6 inch barrel starting point

[Labrat198]

Most of the information I have found online and in books list 4 or 5 inch barrels. Wondering how much I can deviate from the recommended starting point when working up loads for my G40's 6 inch barrel?

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[The_Shadow]

If you are working from loading manuals, you'll be fine but you will see increased velocities with the same loads as shown from the shorter barrels.  The pressure curve will likely be the same for the initial bullet start but be sustained for the extra length of barrel...

[jazzsax8]

My 6" KKM in the G20SF with 22# recoil spring takes an average .2 grain more powder to get to max than the stock barrel with the reported increased velocity.

Marshall

[Benchrst]

Starting point is starting point regardless of barrel length.

[Pablo]

Starting point is starting point regardless of barrel length.

+1

Yeah I was wondering if I was missing something in the OP

[Benchrst]

Starting point is starting point regardless of barrel length.

+1

Yeah I was wondering if I was missing something in the OP

Perhaps fundamentals need to be grasped before loading.

Peak chamber pressure has nothing to do with barrel length.

[Labrat198]

Perhaps fundamentals need to be grasped before loading.

Peak chamber pressure has nothing to do with barrel length.
[/quote]

Why do you think I am here???

Not all the components listed in my books match what I have, so I assume that I should see some changes from the data charts included. I would like to know what changes I should expect to see while I still have all 10 fingers, so I asked. 

[Benchrst]

Perhaps fundamentals need to be grasped before loading.

Peak chamber pressure has nothing to do with barrel length.

Why do you think I am here???

Not all the components listed in my books match what I have, so I assume that I should see some changes from the data charts included. I would like to know what changes I should expect to see while I still have all 10 fingers, so I asked.
[/quote]

If I come across or have come across as crass my apologies.

You now seem to have two questions: Starting point in relation to barrel length, and now components that don't match your load book.

For the original question I suggest something along the lines of The ABCs of Reloading. For the 2nd, nobody can tell you where to start if your components (brass, primer, powder, & bullet) don't match.

For any given published load the one thing that will match is the powder. If your case, primer, and bullet don't, but the bullet is of similar weight and design, then use the load 'starting' point.

[The_Shadow]

I will add that I have used different bullets of the same weight and diameter in substitution with the same powder charges.  They were found to be very close in performance in most instances.  However that being said, no two guns are the exact same, so there will be variations in pressure and velocity that are expected.  If it is current loading data you will more than likely still be under the max pressures for the cartridge providing your gun is in good working order.

Now that Benchrst, is working with a pressure testing system, we can all learn a few things from his results as he shares them.
I for one look over everything, trying to get better understandings, to increase my own personal knowledge, which covers a very broad spectrum to include my many years of handloading, fire department, emergency medical and hazardous materials training.  Not to mention many other things under my many hats.

This site has tons of data listed here that is from known powder and handloader books, as well as what was found in the various pull-downs.  People looking to load for our favorite cartridge, should be soaking up this data and even storing it for their own reference and study.  Nothing last forever, also with photobucket's recent change in terms, all of the pictures I have posted links to on this forum and others may soon disappear...Get them while you can.

[Labrat198]

No worries.

My use of "components" may have lead to some confusion. My books list the barrel length, case, and primmer used and these are the "components" I was referring to. A variety of bullet weights and powder choices are also listed of course. Primers and cases can be purchased and where discussed earlier in the manual as far as what to expect when switching brands of primer or case lot, but no mention was made about the barrel length. I wasn't sure if the longer barrel meant I could bump up the powder a little or if I should leave it alone and deal with the problems an under-powered load can cause.

It may not have been exactly relating to a starting load, but now I know I cannot use the published data for velocity.

[The_Shadow]

Labrat198, many of us who have been around have seen so many wanting data looking for maximums.  They want to load on a progressive press which can lead to many issues at these levels of performance.  I have and do work at upper levels of performance for many cartridges, but I am so anal and OCD, I only hand weigh each and every powder charge.  It is we the handloader that are the absolute quality control for our work.

That being said you will notice some data listed and used that is above that of published info.  Also understand that some people don't provide all of the info need to use this data without taking the steps of working up slowly to see how their own firearm handles the loads being used...

[Benchrst]

I wasn't sure if the longer barrel meant I could bump up the powder a little or if I should leave it alone and deal with the problems an under-powered load can cause.

That's the most intelligent 'noob' (I'm not calling you one, but I am ) question / statement I've read in a long time!

If you're actually thinking a 'starting' load could cause a squib, or other issue, in a longer than 'stated' barrel, bravo!

Many, including myself at one time, reach for the stars, before they can even stand.

In a pistol, that can lead to lost digits. In a rifle, well...

Keep asking questions

[sep]

"I wasn't sure if the longer barrel meant I could bump up the powder a little or if I should leave it alone and deal with the problems an under-powered load can cause."

Lots of good responses by experienced reloaders here. The longer barrel does not mean you should bump up the powder charge. Your starting loads won't be underpowered because of the longer barrel, they'll likely be faster than a 4 or 5 inch barrel. The longer barrel gives the powder (expanding gases) more time to accelerate the bullet. No need to worry about adjusting powder charge weights based on barrel length. I use this principle to my advantage in both pistols and rifles. In my 338 Win mags, I can get 40-60 fps more velocity with 26 inch barrels than my usual 24 inch ones with no change in powder charge weight.