After OCW is determined - start testing jump?
- Thread starter thefitter
- Start date
Re: After OCW is determined - start testing jump?
I was waiting for someone more experienced to chime in, but yeah, that's what I'm doing. HOWEVER, ifnyou are currently loading with some amount of jump, beware that decreasing the jump will increase pressure, it may be advantageous to load a round one powder step below your best for a load with less jump, examine for pressure signs, then proceed.
My overall cow strategy was/is:
First step as on OCW instructions
Second step, took best point, and the one above, one below, split that range into 8 steps
Third, using the best, and it's neighbors from the above, made 3 each of each of 3 powder weight and 3 jumps (the 0.0020 as before, and 0.010", 0.030")
I figure that allows me to truly track the necessary variables, provides adequate stats, and uses less than 25-30rnds per step.
Further refinement if needed
I was waiting for someone more experienced to chime in, but yeah, that's what I'm doing. HOWEVER, ifnyou are currently loading with some amount of jump, beware that decreasing the jump will increase pressure, it may be advantageous to load a round one powder step below your best for a load with less jump, examine for pressure signs, then proceed.
My overall cow strategy was/is:
First step as on OCW instructions
Second step, took best point, and the one above, one below, split that range into 8 steps
Third, using the best, and it's neighbors from the above, made 3 each of each of 3 powder weight and 3 jumps (the 0.0020 as before, and 0.010", 0.030")
I figure that allows me to truly track the necessary variables, provides adequate stats, and uses less than 25-30rnds per step.
Further refinement if needed
Re: After OCW is determined - start testing jump?
For a fussy bullet like the VLD's I do a seating depth test first at min load spec for a given powder.
Then an OCW test
Then fine tuning the powder charge with some 5 shot groups. Pick the best 2 and shoot 15 rounds of each on the same target.
Then if you so feel the need, adjust seating depth again. I've only felt the need to do so 1 time.
For a fussy bullet like the VLD's I do a seating depth test first at min load spec for a given powder.
Then an OCW test
Then fine tuning the powder charge with some 5 shot groups. Pick the best 2 and shoot 15 rounds of each on the same target.
Then if you so feel the need, adjust seating depth again. I've only felt the need to do so 1 time.
Re: After OCW is determined - start testing jump?
I do OCW, then distance from lands then fine tune the charge weight.
I do OCW, then distance from lands then fine tune the charge weight.
Re: After OCW is determined - start testing jump?
If its a fussy bullet i would check depth first and then charge weight.
Go for the ideal OAL you want and then do some minor load development. If they all shoot like crap, more closer to the lands and work from there.
If its a fussy bullet i would check depth first and then charge weight.
Go for the ideal OAL you want and then do some minor load development. If they all shoot like crap, more closer to the lands and work from there.
Re: After OCW is determined - start testing jump?
When I kick off the OCW I try to get something close to start with based on previous experience with that bullet.
Pretty simple really, .050" for TSX's, and .010" for most eveything else. Once I hit the OCW, then I play with that depth a little more to see if it matters. Sometimes it does, sometimes it doesn't.
I pay more attention to runout during R&D than how many give or takes on seating depth.....
When I kick off the OCW I try to get something close to start with based on previous experience with that bullet.
Pretty simple really, .050" for TSX's, and .010" for most eveything else. Once I hit the OCW, then I play with that depth a little more to see if it matters. Sometimes it does, sometimes it doesn't.
I pay more attention to runout during R&D than how many give or takes on seating depth.....
Re: After OCW is determined - start testing jump?
I'm a little puzzled about calling a VLD a fussy bullet because I never had any problems???
I'm a little puzzled about calling a VLD a fussy bullet because I never had any problems???
Re: After OCW is determined - start testing jump?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skinnypitt</div><div class="ubbcode-body">I'm a little puzzled about calling a VLD a fussy bullet because I never had any problems??? </div></div>
The point in that statement was that VLD's tend to be seating depth sensitive, far more than something with a nice, smooth, tangent ogive.
