Question regarding "working up" to max load

[Dan0341]

I will be purchasing a Dillon press in the next couple of weeks and have been reading through the posts on this website. Awesome website! At the same time, I've been reading the Speer Reloading Manual #13. But, I haven't found an answer to my question (although I probably passed over it).

I know that a major rule is to never start with a maximum load. It has been stated that one needs to "work up" in small increments. This is self expanatory, but Alliant's website only lists the charge weight of 4.2grains for the 147gr. I'm assuming this is the maximum grains to be used?

Here are my questions regarding Alliant's recipe:

(1) What would the starting point be if they post 4.2 grains?

(2) Is there a universal formula for starting points when you only see one load posted?

(3)If one load is posted, is this the max load?

I looked in the Speer manual and they do not have a load using Bullseye for the 147grain bullet. I want to use Bullseye powder as it's readily available to me and others have said it works well with my intended application. This load will be used with an open bolt submachinegun (Uzi) and AWCMK9 suppressor.

I know of several people who use 3.5 grains of Bullseye under a 147gr FMJ using Winchester small pistol primers. But, I just don't want to use this as I want to understand "how to" applications of working up a load myself.

For reference, here's Alliant's data page: 147gr Load Data

Thanks in advance for any or all help,

Dan

[rtr]

Dan I'm a new reloader too. The formula I have seen is to start at 10% under the max load, so you would start at 3.8 or so grains and work up. I'm sure some of the more experienced guys here will chime in too.

[Gun Geek]

Yes, always treat a single published number as a max load. Also treat all published data with a bit of skepticism so you can stay healthy.

I use 10% on rifles but on pistols I use 15%. The reason is that on the light weight of the pistol charges, the error in the scale (+/- 0.1gn) can be almost 5% of the charge weight, so the additional 5% can be a huge safety margin. On a 4.2gn load the actual amount is .4gn (10%) to .6gn (15%). At +/- 0.1 gn, you're looking at a range from 0.3gn to 0.7. If you are using very light loads, I'd use 20%.

If you are trying to exaclty duplicate a load, be sure you follow the specs for OAL. Do this if you don't have a chrono and want to be sure you make pf.

If you are developing a load tuned to your blaster, make the cartidge as long as possible (functions in mags, feeds properly, bullet seats firmly). Then start working up until you get the pf and gun function you need - watching for pressure signs.

Welcome to the hobby (obsession). Enjoy and stay safe.

[.40AET]

You may want to try some other powders. Bullseye is the most filthy powder that I have used. I heard that they have been working to improve this, but I have not gone back to it. Look for some fast Hogdon or Winchester powders, they are a lot cleaner than bullseye. Titegroup is clean, fast, and widely used in 9mm (guessed since it's an Uzi). It's also cheap.

[Dan0341]

Thanks for all of the replies. Much appreciated!

Dan

[DogmaDog]

So far in my modest reloading experience, I've started at published starting loads, and loaded several loadings at 0.2gr increments, up to the max load. I've been fortunate enough to find starting and max load data for everything I've tried in one of my reloading manuals.

I'll load about 50 rounds of each load, and then take them all at once to a chrony session. I'll start shooting the lightest load, and watch for pressure signs and function while I chrony, and then proceed with the hotter loads until I reach my target PF.

You should be able to find loading data on powder manufacturer's websites. Winchester, Hodgdon, and Vihta Vuori all have data available.

I'm guessing you'd want to use a small charge weight and a fast powder for a suppressed weapon--that way you'd minimize the gas volume and pressure as the bullet leaves the barrel. Am I correct? Any other reloading considerations for suppressed weapons? (Not that I have any, but I am curious)

I have no idea how you should work up a load for your mortar (60s or 81s?)

Semper Fi,

DogmaDog

[Dan0341]

DogmaDog, you're correct. To get the maximum effect from a suppressor, I need to keep the bullet flight subsonic to avoid the supersonic crack. And I'm looking to reduce the expanding gas from the ejection port. With the open bolt system and the Uzi's heavy bolt, the escaping gas/noise isn't much of an issue. But, I'd like to reduce this to make it as quiet as possible. At the same time, maintain consistent accuracy to about 30 or 35 yards for subgun competitions. Maybe this is asking too much? I may end up making a load that is real quiet and another for competition. I'm still reading and learning and will be purchasing a Dillon press from Brian this coming week (I've never reloaded before). I'm tired of buying expensive subsonic ammo to feed my habit. I also use the same suppressor on my M16/9mm and I can go through it rather quickly.

Regarding pressure signs, what does one specifically look for? I'm assuming bulged cases and or missing primers, but I'm unsure of this. I don't remember reading any specifics or a definition on the issue. When shooting factory ammo, I never had to pay much attention to this.

Good catch on the 0341. I was in a 60mm mortar section. Were you a groundpounder too?

Thanks for the info,

Dan

[DogmaDog]

Dan,

All the subgun stuff sounds pretty cool. Reloading isn't too hard, though it does take some care and patience.

Some high pressure signs (aside from blowing the magazine out of the gun):

burst primers,

flattened primers or primers that look like they've been "burnished" (appear shiny) or have some material sheered off as they slid off the breech during extraction/ejection, or "primer flow" where part of the primer cup expanded into the firing pin hole, and again gets sheared off during extraction/ejection.

Case bulging is more of a function of the shape of your chamber, and any unsupported area in it.

It's usually guys trying to push really light bullets really fast that seem to run into pressure problems. I suspect you won't have too much trouble finding a 147gr subsonic load that won't blow up your gun.

You should try to load your ammo as long as you can in order to maximize the volume inside the case, and minimize chamber pressure. However, don't load so long that the bullets hit the lands upon chambering, or so long that the rounds won't feed reliably.

As far as accuracy, I've had no problems making ammo "accurate enough" for IPSC. I haven't done any rigorous testing with different parameters or anything, but I can get about a 3" group at 25 yards, which is probably closer to my limit than the ammo's.

As for the Marines, I'm still in the reserves. Spent some time as an 0811, then took a circuitous route to infantry by getting commissioned and being a motor transport officer first. Finally made my way to a grunt billet, though, and I'm now leading the Javelins (anti-armor) platoon in a Weapons Company.

DogmaDog (3043-->0811-->3502-->0402-->0302)?!

[Dan0341]

DogmaDog, I appreciate the info.

Thanks!

Dan