A cautionary tale??

[Potashminer]

Perhaps to reinforce why not to use someone's random hand loads in someone else's random rifle??

I have three M1917 based rifles - all chambered for 30-06 - and I want to try to develop one common loading for them. I found some extremes, I think? I used a flat tip insert on a cleaning rod to touch the closed bolt face - and marked the cleaning rod at the muzzle - then I used a wood dowel to press a bullet into the lands from the bolt end of the barrel - and again marked that cleaning rod as it just so touched the tip of that bullet. Then measured the distance between the two marks.

One rifle is a pretty much all "W" parts, with the "W" barrel marked "11-18" - so made in November 1918 - that one was pretty much 3.300", exactly. So, to set up for the common .030" "jump" to start, I would have loaded up at a COAL of 3.270"

A "middle" one has a brand new, never fired "High Standard" barrel as used for the WWII re-builds by USA arsenals in early part of WWII. It was slightly shorter than the "W" barrel above - I got 3.295" - ish. So far, pretty close.

Then a Remington Model 30 - the Remington code on the barrel says it was made in 1926. Same bullet, same process - that one is 3.240" when tight to the lands. I have done this one twice - different bullets from same box - and my measurements are within about 0.001"- 0.002" of each other.

So the comfortable .030" jump in the "W" barrel, would have been about .030" jam into the lands on the Model 30. If I had worked up "warm" loads for the "W" barrel at that COAL, then most likely would have been bad news in the Model 30, if I could have even chambered those rounds.

I thought that I would share what I discovered - I was not expecting that great of difference, one extreme chamber to another.

P.S. I do have a fourth and a fifth 30-06 rifle here - a 1955 Winchester Model 70 and a STIGA sporter - using process described above, I get 3.325" and 3.320 respectively!! This was done with Hornady 150 grain flat base spitzer Interlock bullet - #3031. So, a COAL worked out for this Model 70 or the STIGA , with a .030" jump, would be REALLY bad news in that Remington Model 30.

 

[cosmic]

An additional complication can be the reference bullet you use to establish COAL. Hornady made at least two versions of their 150 gr SP bullet, which can be identified by varying cannelure widths. These variations had different ogive profiles, and would give different COAL's. Ask me how I know....
I've done similar experiments with two Winchester made P14 rifles. To my surprise, the chambers were identical, fired brass could be neck sized and used in either rifle. To boot, Measured COAL was identical.

 

[Potashminer]

I had made an error the first go round with the Model 70 Winchester - I think I was getting contact with the leading face of the extractor, not with the bolt face. I revised Post #1 to show what I get when I was sure that I was measuring from bolt face, not from extractor face.

cosmic - I did not know about the two versions by Hornady. The first time around, I used the same single bullet for the measuring that I did. I received two boxes of Hornady #3031 a few weeks ago - have not even opened the other box yet. Did you find the two kinds in the same boxes, or where they different boxes??

 

[cosmic]

Different boxes - at least one was from a box with the metal seams. This may no longer be an issue with the current offering.

 

[Potashminer]

Curiosity got to me, so I tried again with the longest one - that Model 70 Winchester - this time I used Nosler 180 grain Accubond. I got 3.313" with it.

So, not really certain what that SAAMI call out for Maximum COAL in a 30-06 is used for - 3.340". If I tried to load either the 150 Hornady flat base, or the 180 Accubond, to that length, I would have jammed into the lands on all five of the rifles here.

What I do notice though, is that Hornady #9 manual calls out 3.210" as their COAL for testing that 150 grain flat base bullet, and Nosler #9 calls out 3.330" for their 180 Accubond. The Hornady COAL for their 150 grain Interlock would have had "jump" in any of these 5 rifles - some a LOT more than others. The Nosler COAL for their 180 Accubond would have "jammed" in the Model 70. So, pretty much confirms to me that the only way to know for a particular rifle, is to actually measure it - can not really rely on a reference or on someone else's numbers. A comfortable "jump" in some, will be "jammed" in others. No clue if I have the full range of extreme dimensions here, among these 5. But all close on a GO gauge, and none close on a FIELD gauge, so it does not appear to be related to chamber shoulder dimension - is about the individual throat and lands.

 

[mactroneng]

SAAMI has drawings for both cartridges and chambers, unless I'm reading it wrong the chamber drawing shows a minimum length of 2.7442" from bolt face to lands.

 

[Potashminer]

Yes, I saw that. Does not help a lot about COAL because that would depend on the bullet maker's placement of his ogive on his bullet - at that specific diameter dimension, I think.

Too boot, I am quite sure that SAAMI did not exist until the 1920's or so, and I do not believe that US military is even interested in complying with SAAMI standards, since US military has been making 30-06 ammo and rifles since at least 1906?? For certain, I see similar with SAAMI and with the Swede 6.5x55 - Swedes have made ammo and rifles since late 1800's, and use a longer gauge for the chamber, than SAAMI calls out. So most new Swede 6.5x55 chambers will fail a SAAMI headspace check.

