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Hand Loading for Long Range 3: finding start OAL

Re: Hand Loading for Long Range 3: finding start O

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jmtyndall</div><div class="ubbcode-body">So I drew a picture so that it's easier to understand what I'm asking.

Untitled-2.png


So if I use bullet A to find max COL when the ogive touches the lands, then do I use this same COL @ the ogive for bullets B and C? Or do I have to retake this measurement for each bullet?</div></div>
Retake it for each bullet. The problems that can be encountered can be give you over pressure. The only way that would work is if you had a true chamber gauge that was cut with the same ream used on the barrel. It really isn't that big a deal to do for each bullet profile.
 
Re: Hand Loading for Long Range 3: finding start O


Yeah +1 for what Mechanic said, but i'll throw in that a good tool that gives you measurement off the ogive will get you "pretty close" bullet to bullet. Prolly as close as you need, but do heed Mechanics warning, it is for sure valid, especially if your jamming hard & running hot loads.
 
Re: Hand Loading for Long Range 3: finding start O

I just plan on following what you have here since this is my first "precision" rifle.

Anyways, I redid it for each bullet. All were close to the same except berger VLDs, they were off by a bit so I'm glad I did redo it for each bullet.
 
Re: Hand Loading for Long Range 3: finding start O

I also like to load up a dummy round that has a bullet at the lands and then do a measurement, take a perm marker and write the dimension on the side for reference.
 
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Re: Hand Loading for Long Range 3: finding start O

Tag for later
 
Re: Hand Loading for Long Range 3: finding start O

So I know it may be a noob question but I only just started reloading a couple of weeks ago. And as you can see from my posts I'm new to this community so please be gentle.

Does reducing/eliminating jump always increase the accuracy of your load? The way a couple of these posts sounded, some guns like a little jump and some are designed with more than others.

In reading a couple of the reloading topics I see people listing their loads for .308 win with OALs of over 2.800 inches which is what my reloading manuals list as the Max OAL. Are the reloading manuals just being conservative due to the fact that they can't account for all types and manufactures of firearms?

With that being said, I have reloaded a couple of rounds reproducing the COAL from the round that has given me the best accuracy so far. In your experiences do you think I should scrap that and reload the rounds to get a OAL using the method posted here?
 
Re: Hand Loading for Long Range 3: finding start O

If you want to load each round individually for the best possible accuracy jam em and use the tools and the other methods discussed earlier in the thread (there are other parts to this series this is only like 1 of 4 or 5) and find your chambers dimension for this and follow all instruction discussed previously. Also he's using the jamming for a base line it's been discussed that greater accuracy may be achieved by backing off but for starting off the jamming is suggested as the best possible starting point.

If you don't want to load every bullet individually the 2.800 length printed in your manual and mine will feed out of all fixed and removable .308 magazines.

I'm with the fellow that has a ridiculous amount amount of freebore in my Remington 700P. My bullet is about to fall out of the brass before it touches the rifling. So I load mine to 2.812. cause they still fit in my fixed box magazine.

I've read where the actual design of the bullet is very important to being tolerant of jump to the rifling. I guess VLD's aren't very tolerant of jump and the rounder nose of the Sierra match King's bullets are more forgiving of being jumped since the transition of the bullet into the rifling is a "smoother" transition for the rounder nosed bullets. anyways.

Reloading for Competition by Glen Zeidiker would be a great Christmas gift for you, I think that's where I read the VLD vs round nosed bullet jump theory.

Be very careful about jamming read all of this series and when you have a thorough understanding of the subject and the methods then maybe try the jamming. Unfortunately I don't think it's safe for me to try it in my 700P .308 with only about 3/16ths of inch of bullet in the brass. I could be wrong, but what if I'm not.... Another downside wrote about is that if you need to extract a jammed bullet, it may get stuck in the rifling and your brass can come out without the bullet meanwhile your powder is falling out of the brass. oops.

