I am new here and fairly new to reloading. I have an RCBS uniflow and it will not throw long grain powder like IMR 4350 for my 7mm rem mag.

They advertise like it will throw all powders, but on the instruction sheet it says that it might not consistantly measure long kernal powders. Well mine wont measure them at all, I have to slam the lever up like three times to get it to drop powder.

I dont know if there is something I can do about this or do I need to buy another powder throw?

Thanks
Tanner

tanner
Welcome to the forum. I do not know of any powder measure that will accurately measure long grain powders. I set my measure to throw slightly under the amount I want to load and tricle the rest into the scale. I weigh all my rifle charges.
To be a little more consistant try this. When you raise the handle "tap" it a couple of times at the top of the stroke, lower the handle and "tap" it a couple of times at the bottom. Just be sure you do it the same way each time.

Thanks for the welcome and the help. And yes that is the procedure I use when measuring other powders, but with my IMR4350 it stops about halfway on the upstroke and the grains must be cut in order for the stroke to continue. I have been measuring a slightly lower weight and just addding the rest in my scale pan, just takes awhile. Ohh well guess thats part of it.

Thanks again
Tanner

No harm is done cutting grains, use a "forcefull and consistant stroke", the same each time, quit trying to baby long grain powders..Mine throws pretty consistantly in this manner, enough so that I only weigh every 10 or so..a grain one way or the other means zilch with slow burning long grain powders...consistency is the key and that comes with concentration and practice..

Another option is to use say H414, WW760 opposed to 4350 or another close burning rate powder...

I also have a powder measure baffle in my Powder funnel and that really helps for and easy consistant flow..These are available for $5.00 or so...

If memory serves me correctly that measure comes with two different flow inserts, the green plastic things, make sure you have the one with the big hole screwed in.

I have experimented a lot with the stroke of the powder measure to throw the coarse grained powders accurately. Don't be gentle, give it a hard double tap(after you charge the case), then bring it back down hard and snappy to cut the grains in two. You should be able to throw the charges out of your measure without weighing each charge. With mine, the low to high variation will only be about .3 grains out of a 70 grain charge, and won't affect accuracy.

If you are a handyman you can solve this problem by making a new handle, about 10" long. It will give you enough leverage to cut right through those long grains without the heartache. Otherwise you'd do well to switch to a powder that will meter well. I had this problem with IMR4064. Once it actually came apart on me. What a mess. So I switched to Varget and eliminated the problem. There's usually more than one powder that will serve your purposes.
Best wishes.

Cal - Montreal

The very reason I keep two powder measures on my loading bench (RCBS and Lee) is because RCBS will not, at least for me, allow Consistent charge throws with long-grain powder.

The Lee, with is plastomer construction, is not so critical and will allow much more consistent throwing action.

I don't want to be told to use other powders. I like the groups I've been getting with the powders I'm using. Maybe RCBS should re-think its poder measure design.

As Ray says 'don't baby it". My uniflow will most always throw within 0.10 grains with extruded powders. Just be consistent with your "tapping" at to and bottom of stroke.

When I am adjusting throw weight I throw 4 or 5 charges before weighing. Also keep measure at least 1/3 full.

Wally

The RCBS Uniflow [still with the stock handle] is at the threshold with IMR4895 powder: .032" dia and .056" long.

IMR4350 has even bigger granules: .038" dia and .083" long, per the Harrison and Davis NRA article