9mm Reloading - Seating \ Crimping Question

heylin · May 10th, 2009, 07:50 PM

Well Ive been using my Lee Breech Lock 50th Anniversary kit and RCBS Carbide Dies this weekend on my first stint at reloading.

Ive deprimed, sized, belled and primed about 500 cartridges and am addicted already :). Im ready to get my powder now and have a couple questions about seating and crimping with my RCBS dies (does the seat and crimp in one step).

I played around the crimping setting so the bell was removed and got the seating depth set so that it was identical to the factory rounds I have been using (give or take 0.01 inches). Rounds chambered fine in my Glock, Para and Taurus.

Question 1) is 0.01 inches variance OK for the case length ?

Question 2) should I be using the rounded or flat seating plug for Round nose FMJ ? (the RCBS instructions arent very clear)

Question 3) provided my seating depth is correct and my crimp is correct is there anything I need to wary of in regards to excessive pressure due to bullet being held in place too tight ? how tight is too tight ? is there any way to tell ?

boscobeans · May 10th, 2009, 08:16 PM

I took out 4 different brands of NEW FACTORY ammo in 9mm.
All showed an outer measuremnet at the crimp to be .376 inches.

My reloads in 9 mm. were checked and they are also at .376 inches.

They were made on RCBS equipment and tapered to match factory ammo.

Q#1 Most ammo is speced out to the .000 (thousandth's of an inch)
As far as case length goes, most straight walled brass doesn't lenghten that much.. Once fired brass or new brass should be close to if no dead on with specs out to a few thousandth's of an inch.

Q#2 Use the rounded bullet seater. Prevents you from setting the bullet at an angle.

Q#3 If you can just see the outline of seated bullet in the brass, your crimp should be fine. Too tight and you may deform the bullet or buckle the brass.

bosco

heylin · May 10th, 2009, 08:24 PM

Oops sorry for Q1, I meant the finished catridge length was 0.01 inches shorter then factory round, possiby less.

All my brass is twice fired so as you say it should be 0 variance in case length as its pretty much new brass in reloading terms.

a factory round sits firm in my calipers, and my finished round just manages to wiggle through the same gap with some effort, so its nearly in spec, just seated a hair deeper.

I would play around the seater plug more, but if its clsoe enough I would rather leave it than risk going to long.

boscobeans · May 10th, 2009, 08:42 PM

A hair ( a few .000 of an inch or so ) deeper with the same weight and bullet configuration should be fine, UNLESS YOU ARE WORKING WITH MAXED OUT LOADS.

Remember shape/type of bullet matter, a 124grain FMJ will be a slight bit shorter than a hollow point of the same weight (normally).
bosco

heylin · May 10th, 2009, 08:54 PM

Thank for all the info guys.

My loads are at the bottom end of the range. Max load for 115gr FMJ using ADI-AP70N is 5.0gr, i'll be aiming for 4.5-4.8 range.

Projectiles im using are the same as the factory rounds (Lapua) I order them direct from the ammo manufacturer and am using the same brass again, so any completed rounds are 100% identical in components.

boscobeans · May 10th, 2009, 09:59 PM

I am not that familiar with ADI powders but from what I have read AP70N is the same as CLAYS. If it is 5.0 grains is a fairly HOT load.

bosco

edr9x23super · May 10th, 2009, 10:18 PM

follow the reloading guide! in the guide are the SAAMI specs for each caliber loading. If you are just starting out, this should be your bible, no exceptions!

The reloading guide will have all of the info you are seeking to get secondhand here. The 20 bucks you spend on that guide will be the best you ever spent....

heylin · May 10th, 2009, 10:47 PM

ADI say AP70N is equivalent to Hodge Universal, both are a medium burn rate and suitable for wide range of pistol and rifle calibres.

The ADI load data I have (from ADI) says 4.5 start - 5.0 max for 115gr FMJ which I will be using.

Can I take the powder manufacturers word as gospel ?, also is there any harm starting lower than manufacturers start load ? say 4.3 grains ?.

Ghuqu2 · May 10th, 2009, 10:55 PM

Remember OAL is a MINIMUM, not a max length. You can go over w/ little problem (as long as fits in the mag), but NEVER under. Don't just compare w/ factory ammo, follow the published recipe! As I see it ap70n=Universal (according to this chart). My Lee manual says min. OAL for Universal w/ 115gr fmj is 1.125.

TOF · May 10th, 2009, 11:14 PM

The best advice we can give a new reloader that is several thousand miles away is to follow your load chart religiously untill you get some experience.

Don't worry about what factory ammo OAL is. Load to the OAL called for in the chart for your specific powder bullet and charge. I consider + or - .003" acceptable.

Don't assume or even accept someone elses statement that X and Y powder are equal. Find a load chart for the specific powder you are using or I reccomend you not use it.

Start as close to the bottom of the charge range as practical. Work your way up to heavier charges after evaluating primer, reaction of gun etc.

A chronograph is not absolutely necessary but certainly usefull for comparing to the expected result.

Have fun and stay safe.

