Light loads for the 30-06

[sydney]

Hi--when the weather breaks I want to start working up some light loads for my new 30-06--I have read a number of posts stating that a too light a load can cause headspace problems--at what fps does this start to occur-- I don t want to drill the primer holes
as I load the same cases for hunting loads
Thanks in advance Sydney

[Scharfschuetze]

No problem Sydney.

Load a 150 or so grain bullet to about 1,600 fps and you should maintain your case's base to shoulder dimension. Unique or something similar is a good choice for such an endevour. Load high enough to at least equalize the powder's pressure in the case with that of the pressure generated by the primer in the primer pocket.

If this is your first go around at light loads in the Ought-Six, note that you'll need to add, depending on the rifle, up to 10 minutes of angle to your sight setting to zero the load.

[runfiverun]

the jacketed load will blow the case back up.

[scottfire1957]

Headspace "problems" are a brass sizing problem, not a "load" problem. Your brass resizing dies need to be adjusted correctly, no matter the load.

[Screwbolts]

Depends on your powder choice.

many of the older Speer loading manuals list reduced loads for most calibers and bullet combinations.

What are you trying to achieve, with what powders do you have on hand.?

[TexasGrunt]

The universal light load for rifles is 10 grs of Unique. Your mileage may vary.

[fatelvis]

I've found Harris's "Workhorse load" of 16grns 2400 to be a great place to start with the '06. It meters great, is verrrry mild, position insensitive, and delivers acceptible to very good accuracy. He definitely stumbled on a good load there!

[centershot]

Another good load from the experiments of Ed Harris is 13 grains of Red Dot wit a 150-190 gr. boolit. I use tis with the Lyman #311041-173 gr. GC boolit, it easily shoots into 1" @ 50 yards. Be aware- start with a CLEAN barrel, and be prepared to shoot 30 to 50 rounds to condition the bore for your lead boolits. Shooting loads like this the gun will behave much like a .22 RF match rifle, that is, after cleaning it may take a box (50) of ammo to "condition" the bore again for best accuracy. I can see it happening as I shoot, the fliers start to disappear and a jagged hole starts to appear in the center of the group.

[sydney]

Hi Screwbolt---I have the following powders in stock
4895---4759---760---h380---3031---
Now that I am retired I just want to spend time at the range this summer
Interested to see how the new rifle shoots
Thanks Sydney

[fatelvis]

18.0 grains of 4759 under any 30 cal boolit sized to .310-.311". It'll give you around 1550fps and is accurate in my rifles.

[Moonie]

Which 4895? I like H4895 as it can be loaded to 60% of max safely. My favorite load in my 30-06 was a 245gr gas check Accurate Molds boolit over 35gr H4895 for about 1,950fps. This was very accurate.

[Hick]

If you can find a copy of the Lyman Cast Bullet Handbook, edition 3, you will find lots of light loads for the 30-06. I have seen copies on the internet.

[Char-Gar]

The theory is without sufficient pressure to set the case back against the bolt, the firing pin blow will knock the case forward in the chamber and eventually shorten the cause causing headspace issues.

It is my belief that this is only a theory and not founded in actual shooting. I have fired many thousands of "gallery" loads in the 30-06 and have never experienced a shortened case. You certainly won't experience case shoulder set back with any of the normal cast bullet loads in the 1.2 - 2.0 K fps range.

[Larry Gibson]

Not theory at all. It is the force of the primer explosion in the pocket that drives the case forward, not the firing pin blow. Some years back on this or the old forum this subject was discussed and I ran a test. This is what I posted back then.

Note; there is a difference between what some call a "light" load and a "gallery" load. I differentiate both of those and have another category referred to a "cat's sneeze" loads. To me most "light" loads will not create case headspace problems as the psi generated is sufficient to expand the case. Most "galler" loads with heavier cast bullets also provide sufficient psi to expand the case but many with light for cartridge bullets do not. Cat's sneeze loads, whether with a heavy or light cast bullet have a sufficiently small enough powder charge that the psi will not expand the case. It is with those in rimless cases using LR primers that that the shoulder can be easily set back with but a few firings. This is exasperated if used in a push feed action with a plunger type ejector.


Here's the previous post from years past;

The two above quoted posts have it nailed. I shoot many thousands of squib loads in various calibers but mostly in .30s. Many of theseare rimless cartridges; 30-06, .308, .308 CBC, 7.65, 7.62x39 etc. The squib (cat's sneeze) loads I shoot most often is a Lee 314-90-SWC-TL over 2.7 to 3.2 gr of Bullseye depending on the cartridge. Velocity is around 800 – 875 fps. I found a long time ago the shoulders do in fact get set back with light loads such as those.With many cast loads that use normal for caliber weight bullets in the 1600 to 2000 fpsrange there was little setback. Measurements of shoulder set back or increase are easily taken with a Stoney Point tool. There have been basically the two theories regarding the cause; the firing pin blow theory and the primer theory. I ran the same tests with a fire formed case and inert primers; headspace was not changed. I then used the same fire formed case with live primers only (no load). In as little as two firings there was a measurable decrease in headspace. After five live primers the fired primer was noticeably backed out after firing. NOTE:this increase in headspace was with case taking LR primers. I never experiencethe problem with the .223 Rem or the5.56 Nato with SR primers.

