How many rounds do you guys usually test before making a change?
- Thread starter Tommyquest
- Start date
- Tags
- development load
Re: Q about load development
10 shots in one group fired over a better made chronograph.
10 shots in one group fired over a better made chronograph.
Re: Q about load development
I'll test loads with 4 or 5 rounds each in the beginning. If one of the loads is used for a long range match rifle, I'll test the load with more rounds. If it's for hunting, I'll call it a day, and load that load.
I'll test loads with 4 or 5 rounds each in the beginning. If one of the loads is used for a long range match rifle, I'll test the load with more rounds. If it's for hunting, I'll call it a day, and load that load.
Re: Q about load development
Thanks guys for the replies. When you make changes, what do you usually start with? powder amount? seating depth, etc.?
Thanks guys for the replies. When you make changes, what do you usually start with? powder amount? seating depth, etc.?
Re: Q about load development
Personally I try to find the right charge, then tweak seating depth dependant on what the purpose and how much room you have to work with, Mag length. Throat length.
Mike
Personally I try to find the right charge, then tweak seating depth dependant on what the purpose and how much room you have to work with, Mag length. Throat length.
Mike
Re: Q about load development
I always make 10 rounds of each load and see how each set groups. I usually go out with about 3 different loads to test when I can or get the itch.
I always make 10 rounds of each load and see how each set groups. I usually go out with about 3 different loads to test when I can or get the itch.
Re: Q about load development
I start with a seating depth that averages around .010"-.020" short of the rifling.
I then establish an upper limit for charge weights (generally, about 95% of publshed max, or pressure testing that produces flattened but not sharp edged primers).
I then make up 9 rounds of each of 5 increments arbitrarily determined as 2% of that upper charge limit.
I shoot three sets of three round groups, firing one of each of the 5 increments sequentially at each of 5 separate aimpoints, repeating this twice in a round-robin sequence.
Then I do it all over again two more times until I have fired all 45 rounds.
Group sizes are the average of each of three groups for each increment.
This method forces me to ignore the group aspects and to concentrate on each shot as a separate and distinct exercise. This technique will usually identify at least one accuracy node, which is then refined with smaller increments bracketing the indicated better charge weight.
This is the quickest and most objective technique I've managed to find to date.
Sometimes, however, I find the work has already been done for me. Often, one will find data from other shooters. Posters here will recognize that if I'm interested in the data, I will often inquire about the barrel the data refers to. If that data relates to my own barrel either exactly, or very closely, I will try the load as posted, and have often found better loads, or starting loads, this way than my own development methods have found for me.
My current best .223 load is a direct copy from the Nosler Manual.
Greg
I start with a seating depth that averages around .010"-.020" short of the rifling.
I then establish an upper limit for charge weights (generally, about 95% of publshed max, or pressure testing that produces flattened but not sharp edged primers).
I then make up 9 rounds of each of 5 increments arbitrarily determined as 2% of that upper charge limit.
I shoot three sets of three round groups, firing one of each of the 5 increments sequentially at each of 5 separate aimpoints, repeating this twice in a round-robin sequence.
Then I do it all over again two more times until I have fired all 45 rounds.
Group sizes are the average of each of three groups for each increment.
This method forces me to ignore the group aspects and to concentrate on each shot as a separate and distinct exercise. This technique will usually identify at least one accuracy node, which is then refined with smaller increments bracketing the indicated better charge weight.
This is the quickest and most objective technique I've managed to find to date.
Sometimes, however, I find the work has already been done for me. Often, one will find data from other shooters. Posters here will recognize that if I'm interested in the data, I will often inquire about the barrel the data refers to. If that data relates to my own barrel either exactly, or very closely, I will try the load as posted, and have often found better loads, or starting loads, this way than my own development methods have found for me.
My current best .223 load is a direct copy from the Nosler Manual.
Greg
Re: Q about load development
Greg, do you allow the barrel to cool between 3-round sets (or 9 rounds sets) or does the heat variable have little effect? How small are the differences in your charge weight increments? After identifying which of the 5 increments is the best you'll tweak that charge weight further? Do you also experiment with the seating depths at the same time or separately? Sorry for all the questions. Thanks.
