.45 ACP minimum safe loads for a 625

[lordpaxman]

Having recently acquired the subject gun for competition, I headed to the range for a chrono session with several loads. I like the way Bayou Bullets 200gr SWC punch clean holes, and Rainier RN 230gr are a good plinking round. Powders were mid to fast, and spanned Clays, Target, WST, Sport Pistol, N320, and 244.
I was shooting for 170ish PF, and was surprised every load in the 625 was about 10PF higher than my P220. And, they were well above 170, more like 185-190.
As we don't want to venture into squib territory, is there a way to know the load is still safe even if it's a bit below a published starting load? We have inherent tolerances in our reloading process so it may happen. For those experienced in Quickload, does it predict a minimum safe load? I've resisted it for quite a bit, but, have asked Santa. Who knows, a Labradar did show up under the tree last year.
Thanks in advance for any advice!

 

[Texas10mm]

Lyman Cast Bullet manual, data for .45 Auto Rim. It goes much lower than .45 ACP data.

Starting loads from the #3 manual which I have a .pdf.

3.0 gr Bullseye
4.0 gr Red Dot
4.5 gr Green Dot
4.0 gr 231

 

[Toprudder]

I had pretty good luck with Trailboss in 45acp loads. I would not hesitate trying those for the 625 (which I have). Be warned, though, that Trailboss performs MUCH better with large primers than it does with small primers. I saw > 150 fps difference between the two. But for my normal reduced recoil loads of 45acp, I prefer Clays.

 

[ATLDave]

Your biggest issues are powder-position variability, a stuck bullet, and lousy combustion. These are all things that can be safely (if cautiously) explored without the same kind of risks as exploring what high pressure will blow up a gun! Start at the minimum load and work down until you get what you're looking for... but fire only one round at a time and make sure there's a hole in the target for every trigger pull! If in doubt, open the cylinder, and shine a light (obliquely) in the muzzle and make sure you can see light from the forcing cone. If you're really going to push down low, you should bring a squib rod with you to your testing sessions. During testing, drop the muzzle down before each shot, to get a worst-case, powder-far-from-primer condition.

But if you're consistently clearing 700 fps doing that, you're likely to be safe from squibs. You may need to play around with powder and crimp to get sufficiently-clean combustion for your needs/wants.

 

[mcb]

If your anywhere near Major Power factor (165+ PF) in a 45 ACP then you are far from squib/stick-in-barrel load levels. Start with good published data and work down slowly. I have loaded 200gr and 230gr bullets down into the low 600 fps going for Minor PF loads when I was running 45 ACP production gun (XD-45 Tactical).

Trailboss works good in 45 ACP for Minor PF but depending on your bullet your going to be right up against max load to make Major PF with Trail Boss. It's not a pressure issue here its a case volume issue and Trail Boss can be dangerous if compressed.

I would think that 170 PF would be between Min and Max charge with many of the OP chosen powders. I also would not be afraid to go a tenth or two under minimum with most of those powders to get the velocity I wanted.

Back in 2011-2012 I started shooting a S&W 625 in USPSA Revolver. This was when powder was really hard to find. I worked up a Clays load under a 230gr FMJ I had to go over Hodgdon's Max change a touch to get to Major PF in my S&W625. I switch to coated lead 230 gr and Clays worked much better. Ultimately I turned to Bullseye for my Major PF 230gr 45 ACP load for my S&W 625. It worked well, was available locally at the time, shot soft, and noticeably cleaner than Clays. That said if the OP has N320 I would work a load up with that. You will be hard pressed to find a cleaner powder than N320. I would have used that at the time but couldn't find it back then and what little I had left was reserved for my 40S&W Major load. -rambling

 

[ArchAngelCD]

Very fast powders seem to produce more of a snappy recoil than slightly slower powders IMO. I would go with W244 since you list it. You should use a chrono to check velocity to be sure no squib. You would be surprised how slow you can go in a revolver without problems and the low recoil will help with control of course.

Please keep us updated.

 

[mcb]

Very fast powders seem to produce more of a snappy recoil than slightly slower powders IMO. I would go with W244 since you list it. You should use a chrono to check velocity to be sure no squib. You would be surprised how slow you can go in a revolver without problems and the low recoil will help with control of course.

Please keep us updated.

OP is going for 170 PF loads that is far from super light for 45 ACP, not full power but far from light. Most competitive shooters (USPSA, IDPA and similar) find that for a given Power Factor a lighter chargers of fast powder has less recoil then a heavier charge of slower powder under then same bullet going the same velocity. I believe we had a long winded thread to that end not long ago.

 

[ArchAngelCD]

OP is going for 170 PF loads that is far from super light for 45 ACP, not full power but far from light. Most competitive shooters (USPSA, IDPA and similar) find that for a given Power Factor a lighter chargers of fast powder has less recoil then a heavier charge of slower powder under then same bullet going the same velocity. I believe we had a long winded thread to that end not long ago.