This jamming method may be more geared more towards a custom match chambered rifle where the chambers tolerances are tighter. "Theoretically" a gunsmith could chamber a rifle for a specific bullet that can be jammed at 2.812.... Jammed and fit in the magwell/magezines. I dont think it's actually being done it's just an example of the chambering possibilities and chamber variance also why some people have different dimensions for their jammed OAL's and why people get different results with their hand loads. Several versions of the .308 chambering out there.

So exactly how far out can someone safely load a bullet??? Is 3/16 of an inch in the brass safe??

BTW I'm still getting great results jumping but I bet they'd be better if I could jam them. Just my opinion...
 
Re: Hand Loading for Long Range 3: finding start O


Good Answer 2Clicks...

Yeah 3/16 of case neck is "safe" but neck tension / bullet support will prolly be so little be so little you'll not actually jam, rather the riflings will just shove the bullet deeper into the case on chambering. not to mention it will be far easier to bump the bullet out of alignment while chambering

But go back and read post #1764190 on page one of this thread. Wonderful accuracy can be attained while jumping a bullet. It's generally not jump or die.
 
Re: Hand Loading for Long Range 3: finding start O

Well, I bought a Hornady OAL gauge (the straight one) and a bullet comparator, and determined that the freebore is <span style="text-decoration: line-through">.019</span> 0.190". (Measuring from ogive of bullet seated at lands contact compared to ogive of bullet seated at 2.800") Does this seem about right to you cats? Should I seat to "jam" into the rifling a bit and load for minimums like the sticky post in "Reloading" says?

How is my freebore anyway? What was yours? NOTE: I crossposted this in "Bolt Action Rifles."
 
Re: Hand Loading for Long Range 3: finding start O

I don't chime in much on forums, mostly read posts and books too. I especially enjoy reading what folks here contribute, Tres for sure, and on The Rifleman's Journal blog by German Salazar. One of my fav books is Glen's as mentioned in earlier posts here.

Anyhow, in re-reading parts by Tres, I just thought I'd through out my bit on OAL by using my Stoney Point OAL Gauge (Sinclair now)and by using the seating method whereas, I take a fired case partially re-sized with a Forster Bushing Bump die. I bump the shoulder back no more than .002 and size the neck just enough so that I can get enough tension on the bullet that I can pull it out with a little bit of effort by hand and slide in the case as I close the bolt without pulling back out of the neck when I open it.(sticking to the rifling) My comparisons give me jam at about .004 in based on the amount of neck tension I've applied. Everything is very clean when I start my work. So far my testing and through reading of others, I have found that my VLD's like to be jammed and my non-VLD's e.g. Sierra BTHP and the like prefer .010 to .018 jump depending on my round. .018 w/155 Palma's and .010 with 175's to 180's in my particular rifle which is a 700 40XB-tactical in .308, a consistent one hole shooter @ 100yds.
 
Re: Hand Loading for Long Range 3: finding start O


Thanks for speaking up Vet! Good stuff.

I still get some stickage in my barrel doing it that way no matter how careful I am. But it might be the combination of vld's and my particular barrel.

It's a fine way to go about it if you get consistent results as you know. Thanks for the jam & jump info. Nice rifle by the way.
 
Re: Hand Loading for Long Range 3: finding start O


Here if you guys need me,
Tres
 
Re: Hand Loading for Long Range 3: finding start OAL

Thanks for the info! Very Helpful!
 
Re: Hand Loading for Long Range 3: finding start O

Thanks for all the great info. I'm new to reloading and am very grateful for all the info you have provided,its obviously very time consuming. I've just picked up my first GAP Crusader in 308 and am still working up the best load.
Thanks again
 
Re: Hand Loading for Long Range 3: finding start O



Here to help,
Thanks!
 
Re: Hand Loading for Long Range 3: finding start O

I'm with the other 700P guys that have an insane amount of excess in everything in my chamber - actually sent TresMons a couple of PMs about how over some of my measurements were to confirm with him, as this is my first bolt action rifle and first go around with precision loads.

