How often do you check your PF?

[Dr_Z]

As title suggested, what are you guys doing to ensure that your load stays consistent over time? do you chrono check your load before every major match or do you do it certain times every year? Like once in summer and once in winter. All these questions are based on consistent load formular, same powder, charge, projectile weight, and manufacturer 

[Sarge]

21 minutes ago, Dr_Z said:

As title suggested, what are you guys doing to ensure that your load stays consistent over time? do you chrono check your load before every major match or do you do it certain times every year? Like once in summer and once in winter. All these questions are based on consistent load formular, same powder, charge, projectile weight, and manufacturer 

I shoot over chrono every spring then load more and shoot

[BlindAsABat]

Before every major and usually when switching powder jugs just to make sure. I've seen some big differences between lots from several manufacturers.

[Farmer]

2 hours ago, BlindAsABat said:

Before every major and usually when switching powder jugs just to make sure. I've seen some big differences between lots from several manufacturers.

^^^This and any time there’s a large temp swing. 

[MikeRussell]

8 hours ago, BlindAsABat said:

Before every major and usually when switching powder jugs just to make sure. I've seen some big differences between lots from several manufacturers.

Same here

[twodownzero]

I let the chrono RO tell me every match.

 

[Dr_Z]

19 minutes ago, twodownzero said:

I let the chrono RO tell me every match.

 

Ha I used to do that but I recently went minor all of sudden at a major match . 

[Dr_Z]

10 hours ago, BlindAsABat said:

Before every major and usually when switching powder jugs just to make sure. I've seen some big differences between lots from several manufacturers.

Very good point. I recently went minor at a major match. Turns out that the new batch of bullet has some change in profile and didn't tell me about it. My COL has increased by 0.01 inch. Pretty sure my dies did not walk

[Bigzona]

As a new reloader, I was just reflecting on this question and this is timely. Thank you! Before majors and when changing powder jugs makes a lot of sense to me and I'll be adopting this.

[CharlieD]

I chrono anytime I change powder lots.  I also chrono in both winter and summer to be aware of any major swings in velocity due to temp.  It’s also a good idea to weigh your bullets as manufacturers may change them over time.

[Joe4d]

I tended to find deals on stuff, So powder primer bullet brand and weight wernt always consistent. 
So basically I loaded in lots,,,  Develop a load with set of components, Chrono it,,, load some more chrono it,, before loading all of that set of components. 
I also had set aside what I called "match loads" these got case gauged and generally reloaded once fired Nickle brass. (LEO range pickup purchase) 
Would always Chrono some of these before a major.  Although I never tried to ride the line and was usually about 8 -10 over. Why stress it ? 

 

[twodownzero]

On 8/26/2022 at 7:38 AM, Dr_Z said:

Ha I used to do that but I recently went minor all of sudden at a major match . 

 

I'm pretty sure the closest I ever got was 173.  I know I've seen at least 179 and perhaps more than that.

[Joe4d]

i got 165 at Hawaii state match, my 180's i didnt check weighed 173 grs

 

[Dr_Z]

On 8/26/2022 at 10:29 AM, Bigzona said:

As a new reloader, I was just reflecting on this question and this is timely. Thank you! Before majors and when changing powder jugs makes a lot of sense to me and I'll be adopting this.

Great point! I think I would check PF when switch to a new jug of powder, even with the same brand and type. 

[Dr_Z]

4 hours ago, twodownzero said:

 

I'm pretty sure the closest I ever got was 173.  I know I've seen at least 179 and perhaps more than that.

mine usually range from 169 to 175. I chronoed at sectional match with 169, then Area 5 with 165.2 (almost went minor), and then another major in michigan 162.4 (minor). All without intentionally changing loading data. what changed, however, are 1. I opened and start using a new jug of powder. 2. I start using the projectiles I recently ordered. Too many factors at play here, overall length, variations in powder (from batch to batch), bullet profile, and primers sometimes also make differences. 

[Haalck]

At least once annually but I should do it twice

[twodownzero]

16 hours ago, Dr_Z said:

mine usually range from 169 to 175. I chronoed at sectional match with 169, then Area 5 with 165.2 (almost went minor), and then another major in michigan 162.4 (minor). All without intentionally changing loading data. what changed, however, are 1. I opened and start using a new jug of powder. 2. I start using the projectiles I recently ordered. Too many factors at play here, overall length, variations in powder (from batch to batch), bullet profile, and primers sometimes also make differences. 

