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Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Load development. Where to go first?
12/25/2016
I just got my 280 back from RWS and threw together a load .005" off the lands with 55gr RL19 behind a 162 amax. Groups was about 1.5-1.75" at 125 yards (distance I use in the winter).
My question is where to go first. Do you guys usually mess with OAL, powder type, or powder charge first? Just looking for a sense of direction to eliminate wasting time and supplies.
Thanks!
Rate now:
padom
XFirst Sergeant
Rating: 3.8/5 this site
3050 posts this site
Re: Load development. Where to go first?
12/25/2016
look up Dan Newberry OCW method.
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
Yea that's what I was going to do I think. If I load to the lands (which seems really common when looking at other people's 280 and 280AI loads) and then do the OCW that should help me figure out what's going on.
Rate now:
AntiMatterSHXGunny Sergeant
Rating: 2.9/5 this site
634 posts this site
Re: Load development. Where to go first?
12/25/2016
Another option, if you have the range, is a ladder test.
http://www.6mmbr.com/laddertest.html
Or, there is the simplest method. Just work up in charge weight (0.5 grain at a time) until your groups shrink and your standard deviations are single digit.
Rate now:
SigMarineXSergeant
Rating: 3.2/5 this site
436 posts this site
Re: Load development. Where to go first?
12/25/2016
My sequence for doing a load work-up is:
- Pressure test for maximum load - I do this in .5 grain increments after doing some research and finding out a range of charge weights for the powder I'm going to use.
- I load for an OCW test using Dan Newberry's formula.
- Shoot OCW
- Analyze results to determine the my charge weight from the 3-shot, 3-group window
- Test this charge weight at distance, usually groups at 300 yards
- If accuracy is good, I chrono 10 rounds of that charge weight to get muzzle velocity for my ballistics program
- Make a data card with elevation drops to 1000 yards (longest at our range)
- Go to the range to verify ballistic program drops and make changes based on true drops
Some guys like to load an OCW and do pressure testing at the same time they shoot their OCW. This works if your time challenged but I'm not a fan of having to break-down a large number of loads if pressure shows up before finishing the range of charge weights I'm using for the test.. When I do my pressure tests separate, I usually have only 1-2 rounds to tear apart.
The above method will give you a relatively good load that can be fine tuned with seating depth if desired. This of course depends a lot on the style of bullet and its sensitivity to jump or jam. I use a lot of Berger Hybrids and they are very, very jump friendly. I've not seen significant changes in group size just by changing seating depths. Other bullets, like Berger VLDs, are more jump sensitive and seating depths can make a big difference.
There are many ways to develop a load but this method has well worked for me. YMMV...Sig Marine
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016 Last edited 12/25/2016 by Iamero
Yea probably the best way to do it. I was going to load to lands starting at 54 and go up .3 at a time.
I should have chronoed the 55gr to see where I was at because I want to land 2900-2950.
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
Lamero,
My suggestion is to do the following:
Start at a minimum of 10 thousandths off the lands (preferably 20)
Reason for that is during my testing jammed/kissing loads would shoot real well but when they jumped just a little the load would be off noticeably.
I think the reasoning is jammed starts the pressure wave and remains consistent as it goes down the barrel. Then when you go to a slight jump it distorts that.
If you start off jumping it builds up but I suppose generates enough force to make contact with the lands and continue without too much of a hiccup.
I can't prove any of this but my thoughts since I developed some loads that shot extremely
Well jammed but when I started jumping I had to make powder charge tweaks.
Do either ocw or ladder and go .3-.5 increments (I do .5)
For a fresh barrel I make 40 generic loads (30 thousands off at a low/medium charge) to shoot the barrel in before I do development.
Since you said 125 yards that's fine to do OCW with also. You could do ladder but the incremental steps would be really close with each other and then when you have your velocity jumps you'll see that on target too
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
So should I leave it at .005" off the lands or get a little closer?
