Press To Test

Geek's 65 · December 21, 2013, 02:03 PM

So I loaded both .308 and .270 for the first time and yesterday took them to the range. Good news is that they all went bang when they should have and I actually got some idea of what load worked better for each of the guns (less was actually better but didn't do velocity test yet). But when I looked at the primer on both, it almost looked to me like they all were flattened out a bit. Almost like overpressure even though I was in the heart of the envelop for published loads according to Lyman's 49th.

I hand prime and de-prime if for no other reason than it makes me look at each case to see if there is something wrong. I have loaded probably 500 45ACP and while not a lot, it's enough to say that these primers both primed and de-primed with a lot less squeeze pressure than the 45. Both the .308 and the /270 were primed with Federal Large Rifle Match grade primers.

Loads: (all OAL and case measurements done with Hornady case and OAL comparators)
.270 - Range brass full length sizing to 2.046, trimmed to 2.520, Federal Large Rifle Match grade primer, Nosler 140 gr Partition bullet, seated .030 off the rifling to 2.680, and IMR 4350 49.0 gr to 53 gr in 1.0 grn steps.

.308 - 40 rounds of Win brass once fired and 20 rounds of new Norma brass. All sized to 1.623 and trimmed to 2.005. Same Federal Large Rifle Match grade primers, 40 rounds of 167gr Lapua and 20 rounds of 165gr SGK bullets, actual bullet length (not using comparator) 40 rnds 2.800 and 20 rnds 2.810, and IMR 4064 loaded from 41 to 43 grns in 1.0 grn steps.

Here's what the primers looked like:
270:

308

Problem or just primers that don't seat as snug?

Thanks

G

rebs · December 21, 2013, 04:17 PM

A lot of times the hottest load is not the most accurate load. I develop all my loads for accuracy and not by velocity.

precision_shooter · December 22, 2013, 11:50 AM

I don't see anything wrong with those primers. Most times, an over pressure load that causes a flattened primer, the primer will extrude out and fill in the space around the primer and often times the firing pin dimple will crater significantly and have raised edges. When you decap, look at them. If they are not mushroomed then I would say you are fine. From the outside, Yours look perfectly acceptable to me.

flashhole · December 22, 2013, 02:19 PM

Those primers are fine. Nice round corners. If you use flat primers as a gage of over pressure you still have some headroom. I typically end up 1 or 2 grains below max published data but I don't load for speed for the sake of loading for speed. I load for accuracy and stop when I get a good node. All but one of my rifles showed a low charge and high charge node meaning I generally get two accuracy nodes. Of course I go with the higher velocity.

Good job, keep at it. Nothing beats the confidence you create knowing how your handloads will behave when in the field. I took a buck this year with my 7mm Rem Mag. That load is dialed in and I know exactly what to expect out to 400 yards or so. When I pulled the trigger I knew what to expect and was not disappointed.

Jimro · December 22, 2013, 02:44 PM

Primers look fine.

Good luck on accuracy tuning. I find that I get best accuracy with around 95% case fill with IMR4064 in 308. No need for a compressed max charge.

Jimro

Geek's 65 · December 22, 2013, 03:44 PM

Exactly the confirmation I was looking for. I am reloading the cases as we speak and this time am looking to refine the load for accuracy. Once I get that, I'll look at velocity and see if my loads are close to the book's. Then I will play with the set back and bullet seating to see what goes on there.

Again appreciate the sanity check on this.

G

arizona98tj · December 22, 2013, 04:58 PM

Why not check velocity while working up your load for accuracy? It isn't hard to hit a target at 100 or 200 yds while shooting over the chrono screens. As for me, an accurate load that is going way too slow isn't a good load assuming you want to hunt with it or perhaps shooting something at distance. Perhaps it is just me, but I can't imagine doing load workup without a chronograph present. It is yet another tool in the toolbox that allows me to efficiently and safely develop my hand loads.

Geek's 65 · December 23, 2013, 10:12 AM

Yeah I understand that I could chrono with the initial workup but when I say I am a noobie - it's no joke. Have been lurking and doing lots of reading on what effects bullet seating depth, head space, barrel length and all the buzz words have on accuracy/velocity and THINK I understand it but since I am so new, I am taking this one shot at a time (pun intended). If my load turns out to be so slow that the kinematics are weak at whatever I am shooting at, I will adjust and see how it works. But in my case I want to adjust slowly just to be sure what I think is going to happen is really what happens without some other unwanted surprise. Oh and the most important reason is that I am having fun doing this.

Thanks.

G

AllenJ · December 23, 2013, 12:08 PM

I typically check load accuracy and velocity at separate range trips. It gives me a reason to go shooting more

cw308 · December 25, 2013, 10:53 AM

Primers look fine, just remember that federal cases are thicker and reduce .05 from load data listed. I use the same powder (IMR 4064) primer & FC case as you. 41.5 gr under a sierra 168 gr.HPBT OAL 2.800. In my bolt action I fire form & neck & partcial neck size, works for me. Be Safe Chris

g.willikers · December 25, 2013, 11:10 AM

Here's a good picture and description of what a primer looks like, from a high pressure round:
http://www.accurateshooter.com/techn...sure-analysis/