But, one would think that once everyone making chambers to SAAMI compliant dimensions, would get similar COAL with the same bullet, since the lands same distance from bolt face. But, as mentioned, I found in 5 different rifles that they are all different - albeit that at least two of them made before SAAMI existed. It also might be important to note that SAAMI is a voluntary compliance standard - is not legally enforceable anywhere, and has essentially no bearing, other than as "suggestion", on a home-done chamber reaming job ...

I may very well end up getting a "throating" reamer, to bring the shorter ones up to match the longer ones - but need to see how they shoot first - to see if it makes a difference with my eyes and aperture sights.

 

[downwindtracker2]

I have both a M700 30-06 and a M70 30-06 . Interchangeable load wise. Except the boxes. The M700 has a H&H long one. Opps, one hunting trip.

 

[mactroneng]

Yes, I saw that. Does not help a lot about COAL because that would depend on the bullet maker's placement of his ogive on his bullet - at that specific diameter dimension, I think.

Measure base to ogive instead of COAL. As long as it fits in your mag/action COAL isn't all that useful.

 

[Potashminer]

I agree - but I do not have a precise tool to measure ogive diameter on a bullet. Nor do I have a tool to measure where that ogive diameter would be within the chamber / throat / lands. I had the bullets and I had the rifles, so seemed to work well enough to establish that there was a difference among them. And for sure, as per my second sentence in Post #5 - I am not sure what "maximum" COAL dimensions could actually be used for??

Was the first time for me to use that "cleaning rod down the muzzle" technique - for years, I would find the lands by jiffy marker on bullet, vary the seating depth, repeat, until I could find where a particular depth just so left marks on jiffy marker - then adjusted seater stem down .030" (or whatever I was thinking at the time) and re-seated the bullet - used that for subsequent set up for that seater die. Most definitely not what a precision bench rest guy would do, but seemed to work fine for my hunting rifles. First step is to take a fired case, squish the neck slightly, then jiffy marker a bullet and chamber it - bullet is held by the lands and slides into the case neck - scrapes off the marker - I would re-store it to position and use that as starting point to "find" the lands from the chamber end only.

I did not invent either process - is described either both in reloading manuals or in John Barsness reloading articles - I do not remember where I got the ideas from.

This is the first time that I intend to work up a common load for use in three rifles of mine - all previous that I have done have been for one rifle at a time, so I wanted to know if they were similar or different. I am glad that I found out!

I also do not know that my seating stems contact the bullet only on the ogive either - so, if bullets vary, which I am told that they do or did, so would my loads - and that might be important for some situations - like for bench rest scores??

 

[dan belisle]

I have used the rod measuring method a lot. I'm not surprised that your 30-06 rifles are so varied. Later manufacture seems to be somewhat less in that regard, but not without it. As long as you are using the same bullet you have data that will allow you to find a common length for all your rifles. Adjusting for bullet jump will be another matter, and you may find that you can't get a reasonable compromise. - dan

 

[jamesharrison]

Don't forget about leade wear.

 

[Potashminer]

I have used the rod measuring method a lot. I'm not surprised that your 30-06 rifles are so varied. Later manufacture seems to be somewhat less in that regard, but not without it. As long as you are using the same bullet you have data that will allow you to find a common length for all your rifles. Adjusting for bullet jump will be another matter, and you may find that you can't get a reasonable compromise. - dan

"reasonable compromise" - exactly - I suspect that is what I will have to do in order to get three rifles sharing a common box of ammo. Will all be in the shooting, to know whether that becomes possible for me and these rifles, or not. None of them are even close to "bench rest" type rifles - and I have had minimal experience with aperture sights. So I am hoping to come up with "good enough", at least for now!!

 

[Potashminer]

Don't forget about leade wear.

For sure! Is one of those things that if you do not measure for it, you will never know it is there. Since I have no clue how "fast" these lands will wear with these loads, I suspect I will have to set aside a specific bullet from the box of them, and use that one, from time to time - to see if I can measure any difference occurring. For these rifles and these loads, I do not know if that is measurable within dozens of rounds or hundreds of rounds (or perhaps thousands of rounds??)

 

[downwindtracker2]

I went on the holy grail quest, one load for three different 30-06 of my sons' and mine. Didn't succeed .When one group would close another would open up, so I just used a mid point. Not ideal.

A bit of a warning here. I picked up a BSA P-17 sporter 30-06 as a canoe rifle. I took it out to the range with a run of the mill IMR 4350 180gr load. The one everybody recommends. Off the bench I thought that was snappy. I looked at the Chrony, it was F**** Fast. 2850+ with 4350 is well over pressure. When I bought it, the guy selling it said his dad didn't like the recoil . I thought recoil on a P-17 ??. It's light like a Sherman tank is light. He was right,though, a 220 RN factory would easily put it in 300WM territory. It gets it's own load.