Tom
Greg, do you allow the barrel to cool between 3-round sets (or 9 rounds sets) or does the heat variable have little effect? How small are the differences in your charge weight increments? After identifying which of the 5 increments is the best you'll tweak that charge weight further? Do you also experiment with the seating depths at the same time or separately? Sorry for all the questions. Thanks.
Tom
Re: Q about load development
Greg,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">My current best .223 load is a direct copy from the Nosler Manual.
</div></div>
Is that the W748 load we discussed? If so what was that again? I'm all set up again to run off a bunch of .223. Just ran off 175 today:
100 69 gr SMKs
24 gr h4895,
GM205M
LC Cases
75 52 gr Hornady BTHP Match
25 gr H4895
GM205M
LC cases
I've got 200 RP cases, another 200-300 mixed cases, 1 LB of W748 and a nice selection of 52, 69,and 70 gr bullets, waiting for your answer!
Thanks,
Jeff
Greg,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">My current best .223 load is a direct copy from the Nosler Manual.
</div></div>
Is that the W748 load we discussed? If so what was that again? I'm all set up again to run off a bunch of .223. Just ran off 175 today:
100 69 gr SMKs
24 gr h4895,
GM205M
LC Cases
75 52 gr Hornady BTHP Match
25 gr H4895
GM205M
LC cases
I've got 200 RP cases, another 200-300 mixed cases, 1 LB of W748 and a nice selection of 52, 69,and 70 gr bullets, waiting for your answer!
Thanks,
Jeff
Re: Q about load development
I usually find a starting load and load up 10 rounds each, increasing the charge weight by 0.5gr toward the upper limit of published/known safe pressure loads. The first round is fired as a "fouler", then followed by 3 groups of 3 shots. Ave group size is used. The most accurate load is then selected, and bracketed in 0.2gr increments either side, again 5 lots of 10 rounds. The most accurate of these is then selected, and seatining depth then is adjusted from -0thou, backing off by 5thou at a time, and fired in reverse order (starting at -20th). If I want to refine it any further, I'll do the same process again, only changing the charge weight by 0.1gr.
The whole time I'm looking for pressure signs on each case. If I see any, I stop. I know this seems tedious. It is. I'm considering trying the "ladder method" next time, loading one round each in 0.2gr increments and firing them in order over a chrono. If you then plot the MV against chart weight, you will find flatter parts to the curve. These would be areas where an accuracy node would be. I'd then select a charge weight from the middle of the flat spot and try it. This is more important for LR shooting, as the group size at LR will be more affected by changes in velocity.
I usually find a starting load and load up 10 rounds each, increasing the charge weight by 0.5gr toward the upper limit of published/known safe pressure loads. The first round is fired as a "fouler", then followed by 3 groups of 3 shots. Ave group size is used. The most accurate load is then selected, and bracketed in 0.2gr increments either side, again 5 lots of 10 rounds. The most accurate of these is then selected, and seatining depth then is adjusted from -0thou, backing off by 5thou at a time, and fired in reverse order (starting at -20th). If I want to refine it any further, I'll do the same process again, only changing the charge weight by 0.1gr.
The whole time I'm looking for pressure signs on each case. If I see any, I stop. I know this seems tedious. It is. I'm considering trying the "ladder method" next time, loading one round each in 0.2gr increments and firing them in order over a chrono. If you then plot the MV against chart weight, you will find flatter parts to the curve. These would be areas where an accuracy node would be. I'd then select a charge weight from the middle of the flat spot and try it. This is more important for LR shooting, as the group size at LR will be more affected by changes in velocity.
Re: Q about load development
Queeq;
My Nosler Manual load is 50gr Ballistic Tip, and 26.5gr of W748. I'm using CCI400's right now but originally loaded the CCI BR-4, and Win Brass. Accuracy is about 1/2MOA Benched at 100yd and about 1MOA Prone at 200yd. Very happy with the load, and it doesn't seem to beat the brass up either. I found and tested the load this Winter in 20* weather, and plan on using it as my FV 200yd match load this coming season.
Prior to this my loads were 52SMK and 27.5gr W748, and 55gr Nos BT and 25.4gr W748. The rifle in question is an M700VLS box stock .223 with an older Japanese Tasco 6-24X40 W/Multiplex reticle, and a Leupold JR style windage base and twist-in rings. I think it's a 24" 1:12" barrel, but it's home in NY State and I can't check it right now.