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
I said back off and start at a 10 thousandth jump minimum.
But answer me this: are you mag feeding or single feeding?
If you're mag feeding you need to start st max mag length and work from there.
Reason being is if there is a huge jump difference from being 20 thousandths off the lands single feeding vs when you start mag feeding , you're changing the internal combustion and your original powder node will be off.
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
I am mag feeding and if I load max mag length it will be jammed in the lands. I loaded .005" off the lands and I had about .08" left in the mag
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
Nice man, that's best case scenario imo.
Well you have your options how you approach is up to you.
Rate now:
BraduXFirst Sergeant
Rating: 3.4/5 this site
2158 posts this site
Re: Load development. Where to go first?
12/25/2016 Last edited 12/25/2016 by Bradu
I prefer to start at .015" jump regardless of the bullet. I don't like jamming because most bullets aren't consistent enough to jam in my opinion.
Rate now:
padom
XFirst Sergeant
Rating: 3.8/5 this site
3050 posts this site
Re: Load development. Where to go first?
12/25/2016
For my bolt guns I always do OCW at .02 off lands. Find my OCW then do seating depth to shrink groups.
For semis I do the same as above but start at max mag length.
Rate now:
CharlieNCXGunny Sergeant
Rating: 3.3/5 this site
643 posts this site
Re: Load development. Where to go first?
12/26/2016
Over the years I have read all I could find on the topic, and tried numerous options. The Audette ladder and OCW methods are based on the same principle and will lead to the same answer. A few years ago I quizzed an expert on this topic, and he suggested not to waste time trying to make a bullet shoot that your barrel did not like. He would shoot a few bullet options through a new barrel using known good nominal charges to select the bullet to focus on. Otherwise it's easy to get bogged down in a load development that may not have a good future outcome.
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Load development. Where to go first?
12/25/2016
I just got my 280 back from RWS and threw together a load .005" off the lands with 55gr RL19 behind a 162 amax. Groups was about 1.5-1.75" at 125 yards (distance I use in the winter).
My question is where to go first. Do you guys usually mess with OAL, powder type, or powder charge first? Just looking for a sense of direction to eliminate wasting time and supplies.
Thanks!
Rate now:
padom
XFirst Sergeant
Rating: 3.8/5 this site
3050 posts this site
Re: Load development. Where to go first?
12/25/2016
look up Dan Newberry OCW method.
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
Yea that's what I was going to do I think. If I load to the lands (which seems really common when looking at other people's 280 and 280AI loads) and then do the OCW that should help me figure out what's going on.
Rate now:
AntiMatterSHXGunny Sergeant
Rating: 2.9/5 this site
634 posts this site
Re: Load development. Where to go first?
12/25/2016
Another option, if you have the range, is a ladder test.
http://www.6mmbr.com/laddertest.html
Or, there is the simplest method. Just work up in charge weight (0.5 grain at a time) until your groups shrink and your standard deviations are single digit.
Rate now:
SigMarineXSergeant
Rating: 3.2/5 this site
436 posts this site
Re: Load development. Where to go first?
12/25/2016
My sequence for doing a load work-up is:
- Pressure test for maximum load - I do this in .5 grain increments after doing some research and finding out a range of charge weights for the powder I'm going to use.
- I load for an OCW test using Dan Newberry's formula.
- Shoot OCW
- Analyze results to determine the my charge weight from the 3-shot, 3-group window
- Test this charge weight at distance, usually groups at 300 yards
- If accuracy is good, I chrono 10 rounds of that charge weight to get muzzle velocity for my ballistics program
- Make a data card with elevation drops to 1000 yards (longest at our range)
- Go to the range to verify ballistic program drops and make changes based on true drops
Some guys like to load an OCW and do pressure testing at the same time they shoot their OCW. This works if your time challenged but I'm not a fan of having to break-down a large number of loads if pressure shows up before finishing the range of charge weights I'm using for the test.. When I do my pressure tests separate, I usually have only 1-2 rounds to tear apart.
