RCBS uniflow very inconsistent with N140?

[Pesty]

Hi guys,

Yes first time putting powder in tonight but I'm pretty sure I get the working of it. It's very close to something I do daily for work.

I tried it with the baffle, without the baffle, hopper full, half full. I tried tapping the hopper before every throw. I tried fast throws, slow throws. No matter what I could not get a consistent weight.

From 38.8 to 40gr were the extremes was typically getting 39 one throw 39.4 the next seemingly at random.

Every case was zeroed. I even checked with the calibration weight before every round so I'm pretty sure it's not the scales.

I did buy the powder measure from eBay wondering if that's why he sold it or if maybe N140 is hard to dispense.

Any advice welcome.

Cheers.

[snayperskaya]

I had the same issue with a Lee Perfect Powder Measure with N140 so I just weigh each charge on a balance scale.I believe some powders meter better than others but someone with more experience may be able to tell you more.

[saddler]

SOME of the longer grain powders are a slight problem in some measures

For the Uniflow check out the "hints & tips" on the Brian Enos forum - or, to summarise the advice there - strip the press & polish the internals to a mirror shine.

[WelshShooter]

Stick powders, like Vihtavuori N140, don't meter very well in RCBS uniflow powder measures. I have the same powder measure and cannot throw consistent powder charges using Reload Swiss powders which are also stick powders. Three out of five charges would be good, but the remaining two out of five charges would bind the meter half way through and I had to give it a bit of force to finish dispensing the powder.

There's two alternatives. The first is to throw a light charge and using a powder trickler gradually trickle the remaining powder up to the selected the load. The other is to buy an electronic dispenser that does this for you (e.g. RCBS chargemaster, Lyman Gen6). I use the latter method and I get consistent enough powder charges that vary by ±0.1gr which is acceptable for me and is quicker than hand weighing every charge.

[ovenpaa]

You cannot accurately throw N140 with a culver type powder thrower, they are better suited to spherical powders.

[dromia]

The trick is consistency of operation combined with feel, Consistency has to be learned and using any volume powder thrower is a skill that has to be acquired. In regards to feel you must be aware of the cutting of any powder and when you feel any resistance, crushing or cracking then that charge will not be consistent and needs to go back into the hopper.

I have a Uniflow mounted on my Ammomaster progressive and it throws N140 very consistently but then all mechanically operated throwers seem to, I think the mechanical linkages helps even out inconsistencies of operation and gives better charge variations.

[The Gun Pimp]

Check out the Harrel powder-throwers - they cost around £200 but hardly more accurate than the RCBS. The best it will do is around 0.3 of a grain.

Most benchrest competitors rely on a Harrel however - for 100 yards but, beyond that, we weigh every thrown charge.

It all comes down to the level of accuracy you are looking for.

[Pesty]

Thanks guys

I'll polish the internals then play some more with technique. Possibly try a different powder next time. For my use not sure it's worth paying so much for a powder measure just yet. Still have guns to buy. Will put one on the Christmas list.

. I use the latter method and I get consistent enough powder charges that vary by ±0.1gr which is acceptable for me and is quicker than hand weighing every charge.

Interesting as these were my first I was trying to be precise as possible measured every round and weighed every round till it was exactly the grains I was looking for length etc. Guess I can increase my tollerences.

[The Gun Pimp]

A powder-thrower is just that - a thrower.

Throw the powder-charge into your scale's pan and adjust as necessary.

Within a tenth of a grain is good enough for most shooters.

[WelshShooter]

Thanks guys

I'll polish the internals then play some more with technique. Possibly try a different powder next time. For my use not sure it's worth paying so much for a powder measure just yet. Still have guns to buy. Will put one on the Christmas list.

. I use the latter method and I get consistent enough powder charges that vary by ±0.1gr which is acceptable for me and is quicker than hand weighing every charge.

Interesting as these were my first I was trying to be precise as possible measured every round and weighed every round till it was exactly the grains I was looking for length etc. Guess I can increase my tollerences.

It comes with experience mate. I was the same starting out where I made sure ammo was loaded identically. Experience will tell you how much tolerance is acceptable for your application. My 6.5x47 lapua shoots great no matter what load I put in it whereas my 223 and 308 are a little bit more sensitive to variations in charge weight.