Getting angry with OAL

[HeathSexton]

I have a 180 PT load for my 30/06 that is good, but I would like better. I have only went 1 group at 100yds, but it was around 1.25-1.5" and I know the gun will shoot better. I am out of PT's, but I have a few 180 NBT's tp play with. I made a dummy round to get the oal I could load to and I can never get the same reading. I can move the bullet in the case with my fingers with some effort so the rifling should push it back. I am getting 3.390, 3.386, 3.395, 3.389, etc. What do I need to do to figure settle that? Also, the charge that shot the best with the PT's was 56gr of H414, can I go with the same load or do I need to go down and work back up? The gun is a Ruger MKII, and I have been working on this forever. I think the PT's would shoot better, but I had the same thing going on with them, I thought I was .015 off the lands, turns out after about 2hrs of measuring and remeasuring I could be .040 off.



Thanks

 

[Diriel]

A friend of mine shoots a couple rugers. One thing you need to do is Full length resize a piece of brass and make sure that it has GOOD neck tension. Also make sure the trim to length is at or near book minimum. Both of my friends Ruger's tend "Grab" the bullet and pull it either all the way out of the brass or partially out if you seat it long enough to engage the riflings too hard. A combination of good neck tension, and sneaking up slowly to the riflings is the way to go. You can "Soot" the bullet or use a Sharpie marker so you can see very clearly when the bullet initially touches the Lands. Most dies directions will tell you how many thousandths one revolution of the bullet seater is, so you can use this to adjust to or from the Lands. H414 is good powder for the 30-06, 4350 is also good. Another thing to note is the difference in the bullet Meplat can cause apparent differenced in seating depth, also bullet tip deformity can add to this depending on bullet type.

Good shooting,
Gary

 

[rick smith]

Take an average of your measurements and make a dummy round. Spin the bullet in some 4/0 steel wool and chamber the round. You should see some land marks, back off 0.005," steel wool and try chambering again. Should be able to find the length without a problem. Use magnification and good lighting to see the land marks.Rick.

 

[TScottW99]

My Ruger MK II has a pretty short throat compared to an Encore, H&R and Remington I load for. The other three can not be seated off the lands, the Ruger can be jammed into the lands quite easily so load carefully if yours is like mine.

The easiest way to find your O.A.L. in my opion is to use the Hornady O.A.L. gauge and the proper dummy cartridge they make. The system is so easy even I can use it :lol:

 

[6ppcar]

I take all my measurements from the base of the case to the ogive of the bullet. If you measure to the tip of the bullet it will usually vary some.

 

[HeathSexton]

Thanks guys, I admit I do not have the Hornady OAL gauge or a comparator, yet. It is on my super short list to get though. I have read that if you load to magazine length that you will be fine and will not engage the rifling, you will jammed into the rifling on this one as TScott said. I took the average an it is 3.390, so that is over with, and I have my dummy round set at 3.381. I would like to try some 4350 but no one around here has it and I have just not ordered any. The PT load is plenty good for deer hunting where I am, my shots are usully much shorter than 100yds, but the groups need to be tighter. If this 180 BT load works well I may venture into the world of the AccuBond.


The PT's I have were pulled from some Federal Classics, do factory PT's from Nosler have a cannalure?




Thanks for the help guys, if it gets out of the single digits here today I'm shooting. I'll report back.

 

[Ol` Joe]

I have read that if you load to magazine length that you will be fine and will not engage the rifling

False! The SAAMI OAL is nothing more then the max lenght you can load to and have the cartridge fit in any factory chambered rifles MAGAZINE. The throating varies not only with manufacture but with the same maker and within their line as tooling wears or is resharpened/replaced.

The OAL is a bear to get going from tip of bullet to base of cartridge as you found. The other posts on finding and determining the lenght to ogive are sound and one should work for you. The comparator is really a must though to return to this lenght once you have found it. It not only lets you go to the OAL you want with the BT as example but, switch to a Partition and use the same comparator measurement and you`ll be within a hair of the same distance off the lands with it too. The slight difference in ogive is the reason the distance from lands won`t be matched exact, but it will be only 0.001"/0.002" off if any in my experiance, not worth trying to amend.

BTW, Always drop a couple grains and work back up when changing components. Some changes at times will make a notable difference, you don`t know which ones, bullet, powder lot, brass, until it happens. Play it safe!
I have to admit I rework by only dropping 2gr, and then only loading 2 cartridges at each .5gr increase watching for changes in velocity from my last loads or from extraction, primer appearance, ect. So far it has worked, knock on wood.......

 

[HeathSexton]

Thanks Ol'Joe.


I got the PT's to .010 off the lands and groups at 55yds went from .497" to 2.5". The dummy round showed that I was .027" off with the .497" load. I loaded up some 180 NBT's at .010" off and the 55yds group was 1.5".

 

[HeathSexton]

Shot a lot today. The 180 BT's with the Partition load of H414 just about needed Johnny Hammer to open the bolt, I went down to 53grs of H414 in .5gr steps and it was just starting to act normal and I ran out of bullets. I think another one of my problems is my scope, it's not the greatest and at 100yds I have a heck of a time trying to get it in focus. At 53gr I kept getting two in a hole and a half and then a flyer to open it up. I hope that 52.5 or 52 will correct that.

