in windy conditions. No visible elevation at all.. I lest last round in the chamber for a few minutes on purpose, I actually sat up and had a chat to "cook" the round, the last shot was 3fps faster than the shot before and it was another X.
How much is not the issue anyway, the issue is how big is the node and does the hotter temp put you out of the node. The answer I am not sure but the three loads I shot with win 760 were 50.3, 50.5 and 50.7 and they all grouped really well so it seems from these tests that the node is quite wide.
Not trying to reinvent the wheel as it was said earlier (hard with a powder that has been around for 50 odd years), but this barrel simply would not shoot with 215's, but it is tack driving with 215's and win 760.
Chris

[Pommy Chris]

Chris, I have been saying for years that 215’s are in the outer limit for .308’s and accurate shooting, there is reasons for this that I’m not going to divulge publicly but I’m sure I’ve discussed them with you.

This is the reason I have zoned in a settled on 200’s in a permanent basis.

The other thing I would say you should re-check is your figures on how temp effects velocity, I think your figures are very conservative.

Numbers are correct for better double base powders, but I will be doing my own tests.
I think there are two things at play with 215's, basically 2208 is too fast for 215's and 2209 is fine but there is not really enough room in the case without compressing the powder big time.
The other issue is gun control with 215's, myself and a few others have shot them a lot so had a lot of practice, but I believe it is an issue for many shooters so lighter bullets are a safer bet as the ofdd bad shot costing a five is not going to win comps.
I have a few barrels that love 215's with 2208 and one that I need to beg Betta for which is a stunner . I wont be messing with their loads they just come out for Queens. That said I have a lot of barrels that just dont like 215's with 2208 with any load, I picked one at random for this test, cant argue with the groups or a 60.6 in strong switching winds.
Chris

[Pommy Chris]

Ok did some temperature stability tests today.. First prep for last test was to remove one round from the second detail and put it in the sun to be shot at the end of the day. The rest of the ammo was kept cool in the shade. Next tried cooking a couple of rounds in the chamber for a few minutes, the first time I tried the shot was 1fps lower than the previous shot and the second time it was the same speed so no difference at all here.
We started shooting about 920am and I shot my second detail around mid day. Around 30 minutes before my shoot I wanted to get the round in the sun hotter so we decided to put it on the dashboard of John Anderson's car as it was seriously hot in his car and it was in direct sunlight. I shot my detail and speeds were 2694- 2696 mostly which is very good indeed, the last special round I jumped up and retrieved it off the dash of the car, man this round was even hot to touch!! I loaded the round and shot it, the velocity?? 2704!!! This round was stinking hot and the velocity was only 10fps faster than the rest using an apparently temperature unstable powder! I know for sure I have never shot a bullet ever that was this hot so from this test at least this supposedly heat stability issues with ball powders at least win 760 is rubbish. I intend to do some more tests with a few rounds next time one on ice and the others heated. I will also try some adi loads to see how they perform, I suspect even the stable adi powder would have given a higher velocity when the round is hot to touch..
Chris

[Gyro]

Nice work Chris ! It's certainly a very important part of precision shooting.

I went a little OCD on it once and made a little heating unit that allowed the mound ammo box to be kept at a set temp. The loaded rounds were contained in an insulated solid block of ally with drilled holes and that block when lifted off the heater kept the ammo at a stable temp for ages.

Ticked that box !!!

[Pommy Chris]

Nice work Chris ! It's certainly a very important part of precision shooting.

I went a little OCD on it once and made a little heating unit that allowed the mound ammo box to be kept at a set temp. The loaded rounds were contained in an insulated solid block of ally with drilled holes and that block when lifted off the heater kept the ammo at a stable temp for ages.

Ticked that box !!!

I shared a room with Tim when we shot Lower Light, I was a little alarmed when he plugged his bullet warmer in at the foot of my bed electric heating elements and bullets what could possibly go wrong?

[RDavies]

Nice work Chris ! It's certainly a very important part of precision shooting.

I went a little OCD on it once and made a little heating unit that allowed the mound ammo box to be kept at a set temp. The loaded rounds were contained in an insulated solid block of ally with drilled holes and that block when lifted off the heater kept the ammo at a stable temp for ages.

Ticked that box !!!

I shared a room with Tim when we shot Lower Light, I was a little alarmed when he plugged his bullet warmer in at the foot of my bed electric heating elements and bullets what could possibly go wrong?

That could make an effective alarm clock. . This is not the first time I have heard of people do this with ammo to keep it UP to a stable temperature, not down as some suggest for some reason.

It might be a handy solution if we start getting a steady supply of RS52 powder into the country.

[Pommy Chris]

I played with temps again at the weekend and the big difference was cold. The bullets were kept in a bag with ice blocks and the shot was a very low 4. The hot was just a high 5 but this time the round was so hot I could hardly handle them so I think adi powder would have given similar results. Leaving the round in the chamber for ages seems not to really matter, but extreme changes do especially cold so I agree a bullet warmer would basically eliminate any temperature stability issues.
Chris