Here's some of the specs in my Rem 700P in .308:
Headspace/Shoulder Length: 1.564"
Chamber Length: 2.055" (really? .050 over the trim-to length?)

When I use the Hornady OAL Gauge and Comparator, here's some of the ridiculous dimensions I get using their case and a 168 SMK:
COAL: 2.927"
Base to Ogive: 2.363"
If I were to seat bullets to those spec (and obviously they wouldn't fit the magazine in my AICS) I would have such a ridiculously small amount of bullet contact to neck that it doesn't even sound possible. Just as a quick reference, the base of the bullet would be just about flush with where the case neck changes its angle to the shoulder, meaning about half of the case neck would have contact and the other half would be the boat tail.

I spent hours going over and over with the Hornady OAL gauge, jamming rounds and trying the "cut slots in the case neck for tension" and jam it method. I even used a piece of folded paper to move the plastic rod on the OAL gauge to make sure I wasn't using caveman strength with it and jamming the round, but to no avail. The only spot I get a definitive "stop" where the ogive meets the throat is wayyyy out there at the 2.363" length.

Anyone else with the 700P have measurements that sound in the ballpark of this?
 
Re: Hand Loading for Long Range 3: finding start OAL

I read this was one of several "chapters". Can anyone tell me if this is the first of many or where the others are to read. I really enjoyed reading this chapter and learned a lot as to why this is needed.

Great Read!
 
Re: Hand Loading for Long Range 3: finding start OAL

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CardiacKid</div><div class="ubbcode-body">I'm with the other 700P guys that have an insane amount of excess in everything in my chamber - actually sent TresMons a couple of PMs about how over some of my measurements were to confirm with him, as this is my first bolt action rifle and first go around with precision loads.

Here's some of the specs in my Rem 700P in .308:
Headspace/Shoulder Length: 1.564"
Chamber Length: 2.055" (really? .050 over the trim-to length?)

When I use the Hornady OAL Gauge and Comparator, here's some of the ridiculous dimensions I get using their case and a 168 SMK:
COAL: 2.927"
Base to Ogive: 2.363"
If I were to seat bullets to those spec (and obviously they wouldn't fit the magazine in my AICS) I would have such a ridiculously small amount of bullet contact to neck that it doesn't even sound possible. Just as a quick reference, the base of the bullet would be just about flush with where the case neck changes its angle to the shoulder, meaning about half of the case neck would have contact and the other half would be the boat tail.

I spent hours going over and over with the Hornady OAL gauge, jamming rounds and trying the "cut slots in the case neck for tension" and jam it method. I even used a piece of folded paper to move the plastic rod on the OAL gauge to make sure I wasn't using caveman strength with it and jamming the round, but to no avail. The only spot I get a definitive "stop" where the ogive meets the throat is wayyyy out there at the 2.363" length.

Anyone else with the 700P have measurements that sound in the ballpark of this? </div></div>

Well after more searching on this site and others, I'm finding that these chamber tolerances are pretty common for the 700P and similar models. In other words, touching the lands really isn't feasible given the very little amount of bearing surface I'd have on the case neck - at least that's what many others have decided as well.

Is there a viable alternative to maintain a level of consistency? My thought process is first to look at COAL to determine the max length I could feed in my mags (looks like 2.810 should be in the ball park, and again - to even reach the lands I'd be loading around 2.937).
From here, could I seat using consistent ogive depth as the common denominator right? IE, COAL is going to hover in the sub 2.810" range but ogive depth will be consistently 2.XXX. Anyone have experience with this? Thanks
 
Re: Hand Loading for Long Range 3: finding start OAL

Disregard my post, I'm an idiot, and found them.

Thank you for the great information!
 
Re: Hand Loading for Long Range 3: finding start OAL

Cardiac,

Give the barreled action to a gunsmtih. Just have him set the barrel back 1/8" or so and run a match reamer in the barrel. Quick & easy fix for all that free bore....
 
