I have a question for the experienced. When your shooting 1" groups at 100 yards and want to fine tune for a smaller pattern what would you adjust first, powder or coal? I've done some research on this and nowhere does it say how close your shots should be with powder adjustments before playing with coal or vice versa. Any solid answer or even reccomendations for this? Fyi I'm shooting 308 running 168 grn a max 42 grns of 4064 and .020 off the lands. My max coal is 3.022
Adjust powder or coal?
- Thread starter towman32
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jwrowland77
New member
Must be shooting a Rem 700. Lol
Assuming you've done a proper workout as recommended, then the only thing left to do is adjust OAL.
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Assuming you've done a proper workout as recommended, then the only thing left to do is adjust OAL.
Sent from my iPhone using Tapatalk
bacardisteve
New member
Some combos like to be seated right up to the lands other like a jump. You will never know untill you experiment. I have a weatherby in 257wby and my loads jump .090 bit they are sub moa accurate.
g.willikers
New member
^^^
Yes, you are asking the wrong folks.
You need to discuss this with your rifle.
If my rifle was doing consistent 1" groups at 100 yards, I'd probably focus on other things to improve my shooting.
Yes, you are asking the wrong folks.
You need to discuss this with your rifle.
If my rifle was doing consistent 1" groups at 100 yards, I'd probably focus on other things to improve my shooting.
berettaprofessor
New member
I'd suggest powder first. OAL shouldn't make THAT much difference. You may even need to start over with a different powder/bullet combination.
If you are going to mess with OAL, I'd move it further from the lands in your instance. At 0.020", you're already about as close to the lands as you can safely and routinely get. Any closer and you'll start running into issues closing the bolt or dangerous pressures if you're off a little on a round or two.
towman32
I'm a bench rest shooter, Remington 700 308 cal. I'm using same powder IMR 4064 the bullet I reload most of the time is the Sierra 168 gr HPBT Matchking. Just started with the A - Max 168 gr HPBT at the beginning of the summer. If your shooting with the barrel that came with the Remington , I would suggest stay with the 2.800 OAL measurement , it's better to measure to the bullets ogive. A shooting friend shoots HMS match Hornady A - Max 168's gives me his brass. He gave me one of his bullets to check powder weight & seating lengths. When removing the powder it looked like 4064 that doesn't mean much though, but a good starting point. 40.3 grain weight , 2.800 OAL . All his tipped A-Max match bullets measured from the base to the tip were 2.800 exact. So I used that same specs. With the 4064 40.3 grains 2.800 gives me a .015 jump , groups 3/4 " at 200 yards . Your Remington with a stock Rem. barrel will have such a long throat would be to long to come close to the lands. Work up from 40.3 grains your OAL at 2.800 and let me know how it goes. Hope I Helped.
I'm a bench rest shooter, Remington 700 308 cal. I'm using same powder IMR 4064 the bullet I reload most of the time is the Sierra 168 gr HPBT Matchking. Just started with the A - Max 168 gr HPBT at the beginning of the summer. If your shooting with the barrel that came with the Remington , I would suggest stay with the 2.800 OAL measurement , it's better to measure to the bullets ogive. A shooting friend shoots HMS match Hornady A - Max 168's gives me his brass. He gave me one of his bullets to check powder weight & seating lengths. When removing the powder it looked like 4064 that doesn't mean much though, but a good starting point. 40.3 grain weight , 2.800 OAL . All his tipped A-Max match bullets measured from the base to the tip were 2.800 exact. So I used that same specs. With the 4064 40.3 grains 2.800 gives me a .015 jump , groups 3/4 " at 200 yards . Your Remington with a stock Rem. barrel will have such a long throat would be to long to come close to the lands. Work up from 40.3 grains your OAL at 2.800 and let me know how it goes. Hope I Helped.
So here's my take on this and I'll add this is for the more experienced reloader that's worked with the rifle before . New to reloading guys should strictly stick to published data .
Your start COAL should be as close to the lands as possible , At the lands or mag length depending on your rifle and how you load the firearm . Meaning you start at minimum charge with maximum length . This has NOTHING to do with a bullet seated closer to the lands will be more accurate . As many know that is simply not true .
The reasoning is pretty simple . "IF" your cartridge combo is able to be seated at or in the lands ( some can't even come close Which makes this next part less critical ) . You start there because when and or if your load work up ends up at max pressure . When you start to adjust seating depth there is only one direction to go . That is off the lands which should be safe to do because the pressure should be reduced the further you get from the lands ( to a point ) .
Doing it the other way around , meaning starting WAY off the lands . "IF" your final charge that shoots well before fine tuning is at max pressure with the bullet way off the lands . You only have one direction to go again . How ever this time it's closer to the lands . This Generally will raise start pressures the closer you get . If you were already at max pressure . Seating the bullet closer and closer to the lands can increase the pressure to an unsafe place .