 

[Guest]

My advice is to get a good supply of bullets, load up some rounds in a 'workup' (starting at 10% below book max and working up to book max) to determine what the best powder charge is for the bullet you're using (I've come to the point of using three rounds of each charge weight to test for pressure during workup). Do this for each bullet/powder combination you have, then head to the range for a session. Once you have the most accurate groups out of those loadings (for each bullet/powder combo) you can play with powder charge around that point, moving around .2-.5gr to either side of your 'best charge' from range session #1. Then go shoot those. One or two will likely be better groups than the others, and you can then play with seating depth on those powder charges to find the best load. Be sure to let your barrel cool between shots (it helps to take multiple rifles, including a 22lr) and you'll likely find the best combination for your gun. What you've done so far is on the edge of unsafe (since you had to hammer open the bolt on some loads), so you should be more careful and thorough in your loadwork, I think. If you don't have enough bullets to do a full workup, you don't have enough bullets to load and shoot to find a good combination. As for the scope, at 100yds, it should be fine, even if it's got yellow glass with bubbles in it. Try cleaning the lenses with a lenspen, and then focus the crosshairs at 100yds so they are clear and the target is clear, too. If the scope has an adjustable objective, set it on 100, and leave it alone until you get the crosshairs focused, then use the AO to adjust the paralax, which is what it's meant for anyway.

 

[HeathSexton]

I did not have to hammer the bolt open, but it was sticky, this is the same load that works fine with the 180 Partition. I shot 30 rounds today, so I had over half of a box of ballistic tips. 3 at each charge and a a reload when I saw a decent group.


The reason I did not drop the powder charge is I have heard people say that similar weight bullets will be close in performance with similar charges, Apperantly not and I see that now, I have learned something. Next time I now know to drop down and start working.

 

[Guest]

Roger that, my misunderstanding. glad you were able to learn without any personal impact. I've had times like that, too. what you experienced is the difference in bearing surface between bullets. what you originally heard is good info, but it applies more to working up than just subbing bullets. I hate to backtrack, too, though, and have had similar experiences with switching cases on a load. As for buying bullets, I like 100 count boxes for just the reason you describe - maybe Nosler should offer theirs that way? I use a lot of Hornady and Speer for initial load development because of that.

 

[HeathSexton]

New guy question time and it may be a dumb one, so bear with me. Lets say I have a load that shoots good and has no pressure signs and it is .030 off the lands, if you were to move that load up to say .005 off the lands would pressure increase? I know that engaging the rifling will spike it, but how about moving the bullet without touching the lands? I know POP and JD have some hot rod loads and they have their bullets seated far out. If this spikes pressure how do you get speed without major pressure?


My main goal is to have safe and accurate loads, but extra speed is also nice.


10-4 on the 100 pack bullets, next time I am going to load up these were just in a pack when I bought the reloading stuff so I figured I would burn them.

 

[Norm]

I just loaded my first batch ever 30-06 with 180gr Partition 2nds so I'm far from a expert. As soon as it gets above freezing I'll go try them out at the range.

To measure the depth of the lands on my Howa 1500, I just put a new bullet in a fired case and rolled the neck a little to keep a little tension on the bullet. I chambered and measure it about 20 times and came up with a couple odd numbers I threw out of the mix. When I thought I had right, I set the dummy round at max length tightened up the neck and checked that the length didn't change after chambering the round 10 times. Next I seated the bullet .010 long and checked it again to make sure it was pushing it back .010 after chambering. My rifle came out at 3.365 . I think the speer manual said start .010 -> .030 off the lands being careful not to touch them.

COAL was listed as 3.340 so I made a few rounds at this length which will put me .025 off the lands. I also made a batch at 3.350 which should be .015 off the lands. I made loads in each length starting 1 grain over min and stopping 1 grain under max using H4350. Max load with H4350 is 100% case capacity so I figured it would be hard to screw up .

One thing I noticed is both Winchester and Remington factory 180's measured 3.290 OAL. The Partition 2nd's have a cannelure, if I seated to the depth of the cannelure it would make the OAL 3.290 -> 3.300. Maybe that's so they won't have issues with auto loaders ??

Not sure if this will make a difference but I know my gun shoots decent with Remington core-lokt 180's, but not as well with Winchester pointed soft point 180's and Federal 180 partitions.

 

[Guest]

New guy question time and it may be a dumb one, so bear with me. Lets say I have a load that shoots good and has no pressure signs and it is .030 off the lands, if you were to move that load up to say .005 off the lands would pressure increase? I know that engaging the rifling will spike it, but how about moving the bullet without touching the lands? I know POP and JD have some hot rod loads and they have their bullets seated far out. If this spikes pressure how do you get speed without major pressure?


My main goal is to have safe and accurate loads, but extra speed is also nice.


10-4 on the 100 pack bullets, next time I am going to load up these were just in a pack when I bought the reloading stuff so I figured I would burn them.

As for pressure spikes, there's just never any real way to tell until you hit the wall, so to speak. The whole idea is that if you have a great load that is .030" off, and you decide to move it to .005" off, you drop back and work up. You'll likely find that you can generate the same pressures with less powder, but you'll have better accuracy because you hit the right 'harmonic' as far as bullet jump and barrel vibration. Go figure...

 

[rick smith]

Bullet seating close to the lands for a hunting round is not necessary or desireable. I never go closer than 10 off and many are more than that. If you are getting good accuracy at 30 off, leave it there. There is no magic about being close to the lands. Some of the WBY Mags shoot extremely well and the bullet is out of the case before it gets to the lands. Touching the lands or into them is a benchrest technique. Don't do that with hunting rounds or one day you may pull a bullet and dump a load of powder into your chamber. Hunt will be over until you can get it cleaned out. There is more than one sweet spot you can seat to.Rick.