 

The only variable is cutting it too close.  By the way, there are no decimal places in power factor.  165.2 is 165.  162.4 is 162.  If you're not 172-175, you're too close.

[Dr_Z]

My point is that I kept using the same load and my PF has been 169 -175 for a good two years (chronoed at majors as well as by myself). It has seen a rapid deterioration just recently. Hence my initial post, things can change even though they are supposed to stay the same. I never aimed for anything below 170. My load data was initially developed for my gun to deliver 170 -175 PF (200 gr BBRNFP, 4.1 gr sport pistol, 1.18 COL, crimp to 0.422).

 

On a side note. How soon do you start to see a noticeable drop in PF through the same barrel (40 cal) and need to bump the charge? My barrel has seen about 40K rounds ( all coated blue bullet 200 gr RNFP), the rifling is in great shape. It's hard to believe that it's been worn down to the point where I must bump the charge. 

[Dr_Z]

8 hours ago, twodownzero said:

 

The only variable is cutting it too close.  By the way, there are no decimal places in power factor.  165.2 is 165.  162.4 is 162.  If you're not 172-175, you're too close.

I think you misunderstood me.

[StefVanHauwe]

In our club we organize a Chrono session using a Labradar at the end of the training approximately every 2 months. Then all competitors who wishe can voluntarily check their PF. Always interesting.

[Farmer]

20 hours ago, Dr_Z said:

My point is that I kept using the same load and my PF has been 169 -175 for a good two years (chronoed at majors as well as by myself). It has seen a rapid deterioration just recently. Hence my initial post, things can change even though they are supposed to stay the same. I never aimed for anything below 170. My load data was initially developed for my gun to deliver 170 -175 PF (200 gr BBRNFP, 4.1 gr sport pistol, 1.18 COL, crimp to 0.422).

 

On a side note. How soon do you start to see a noticeable drop in PF through the same barrel (40 cal) and need to bump the charge? My barrel has seen about 40K rounds ( all coated blue bullet 200 gr RNFP), the rifling is in great shape. It's hard to believe that it's been worn down to the point where I must bump the charge. 

Did you happen to take a max OAL measurement when the bbl was new for a comparison? I had a custom TC bbl that “grew” .010 after break in and another .010 after another 500 or so. Now granted, this is a rifle caliber with jacketed bullets but the leade does get longer with round count and most of the time you cannot see it. 

[Orlandoech]

Two to three times a year for me, Im OCD though.

[Reloader98]

Personally, I think it’s important to check loads, but at the end of the day it’s more important to keep track of your powder drops while loading the ammo. Let me explain. 
 

if your making a few thousand rounds for the shooting season all at once or all in a couple of weekends like I do. Then you have to ensure that your powder drops are staying consistent while loading the ammo. 
 

what I do is check every 50 or so rounds and take a price of brass off the press and check the powder, I do that with three pieces of brass that have powder in them (I have a progressive press). Then wait until the next 50 or so rounds to make sure the drop of powder is consistent throughout the thousands or rounds made at a time. Kind of annoying, I know, but you will never question your loads come range day at a major match. 
 

It all starts with your load development, when doing load development with new powders, primers, bullets etc. you want to chrono and work that load dev until you have the desired PF. And maybe once winter comes, check that load again. But for the most part, what I have described has worked well for me and others that I know. 
 

or you can just have 173 and above PF and say f*#k it to chrono lol. Still good to check in winter though. Personally I’m in VA so winter is basically the end of matches for a couple months until it’s no longer snowing and freezing cold. So I don’t have to worry much.  If your up north or farther down south you may have other things to worry about such as cold weather during most of the shooting season or high moisture from high humidity areas like Florida. 
 

hope this helps, 

 

Tony 

[Cnickolas]

On 8/26/2022 at 7:29 AM, Bigzona said:

As a new reloader, I was just reflecting on this question and this is timely. Thank you! Before majors and when changing powder jugs makes a lot of sense to me and I'll be adopting this.

Also include major temperature changes. 

[Bigzona]

Noted! Thank you!