Then there's the idea that if you started at the lands and later you find .040 off the lands is much better . Well bringing the bullet back off the lands should reduce pressure some . Maybe leaving the bullet at the lands and reducing the charge .3gr to .5gr will do the same thing . My jury is still out on that because you should have already been there and past it on your initial load development . That .3 to .5gr less data should already exist in your notes at that COAL .
This is a recent OCW test where I was at the point of adjusting seating depth . You can clearly see the closer I get to the lands the tighter the groups get . How ever I followed the OCW method very close and started pretty far off the lands . 2.855 is just kissing the lands for this combo and I started at 2.815 .
The issue turned out that at 2.845 I get sticky bolts every once and a while that I do not get at 2.815 . That said I ended up at 2.850 as my final COAL and except the occasional sticky bolt to shoot right around 1/2 moa at 300yds
Your start COAL should be as close to the lands as possible , At the lands or mag length depending on your rifle and how you load the firearm . Meaning you start at minimum charge with maximum length . This has NOTHING to do with a bullet seated closer to the lands will be more accurate . As many know that is simply not true .
The reasoning is pretty simple . "IF" your cartridge combo is able to be seated at or in the lands ( some can't even come close Which makes this next part less critical ) . You start there because when and or if your load work up ends up at max pressure . When you start to adjust seating depth there is only one direction to go . That is off the lands which should be safe to do because the pressure should be reduced the further you get from the lands ( to a point ) .
Doing it the other way around , meaning starting WAY off the lands . "IF" your final charge that shoots well before fine tuning is at max pressure with the bullet way off the lands . You only have one direction to go again . How ever this time it's closer to the lands . This Generally will raise start pressures the closer you get . If you were already at max pressure . Seating the bullet closer and closer to the lands can increase the pressure to an unsafe place .
Then there's the idea that if you started at the lands and later you find .040 off the lands is much better . Well bringing the bullet back off the lands should reduce pressure some . Maybe leaving the bullet at the lands and reducing the charge .3gr to .5gr will do the same thing . My jury is still out on that because you should have already been there and past it on your initial load development . That .3 to .5gr less data should already exist in your notes at that COAL .
This is a recent OCW test where I was at the point of adjusting seating depth . You can clearly see the closer I get to the lands the tighter the groups get . How ever I followed the OCW method very close and started pretty far off the lands . 2.855 is just kissing the lands for this combo and I started at 2.815 .
The issue turned out that at 2.845 I get sticky bolts every once and a while that I do not get at 2.815 . That said I ended up at 2.850 as my final COAL and except the occasional sticky bolt to shoot right around 1/2 moa at 300yds
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I want to add, after shooting 4000+ rounds through my stock Rem. 700 LTR 308 cal. Had the action blueprinted , new match Rock Creek M24 barrel installed . The new barrel had a short throat , I could jump or jam my reloads. Using a Sierra 168 gr MK I found tight groupings with a .006 jam & also a .009 jump. Using A - Max 168 gr. HPBT best group .015 jump . Found by measuring store bought Hornady match 168's , from base to tip all measured 2.800 . Maybe because of the tipped bullets ? I know its best to measure to the ogive , with Sierra the tip isn't as exact, will give the TMK's a try. Some barrels you can't jam due to , too much free bore. Not enough neck to hold the bullet in position.
firewrench044
New member
I did better with Varget with the 168s
and found the Amaxs liked to be 10 to 15 thou. off the lands
My 700 prefers the 175 MKs
and found the Amaxs liked to be 10 to 15 thou. off the lands
My 700 prefers the 175 MKs
berettaprofessor
New member
MetalGod and others; I'll admit, I'm really just a newby reloader (2+ years) who has learned most of what I think I know from this and other forums....so I could easily be wrong. But from what I think I understand, the above is not correct. If you're at maximum pressure and you shorten your OAL, you are going to INCREASE PRESSURE, not decrease it. I realize if you are at maximum pressure and at an OAL just short of the lands, increasing to the lands will raise pressure as well. But I believe the above advice you gave is dangerous. Please explain to me how I'm wrong.
firewrench044
New member
I was not happy with 168s ether that is why I went to 175s
( they use the same hole at 100 and 200 )
Each rifle is different, some my shoot better with 168s than others
same with powder
with the 168s mine shot best with Varget
4064 was a very close second
( they use the same hole at 100 and 200 )
Each rifle is different, some my shoot better with 168s than others
same with powder
with the 168s mine shot best with Varget
4064 was a very close second
towman32
That's different . Savages you should be able to jump or jam. Their bolt guns are accurate, I would still try the match A- Max load IMR 4064 40.3 grains with OAL of 2.800. Sorry , for some reason I thought you had a Remington. What brass are you using.? Are you full or neck sizing? Sized cases to what case headspace? Hunting or benchrest?
That's different . Savages you should be able to jump or jam. Their bolt guns are accurate, I would still try the match A- Max load IMR 4064 40.3 grains with OAL of 2.800. Sorry , for some reason I thought you had a Remington. What brass are you using.? Are you full or neck sizing? Sized cases to what case headspace? Hunting or benchrest?