They can be easily tuned for depth, but it actually requires testing to do it. The general behavior of a bullet like (for example reasons only) the 30c 175gr SMK is that you load it to 20thou off the lands or at mag length and simply shoot it. The vast majority of the time is that it will stack circles when that node is hit.
I've had numerous times with VLD's that simply changing the seating depth by 0.010" took a rifle from 1.5 MOA to 0.3 MOA
Based on that experience, I find it hard to sort out powder charge without doing a seating depth test at the very beginning.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skinnypitt</div><div class="ubbcode-body">I'm a little puzzled about calling a VLD a fussy bullet because I never had any problems??? </div></div>
The point in that statement was that VLD's tend to be seating depth sensitive, far more than something with a nice, smooth, tangent ogive.
They can be easily tuned for depth, but it actually requires testing to do it. The general behavior of a bullet like (for example reasons only) the 30c 175gr SMK is that you load it to 20thou off the lands or at mag length and simply shoot it. The vast majority of the time is that it will stack circles when that node is hit.
I've had numerous times with VLD's that simply changing the seating depth by 0.010" took a rifle from 1.5 MOA to 0.3 MOA
Based on that experience, I find it hard to sort out powder charge without doing a seating depth test at the very beginning.
Re: After OCW is determined - start testing jump?
I like SAAMI lots and lots. I figure the max OAL specified in the bullet makers' load manuals is a good length to load to. I don't subscribe to maximum accuracy at any/all costs. I prefer to have ammo that will always feed and function, and should not become a hazard to others should it become misplaced.
Greg
I like SAAMI lots and lots. I figure the max OAL specified in the bullet makers' load manuals is a good length to load to. I don't subscribe to maximum accuracy at any/all costs. I prefer to have ammo that will always feed and function, and should not become a hazard to others should it become misplaced.
Greg
Re: After OCW is determined - start testing jump?
Yeh Greg I thought you were alright man... but now you suck
Just kidding
Greg thats why i tend to have two loads... one is mag length, the others are all LR hammer rounds.
I use my rifle for two things. Targets and hunting.
Targets and LR Hunting get the hammers.
Hunting within 300 yards get mag length with a little sacrifice (imo) on accuracy
Your beliefs are 100% justified.
Yeh Greg I thought you were alright man... but now you suck
Just kidding
Greg thats why i tend to have two loads... one is mag length, the others are all LR hammer rounds.
I use my rifle for two things. Targets and hunting.
Targets and LR Hunting get the hammers.
Hunting within 300 yards get mag length with a little sacrifice (imo) on accuracy
Your beliefs are 100% justified.
Re: After OCW is determined - start testing jump?
Are any bullets really seating depth sensitive? Think about it.......The bullet starts its course in relationship to the center of the bore. There is only one way out and that is dead straight.
Are any bullets really seating depth sensitive? Think about it.......The bullet starts its course in relationship to the center of the bore. There is only one way out and that is dead straight.
Re: After OCW is determined - start testing jump?
Yes
Aggresive ogive bullets are sensitive.
But when you think about it, sensitive is really a description that is subject to interpretation.
To some, the bullet leaving the more might be adequate.
If i hand load Berger VLD's for a rifle with a match grade barrel and Im getting 1" (1moa) groups at 100 yards, I will be far from impressed... Yet to some people this might be considered a reasonable group.
So if someone told you to seat those VLDs on the lands, and all of a sudden that group went from 1" to 1/4", would you say those bullets are not sensitive to seating depth?
At the end of the day accuracy AND precision are achieved from loading perfect ammunition. Perfect brass with concentric necks, with a powder charge with the least MV variation, with projectiles seated with zero run out.
I cannot prove this, however I have found a trend in MY shooting, that seating depth does make a difference and the screamer groups that i have shot are from bullets that touch the lands... I would expect to see more fliers come from projectiles with large jumps and loads of runout.
Just my 0.02
Yes
Aggresive ogive bullets are sensitive.
But when you think about it, sensitive is really a description that is subject to interpretation.
To some, the bullet leaving the more might be adequate.
If i hand load Berger VLD's for a rifle with a match grade barrel and Im getting 1" (1moa) groups at 100 yards, I will be far from impressed... Yet to some people this might be considered a reasonable group.