Sorry I didn't respond sooner, but I had to drop the Honda off at the repair shop this AM; the 15 year-old gas tank has rusted out and I need to have it replaced. Taking a nasty hit this month.
Greg
Queeq;
My Nosler Manual load is 50gr Ballistic Tip, and 26.5gr of W748. I'm using CCI400's right now but originally loaded the CCI BR-4, and Win Brass. Accuracy is about 1/2MOA Benched at 100yd and about 1MOA Prone at 200yd. Very happy with the load, and it doesn't seem to beat the brass up either. I found and tested the load this Winter in 20* weather, and plan on using it as my FV 200yd match load this coming season.
Prior to this my loads were 52SMK and 27.5gr W748, and 55gr Nos BT and 25.4gr W748. The rifle in question is an M700VLS box stock .223 with an older Japanese Tasco 6-24X40 W/Multiplex reticle, and a Leupold JR style windage base and twist-in rings. I think it's a 24" 1:12" barrel, but it's home in NY State and I can't check it right now.
Sorry I didn't respond sooner, but I had to drop the Honda off at the repair shop this AM; the 15 year-old gas tank has rusted out and I need to have it replaced. Taking a nasty hit this month.
Greg
Re: Q about load development
Thanks Greg.
Thanks Greg.
Re: Q about load development
I don't do anything special about cooling, but I take enough time to ensure the barrel never gets hot enough to be uncomfortable to the touch using the back of my palm. Because each of the first, second, third, etc., rounds of each group get fired roughly at about the same stage of barrel heating, then the overall effect is to shoot each group in a roughly similar barrel heating regime, eliminating unequal heating as a factor between groups.
If, for instance, I'm working with an overall charge somewhere around 25gr, the initial 2% increment equates to about .5gr. So charges would be arbitrarily, and for the sake of discussion, 25.0, 24.5, 24.0, etc. If the 24.5 increment comes out best, then I would bracket the charges at 24.7, 24.5, 24.3, etc., and see if any of these improves the grouping consistently.
Generally, I simply set the OAL at the beginning, averaging 5 dummy rounds point of OAL/rifling engagement and shortening that measurement by about .010". To me, the 'optimum' OAL engagement isn't determined by accuracy, but by consistently jumping (or not jumping) to the lands.
I don't seek ultimate accuracy, I seek acceptable accuracy. I define that as 1/2MOA at 100 benched, 1MAO at 200yd prone, and 2MOA at 1000yd prone.
When you test, you never, never, never, ever, ever, ever change more than one variable at a time. Otherwise you won't know which variable worked, didn't work, or cancelled another variable out.
Greg
I don't do anything special about cooling, but I take enough time to ensure the barrel never gets hot enough to be uncomfortable to the touch using the back of my palm. Because each of the first, second, third, etc., rounds of each group get fired roughly at about the same stage of barrel heating, then the overall effect is to shoot each group in a roughly similar barrel heating regime, eliminating unequal heating as a factor between groups.
If, for instance, I'm working with an overall charge somewhere around 25gr, the initial 2% increment equates to about .5gr. So charges would be arbitrarily, and for the sake of discussion, 25.0, 24.5, 24.0, etc. If the 24.5 increment comes out best, then I would bracket the charges at 24.7, 24.5, 24.3, etc., and see if any of these improves the grouping consistently.
Generally, I simply set the OAL at the beginning, averaging 5 dummy rounds point of OAL/rifling engagement and shortening that measurement by about .010". To me, the 'optimum' OAL engagement isn't determined by accuracy, but by consistently jumping (or not jumping) to the lands.
I don't seek ultimate accuracy, I seek acceptable accuracy. I define that as 1/2MOA at 100 benched, 1MAO at 200yd prone, and 2MOA at 1000yd prone.
When you test, you never, never, never, ever, ever, ever change more than one variable at a time. Otherwise you won't know which variable worked, didn't work, or cancelled another variable out.
Greg
Re: Q about load development
Thanks guys for all the pointers. My rig arrived today from Patriot so I'm looking forward to using these tips.
Thanks guys for all the pointers. My rig arrived today from Patriot so I'm looking forward to using these tips.
