Author Topic: length and projectile questions from a newbie  (Read 5813 times)

Offline King Hugh

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length and projectile questions from a newbie
« on: March 31, 2015, 09:34:34 AM »
Hello…questions from a newbie

I have recently started reloading…been researching for over a year and took me a really long time to “pull the trigger” and try reloading some of my old brass…and then even a bit longer to ACTUALLY pull the trigger and drop the hammer on one of my own homemade rounds. I held on for dear life…scrunched my eyes and looked away when I fired it…I was sure the gun was going to blow up in my hand…I had pictures of a mushroom cloud over top of my range and little pieces of ME everywhere all because my round was 1/10,000th of an inch off or had 1 speck too much powder.

I’m assuming everybody goes through that in the beginning…right? C’mon..help out my ego here… ::)

Anyway…nothing bad happened everything worked as it should and the holes ended up where they were supposed to on the target…so now I’m hooked.

I’ve got a few questions I’m hoping you all can help me with…

First is related to the overall length of my finished rounds. Even using the same projectile and the press unchanged from round to round there is still a couple thousands variation…everything is locked down tight and it’s a digital caliper that I use that I make sure is zeroed before each measurement…but still a variation. I’m guessing that as long as none are below the minimum length listed in the manual I don’t need to worry? Maximum length is whatever will feed/chamber in my gun?

Related question…how do you measure overall length with a flat nosed or a hollow point projectile? Everything else being equal the flat nosed or hollow point will be shorter than a round nose projectile since the “nose” part is missing. Does the flat point for example just get seated shallower in the brass?

Projectile question…I know the load data in the manuals is for optimum performance but for starting loads to play with would any projectile of the specified weight work. For example…for the powder that I have available to use, 115 grain hollow point bullet has load data in my book…but a 115 grain FMJ doesn’t….can I load to the powder charge for the Hollow Point and use the FMJ projectile? I guess the question is if the weight of the projectile is the same why does it matter what shape it is or what it’s made out of. 

I’m sure I’ll have a ton of other questions moving forward but those are the ones burning my brain today!

Thank you in advance for anything you can share with me!

 

Offline armymars

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Re: length and projectile questions from a newbie
« Reply #1 on: March 31, 2015, 10:12:18 AM »
  Different bullets have different jackets. This means different resistance to the bore of the gun which means different pressures. Different bullets have different shapes. This means different amount of jacket coming into contact with the barrel which means different amount of pressure.
  The over all length of a loaded round is often dictated by the bullet shape. The minimum length is what you need to worry about as long as it feeds and does not touch the lands of the barrel.
  Some reloading books go by bullet weight only because they make sure that their maximum load is safe for all bullets of that weight that can easily be bought by us. Lee Reloading manual is one. Do not substitute until you get lots of practice reloading. For instance Hornady bullets have harder jackets then Serria bullets and their jackets are thicker to. I hope this helps.

Offline SOprep

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Re: length and projectile questions from a newbie
« Reply #2 on: March 31, 2015, 10:47:54 AM »

Projectile question…I know the load data in the manuals is for optimum performance but for starting loads to play with would any projectile of the specified weight work. For example…for the powder that I have available to use, 115 grain hollow point bullet has load data in my book…but a 115 grain FMJ doesn’t….can I load to the powder charge for the Hollow Point and use the FMJ projectile? I guess the question is if the weight of the projectile is the same why does it matter what shape it is or what it’s made out of. 


Have you looked for load data from the projectile manufacturer?  Often they will have more specific data than a general reloading manual.

Offline Carl

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Re: length and projectile questions from a newbie
« Reply #3 on: March 31, 2015, 11:21:56 AM »
I load by data in loading manuals BUT for hollow or flat/round point ...I always 'profile' a loaded round
to see that it stays within the profile of a loaded "BALL" round to help prevent feed issues that occur when
not within design parameters of the weapon.

SPRING in the metal of your press and your brass can cause minor variance in loaded rounds,withing
design...not much problem besides slight velocity/accuracy variables.

Offline Mortblanc

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Re: length and projectile questions from a newbie
« Reply #4 on: March 31, 2015, 11:36:41 AM »
It used to be that we would recommend buying more than one reloading manual, now days it is easier to say check more than one internet source.

Max OAL is a relative term and is based on several factors, often one of them is magazine length and has nothing to do with performance.  If it is under max OAL in the book and functions through the magazine I would not worry.

Factory rounds will come in a variety of lengths and except for FMJ will seldom share a uniform OAL.  Reliability of feeding is the primary concern.

Bullet weight, jacket thickness, core material???

It will be insignificant.

