Question about 45 colt blow back

[SamGoldstein]

I reload my 45 Colt rounds. Usually I do 8.0 grains of Unique for a 200gr or 250gr bullet. I've noticed a lot of burnt powder on the casing almost halfway down the brass on one half of the case. Is this because I need to anneal the case mouths? Or is this not enough powder? Too light a bullet? I read that if I anneal the case mouth it reduces the life of the case. I have never annealed any 45 colt case, and I've reloaded them many times. I don't even think pistol brass is normally annealed. I'm using Starline brass. Any help appreciated.

[JagerDog]

That's pretty light. Alliant lists 9.5 gr.

Aside from sooty brass, it's really not an issue though.

[SamGoldstein]

That's pretty light. Alliant lists 9.5 gr.

Aside from sooty brass, it's really not an issue though.

9.5 grains is pretty heavy load for a handgun. But I'll try it for my rifle.
I use LRNFP at about BNH 12-15.

[MongooseV8]

Unique is a dirty powder. You can try adjusting your loads to minimize it but Ive never totally gotten rid of the soot.

[fast54vw]

[Pablo5959]

That's pretty light. Alliant lists 9.5 gr.

Aside from sooty brass, it's really not an issue though.

I believe Alliant list are do not exceed loads. Reduce by 10% for starting loads.

[Sandspider500]

8gr of unique is a pretty light load with a 200gr bullet, probably somewhere around 8,000 cup and for a 250gr lead bullet somewhere around 12,000 cup. You can bump your charges up a bit but you're still going to have soot on the cases. Just tumble em.

[slamfire1]

I run 8.5 grains Unique with a 250 and still get case sooting. This is not unexpected based on two things: brass reaction, low pressure of the cartridge.

I don't know this for sure, because I have not seen an analysis or test of the reaction of the case walls, but I believe that soot comes about because the case is either relaxed off the chamber walls as the pressure increases, or is relaxing off the chamber walls as pressure decreases. I think it is the latter

Notice the soot on these once fired 45ACP cases. These are light target loads, and what do you know, soot.



this case design only functions because the front of the case relaxs off the chamber walls so quickly, that it does not stick, while the case is being extracted.



Let me discuss something that was driven out of the shooting community by frauds such as P.O Ackley, who essentially claimed the cartridge case is a structure member, there to "reduce bolt thrust". There is a wagon load of psuedo science in the shooting community about cases. A cartridge case is a gas seal. It also holds the bullet, powder, and primer together. It took centuries for the manufacturing and materials technology to develop such that shooters no longer had to pour powder and ball down the muzzle. Self contained cartridges are a wonder. But that brass case is simply a gas seal, in operation, sealing off the back end of the barrel from gas release. The pressure curve increases, and then it decreases, and the brass is reacting to the pressure changes on both ends of the pressure curve.

While the cartridge case seems strong, that is merely our monkey brain in operation. Your monkey brain was evolved in a 14.5 psia atmosphere and has no concept of what happens in a 15,000 to 65,000 psia world. So, to the monkey brain, the brass case appears strong. The monkey can't bite through the case with its teeth, can't crush the case in its paws, therefore the case appears strong to the monkey. However, in a 15,000 to 65,000 psia environment, the brass case is not really strong. It has to be supported by the chamber or it will rupture. Only the case head is strong enough to hold a little pressure by itself, and it can't take much, it still has to be supported, at least the pressure vessel part.

I have talked to guys who own and shoot M52 S&W's. This is strictly a 38 Special wadcutter pistol and the case sticks so much out of the chamber



that loads above 2.7 grs Bullseye w a 148 LWC bullet, will burst the case head. There is a lot of unsupported case head in this picture.

The next issue, low pressure cartridge. You want clean burning powder?, you do it by raising pressure and temperature The combustion of propellant is inherently inefficient. There will always be a certain amount of powder that is not combusted, or partially combusted. The best way to increase powder combustion, and reduce soot, is by jacking the pressure way the heck up and getting gas nice and hot!

I do have to say, powders that are clean burning, are also fast burning and hot. One example is Titegroup, which has a reputation for kabooms. Clean and fast burning powders are not tolerant at maximum loads. A little too much powder in the case, and kaboom! Oh sure they are clean burning, but they get that by having a fast pressure curve rise, and by being hot. Hot powders will burn out your barrel faster than cool powders. Not really a problem in pistols, but was historically an issue in early smokeless gunpowders. Some of the early stuff was hot and erosive and ate rifle barrels.

This is Unique, the load was a 240 LSWC 8.5 grains Unique, 44 Magnum brass, about 1000 fps in this pistol.



And there is soot on the cylinder. And there was soot on the cases. But the load is accurate, powerful, and I can clean my cases in a tumbler, and I can clean the pistol with bore cleaner.

this is a 45 LC with a 250 LRN, 8.5 grains Unique. Also sooty, pistol and cases. But I just have to clean it off.



Don't OCD about cartridge cleanliness, as long as the case seals, the bullet goes where it is supposed to go, the world is good.

Wish I could shoot this good.



this shooter had a President's 100 patch on his uniform. And so did most of the guys around me. They were amazing shots.

[hermosabeach]

Brass gets harder as it is worked. Over time this leads to cracks between the hard area and the softer areas.

With a bottleneck cartridge, the shoulder is where one anneals the brass so the cartridge is less likely to have the brass split in 2 horizontally.


Pistols and revolvers don’t work the brass the same way as most are straight and most have a lot less pressure than a rifle round.

I have to use the word MOST as there are handgun rounds with necks...
357 sig
5.7
7.62 x 25

Lost goes on and on...



Anywho - that is my longer attempt at explaining why annealing your .45 LC is not the solution you need for powder marks on the outside of fired cases.


Have you reloaded with gas checks? Do these help?


Have you measured your chambers? Are they match tight or Glock sloppy?

[hermosabeach]

The lead wipe clothes by birch wood Casey are a must in my cleaning kit

Super easy way to clean carbon off the end of a cylinder and out of a cylinder and forcing cone

[pennstater]

OP, 8.0-8.5gr Unique has been a standard for the .45 Colt for a loooong time. Try a slightly tighter crimp; not a lot, slight. It worked for me. I still get a bit of soot, but, not like before. Also, do you have any Universal on hand? If so, get back to me.

MLC

[AtomicOrange]

Is this a new development, or have you always seen the soot with that load and gun combo? I have only experienced that with light loads (not expanding the cases and sealing well) and slowish powder. Maybe try a different powder or charge. As already mentioned, Universal works really well in .45 colt, in my experience. Loose cylinder chambers could also contribute to the soot?

[golfish]

OP, 8.0-8.5gr Unique has been a standard for the .45 Colt for a loooong time. Try a slightly tighter crimp; not a lot, slight. It worked for me. I still get a bit of soot, but, not like before. Also, do you have any Universal on hand? If so, get back to me.

MLC

I wonder how the BE-86 does?

[JagerDog]

I believe Alliant list are do not exceed loads. Reduce by 10% for starting loads.

This is reduced 15%. Light load issues are to be expected with light loads.

And just "cowboy action" loadings.

Nowhere near "Ruger" loadings, albeit OP didn't spec his pistol (or rifle).

If you just want mild loads, I'd go to a faster powder.

[bruce381]

"Let me discuss something that was driven out of the shooting community by frauds such as P.O Ackley, who essentially claimed the cartridge case is a structure member, there to "reduce bolt thrust"

please explain this more I thought that is true in that the case holds onto the chamber wall until the pressure drops which does reduce bolt face loads. like I was always told to keep chamber dry of oil or the case would slam back on bolt and cause problems is that wrong?