What is LT-31??

[Richard]

I asked Bro D but I can't remember exactly what he said. I remember is was half and half but don't know if that was by weight or volume.
Don't know if I'll go there or not, used N-133 forever and pretty well know how to tune it. But it does sound interesting enough to play with at some point.

Richard

 

[Boyd Allen]

Since they are so closely matched in density and grain shape, I doubt that it matters whether you go by weight or volume. I would be sure to devise a very good method for mixing, like doing a slow simultaneous pour into a single funnel, and then rolling and tumbling the receiving container for some time.

 

[Mike Bryant]

Richard, he mixes it half and half by volume. It would be interesting to do that and then weigh each part and see what it weighs.

 

[Richard]

Ok

Thanks for the info.

Richard

 

[Bro.D]

Lt-31

Mike is exactly right...I mix 50/50 by vol. Let me know how it works for you. Bro.D

 

[rkittine]

OK, is this Half LT30 and Half LT32 to get LT31?

 

[Bro.D]

Lt-31

Yes...half LT-30 and half LT-32 by vol give LT-31. Bro D

 

[pablo]

Richard, he mixes it half and half by volume. It would be interesting to do that and then weigh each part and see what it weighs.

Mike, the LT 32 is a little heavier, not much. I've been told that 32 is 30 with retarder on it.

 

[Woody]

Yes...half LT-30 and half LT-32 by vol give LT-31. Bro D

Does it really matter if it's weight or volume, as long as you do it consistently? It would seem that the only difference would be you'd get LT 30.993 or maybe LT 31.011 depending on your choice.

 

[Bro.D]

Yup...

Woody I think you are right. ✌ By vol is just the way I have done it. Bro.D

 

[Gene DeLoney]

I mix it half and half by weight. Be sure to mix it well however you do it. Lou M. recommended starting load of one Gr. less than whatever you were using of LT 32. For me that was 27.4 of the LT 31.
Side note: Shooting that load and Berger Column bullets produced the Light Grand win at the Cactus for me.
Gene

 

[JerrySharrett]

Do a 'bulk density" test then you will know. Bulk density is "weight per unit volume". i.e. fill a container with Lt-30 then weigh it. Now fill the same container with Lt-32 and weigh it. If both weigh the same, mix the powders either way. A new 12 gage 3" hull works well. Any container that is at least twice as tall as it is wide works best.

Having shot many powder mixes over the years I have found the most important thing for load consistency is to thoroughly mix the blends.
Never try to mix powders with greatly differing granules, stick vs ball, etc. Some folks load duplex loads but that will not work for maximum accuracy loads.

Putting the mixes in a clean case tumbler then running it OUTSIDE for an hour or so seems to get the job done.


.

 

[Dave Coots]

Question

What is to be gained by mixing?

 

[Gene DeLoney]

Do a 'bulk density" test then you will know. Bulk density is "weight per unit volume". i.e. fill a container with Lt-30 then weigh it. Now fill the same container with Lt-32 and weigh it. If both weigh the same, mix the powders either way. A new 12 gage 3" hull works well. Any container that is at least twice as tall as it is wide works best.

Having shot many powder mixes over the years I have found the most important thing for load consistency is to thoroughly mix the blends.
Never try to mix powders with greatly differing granules, stick vs ball, etc. Some folks load duplex loads but that will not work for maximum accuracy loads.

Putting the mixes in a clean case tumbler then running it OUTSIDE for an hour or so seems to get the job done.


.

I use a scale that has a tare weight function. Set an empty container on the scale, zero, and then fill the container with 1 pound of LT30. Put that into the mixing container. Refill with 1 pound of LT32, put that into the mixing container then blend. I found that using a square jar for the mixing turned around and around for a while mixes the two quite well.
Gene

 

[Gene DeLoney]

What is to be gained by mixing?

By mixing the two you can get the same velocity with about a grain less powder.
A grain less will put the powder level down in the neck thus avoiding a compressed load.
Gene

 

[Dave Coots]

I wondered if that was the case. I've shot 29.4gr of Lt32, lot 1, 2, and 10 for a few years. I dump my pan of powder into a funnel with a 2" drop tube and do not have a compressed load. Might not happen directly from the measure though. I'll check that sometime.

Later
Dave

 

[CubCouper]

We started mixing up LT31 when we found that Lot 10 of LT32 seemed too lethargic to be useful... I had 4 jugs of the stuff and decided to try and salvage it. Cut in some LT30 and it suddenly was a game changer. Mixing wasn't really necessary with Lot 1,3, or 6 -- they were hot enough on their own. I haven't tried the newer lots yet.

My overall observation was that a mild load (27.3 down to 26.9) would cover a whole day from 45-50 degrees up into the mid 90's. Best part was no big blow-up if you missed an adjustment... when 133 goes out of tune you get a .375, when LT31 goes out of tune you get a .275.

 

[Dave Coots]

Ok 29.4 gr of lot 10 was 3475 on a Labradar. I dropped 29.6 of lot 10 today with a 6" drop tube, half way up the neck. So??? PS..I edited my post from 3375fps to 3475fps. I have no problem mixing powder.. . when there is a reason to do so. I don't see one in this case.

Later
Dave