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Re: cartridge length

Posted: 01 Jan 2019 21:21
by Macd
The bullet length reported for the 125 XTPFP is 0.547. The 125 XTPHP is listed as .558. That is a difference 0.011. The FP Loaded .003 short than specified for the HP is actually means less seated depth. My computer with Quickload installed is undergoing an upgrade so I can't double check the data is correctly copied.

Here is the link to the forum I referred to in an earlier post.

http://www.shootforum.com/forum/bulletdb.html

I also note that you are shooting the 38 special load in a .357 magnum revolver. Lots of pressure room for a 38 load in that revolver. Max load for regular 38 is 17,000 psi, 38+P 20,000 and 38+P+ is 22,000 psi. The 357 mag maxs at 35,000 psi

Re: cartridge length

Posted: 02 Jan 2019 14:04
by mikld
Well here's an other "I do this..." post. I determine my OAL in a few different ways. For revolver bullet seating I seat to the cannalure/crimp groove and disregard book OAL. Most bullet designers are smarter than I am and the crimp groove/cannalure is located in the proper place. For my semi-autos I'll start with close to the book OAL and use the plunk test to "tweek" the OAL, often starting long and shortening if necessary. For my rifles I'll go with the manufacturer's recommendation for their specific bullet's OAL. I will stay with mfg. OAL for all the load work up and last, if necessary work on seating depth/distance to lands. I also think the OAL listed in a manual is what the lab used, and not necessarily the optimum measurement. (I record all pertinent info/dimensions so I only have to determine what works once).

I may be wrong but I think a reloading manual tell us; "here's the industry standard, and here's what we used in our listed equipment".

Re: cartridge length

Posted: 02 Jan 2019 15:34
by Ohio3Wheels
mikld wrote:snip

I may be wrong but I think a reloading manual tell us; "here's the industry standard, and here's what we used in our listed equipment".
My thoughts on that are very much the same. The vast majority of the data is collected using the world famous universal receiver. That's a good thing I think. If most all manufactures use the same equipment we have a chance that some variables have been eliminated from the process.

Make smoke,

Re: cartridge length

Posted: 02 Jan 2019 23:39
by Old Scribe
Yep. I watch the OAL closely in my rifle reloading. I agree what milkld posted about the folks manufacturing bullets. My revolver bullets with a cannelure are crimped at the grove. Never had a problem.

Re: cartridge length

Posted: 03 Jan 2019 11:02
by horseman
COAL in your reloading manual is as stated previously. It's the length that "they" used for that particular loading. They're "guidelines" for handloaders. The true maximum COAL length for revolvers is the length of the cylinder, for any weapon with a magazine then that's the "maximum" and for a rifle it is the length of the chamber, lever guns is what it will feed. That doesn't mean these are the "best" lengths but that would be the "maximum". As far as increased pressure or less pressure with COAL"s, like in most things reloading "it depends".....but as a blanket statement that this is what happens isn't necessarily true.

Re: cartridge length

Posted: 03 Jan 2019 20:31
by larryw
+1 Very well said Horseman.

Re: cartridge length

Posted: 04 Jan 2019 10:34
by Macd
horseman wrote:COAL in your reloading manual is as stated previously. It's the length that "they" used for that particular loading. They're "guidelines" for handloaders. The true maximum COAL length for revolvers is the length of the cylinder, for any weapon with a magazine then that's the "maximum" and for a rifle it is the length of the chamber, lever guns is what it will feed. That doesn't mean these are the "best" lengths but that would be the "maximum". As far as increased pressure or less pressure with COAL"s, like in most things reloading "it depends".....but as a blanket statement that this is what happens isn't necessarily true.
There are exceptions to every general statement and I agree this applies also to reloading. The new reloader should follow the general rule until they have sufficient knowledge and experience to deviate. COL in almost all situations will affect peak pressure. How much depends on many other variables. Can it make a load unsafe? Yes, in some combinations. Can it affect consistency in FPS and accuracy? Yes, again depending on other load characteristics. Is it a linear relationship. No, but I think we can all agree it is an important one for the handloader to learn about and respect.