I was under the impression he was looking for a light load and only referenced the 170 PF he was producing. Of course I could easily be wrong, it happens a lot lol.

 

[lordpaxman]

Thanks for all the replies!

But for my normal reduced recoil loads of 45acp, I prefer Clays.

I need to hit the magical 165 number, for me to be comfortable, that's more like 170. I've found with the 200gr BB SWC, Clays at the max will just make that. OTOH, I needed to load Target below "starting" weight to bring it down to 170. Sport Pistol I'm still way over PF. For this task, I'm not looking for reduced recoil, but would like to know the lower limits or how close to them I am. I do have Trailboss and Hodgdon's reduced recoil papers.

But if you're consistently clearing 700 fps doing that, you're likely to be safe from squibs.

How likely? And, I would think it'd depend on bullet weight and type along with the powder. That's why I was thinking maybe QL can predict this?

If your anywhere near Major Power factor (165+ PF) in a 45 ACP then you are far from squib/stick-in-barrel load levels.

That's what I would hope, but, would like to know how near, and what are the variables. I had a squib once when plated bullets first came out and they said to use lead data (have since said use jacketed data) with .38 special, TG and the starting charge weight. It's not a problem to deal with a squib when chronoing, but I don't want to when run and gun time comes.

I would go with W244 since you list it.

I'm starting to like 244 more and more, but I do prefer WST in .45. I go by that "variety is the spice of life" adage. That, and, I want to be somewhat prepared for the next powder shortage and have a few bases covered.

 

[ATLDave]

How likely? And, I would think it'd depend on bullet weight and type along with the powder. That's why I was thinking maybe QL can predict this?

That's what the experimentation/testing is for. It's going to depend on stuff like your barrel. A round that will clear the barrel on a 4" revolver with a tight B/C gap might stick in one with an 8 3/8" barrel with a looser gap. You work your way down, testing a decent number of rounds in all powder positions. With your labradar, if you start seeing some come out at 50+fps slower than others loaded with the same charge and data, that may be a good signal you've gotten into a wonky range.

But, from my experience, there's a lot of room at the bottom. I've got a S&W Model 19 that I regularly use to launch 38 special projectiles at a speed that makes the bullet visible in flight over 30 or 50 feet (as a copper streak) in the right lighting.

 

[mcb]

That's what I would hope, but, would like to know how near, and what are the variables. I had a squib once when plated bullets first came out and they said to use lead data (have since said use jacketed data) with .38 special, TG and the starting charge weight. It's not a problem to deal with a squib when chronoing, but I don't want to when run and gun time comes.

As I said I have run 230 gr down to just over 600 fps without any squib issues. I looked at my database and I have used W231, Trail Boss, and Clays to launch 230gr FMJ at 620-640 fps. I have used Trail Boss and Titegroup to shoot 200gr LRNFP at ~700 fps. If you already have safe loads that are well above you targeted 170 PF just work down slowly in small increments. The loads I mentioned above were all ~140 PF loads and never had a squib issue. I would take your current 185+ PF loads make a few. Back the powder charge off 0.2 gr (0.1 if you're the really nervous type) make a few more, do that again and make a few more. You will have three loads, your original, a -0.2 gr and -0.4 gr load. Chrono each load and plot the resulting data, charge weight vs average velocity, in Exel or similar. Do a linear regression fit and you should be able to interpolate/extrapolate the powder charge you need to get the velocity/power factor you want. Obviously checking that these loads are still under the maximum charge for the components you are using.

QuickLoads is a good useful program but it will not predict a squib situation well. The combustion simulation it uses does not work accurately at really low pressures and the barrel friction which would be critical to squib/stuck predictions is very hard to model and very particular to each gun. Those two issues makes QuickLoads a less than reliable predictor of a squib.

 

[lordpaxman]

That's what the experimentation/testing is for.

Will do. I’ve been doing this, it’s just a matter of how far to go, and, how to know you’re in dangerous territory. By that I mean you can reload per your process and the tolerances and be squib free. I’ll be sure to look out for the wonky loads.

QuickLoads is a good useful program but it will not predict a squib situation well.

That’s good to know. I still have it on Santa’s list, but, I can understand the limitations of the model. Thanks for the FPS/PF numbers, it’s nice to know some data points to keep that in mind as I’m developing these loads.

 

[jmorris]

You can go pretty low. I shot SSR for years with cast/coated Precision 230’s at 130 PF, 2.8 gn of Clays just over 550 FPS (you could see the bullet on its way).

Even though 550 is slow, it’s pretty far from being stuck in the barrel. Shot many thousands of them before switching over to 45 GAP brass because it can be mooned/demooned without any tools and the SPP allows a lighter trigger pull while retaining 100% ignition.