Accurate ammo on Dillon 550


Whopper Stopper
January 2, 2007, 09:41 PM
Just wondering how many load for long range precision shooting on a Dillon 550. I am setting up for some 1000 yard shooting and currently own a 550. So far I am a long way from 50 an hour. For me it seems there is a lot of tinkering around ( for instance today it took over 45 min. to get the powder to drop consistantly using H 4350). Do any of you use it strictly as a single stage one at a time press? I am wondering if I should just pick up a single stage or continue on with the Dillon. Can you win matches loading on a Dillon? They (Dillon) claim you can. Thanks for any comments, all are welcome.


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Father Knows Best
January 2, 2007, 10:34 PM
Can you? Sure. Will you? That depends on a lot more than what press you are using.

I load rifle ammo for matches on a Dillon RL550B, but I'm not exactly a serious competitor with the rifle. My matches are local club matches with nothing but bragging rights and a beer tab on the line. I load 6.5x55 for my Swede and .30-06 for my 03A3 and M1 Garands using the Dillon.

My advice is that if you are serious about top quality ammo, get a single stage. You'll be loading in small enough quantities that the progressive aspects of a 550 will be more of a pain than they're worth. My Dillons (I have three, actually) are mainly used for loading pistol ammo and shotshells, and I load both of those by the tens of thousands of rounds. I develop rifle loads, and so small batches of rifle ammo, on the single stage.

January 2, 2007, 10:37 PM

The Dillon powder measure doesn't work well with all powders, which is probably some of your problem. Since you already own a 550, I'm not going to suggest buying a Hornady LnL because the powder measure is better. But here are some reasonable solutions:

1. Select a powder that'll meter better in your 550's measure.

2. Buy a Hornady LnL powder measure and case activated powder drop and use it, along with the rifle micrometer insert, for loading rifle (No inserts needed) on your 550. I know many folks who's done this quite successfully because it handles powder well and is quick and easy to adjust. You can also use an RCBS Unflow, but the Hornady has a larger powder bins, so you don't have to fill it as often. (I have both.) The LnL measure meters most rifle powders very accurately for me, including 4895. I think it'll handle your powder just fine.

Finally, the 550 (One of which I used to own.) does pretty well for the most part at the shorter ranges. But when I reloaded for High Power, I used a single stage press for the 600 yard line and didn't know anybody who didn't. But I also used a heavier weight bullet and a very different load for that range as well.

I hope this helps,


January 3, 2007, 05:19 AM
The Dillon pwder will do just fine with any powder IF you are willing to put as much effort into it as you would with making long range ammo on a single stage.
The drop tube is the most common issue with the Dillon measure. Take the measure apart completely and polish all the inside surfaces. If this doesnt help a lot PM me. I have a bucket full of ways to make it better, and only 1 of those will have cost involved. Much less cost than cobbling a Hornady or other measure onto your press. Which tends to be the same problem in a different color.
Kiss your warranty good by if you do the following Mod to your press:
This is done to stabilize the toolhead. Remove the two pins that keep the toolhead in place. Drill and tap the 2 holes in the toolhead for either 6-32 or 8-32 tap. Drill the two holes in the top of the press to accept the appropriate screw. Install the toolhead with the 2 new screws and just snug them so the top of the toolhead is in firm contact with the press. This helps with more accurate bullet seating and makes a more consistant cycle of the powder measure. I do not shoot long range compettition. I do shoot long range PDs and such. My powder measure drops well within the standard plus or minus .1, and unless you are using a lab grade scale you probably cant realisticaly measure better than that anyway.

January 3, 2007, 06:49 AM
"I have a bucket full of ways to make it better, and only 1 of those will have cost involved. Much less cost than cobbling a Hornady or other measure onto your press. Which tends to be the same problem in a different color."

1. You don't have to cobble a Hornady or RCBS measure onto a 550. Installing it is as easy as installing a die. In fact, the bottom half of the mechanism is essentially a die. Since many folks buy extra measures for their Dillon toolheads anyway and the Hornady & RCBS costs about the same as the Dilon powder measures, it's a minimal cost option and is normally done. And both of those measures will already have the performance gotten from modifying a Dillon.

