Lee 401-175 and 10mm seeking advice on start load

[Strtspdlx]

This is a modified mold so it has a flat base. It ends up at 180gn. Pulled my barrel and measured and standard lube it's 1.235" Max oal and with powdercoat its 1.230". I should probably go .010" shorter because those are to the lands. I'm using titegroup and in Lyman cast bullet 4th start load is 5gn and oal is about .010" longer. So I'm seating deeper with less capacity because of the flat base and more so with powdercoat because the coating takes up space. I was going to start with 4.8gn but after reading I want to be positive this is a good starting point because of the pressures generated by 10mm. After the gun is out of warranty it'll likely go to Doug guy to fix the throat so I can use published data. But the data I used is for an rcbs 40-180-fn. if I remember correctly. If anyone has suggestions I'm open to them. I don't want to do something stupid because I was too stubborn to ask.

[fredj338]

Not sure what you are trying to do but sounds like you just want light plinking loads. Your 5gr is below starting data for 180gr jacketed, so I would think you are fine. OAL is important, but less so when your loads are below midrange. It just doesn't move the pressure needle much. IMO, lead bullets & TG are just not the best choice, but if it is what you have, then go for it.
BTW, I didn't know guns ever really go out of warranty. The good manuf pretty much service them for years.

[reddog81]

If 4.8 cycles the action, is accurate, and the bullets don't jam you're golden.
Since you're below the starting load I wouldn't be to worried about the short OAL effect on pressure. Getting the bullets to seat so they fit the magazine, throat and feed correctly are the most important things to worry about when trying out a new bullet and your loads are below mid-range.
Like Fredj338 above mentions TG isn't the most popular powder with lead bullets in 10mm, but there's only one way to see if it works for your gun and that is to try it out.

I wouldn't worry about the flat base and powder coat taking up extra space. That's bordering on the edge of overthinking it for pistol reloading.

[JonB_in_Glencoe]

I guess I'll pile on here (about titegroup).
Before I started casting, I used titegroup often (for j-words) and I loved it, in all my auto-pistol loads (including 9mm, 40, and 45acp). I'm not sure what it is about Titegroup? maybe it's hot (temperature) burn? or longer pressure curve? but generally caused lead fouling with boolits. I switched to Red dot as well as Bullseye for auto pistol loads and solved the fouling issues and improved accuracy.

[TexasGrunt]

Check the .40 Short and Weak data for the same powder and boolit. Depending on how your pistol is sprung you should be able to use close to top end Short and Weak data.

[Strtspdlx]

more or less I just wanted a good starting point so I can work up and see where it suits me best, I'm limited on powders right now, hopefully I can change that soon and have a little bit larger assortment to play with. I have a few different style bullets also, including 180gn plated and jhp.

[Strtspdlx]

Did you notice fouling with straight lead? was any of it powdercoated? I have some pc stuff I'm going to give a try and see if it works out but I still haven't decided where I'm going to start exactly.


I guess I'll pile on here (about titegroup).
Before I started casting, I used titegroup often (for j-words) and I loved it, in all my auto-pistol loads (including 9mm, 40, and 45acp). I'm not sure what it is about Titegroup? maybe it's hot (temperature) burn? or longer pressure curve? but generally caused lead fouling with boolits. I switched to Red dot as well as Bullseye for auto pistol loads and solved the fouling issues and improved accuracy.

[JonB_in_Glencoe]

Did you notice fouling with straight lead? was any of it powdercoated? I have some pc stuff I'm going to give a try and see if it works out but I still haven't decided where I'm going to start exactly.
It's interesting you ask that.
I haven't stepped into PC yet, and probably never will...BUT, I got some TC-TL style 40 cal samples from another member that were PC'd via the piglet method. Now I got those after I quit using TG, I loaded them using my trusted/successful Red Dot load and got burnt plastic fouling. I should add, that I had that TC-TL mold and would use 45-45-10 and had lead fouling with TG as well as Red Dot with the style boolit... it wasn't until I got the traditional lube groove boolit mold, when I started having success in 40...and I should add, I never tried TG with that traditional lube groove boolit, so who knows? maybe my problem was more about the TL boolit...this isn't something I thought before, it just came to me, as I'm typing this all out.