I am trying to get away from R-22 because of the temp sensitive issues it has and I am looking for something that has an equal burn rate. From what I found IMR-7828 is pretty close. Is IMR-7828 as temp sensitive as R-22?
7828 is actually a bit slower than R-22. Ramshot Magnum would be a good choice for a relatively temperature insensitive powder in that range. Closer to R-22's burn rate you have Hogdon's H-4831 which is one of their "extreme" powders that are supposed to be unaffected by temperature. 4831 is just a tad faster than R-22. Hope this helps. A good burn rate chart to check is on www.ramshot.com . Good Luck,
Dakor, Since about 1986, I have tested IMR7828 in a numerous rifles and bullet weights, and found that although in many instances it delivers the highest velocity, it also is a bit unpredictable and spikey with pressures. It is for that reason that I have never used it in a field load in one of my rifles.
I have also read numerous reports that Ramshot Magnum is temp stable, but it appears from data I have seen to be 2 - 3 grains slower burning than Re22. However, I have not tested the powder, as it has not been imported into Australia.
I have found that my current tins of IMR 7828 which were purchased between 1986 and 1990, seem a tad faster burning than data from some other users.
I have found that Re 22, IMR 7828, Viht N560, Viht N165, Win WXR, AR 2213sc(H4831sc), and the long discontinued W785 all seem to produce Max pressure with load variation of 0.5 to 1.0 grains. As an example, I have listed below velocities obtained at about max pressure with most of above powders with the 69 grain Sierra HPBT in a 22/250AI on 25/08/2003. (Temp 14C, Rem Cases, Rem 91/2M primer:
43.5 Win WXR - 3439 fps
44.0 Win 785 - 3359 fps
44.0 Vith N165- 3378 fps (Near Max)
44.0 AR 2213sc- 3264 fps
43.5 Viht N560 - 3326 fps
44.0 Re 22 - 3416 fps
46.0 Win WMR - 3402 fps
At this stage I cannot recommend a powder that would be temp stable to replace Re 22. H4831sc (AR 2213sc in Oz) is supposed to be temp stable, but the velocities it has produced in many of my tests have been disappointing. Maybe I have had "dodgy" tins. Hope the above helps, Brian.
I have seen a few posts from other people saying that RL22 is temp sensitive. I shoot it in several of my guns and I really cant say that it is any more temp sensitive than any other powder in this burn rate. One problem that it absolutely has is LOT-SENSITIVITY it varies more from lot to lot than any other powder I have ever used. just find a lot that works well and buy 5# to 10# IMHO Hodgdon's EXTREME powders that claim temp insensitivity is a little more hype and marketing propaganda than actual reality.
IMR-7828 is a great powder also but your gun might not like it. It is more consistant from lot to lot though.
It takes 43 muscle's to frown and 17 to smile, but only 3 for proper trigger pull.
The problem I am having is I have to have a summer load and winter load with my 6-284 and it is getting old. I have 6lbs of the same lot of R-22. If I work up a load when it is in the 70's or higher when the winter rolls around and she gets down in the teens I can lose as much as 100fps. I am even using a fed 215 primer. I have used H-4831 but it does not seem to work to well with anything over 95gr bullets. I need something a little slower when I step up to the 105 or 107gr bullets. I have been playing around with H-1000 but it seems a little slow for the 6-284. I will say the Hodgon powders do not very much in fps between winter and summer in any of the rifle's I have tried them in. The most I have seen is 25 to 30 fps loss and that was below zero. I just need something that is either as slow or a tad slower then R-22 and a little more stable. If the climate I lived in stayed within 30 to 40 degrees between summer and winter it would not be a problem but that is not the case in ND. Maybe I am just searching for something that is not out there. I would like to try ramshot but I would not even know where to find it around here. Even cabelas does not have it.
Dakor, Summer and Winter loads are a fact of life for many of us, and with some bullet weights in my rifles, I cannot avoid it, with the powders I have at my disposal here in Oz.
Although there have been 4 days over 41C (106F) during the last week in Adelaide in South Oz, I never hunt or test when it is that hot, and my hunting temperature range would be 0C - 35C.
Also, I agree with UncleB's comment that Lot to Lot variation is also a major issue with many powders, including the so called Extreme Powders, many of which are manufactured by ADI here in Oz. Also, I remain to be convinced as to how insensitive the so called "Extreme Powders" really are.
However, I agree that H1000 seems reasonable, but I have recently exhaused my supply of it, and replaced it with AR2217,which according to ADI is the same powder.
Custom 25/06AI- Nosler 115BT, Rem Cases, Rem 91/2M Primer
63.0/H1000- 3,236 fps - 20C (Near Maximum)
63.0/H1000- 3,271 fps - 30C (Maximum)
I quickly discovered that I had to drop my maximum load in my 25/06AI with Nosler 115Bt from 63.0/H1000 to 60.0/AR2217. So there is obviously significant Lot to Lot variation.
I searched my records for data with IMR 7828, and found that in 1988 I worked up to maximum loads with IMR 7828 in my 25/06AI with the Nosler 120 SPBT, Rem Cases, and Federal 215 primer: The results were:
I also had similar velocity variation with temperature changes using IMR 7828 in a 220 Swift AI, and 224 Clark.
Vihtavour N165 is a tad slower than Re22, but have not yet tested it with wide enough temperature variation to form an opinion as to whether it is an improvement on Re22. Hope that the above is of some help. Brian.
dakor, I'm dont know what side of Nodak you live in, but Ramshot powder is imported and sold by Western Powder Co. in Miles City, MT. You can get their phone number from their website and call them. They will be able to tell you if there is a dealer close to you. Good luck,