2. Once installed, there is NO problem. You clean it and start using it like you would if it were sitting on your bench. Simple and easy to setup and use.

"Kiss your warranty good by if you do the following Mod to your press:"

Losing a lifetime no BS warranty is perhaps the most expensive modification to a press I can think of. Less than a hundred bucks for a powder measure setup or lose forever your ability to get Dillon warranty support. Not a hard choice to make.

January 3, 2007, 06:54 AM
I don't shoot long range so I can't contribute much there, but wrt to the mod to lock down the toolhead . .there's a kit out there from Uniquetek (I believe) which will do the same thing and will only require you to modify the toolhead and not the press so the most you'd be out is the cost of the kit and the toolhead.

Just my .02

(I don't know what type of accuracy is required for the shooting you do and I imagine it's much higher than what I'm shooting but I regularly get under 7/8ths of an inch at 100 yards using it as a progressive and not doing anything like weighing my cases, weighing my bullets, etc. FWIW)

Have a good one,

January 3, 2007, 12:07 PM
IMO you're never going to achieve the consistency you want with any of the powder measures using an extruded power, which if I recall is what H430 is. If that is your powder and you want tight tolerances I would suggest a digital dispense and scale setup or I would look at changing to a spherical or flake powder if you want consistency using a powder measure.

By the way Dave suggestion won't affect your warranty. I use a RCBS Uniflow powder measure with a baffle and on ball powder I never see a deviation on my scale (like mc223 said the scale can only see .1) and on flake powder I occasionally see 0.1 grain deviation. I check my charge every 25 rounds. However, on extruded powders it can fluctuate 0.3 grains and why I load my 30-06 and 22-250 with IMR3031 on my Rock Chucker and set my powder measure low and then trickle them to target.

January 3, 2007, 12:37 PM
David Tubb loads on a Dillon, so I suspect it will not prevent you from winning. Most guys weigh each charge for 600yds an longer.


January 3, 2007, 04:45 PM
I have the 550 and the Hornady LNL Auto. In my experiences, the LNL powder measur is more accurate and consistent with extruded powders. However, neither is accurate enough for my standards.

I load all rifle ammo on a single stage, weighing each charge. The only exception is the 223 with ball powder, which I prefer to load on the Hornady.

January 3, 2007, 08:03 PM
You guys make it way too hard.

If you're concerned about ultimate accuracy and 1/10th of a grain powder charge, forget the measure and just weigh and trickle your charges, then put the case in the 550 to seat the bullets. That's what I do for my 1,000 yard gun

Actually, I've got a free standing rotary that I use to throw the 1st charge, then trickle up using my PACT with one of the little hour glass tricklers.

If you use long stick powders, there isn't any measure that's going to consistently throw +/- 1/10th. That small of an amount is maybe a few sticks of powder.

January 3, 2007, 08:30 PM
Thrown charges are more accurate than trickled charges anyway. Shoot the ammo and see what it does, that is the ONLY way to quantify if what you are doing is helping or not.

Tapping the holes and locking the tool head down will help if you use it as a turret press. If you load progressively it won't help, the brass in station one and two force the toolhead up against the rails each and every time whether you want it to or not.

I have loaded some 223 that is easily MOA on my 550's, the difference is I was using a short cut extruded powder. I think it makes the powder measure operate a little more smoothly, but I don't honestly remember the last time I used full stick powder in a Dillon to tell how much better it is.

Whopper Stopper
January 3, 2007, 08:33 PM
Thank you very much for the plethora of tips and suggestions. I am still at the barrel breaking in stage so I have not had a chance to test groups. For the most part I have to (want to) stay with the H 4350. It is a tested powder for what I am doing. I will probably try and conquer the powder measure first with a good cleaning and polishing. I will probably have to go the trickler route and weigh each load. I also will wait to see how things work out, but.... getting a single stage press for this might solve a lot of headraces. As was implied I an not trying to set any speed records to begin with, so the 550 may be a little over board for this application. I have other hunting rifles and hand guns that I load for and up to now I have always been satisfied with what the Dillon could do. It was this new adventure into one shot holes that had me wondering. Anyway, again Thank You for the time spent helping me with advice and ideas. I very much appreciate it.


