Variance in load data?

[Spike_351]

I'm currently working on a load for a 230 gn lead TC for my 45. Acp.....unfortunately I'm finding a pretty large difference in OAL between my Lyman cast bullet handbook and my Lee 2nd addition. The Lyman states 5.2 gn at 1.170 OAL and the Lee states 5.1 at 1.270...that's 0.100 difference...which is fairly large.....am I just being paraniod or what?

 

[Clay Pigeon]

Yes, you are being paranoid.

 

[mssmith44]

I don't think paranoid is the correct word. Just observant.
The lyman and lee are different bullets. Which do you have?
Or do you have an unknown?
The way to measure the max OAL for your barrel is to drop a bullet into
the barrel. Measure the distance to the back of the bullet.
Measure the bullet length. Add to get Max OAL for your barrel.
If it is longer than max OAL 1.275" for 45 ACP, use that.'
Otherwise us your measured max OAL or shorter.

 

[Spike_351]

Thanks guys. So to answer questions yes I have the Lee bullet, (these are rounds I have casted myself with the Lee mold). So I loaded 10 of each. The Lyman data allowed the bullet to chamber with no issues, however the lee data would not allow the round to fully chamber. So I gradually shortened the overall length and found out that until I was at 1.2 or less that the round would not chamber. So I believe I have a good starting point for these rounds. I really appreciate everyone's input. The firearm it's self is a para expert 1911 incase anyone was interested.

 

[Clay Pigeon]

I would suggest that you work on repeatably when you are casting, The use of a thermometer to know what is happening in the lead pot along with keeping a constant mold temp and keep the same motions when filling your mold. A great place to read about casting is on BPCR shooting sites and castboolits.com

 

[bigedp51]

Read the post below and pay attention to the posts and illustrations by Wobbly. This method applies to any pistol and what is in the manuals are basic guidelines for OAL

How to determine Max OAL for a CZ Pistol

https://czfirearms.us/index.php?topic=34225.0

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[Spike_351]

So, to follow up with everyone, I test fired 10 rounds each, one at 1.170 and the other at 1.2, both fired and functioned flawlessly and consistently and showed no signs of over pressuring. I appreciate everyone's help and input.