So if someone told you to seat those VLDs on the lands, and all of a sudden that group went from 1" to 1/4", would you say those bullets are not sensitive to seating depth?
At the end of the day accuracy AND precision are achieved from loading perfect ammunition. Perfect brass with concentric necks, with a powder charge with the least MV variation, with projectiles seated with zero run out.
I cannot prove this, however I have found a trend in MY shooting, that seating depth does make a difference and the screamer groups that i have shot are from bullets that touch the lands... I would expect to see more fliers come from projectiles with large jumps and loads of runout.
Just my 0.02
Re: After OCW is determined - start testing jump?
That remark about starting out centered is a part of the reasoning behind my partial length neck sizing technique. By only resizing the end portion of the neck's length, the lower neck portion remains expanded to nearly full chamber neck diameter. This assures that the case and the seated bullet start out as near to centered within that chamber neck as is possible. Necks that are resized full length have more, perhaps too much, 'wiggle room'.
I'm not sure about it, but I suspect that this technique might also limit the formation of donuts, and perhaps minimize the effects of any that may form.
Finally, the partial length neck sizing reduces the contact area between neck and bullet, consequently reducing neck tension. My research suggests that the best neck tension is the amount that grasps the bullet least, while remaining adequate to prevent bullet displacement during ammunition handling. By adjusting the neck resizing length, this precisely adequate degree of neck tension can be checked and adjusted.
Partial length neck resizing is a means to allow neck tension management with a standard F/L resizer die. It is achieved by backing the die off so it the case doesn't enter as deeply. This also leaves the very bottom base portion of the case wall unresized. My experience is that once expanded, the additional case wall diameter seldom causes any problems, and by reducing brass working in the area, its integrity may be improved.
If and when shoulders get tight, the dies can be adjusted to bump them, then returned to the partial length adjustment for the next loading. Alternatively, a bump die can be used, and I find that dies for sibling cha,berings can serve this purpose, as when using a .308 Win F/L die to bump .260 Rem case shoulders.
This is not some way out harebrained fluky conception, but rather an old historic BR handloading technique used by precision shooters in the days when F/L resizing dies were the only type available. My Eldest Brother used to be one of those folks, and passed the technique on to me.
Greg
That remark about starting out centered is a part of the reasoning behind my partial length neck sizing technique. By only resizing the end portion of the neck's length, the lower neck portion remains expanded to nearly full chamber neck diameter. This assures that the case and the seated bullet start out as near to centered within that chamber neck as is possible. Necks that are resized full length have more, perhaps too much, 'wiggle room'.
I'm not sure about it, but I suspect that this technique might also limit the formation of donuts, and perhaps minimize the effects of any that may form.
Finally, the partial length neck sizing reduces the contact area between neck and bullet, consequently reducing neck tension. My research suggests that the best neck tension is the amount that grasps the bullet least, while remaining adequate to prevent bullet displacement during ammunition handling. By adjusting the neck resizing length, this precisely adequate degree of neck tension can be checked and adjusted.
Partial length neck resizing is a means to allow neck tension management with a standard F/L resizer die. It is achieved by backing the die off so it the case doesn't enter as deeply. This also leaves the very bottom base portion of the case wall unresized. My experience is that once expanded, the additional case wall diameter seldom causes any problems, and by reducing brass working in the area, its integrity may be improved.
If and when shoulders get tight, the dies can be adjusted to bump them, then returned to the partial length adjustment for the next loading. Alternatively, a bump die can be used, and I find that dies for sibling cha,berings can serve this purpose, as when using a .308 Win F/L die to bump .260 Rem case shoulders.
This is not some way out harebrained fluky conception, but rather an old historic BR handloading technique used by precision shooters in the days when F/L resizing dies were the only type available. My Eldest Brother used to be one of those folks, and passed the technique on to me.
Greg
Re: After OCW is determined - start testing jump?
Greg,
I marvel at your wisdom and post count
your friend from the land down under,
vman
hehehe
Greg,
I marvel at your wisdom and post count
your friend from the land down under,
vman
hehehe
Similar threads