Re: Hand Loading for Long Range 3: finding start OAL

Once again a job well done, I have been reading through each of your steps and learning a lot...thanks!
 
Re: Hand Loading for Long Range 3: finding start OAL

Thats a great write up on this and enjoyed it,, have learned alot here that i didnt know, but i have a question on the ogive from bullet to bullet( 168gr vs the 175gr smk)both sierra, shouldnt the ogive be alittle longer on the 168gr than the 175gr, from my method of trying to find the ogive of these bullets are diffrent, My method of getting this is i chamber a empty round (dummy round) (No powder,no primer)with bullet im loading,and ease it in until i close the bolt,(by doing it like this,,, it should put the bullet into the lands)i pull it out and checked it, i do this several times to make sure im getting the same thing (length. Is this the right way of doing this are am i going in the wrong direction on this.
 
Re: Hand Loading for Long Range 3: finding start OAL

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CardiacKid</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CardiacKid</div><div class="ubbcode-body">I'm with the other 700P guys that have an insane amount of excess in everything in my chamber - actually sent TresMons a couple of PMs about how over some of my measurements were to confirm with him, as this is my first bolt action rifle and first go around with precision loads.

Here's some of the specs in my Rem 700P in .308:
Headspace/Shoulder Length: 1.564"
Chamber Length: 2.055" (really? .050 over the trim-to length?)

When I use the Hornady OAL Gauge and Comparator, here's some of the ridiculous dimensions I get using their case and a 168 SMK:
COAL: 2.927"
Base to Ogive: 2.363"
If I were to seat bullets to those spec (and obviously they wouldn't fit the magazine in my AICS) I would have such a ridiculously small amount of bullet contact to neck that it doesn't even sound possible. Just as a quick reference, the base of the bullet would be just about flush with where the case neck changes its angle to the shoulder, meaning about half of the case neck would have contact and the other half would be the boat tail.

I spent hours going over and over with the Hornady OAL gauge, jamming rounds and trying the "cut slots in the case neck for tension" and jam it method. I even used a piece of folded paper to move the plastic rod on the OAL gauge to make sure I wasn't using caveman strength with it and jamming the round, but to no avail. The only spot I get a definitive "stop" where the ogive meets the throat is wayyyy out there at the 2.363" length.

Anyone else with the 700P have measurements that sound in the ballpark of this? </div></div>

Well after more searching on this site and others, I'm finding that these chamber tolerances are pretty common for the 700P and similar models. In other words, touching the lands really isn't feasible given the very little amount of bearing surface I'd have on the case neck - at least that's what many others have decided as well.

Is there a viable alternative to maintain a level of consistency? My thought process is first to look at COAL to determine the max length I could feed in my mags (looks like 2.810 should be in the ball park, and again - to even reach the lands I'd be loading around 2.937).
From here, could I seat using consistent ogive depth as the common denominator right? IE, COAL is going to hover in the sub 2.810" range but ogive depth will be consistently 2.XXX. Anyone have experience with this? Thanks</div></div> Yes, my remington was the same way, they have a long throat, i had my gun rebarreled
 
Re: Hand Loading for Long Range 3: finding start OAL

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CardiacKid</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CardiacKid</div><div class="ubbcode-body">I'm with the other 700P guys that have an insane amount of excess in everything in my chamber - actually sent TresMons a couple of PMs about how over some of my measurements were to confirm with him, as this is my first bolt action rifle and first go around with precision loads.

Here's some of the specs in my Rem 700P in .308:
Headspace/Shoulder Length: 1.564"
Chamber Length: 2.055" (really? .050 over the trim-to length?)

When I use the Hornady OAL Gauge and Comparator, here's some of the ridiculous dimensions I get using their case and a 168 SMK:
COAL: 2.927"
Base to Ogive: 2.363"
If I were to seat bullets to those spec (and obviously they wouldn't fit the magazine in my AICS) I would have such a ridiculously small amount of bullet contact to neck that it doesn't even sound possible. Just as a quick reference, the base of the bullet would be just about flush with where the case neck changes its angle to the shoulder, meaning about half of the case neck would have contact and the other half would be the boat tail.