December 21, 2013, 02:03 PM	#1
Geek's 65 Member Join Date: September 16, 2013 Posts: 17	Press To Test So I loaded both .308 and .270 for the first time and yesterday took them to the range. Good news is that they all went bang when they should have and I actually got some idea of what load worked better for each of the guns (less was actually better but didn't do velocity test yet). But when I looked at the primer on both, it almost looked to me like they all were flattened out a bit. Almost like overpressure even though I was in the heart of the envelop for published loads according to Lyman's 49th. I hand prime and de-prime if for no other reason than it makes me look at each case to see if there is something wrong. I have loaded probably 500 45ACP and while not a lot, it's enough to say that these primers both primed and de-primed with a lot less squeeze pressure than the 45. Both the .308 and the /270 were primed with Federal Large Rifle Match grade primers. Loads: (all OAL and case measurements done with Hornady case and OAL comparators) .270 - Range brass full length sizing to 2.046, trimmed to 2.520, Federal Large Rifle Match grade primer, Nosler 140 gr Partition bullet, seated .030 off the rifling to 2.680, and IMR 4350 49.0 gr to 53 gr in 1.0 grn steps. .308 - 40 rounds of Win brass once fired and 20 rounds of new Norma brass. All sized to 1.623 and trimmed to 2.005. Same Federal Large Rifle Match grade primers, 40 rounds of 167gr Lapua and 20 rounds of 165gr SGK bullets, actual bullet length (not using comparator) 40 rnds 2.800 and 20 rnds 2.810, and IMR 4064 loaded from 41 to 43 grns in 1.0 grn steps. Here's what the primers looked like: 270: 308 Problem or just primers that don't seat as snug? Thanks G

December 22, 2013, 11:50 AM	#3
precision_shooter Senior Member Join Date: September 8, 2007 Location: DFW, Texas Posts: 2,475	I don't see anything wrong with those primers. Most times, an over pressure load that causes a flattened primer, the primer will extrude out and fill in the space around the primer and often times the firing pin dimple will crater significantly and have raised edges. When you decap, look at them. If they are not mushroomed then I would say you are fine. From the outside, Yours look perfectly acceptable to me. __________________ "Laws that forbid the carrying of arms...disarm only those who are neither inclined nor determined to commit crimes...Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man." - Thomas Jefferson, 1776

December 22, 2013, 02:19 PM	#4
flashhole Senior Member Join Date: February 9, 2005 Location: Owego, NY Posts: 2,000	Those primers are fine. Nice round corners. If you use flat primers as a gage of over pressure you still have some headroom. I typically end up 1 or 2 grains below max published data but I don't load for speed for the sake of loading for speed. I load for accuracy and stop when I get a good node. All but one of my rifles showed a low charge and high charge node meaning I generally get two accuracy nodes. Of course I go with the higher velocity. Good job, keep at it. Nothing beats the confidence you create knowing how your handloads will behave when in the field. I took a buck this year with my 7mm Rem Mag. That load is dialed in and I know exactly what to expect out to 400 yards or so. When I pulled the trigger I knew what to expect and was not disappointed. __________________ ,,, stupidity comes to some people very easily. 8/22/2017 my wife in a discussion about Liberals. Are you ready for civil war?

December 22, 2013, 02:44 PM	#5
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	Primers look fine. Good luck on accuracy tuning. I find that I get best accuracy with around 95% case fill with IMR4064 in 308. No need for a compressed max charge. Jimro __________________ Machine guns are awesome until you have to carry one.

December 22, 2013, 03:44 PM	#6
Geek's 65 Member Join Date: September 16, 2013 Posts: 17	Thanks All Exactly the confirmation I was looking for. I am reloading the cases as we speak and this time am looking to refine the load for accuracy. Once I get that, I'll look at velocity and see if my loads are close to the book's. Then I will play with the set back and bullet seating to see what goes on there. Again appreciate the sanity check on this. G

December 21, 2013, 04:17 PM	#2
rebs Senior Member Join Date: January 10, 2012 Posts: 3,881	A lot of times the hottest load is not the most accurate load. I develop all my loads for accuracy and not by velocity.

December 22, 2013, 04:58 PM	#7
arizona98tj Senior Member Join Date: December 10, 2007 Location: Arizona Posts: 980	Why not check velocity while working up your load for accuracy? It isn't hard to hit a target at 100 or 200 yds while shooting over the chrono screens. As for me, an accurate load that is going way too slow isn't a good load assuming you want to hunt with it or perhaps shooting something at distance. Perhaps it is just me, but I can't imagine doing load workup without a chronograph present. It is yet another tool in the toolbox that allows me to efficiently and safely develop my hand loads. __________________ stu-offroad.com Largest Jeep TJ project site on the web! (now with guns)

December 23, 2013, 10:12 AM	#8
Geek's 65 Member Join Date: September 16, 2013 Posts: 17	Yeah I understand that I could chrono with the initial workup but when I say I am a noobie - it's no joke. Have been lurking and doing lots of reading on what effects bullet seating depth, head space, barrel length and all the buzz words have on accuracy/velocity and THINK I understand it but since I am so new, I am taking this one shot at a time (pun intended). If my load turns out to be so slow that the kinematics are weak at whatever I am shooting at, I will adjust and see how it works. But in my case I want to adjust slowly just to be sure what I think is going to happen is really what happens without some other unwanted surprise. Oh and the most important reason is that I am having fun doing this. Thanks. G

December 23, 2013, 12:08 PM	#9
AllenJ Senior Member Join Date: December 11, 2009 Location: Northern California Posts: 1,766	I typically check load accuracy and velocity at separate range trips. It gives me a reason to go shooting more

December 25, 2013, 10:53 AM	#10
cw308 Senior Member Join Date: September 2, 2010 Location: Plainview , Long Island NY Posts: 3,863	Primers look fine, just remember that federal cases are thicker and reduce .05 from load data listed. I use the same powder (IMR 4064) primer & FC case as you. 41.5 gr under a sierra 168 gr.HPBT OAL 2.800. In my bolt action I fire form & neck & partcial neck size, works for me. Be Safe Chris

December 25, 2013, 11:10 AM	#11
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	Here's a good picture and description of what a primer looks like, from a high pressure round: http://www.accurateshooter.com/techn...sure-analysis/ __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.”