Using #d drills I gradually increased the flash holediameter with a progressively larger drill. Using a different fire formed casewith each larger drill and firing 5 primers I then measured the headspace before firing and after. As the size of the flash hole increased the headspace decrease lessoned. With a # 29 drill there was no longer any decrease in headspace. I dedicated five .308 cases and five 30-06 cases that were well fire formed to their respective rifles chambers and drilled the flash holes with the #29 drill. Over the next few days I fired 50 shots with each case. There was an indoor 50” range where I was stationed so it wasn’t all that bad. After the 50 firings there was negligible change in headspace with any of the five cases of each cartridge. The results of my test firmly demonstrate do me that it was the force of the primer explosion that drove the case forward and set back the shoulder. The squib (cat's sneeze) load does not have the pressure to expand the case out to fit the chamber. By drilling out the flash hole the force of the explosion mostly went directly into the case as there is little rim left to contain it. Two other side benefits that were unforeseen; the extreme spread and standard deviations of the velocity readings improved and the case position sensitivity of the small charge was greatly reduced.

As a result of the above tests I dedicated fire formed cases for squib loads (cat's sneeze) for each rifle in rimless cases and drill out the flash holes. I have fired them many, many times now with no further change in headspace.Besides the squib load (cat's sneeze) mentioned I also use 311631 (# may be wrong but it’s the118 gr GC 32-20 bullet) with Unique in the above cartridges loaded to 1400 fpsor so for a little more powerful small game load. The flash hole drilled caseswork just fine for those. I now use the flash ole drilled cases for all my rimless cartridges using LR primers for squib (cat's sneeze) and really light loads.


Some time after this test I acquired the Oehler M43 PBL which enables me to measure pressures. I have loaded the 311291 cast bullet over AA4350 to 2500 fps in my Palma .308W using cases (LC from the same lot) with and w/o the flash holes drilled. There was no discernible increase in psi using flash hole drilled cases. The psi went to 47,000.

Larry Gibson

[fastdadio]

I've been playing with the data here.
http://www.gmdr.com/lever/lowveldata.htm
So far 7.5 grains of Tite Group are shooting tiny groups for me. And as mentioned above, 4895 looks to be the best bet in your powder supplies.

[Tom W.]

I use the aforementioned red dot load with 160 - 180 grain gas checked boolits to fireform my 30/06 A.I. loads. They generally shoot really low at 25 yards, but with proper holdover make really tight groups. I don't bother to move my scope adjustments as I just use them for fireform loads.

[vrh]

I load my 30-06 with a Powder Coated Lee 170 gr cast bullet. Sized to .309. I use 16 gr. of Unique Powder. I believe it is pushing that bullet at around 1750 FPS. Once I got everything sighted in at 100yds., my group stays near 1 1/2 inch to 2 inches at 100 yds. Love the lost heavy recoil too.

[Scharfschuetze]

I shoot many thousands of squib loads in various calibers but mostly in .30s. Many of theseare rimless cartridges; 30-06, .308, .308 CBC, 7.65, 7.62x39 etc. The squib (cat's sneeze) loads I shoot most often is a Lee 314-90-SWC-TL over 2.7 to 3.2 gr of Bullseye depending on the cartridge. Velocity is around 800 – 875 fps. I found a long time ago the shoulders do in fact get set back with light loads such as those.With many cast loads that use normal for caliber weight bullets in the 1600 to 2000 fpsrange there was little setback. Measurements of shoulder set back or increase are easily taken with a Stoney Point tool. There have been basically the two theories regarding the cause; the firing pin blow theory and the primer theory. I ran the same tests with a fire formed case and inert primers; headspace was not changed. I then used the same fire formed case with live primers only (no load). In as little as two firings there was a measurable decrease in headspace. After five live primers the fired primer was noticeably backed out after firing.

Larry, your results are identical to my tests of many years ago with regard to the "shrinking case phenomenon." I have been drilling out flash holes for well over 40 years now for my small game and gallery (squib loads-cat sneeze loads) in the Ought-Six and I'm satisfied that it's the pressure in the primer pocket and not the firing pin that is causing the rimless cases to shrink on firing.

I do keep my enlarged flash hole cases segregated from my standard cases as I have noticed differences in accuracy between the modified cases and standard cases occasionally. Sometimes the accuracy is better with enlarged FHs and sometimes it's worse in various rifles and loads. I've never found it to be consistent though one way or the other from load to load or rifle to rifle.

Chronograph data on my equipment shows only a minor variation in velocity between the modified and unmodified cases with the same components otherwise; but, as noted above, they do group differently sometimes.

So as I posted in post number two: for the OP who doesn't want to drill out his FHs for a light load in his Ought-Six, load high enough so that the pressure in your cartridge case/chamber is greater than the explosive pressure of the primer in the primer pocket and you'll be fine with no need to drill out the FHs. Lots of good loads to accomplish this in the posts above.

While most reloaders here are familiar with the gauges used to take these case measurements, some may not be so I'll post a photo of the gauges that I use: Stoney Point (now Hornady), Mo's and RCBS. These gauges are also great to adjust your sizing dies to your rifle's HS dimensions.

[Shiloh]

How does a light load affect chamber dimensions?? It doesn't.

SHiloh

[Screwbolts]

Yup, your 4759, would be my choice to start and 18 grains is a great place to start having fun.

Ken