No problem , lets see if i can explain it . I Know what im thinking but it does not always translate to paper well
With a jump to the lands you get gases that blow by/around the bullet before it engages the lands as well as the bullet moving forward with no resistance creating more space behind it for the gas to expand . That extra space and blow by reduces start pressures .
If the bullet is at or in the lands there is no blow by or quick bullet movement increasing case volume and all gases produced are immediately turned into pressure .
Rifle is not the same as hand gun in respect to seating deeper . You can seat deep with rifle with less effect then hand gun . When i say deeper i don't mean deeper then minimum . I'm talking in relation to your current seating depth assuming it's more then minimum .
Example book says 2.800 , your max to/at lands is 2.860 and your loaded COAL is 2.830 you will have less start pressure if you go back to 2.800 then you will going forward to 2.860 for the reasons explained above . You need to seat the the bullet pretty deep in the case taking up critical case volume to cause a similar pressure spike .
Hand gun cases have much less internal case volume to play with then rifle cases as well as hand gun powders burn much faster filling that small case volume much quicker then the large rifle case with much slower burning powders .
Now that's a general explanation . There are exceptions to the rules when you change burn rates to case volume to bullet diameter
With a jump to the lands you get gases that blow by/around the bullet before it engages the lands as well as the bullet moving forward with no resistance creating more space behind it for the gas to expand . That extra space and blow by reduces start pressures .
If the bullet is at or in the lands there is no blow by or quick bullet movement increasing case volume and all gases produced are immediately turned into pressure .
Rifle is not the same as hand gun in respect to seating deeper . You can seat deep with rifle with less effect then hand gun . When i say deeper i don't mean deeper then minimum . I'm talking in relation to your current seating depth assuming it's more then minimum .
Example book says 2.800 , your max to/at lands is 2.860 and your loaded COAL is 2.830 you will have less start pressure if you go back to 2.800 then you will going forward to 2.860 for the reasons explained above . You need to seat the the bullet pretty deep in the case taking up critical case volume to cause a similar pressure spike .
Hand gun cases have much less internal case volume to play with then rifle cases as well as hand gun powders burn much faster filling that small case volume much quicker then the large rifle case with much slower burning powders .
Now that's a general explanation . There are exceptions to the rules when you change burn rates to case volume to bullet diameter
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To finish my last post I have a savage law enforcement fcp McMillan, 24 in barrel and a 1:10 twist. It would seem there are alot of opinions on wich way is right. Not sure who is right or wrong. Beretta professor is it possible you are confusing case pressure and chamber pressure? I'm new as well only doing this 3 years now. Trying to fine tune my skills. I have shot tighter groups before but no consistency with my replica loads. One thing I know could be a factor is all my different casings. (Headstamps)
It will be awhile before I can hit the range again but when I do I will report back. I've worked up my loads but only broke them down by .5 grns. I think I will try dropping .2 and see how it does. Thanks for all the info guys I will continue to read anyone else's posts. And METAL GOD that was a hell of alot of info. Not sure I should start with max oal but will definitely start pushing it towards the lands and see. I know last year I loaded some 168 grn a max with 43 grns 4064 and at .005 off the lands I was blowing an occasional primer out of the case. I think I will play it safe and work up.
It will be awhile before I can hit the range again but when I do I will report back. I've worked up my loads but only broke them down by .5 grns. I think I will try dropping .2 and see how it does. Thanks for all the info guys I will continue to read anyone else's posts. And METAL GOD that was a hell of alot of info. Not sure I should start with max oal but will definitely start pushing it towards the lands and see. I know last year I loaded some 168 grn a max with 43 grns 4064 and at .005 off the lands I was blowing an occasional primer out of the case. I think I will play it safe and work up.
CW 308
I'm using a wide variety of winchester, pmc,lc,hornady match, lc match, Federal etc. I'm sizing full length due to shooting with friends and not keeping track of who's brass was whos. As for head space I just use a head space guage (no numbers to report if it fits flush I know it works). And bench for now. Would you reccommend good brass to use?
I'm using a wide variety of winchester, pmc,lc,hornady match, lc match, Federal etc. I'm sizing full length due to shooting with friends and not keeping track of who's brass was whos. As for head space I just use a head space guage (no numbers to report if it fits flush I know it works). And bench for now. Would you reccommend good brass to use?
Towman32 said:
No not at all , I never mentioned velocity and clearly stated in my OP
.Me said:
I'm saying its OK to jam in the lands as long as that's where you start your load development with the minimum charge . You may even want to consider starting .5 to 1gr under . My explanation above and now possibly suggesting starting below minimum is why I started my OP with
Me said:
Im in no way suggesting someone new to reloading should just grab any rifle jam the bullet in the lands and go for it .
My point was to your specific question , should you adjust the charge or seating depth to fine tune . If you're likely at max pressure , id be careful getting into or jammed in the lands . You say you're .020 off the lands . If I were adjusting that load and felt closer may be better . Id move up in .005 increments very carefully . At the same time id have no issues seating deeper in .010 increments assuming you are seated well out from minimum or manuals suggested start length
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