The above method will give you a relatively good load that can be fine tuned with seating depth if desired. This of course depends a lot on the style of bullet and its sensitivity to jump or jam. I use a lot of Berger Hybrids and they are very, very jump friendly. I've not seen significant changes in group size just by changing seating depths. Other bullets, like Berger VLDs, are more jump sensitive and seating depths can make a big difference.
There are many ways to develop a load but this method has well worked for me. YMMV...Sig Marine
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016 Last edited 12/25/2016 by Iamero
Yea probably the best way to do it. I was going to load to lands starting at 54 and go up .3 at a time.
I should have chronoed the 55gr to see where I was at because I want to land 2900-2950.
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
Lamero,
My suggestion is to do the following:
Start at a minimum of 10 thousandths off the lands (preferably 20)
Reason for that is during my testing jammed/kissing loads would shoot real well but when they jumped just a little the load would be off noticeably.
I think the reasoning is jammed starts the pressure wave and remains consistent as it goes down the barrel. Then when you go to a slight jump it distorts that.
If you start off jumping it builds up but I suppose generates enough force to make contact with the lands and continue without too much of a hiccup.
I can't prove any of this but my thoughts since I developed some loads that shot extremely
Well jammed but when I started jumping I had to make powder charge tweaks.
Do either ocw or ladder and go .3-.5 increments (I do .5)
For a fresh barrel I make 40 generic loads (30 thousands off at a low/medium charge) to shoot the barrel in before I do development.
Since you said 125 yards that's fine to do OCW with also. You could do ladder but the incremental steps would be really close with each other and then when you have your velocity jumps you'll see that on target too
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
So should I leave it at .005" off the lands or get a little closer?
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
I said back off and start at a 10 thousandth jump minimum.
But answer me this: are you mag feeding or single feeding?
If you're mag feeding you need to start st max mag length and work from there.
Reason being is if there is a huge jump difference from being 20 thousandths off the lands single feeding vs when you start mag feeding , you're changing the internal combustion and your original powder node will be off.
Rate now:
Iamero
XFirst Sergeant
Rating: 3.2/5 this site
3309 posts this site
Re: Load development. Where to go first?
12/25/2016
I am mag feeding and if I load max mag length it will be jammed in the lands. I loaded .005" off the lands and I had about .08" left in the mag
Rate now:
GhengisAhn175XFirst Sergeant
Rating: 3.4/5 this site
2528 posts this site
Re: Load development. Where to go first?
12/25/2016
Nice man, that's best case scenario imo.
Well you have your options how you approach is up to you.
Rate now:
BraduXFirst Sergeant
Rating: 3.4/5 this site
2158 posts this site
Re: Load development. Where to go first?
12/25/2016 Last edited 12/25/2016 by Bradu
I prefer to start at .015" jump regardless of the bullet. I don't like jamming because most bullets aren't consistent enough to jam in my opinion.
Rate now:
padom
XFirst Sergeant
Rating: 3.8/5 this site
3050 posts this site
Re: Load development. Where to go first?
12/25/2016
For my bolt guns I always do OCW at .02 off lands. Find my OCW then do seating depth to shrink groups.
For semis I do the same as above but start at max mag length.
Rate now:
CharlieNCXGunny Sergeant
Rating: 3.3/5 this site
643 posts this site
Re: Load development. Where to go first?
12/26/2016
Over the years I have read all I could find on the topic, and tried numerous options. The Audette ladder and OCW methods are based on the same principle and will lead to the same answer. A few years ago I quizzed an expert on this topic, and he suggested not to waste time trying to make a bullet shoot that your barrel did not like. He would shoot a few bullet options through a new barrel using known good nominal charges to select the bullet to focus on. Otherwise it's easy to get bogged down in a load development that may not have a good future outcome.