I spent hours going over and over with the Hornady OAL gauge, jamming rounds and trying the "cut slots in the case neck for tension" and jam it method. I even used a piece of folded paper to move the plastic rod on the OAL gauge to make sure I wasn't using caveman strength with it and jamming the round, but to no avail. The only spot I get a definitive "stop" where the ogive meets the throat is wayyyy out there at the 2.363" length.

Anyone else with the 700P have measurements that sound in the ballpark of this? </div></div>

Well after more searching on this site and others, I'm finding that these chamber tolerances are pretty common for the 700P and similar models. In other words, touching the lands really isn't feasible given the very little amount of bearing surface I'd have on the case neck - at least that's what many others have decided as well.

Is there a viable alternative to maintain a level of consistency? My thought process is first to look at COAL to determine the max length I could feed in my mags (looks like 2.810 should be in the ball park, and again - to even reach the lands I'd be loading around 2.937).
From here, could I seat using consistent ogive depth as the common denominator right? IE, COAL is going to hover in the sub 2.810" range but ogive depth will be consistently 2.XXX. Anyone have experience with this? Thanks</div></div> Yes, my remington was the same way, they have a long throat, i had my gun rebarreled </div></div>

My LTR is long throated as well. With my measured COAL the bullet is barely in the case neck.
 
Re: Hand Loading for Long Range 3: finding start OAL


Not much you can do with one of those except have the barrel set back and re chambered with a match reamer.....
 
Re: Hand Loading for Long Range 3: finding start OAL

Being I am running ACIS mags I am just loading to the max magizine length which righ now is about 2.829 for my 308 with 168 Berger VLDS. I do not seem to be hiiting the lands but I haven't measured yet either. I will measure after reading this, but if the cartridge fits in the mag is it a safe rule of thumb that your are most likely not jammed?
 
Re: Hand Loading for Long Range 3: finding start OAL

This is absolute "MUST KNOW" info and should never, IMHO, be removed from where it's at as a "Sticky". Thanks a million for the great insight.
 
Re: Hand Loading for Long Range 3: finding start OAL

Hello, been reading your article and decided to give this one a try. But I gotta say.... kinda worried about my results. I'm shooting a savage 308 10FP.Im using Sierra 168g HPBT match bullets. Now, the Lyman manual I have says for this bullet you set the OAL at 2.775". I used the method you showed... read it twice... did it twice and did 5 measurements each time. Average OAL was 2.626. I added .010" as you mentioned for a total length of 2.636. After putting the completed round next to a bullet made the recommended length in the manual there's a noticeable difference. This one looks a bit short. But it's only .139" off from the book. For the record I am using the minimum charge of 38 grains with IMR4895 so its not close to a max load. Do you think that measurement is totally off? Please assist. Thanks for all your work its really good and I've enjoyed reading your posts.
 
Re: Hand Loading for Long Range 3: finding start OAL

Are the advantages for jamming and jumping getting to higher velocitys without using as much powder? The seating depth for reloading manuals says 2.8oo" for 308 would that be considered jumped? and if you were to start .010 jammed would you start at the minimum powder charge. Example 175 smk with varget starting load from hodgdons website is 42 grains.
 
Re: Hand Loading for Long Range 3: finding start OAL


Russell,
If you feel solid about the measurements that came from the chamber in YOUR rifle- go with it indeed. How can Lyman know the chamber length/dimensions of YOUR rifle? Go for it.

N.Shooter- No bullet seating depth in relation to the riflings has nothing to do with velocity- it is pursuit of better accuracy only...

mrjimsfc- thanks!
 