January 4, 2007, 04:24 AM
I'm right up the road from you, across the river near Pine City. Where do you shoot?

Whopper Stopper
January 4, 2007, 04:58 AM
I am a member of the Forest lake Sportsmens club, they have a web site if you Goggle them. It's a decent range that allows you to shoot out to 400 yards. I was born and raised in Pine City. Cripes next thing you know you will tell me you know the Bistrams!

Master Blaster
January 4, 2007, 09:13 AM
If you read your 550 instructions it says that when you lock the dies after adjusting them, you should have a case in each station and the ram raised, if you do this with all the dies at the same time, it will eliminate any varriation because the tool head will be in its optimum position forced up against the frame, just like when you are reloading and the dies will be aligned to the press together.
I only load pistol on my 550, rifle loading is done on a rock chucker. I have trickled loads but I find it doesnt imporve accurracy noticably over thrown charges with .223 or .308 that I shoot.

I stopped trickling and just use my Redding Br powder measure. The reason is that I watched Benchrest shooters using .22ppc at my club, load rounds at the range using a Harrel measure. I asked on e of them why he doesn't trickle, he said that it doesn't improve accuracy any, and that varriations in humidity may actually cause trickling to be a bad thing especially if the rounds are loaded on different days. He also told me that neck turning, weighing cases, and consistent seating are more important.


January 4, 2007, 10:57 AM
Go look at this web site, he has taken the Dillon 550 to a different level.

January 4, 2007, 12:19 PM
Thrown charges are more accurate than trickled charges anyway.

I've never seen a set of targets that showed this is true. The only thing I've seen is that weighing individual powder charges buys you virtually nothing until you get to at least 600yds.

January 4, 2007, 01:49 PM
I've seen is that weighing individual powder charges buys you virtually nothing until you get to at least 600yds.

This is very possibly true but I would like to see some data to back that statement up before it can be filed away as fact. I am not implying you are incorrect but accuracy is really nothing more then the sum and differences of variables. Therefore the more variables you remove you increase your odds for better accuracy.

January 4, 2007, 02:44 PM
I have loaded up 10rds and fired them into one target. Half of them contained powder charges that were heavy by 0.3grs and the other half were light by 0.3grs. They'll go into the same size group at 100 or 200yds that 10 "perfect" rounds would.

I agree that consistancy is good. But charge weight variety just isn't as important as every supposes it is. I've yet to talk to someone that's done a controlled experiment who's said "yes, weighing individual charges makes a siginificant difference in goup size."

January 4, 2007, 04:46 PM
That's good information that you provided. I am sure the type of powder, and the amount of the charge all play a part in how much variability three tenths of grain would make. If you are using say a 30 gr charge with an extruded powder a +/0.3 gr. variance is only a 2% swing and probably not be factor since there are so many other factors in play.

January 4, 2007, 04:52 PM
It's worth finding out what loads are more insensitive to variance in charge weight. I do all my load development with "worst case" componenets. The brass I use are the rejects which are well outside the average and I don't weight the charges. If it won't shoot well, I move on.


January 4, 2007, 11:09 PM
Find a benchrest competitor that trickles each charge, then you will have your answer.

January 5, 2007, 04:21 AM
I do as a matter of know a few of the Bistrams. Jerry and his son Rich, and Dave. But please dont hold it against me. I have only been in this area for 3 years.
Good luck with the 550.

January 5, 2007, 09:40 AM
As I had stated in a previous post that I have been loading match grade ammo in 308 on my Dillon 550B for over 15 years and will put up my ammo against any factory ammo. BTW I am shooting a match grade M1A in 600 yd matches and have won a few with my Dillon and M1A.

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