Case length too short?

Bwstone · July 10, 2014, 09:16 PM

First, I am new to this. I've done tons of reading and have found varying answers. Here's my situation.

I'm loading for my 300WM. I'm starting with just 50 rounds. All of my brass is once fired with the exception of 18 pieces that I had with 165gr bullets in them. I'm loading 180gr.

On the 165gr bullets, I pulled the bullets, cleaned the cases and then ran them through the deprime/resize die. All the once fired brass came out at the prescribed 2.62" (or within .002). All the unfired brass from the 165gr batch came out at 2.595".

Should I load that brass or did I make a mistake by not using them after they had been fired?

Thanks for any help. The last thing I want to do is load a round that will be detrimental to my gun or me!

green_MTman · July 10, 2014, 09:44 PM

i typicaly dont trim new brass.it wont hurt the gun and the case lenth differences are within a reasonable margin of error.i dont know why you pulled and deprimed the 165 gr bullets.use them for target practice.

once you have fired them all once and there tumbled,cleaned deprimed and reized then trim down to the case lenth in your manual.

absolute consistancy is mainly good for match or long range hunting loads and it will take a lot of trials to find the accurate load you want anyway.so perfection in case lenth with a new gun and a new load wont do much for you.

Bwstone · July 10, 2014, 09:58 PM

Thanks!

Jay24bal · July 10, 2014, 10:05 PM

Yeah, I would not worry about it.

You are well within a safe margin.

Load em up, and see what happens! Good luck embarking down this very addicting path

243winxb · July 10, 2014, 10:08 PM

No reason to not use the short brass. SAAMI maximum length is 2.620" When brass gets longer, trim back to 2.610" This is after full lenght resizing. SAAMI working range is 2.620" to 2.600" http://www.saami.org/specifications_...ex.cfm?page=CC The trim length may get shorter, after firing, with low to mid-range loads. FL sizing will increase it.

Bwstone · July 10, 2014, 10:10 PM

Addicting is right! I can't wait to get these rifle rounds completed, test them and then get started on my handgun rounds. I can see a progressive press in my future!

green_MTman · July 11, 2014, 07:20 AM

with brand new brass loading with slighty short brass if anything it should lower pressure.when brass has been fired a few times and get brittle thats a different story.

i am not experienced enough with .300WM to know when it would get brittle,but not within the first coupe loadings.

letting brass get longer then proper case lenth is a bigger problem

F. Guffey · July 11, 2014, 07:47 AM

http://www.saami.org/PubResources/CC...r%20Magnum.pdf

2.270" measured from .420" as in the distance from the round hole of .420 to the head of the case is far more important than the length of the case from the mouth of the case to the case head.

Quote:

I pulled the bullets, cleaned the cases and then ran them through the de-prime/resize die

Why? You knew the new unfired ammo would chamber, I would suggest you measure before sizing, then measure again. Nothing like knowing cause and effect. Had you measured before firing you would have known the case did not increase in length from the mouth to the case head as much as it did from the shoulder to the case head.

MEANING! Full length sizing is not always necessary when sizing cases that are pinned to the rear with a belt, or rim.

F. Guffey

Bwstone · July 11, 2014, 07:53 AM

Thanks for the reference. I'll dig into it.

Also, and again I'm new to this and may be wrong, I understood that my RCBS die set only neck sized my case, not full length resized. I'll look into this as well.

F. Guffey · July 11, 2014, 08:24 AM

Quote:

and then ran them through the deprime/resize die.

Quote:

I understood that my RCBS die set only neck sized my case, not full length resized. I'll look into this as well.

Necking the neck down lengthening's the neck, when the sizer plug is pulled through the neck when the ram is lowered the neck shortens.

I have case forming dies for the 300 Win mag, I have neck sizing dies, BAR dies, and I have standard full length sizing dies. For me when sizing a belted case I want to leave the shoulder where I found-er, that is part of my 'leaver policy'.

F. Guffey

Bwstone · July 11, 2014, 03:35 PM

I'll check and see which ones I have. Thanks. Shows me how much I have to learn!

July 10, 2014, 09:16 PM	#1
Bwstone Junior Member Join Date: August 12, 2013 Posts: 8	Case length too short? First, I am new to this. I've done tons of reading and have found varying answers. Here's my situation. I'm loading for my 300WM. I'm starting with just 50 rounds. All of my brass is once fired with the exception of 18 pieces that I had with 165gr bullets in them. I'm loading 180gr. On the 165gr bullets, I pulled the bullets, cleaned the cases and then ran them through the deprime/resize die. All the once fired brass came out at the prescribed 2.62" (or within .002). All the unfired brass from the 165gr batch came out at 2.595". Should I load that brass or did I make a mistake by not using them after they had been fired? Thanks for any help. The last thing I want to do is load a round that will be detrimental to my gun or me!

July 10, 2014, 10:05 PM	#4
Jay24bal Senior Member Join Date: December 13, 2011 Location: Cleveland, OH Posts: 735	Yeah, I would not worry about it. You are well within a safe margin. Load em up, and see what happens! Good luck embarking down this very addicting path __________________ I like guns. Once Fired Brass, Top quality, Fast shipping, Best prices. http://300AacBrass.com/ -10% Coupon use code " Jay24bal "

July 10, 2014, 10:08 PM	#5
243winxb Senior Member Join Date: July 26, 2011 Location: USA Posts: 1,730	300 win. Mag. No reason to not use the short brass. SAAMI maximum length is 2.620" When brass gets longer, trim back to 2.610" This is after full lenght resizing. SAAMI working range is 2.620" to 2.600" http://www.saami.org/specifications_...ex.cfm?page=CC The trim length may get shorter, after firing, with low to mid-range loads. FL sizing will increase it.

July 10, 2014, 09:44 PM	#2
green_MTman Senior Member Join Date: March 27, 2014 Location: southeastern Vermont,USA Posts: 325	i typicaly dont trim new brass.it wont hurt the gun and the case lenth differences are within a reasonable margin of error.i dont know why you pulled and deprimed the 165 gr bullets.use them for target practice. once you have fired them all once and there tumbled,cleaned deprimed and reized then trim down to the case lenth in your manual. absolute consistancy is mainly good for match or long range hunting loads and it will take a lot of trials to find the accurate load you want anyway.so perfection in case lenth with a new gun and a new load wont do much for you.

July 10, 2014, 09:58 PM	#3
Bwstone Junior Member Join Date: August 12, 2013 Posts: 8	Thanks!

July 10, 2014, 10:10 PM	#6
Bwstone Junior Member Join Date: August 12, 2013 Posts: 8	Addicting is right! I can't wait to get these rifle rounds completed, test them and then get started on my handgun rounds. I can see a progressive press in my future!

July 11, 2014, 07:20 AM	#7
green_MTman Senior Member Join Date: March 27, 2014 Location: southeastern Vermont,USA Posts: 325	with brand new brass loading with slighty short brass if anything it should lower pressure.when brass has been fired a few times and get brittle thats a different story. i am not experienced enough with .300WM to know when it would get brittle,but not within the first coupe loadings. letting brass get longer then proper case lenth is a bigger problem

July 11, 2014, 07:53 AM	#9
Bwstone Junior Member Join Date: August 12, 2013 Posts: 8	Thanks for the reference. I'll dig into it. Also, and again I'm new to this and may be wrong, I understood that my RCBS die set only neck sized my case, not full length resized. I'll look into this as well.

July 11, 2014, 03:35 PM	#11
Bwstone Junior Member Join Date: August 12, 2013 Posts: 8	I'll check and see which ones I have. Thanks. Shows me how much I have to learn!