new reloader, a few questions

T

tedbeau

New member
I just got my equipment set up and have a few questions.

1. When I ran my first batch of cases through my tumbler, as I was emptying it I found a live round in with the brass. It must have gotten mixed in when I picked up brass at an IDPA practice session.

I know powder shape and surface area affects the burn rate and pressure, so would the case being in a tumbler for 2 hours beak down the powder? I would think it might, and cause it to burn differently. Would it be safe to shoot a round that's been vibrator tumbled?

Secondly I want to eventually load light charges for shooting IDPA. Since I shoot 40S&W 180 grain bullets, I need to be above 700 fps to make power factor. I don't want to go to far from this because I shoot the sub-compact Glock 27 and want to keep recoil manageable.

The minimum charge the data I find 4.4 grains of HP-38 at a speed of 872 fps. I want to reduce the charge to get it slower. But my Lyman reloading book says to be careful if using less than the minimum starting powder charge. Other than the gun not cycling, or a squib stuck in the barrel what are the issues with lesser powder charges? The Lyman book makes it sound like it could build to much pressure. Is this possible?
 
Welcome to TFL. We're glad to have you on board.

I've accidentally tumbled live rounds. And some people do it intentionally (mostly rifle loaders, to get the lube off and otherwise make them spiffy looking after the loading process is complete). The tumbled live round will be fine. Go shoot it.

As far as getting your velocity down to just make PF, are you using lead, or plated/jacketed bullets? Because with lead, you can do it with little fear of a stuck bullet. Plated or jacketed is more concerning - but shouldn't be a problem either. Lead has quite a bit less barrel friction than plated or jacketed. Either way, assuming you have a chronograph, you can start at Lyman's minimum charge (or other reliable published data), and work down to it. You'll definitely want to use a fast powder - like W231/HP-38 - something that pops fast and consistent at low pressures.

IDPA has their power factor set to be achievable with most common guns properly cycling, etc. So you're not the only guy doing what you're trying to do. And I doubt that the IDPA gods - all shooters themselves - would put PF so low that stuck bullets could be a problem.

I shoot IDPA, but I shoot SSR (Stock Service Revolver), so I only need to make a PF of 105 ;)
 
Any time the published data is being ignored, you're on your own.
As to whether a powder load of less than the minimum in the load data can cause pressure problems:
It might depend on how much powder is actually in the case.
The less powder that's being used, the more it can spread out inside the case and possible cause strange pressure results.
At least that's the way it's explained in some of the load manuals.
 
In making reduced loads such as you are desiring, the biggest problem probably won't be the risk of a squib as much as your action not cycling. I don't see a problem with using the Hodgdon data. I'd make up about twenty rounds and see how your gun likes it. If you have access to a chronograph, that would be great.
 
Thanks

Thanks for the replies. I did make some reduced powder loads and they all worked ok.

I did talk to a guy I know that has a chronograph and he said he would set it up so I can test my loads out of my gun. If I fall just short I would still be ok because I can have the rounds fired out of a glock23 and as long as they make the power factor than they are good to go.

As far as components go I will be shooting plated bullets, at least for now. I have Berrys and Xtreme 180 grains, and I am using HP-38 powder. I also already was aware that it uses the same data as Winchester 231.

Interestingly, I saw the article from guns magazine on the 40 lite loads. Unfortunately he doesn't list data for plated 180 grains and I think the data for jacketed is different than plated.
 
Plated bullets are usually loaded to the recipes published for lead bullets. Thicker-plated bullets can handle closer to jacketed velocities and pressures, but care is to be exercised.

About low/light loads. It is said, though some do not believe, that light charges of slow powders in large volume cases can experience erratic pressures, including spikes that can destroy guns.

Research these:

S.E.E. (Secondary Explosive Effect)

Detonation

Flashover

The existence of these phenomenon, while debatable, are the realm of interior ballistics, an arcane science that is still not entirely understood.

My advice is: Be safe. Always, All ways. Low probability, high consequence risks should be well thought out before taking.

Lost Sheep

p.s., having mentioned the concept of slow powder with light loads, it behooves me to also mention that fast powders, which are usually safe with light loads, may present some risk, too. I have read one first-hand account of a guy blowing up a Thompson-Contender with a light load of fast powder while fire-forming cases. Everything went fine if the powder was piled up at the rear of the case close to the primer. Then he paused shooting and lowered the muzzle. When he raised up to horizontal, the powder (obviously) was piled up near the base of the bullet. He fired and the gun dissassembled itself catastrophically. (No injuries). After a thorough search, most of the gun was recovered, but it was toast.

Position sensitivity is a factor, too.
 
I load .40 s&w almost exclusively below the starting minimum you will find for all the powders that I use. My most used bullet is the 175 coated lead swc so I need 715 fps for IDPA power factor for ESP. I have a Springfield XDm 525 so I can change out the recoil spring to go lighter or heavier(which I always go lighter). Some of the powders I have tried include Accurate # 2,5,7,Clays,Universal,Unique,Clay Dot,HP-38,Titegroup,Power Pistol and Blue Dot. With every one of these powders I loaded down until the gun wouldn't run with the factory (18#) spring then down to failure with a 16# spring then the same with a 14#. Nothing has blown up and all bullets have exited the barrel and gone to the target. I found I could make power factor with all but the very lightest loads but I settled on a load that gives me about a 135000 power factor so that I know it will run the gun in all conditions-shooting support hand in very cold weather will expose marginal ammo. I won't list loads here that are "below book" but I will say I shoot IDPA,bowling pin matches and steel matches with satisfactory success and all my competition loads are below starting loads in the manuals. It can be done.
 
Has anyone mentioned to try older powders like Unique or Bullseye because of their smoother pressure curve. Recoil with some powders are perceived less because they are a relatively slower push rather than a fast slam......and you still get the fps you need.
 
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