My Hornady book lumps all 9mm bullets of the same weight into the same pot, JSP/HP/FMJ.  Yours probably leaves one off because they assume you will simply transfer the data between identical bullet weights.

The difference between charges from one manual to another is going to make that point moot also.  My Hornady book lists 9mm loads, with one common powder, 1/2 grain higher for starting load and 1/2 grain lower for max load than my Lyman book.

What Hornady considers a hot load is just an "adequate" charge according to Lyman.  That means even the manufacturers have some fudge factor in their recommendations to allow for these variations.
« Last Edit: March 31, 2015, 11:48:48 AM by Mortblanc »

Offline Carl

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Re: length and projectile questions from a newbie
« Reply #5 on: March 31, 2015, 11:48:58 AM »
The load manuals are good reference ,but claim no responsibility ...even for their published material.
Start below and work up several small batches to determine accuracy...KEEP GOOD WRITTEN RECORDS
OF TEST LOADS AN RESULTS so you don't create a problem more than once.

Offline Mortblanc

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Re: length and projectile questions from a newbie
« Reply #6 on: April 01, 2015, 09:09:44 AM »
Starting low and working up sounds like good advice, but one must remember not to start at a point BELOW the recommended minimum load!

JSP and JHP bullets tend to shed jackets inside the barrel when the velocities get to low. 

Lead bullets at reduced charges tend to give extreme pressure fluctuations and many good target pistols have been blown up when charges were reduced below recommended weights.

And today's loading data manuals are so conservative that the max load is generally a very safe load.

I have a couple of reloading manuals from the 1950s that list rifle starting loads that are near max loads in 21st Century manuals using the same powders and projectiles.

Back in those days we paid more attention to the fired cases and watched for pressure signs more than folks seem to today.  Group size and pressure signs were the two primary concerns since no one owned a chrono and velocity was mostly a guesstimation more than a factual statement.   


Offline Carl

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Re: length and projectile questions from a newbie
« Reply #7 on: April 01, 2015, 10:30:40 AM »


Lead bullets at reduced charges tend to give extreme pressure fluctuations and many good target pistols have been blown up when charges were reduced below recommended weights.

And today's loading data manuals are so conservative that the max load is generally a very safe load.

I have a couple of reloading manuals from the 1950s that list rifle starting loads that are near max loads in 21st Century manuals using the same powders and projectiles.

Back in those days we paid more attention to the fired cases and watched for pressure signs more than folks seem to today.  Group size and pressure signs were the two primary concerns since no one owned a chrono and velocity was mostly a guesstimation more than a factual statement.   

Though I am only a Master loader with 35 years experience..
I have never seen a weapon damaged by too light a powder charge though
some are damaged by follow-up shots behind a projectile that didn't leave the
barrel and this was the shooters fault.

Old manuals are wonderful for occasional reference BUT are not to be used
as powder mix does change from time to time as do methods of measuring pressure and velocity
Your old manuals do not reflect the current powder ,even though the name is the same,
the powder is NOT.

DO NOT USE OLD DATA ABOVE CURRENT DATA as the powder is often not the same as chemistry is OFTEN CHANGED.
This is why manuals change data from time to time ,to keep up with chemistry and methods of pressure measurement.
Common sense and up to date manuals are important.

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Re: length and projectile questions from a newbie
« Reply #8 on: April 01, 2015, 12:30:18 PM »
DO NOT USE OLD DATA ABOVE CURRENT DATA as the powder is often not the same as chemistry is OFTEN CHANGED.
This is why manuals change data from time to time ,to keep up with chemistry and methods of pressure measurement.
Common sense and up to date manuals are important.

That is a VERY good point.

Offline King Hugh

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Re: length and projectile questions from a newbie
« Reply #9 on: April 04, 2015, 02:22:31 PM »
Thank you everybody for the information. I do have a few different manuals (all current) and have looked at some manufacturers web sites for data...

I guess what I got stuck on was that everything you read and everybody you talk too stresses that you need to follow everything EXACTLY...but in practice having a finished round be off by a few thousandths isn't that big a deal.

I've still got a lot to learn! In the end as long as I have rounds that will hold a reasonable group at 60 feet I'm happy. I reload mostly for the economics since I like to shoot IDPA, I'm not looking for a single hole group at a mile and a half.

I'm sure I'll be back with other questions.

Thanks again!

Offline armymars

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Re: length and projectile questions from a newbie
« Reply #10 on: April 04, 2015, 02:38:34 PM »
  There are a few powders that are finicky. If I use the wrong primer with Universal, even though nether primer is a magnum primer I'll split the some cases length wise in my 40 S&W.