Re: Hand Loading for Long Range 3: finding start OAL

Great stuff gentlemen....was just having discussion with a friend yesterday regarding OAL.
This helped tremendously
Thanks
 
Re: Hand Loading for Long Range 3: finding start OAL

Why once you have a dummy round with test bullet seated to Oal insert tip of dummy round into muzzle rest against rifeling measure from base of case to barrel(example Oal 2.840,base of case to muzzle 2.159) so as a reference when getting different bullet measure Oal of bare bullet, then insert tip of bare bullet into muzzle and measure muzzle to base of bullet. Now add difference to 2.159 for coal
 
Re: Hand Loading for Long Range 3: finding start OAL


Sorry Tyron I'm having trouble following what your stating (or asking?) as you wrote it. Could you make it more clear? Sorry & thanks.
 
Re: Hand Loading for Long Range 3: finding start OAL


So I know the rifle is safe, and every one else can see that it is safe from a distance.
 
Re: Hand Loading for Long Range 3: finding start OAL

Tresmon: I am trying to confirm oal to the rifling. Similar to the method of smoking the bullet with a candle, I color the entire bullet with a sharpie, chamber the dummie round and look for a mark in the ink that shows up as a line along the longitude. When I measured the oal using the Hornady lnl gauge I got 2.209" to the ogive on Amax 178s. But I am continuing to see the line which I thought would be a rifling , down to 2.192". Is there something besides rifling that would make a mark on the bullet? Maybe as the dummie round is extracted the bullet swipes the action on the way out? Is there a good way to double check the oal of a dummie round once it's measured with a gauge? If its in here, I'm sorry, I didn't see it.
 
Re: Hand Loading for Long Range 3: finding start OAL

Many Benchresters seat the dummy
Extract it
look for square land marks equally long as wide, and that is the Jam length which is longer than factory in most cases and often will not fit in magazines. But that is the best way to assess the lengho to the ogive in the lands.
 
Re: Hand Loading for Long Range 3: finding start OAL

So I figured out I was looking at the wrong marks. The lands show up as squares. I seated bullets from 2.211" at the ogive down to 2.193" in small increments and I'm still seeing the square marks, ever so light. My lnl oal gauge measurement had me at 2.209". What's the advice? Once the bullet is no longer in the rifling, the square marks will go away completely, right? Thanks!
 
Re: Hand Loading for Long Range 3: finding start OAL

Just load the dummy round extra long
Chamber it by closing the bolt
the lands push the bullet into the case
Then the landmarks should be equally long as wide.
I do not color the bullet, but most do.
that measurement to the ogive is the "Jam" (but Tony Boyer uses -.003 so that when you extract a loaded round it does not disassemble in the chamber dumping powder in the action
smile.gif
) as it is known in Benchrest.
Then you work your lengths backward from the JJam when you have your best group. Vary powder charge first then cartridge length.
This also is his tuning method:

Tuning Method

1.Boyer Jam= Jam-.003 prevents disengagement of loaded bullet


2.Load Groups of Three 3 @ __Clicks
Upward


3. Pick best shooting conditions Shoot each set


4.Best one or two loads should be apparent


5.Load 5 Rounds for the two BEST LOADS Fire for Group


6.Pick the Best of the above group and Adjust Seating -.003”

7. Load 5 or 10 and shoot groups

8. If Improvement is seen Adjust depth -.002”

9. Load 5 or 10 rounds and shoot groups

9 If groups do not improve or open up stick with Jam Length
 
Re: Hand Loading for Long Range 3: finding start OAL

Tres,

Great right up and very informative! I do have a question for you regarding sizing brass. I have a full custom built 6.5 Lapua on a Surgeon 591. Using the Lapua brass fireformed, I can still fit this into my chamber with little to no tension when closing the bolt w/o the firing pin assembly installed. I've adjusted the die way out, all the way to touching the shell holder, with little to no difference in bolt close. I have heard that this is not that unusual to find with high quality brass and a tight custom chamber. Is this true? Also, with all that being said, if i can still chamber a fired round with little to know tension bolt close, should I just let it be and neck size?

Thanks in advance and again.....great right up.

Seth
 
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