May 10th, 2009, 08:54 PM	#5
heylin Member Join Date: Oct 2008 Location: New Zealand Posts: 371	Thank for all the info guys. My loads are at the bottom end of the range. Max load for 115gr FMJ using ADI-AP70N is 5.0gr, i'll be aiming for 4.5-4.8 range. Projectiles im using are the same as the factory rounds (Lapua) I order them direct from the ammo manufacturer and am using the same brass again, so any completed rounds are 100% identical in components. __________________ ------------------------------------------------ War is not about dying for your country, but making your enemy die for his. ------------------------------------------------

May 10th, 2009, 10:18 PM	#7
edr9x23super Distinguished Member Join Date: Jun 2006 Location: Texas Posts: 1,733	follow the reloading guide! in the guide are the SAAMI specs for each caliber loading. If you are just starting out, this should be your bible, no exceptions! The reloading guide will have all of the info you are seeking to get secondhand here. The 20 bucks you spend on that guide will be the best you ever spent.... __________________ "Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are inevitably ruined". - Patrick Henry

May 10th, 2009, 10:47 PM	#8
heylin Member Join Date: Oct 2008 Location: New Zealand Posts: 371	ADI say AP70N is equivalent to Hodge Universal, both are a medium burn rate and suitable for wide range of pistol and rifle calibres. The ADI load data I have (from ADI) says 4.5 start - 5.0 max for 115gr FMJ which I will be using. Can I take the powder manufacturers word as gospel ?, also is there any harm starting lower than manufacturers start load ? say 4.3 grains ?. __________________ ------------------------------------------------ War is not about dying for your country, but making your enemy die for his. ------------------------------------------------

May 10th, 2009, 10:55 PM	#9
Ghuqu2 Member Join Date: Apr 2007 Location: Missouri Posts: 288	Remember OAL is a MINIMUM, not a max length. You can go over w/ little problem (as long as fits in the mag), but NEVER under. Don't just compare w/ factory ammo, follow the published recipe! As I see it ap70n=Universal (according to this chart). My Lee manual says min. OAL for Universal w/ 115gr fmj is 1.125. __________________ "The millions of people, armed in the holy cause of liberty, and in such a country as that which we possess, are invincible by any force which our enemy can send against us." Patrick Henry 1775 Vegetarian: Indian for inept hunter.

May 10th, 2009, 11:14 PM	#10
TOF Member Join Date: Mar 2008 Location: Arizona Posts: 226	The best advice we can give a new reloader that is several thousand miles away is to follow your load chart religiously untill you get some experience. Don't worry about what factory ammo OAL is. Load to the OAL called for in the chart for your specific powder bullet and charge. I consider + or - .003" acceptable. Don't assume or even accept someone elses statement that X and Y powder are equal. Find a load chart for the specific powder you are using or I reccomend you not use it. Start as close to the bottom of the charge range as practical. Work your way up to heavier charges after evaluating primer, reaction of gun etc. A chronograph is not absolutely necessary but certainly usefull for comparing to the expected result. Have fun and stay safe. __________________ "Those who hammer their guns into plows will plow for those who do not." - Thomas Jefferson

May 10th, 2009, 07:50 PM	#1
heylin Member Join Date: Oct 2008 Location: New Zealand Posts: 371	9mm Reloading - Seating \ Crimping Question Well Ive been using my Lee Breech Lock 50th Anniversary kit and RCBS Carbide Dies this weekend on my first stint at reloading. Ive deprimed, sized, belled and primed about 500 cartridges and am addicted already :). Im ready to get my powder now and have a couple questions about seating and crimping with my RCBS dies (does the seat and crimp in one step). I played around the crimping setting so the bell was removed and got the seating depth set so that it was identical to the factory rounds I have been using (give or take 0.01 inches). Rounds chambered fine in my Glock, Para and Taurus. Question 1) is 0.01 inches variance OK for the case length ? Question 2) should I be using the rounded or flat seating plug for Round nose FMJ ? (the RCBS instructions arent very clear) Question 3) provided my seating depth is correct and my crimp is correct is there anything I need to wary of in regards to excessive pressure due to bullet being held in place too tight ? how tight is too tight ? is there any way to tell ? __________________ ------------------------------------------------ War is not about dying for your country, but making your enemy die for his. ------------------------------------------------

May 10th, 2009, 08:24 PM	#3
heylin Member Join Date: Oct 2008 Location: New Zealand Posts: 371	Oops sorry for Q1, I meant the finished catridge length was 0.01 inches shorter then factory round, possiby less. All my brass is twice fired so as you say it should be 0 variance in case length as its pretty much new brass in reloading terms. a factory round sits firm in my calipers, and my finished round just manages to wiggle through the same gap with some effort, so its nearly in spec, just seated a hair deeper. I would play around the seater plug more, but if its clsoe enough I would rather leave it than risk going to long. __________________ ------------------------------------------------ War is not about dying for your country, but making your enemy die for his. ------------------------------------------------

May 10th, 2009, 08:42 PM	#4
boscobeans Senior Member Join Date: Jul 2008 Location: upstate new york Posts: 714	A hair ( a few .000 of an inch or so ) deeper with the same weight and bullet configuration should be fine, UNLESS YOU ARE WORKING WITH MAXED OUT LOADS. Remember shape/type of bullet matter, a 124grain FMJ will be a slight bit shorter than a hollow point of the same weight (normally). bosco

May 10th, 2009, 09:59 PM	#6
boscobeans Senior Member Join Date: Jul 2008 Location: upstate new york Posts: 714	I am not that familiar with ADI powders but from what I have read AP70N is the same as CLAYS. If it is 5.0 grains is a fairly HOT load. bosco

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