 

[Fox]

Never trust anyone else's reloads, period.

If you are wanting a common load though you don't have to look at any jump to the lands, just load to the SAAMI specs and verify safe, work up a load in all the guns that shoots across the board as a best case and you are done.

 

[Potashminer]

Never trust anyone else's reloads, period.

If you are wanting a common load though you don't have to look at any jump to the lands, just load to the SAAMI specs and verify safe, work up a load in all the guns that shoots across the board as a best case and you are done.

I guess that is what I discovered. SAAMI does not have a spec for individual bullets or weights - they do call out a maximum COAL length, but if I loaded either the 150 Hornady or the 180 Nosler Accubond to that length, both bullets would be significantly "jammed" into the riflings on all the 30-06 rifles here. As mentioned above, using the recommended COAL, as tested by Hornady, for the Hornady 150 grain bullet, there would have been more or less "jump" in all five rifles. Using the Nosler recommended length for their 180 grain Accubond, it would be "jammed" in all the five rifles here. Might not be an issue with rifles made later than 1955, but I do not own any "new" 30-06.

SAAMI does call out a distance from bolt face to lands - so if the chamber was cut to SAAMI standard, and if the re-loader measured to the bullet ogive, not the bullet tip, then could go with that, I guess. But that needs a tool to measure to the ogive on the bullet - which I do not have - and assumes that the chamber does meet SAAMI specs, which an owner will not know without measuring it.

From another post that I started - the three rifles of interest to me are all made during or shortly after WWI - two of them, for sure, before SAAMI existed. At that time, the USA military loading was 150 grain flat base, pointy tip, bullet at 2,700 fps. What those rifles were made to use. Several hundred fps slower than "modern" loadings are advertised at. I am presuming that such a similar-to-WWI loading will follow the sight settings on these rifles.

 

[Potashminer]

I went on the holy grail quest, one load for three different 30-06 of my sons' and mine. Didn't succeed .When one group would close another would open up, so I just used a mid point. Not ideal.

A bit of a warning here. I picked up a BSA P-17 sporter 30-06 as a canoe rifle. I took it out to the range with a run of the mill IMR 4350 180gr load. The one everybody recommends. Off the bench I thought that was snappy. I looked at the Chrony, it was F**** Fast. 2850+ with 4350 is well over pressure. When I bought it, the guy selling it said his dad didn't like the recoil . I thought recoil on a P-17 ??. It's light like a Sherman tank is light. He was right,though, a 220 RN factory would easily put it in 300WM territory. It gets it's own load.

Were those 180 grain bullets that you used maybe jammed into the lands on that BSA P-17?? If bullet is jammed on chambering, I believe that is like adding several grains of powder - results in higher pressures. Somewhere in pieces here is a BSA conversion - I know I used one BSA P-17 receiver to make up a "wanna be" Rem 30, and I have used a BSA P-14 action on a sporter, but I am not certain if they used the original WWI barrels, or if they always made and installed new barrels for their conversions.

 

[Fox]

I guess that is what I discovered. SAAMI does not have a spec for individual bullets or weights - they do call out a maximum COAL length, but if I loaded either the 150 Hornady or the 180 Nosler Accubond to that length, both bullets would be significantly "jammed" into the riflings on all the 30-06 rifles here. As mentioned above, using the recommended COAL, as tested by Hornady, for the Hornady 150 bullet, there would have been more or less "jump" in all five rifles. Using the Nosler recommended length for their 180 grain Accubond, it would be "jammed" in all the five rifles here. Might not be an issue with rifles made later than 1955, but I do not own any "new" 30-06.

SAAMI does call out a distance from bolt face to lands - so if the chamber was cut to SAAMI standard, and if the re-loader measured to the bullet ogive, not the bullet tip, then could go with that, I guess. But that needs a tool to measure to the ogive on the bullet - which I do not have - and assumes that the chamber does meet SAAMI specs, which an owner will not know without measuring it.

From another post that I started - the three rifles of interest to me are all made during or shortly after WWI - two of them, for sure, before SAAMI existed. At that time, the USA military loading was 150 grain flat base, pointy tip, bullet at 2,700 fps. What those rifles were made to use. Several hundred fps slower than "modern" loadings are advertised at. I am presuming that such a similar-to-WWI loading will follow the sight settings on these rifles.

Ya, I totally get that.

Just looked up the numbers through hodgedon, they have 3.3, 3.23 and 3.25 depending on the bullet profile.

I know what you mean though, 6.5x55mm swedish M38 mauser will not take 160gr RN bullets designed for the long throat M96.

 

[Potashminer]

Swede M38 will most definitely chamber 160 grain Round Nose - at least the Hornady # 2640 that I have here - just have to load them shorter to get some "jump" - and adjust your powder loading accordingly. Requires you to "find the lands" - with that bullet - to know.

A great number of "M38" were converted at Carl Gustaf armoury - from M96 rifles - so same throat - some people call those ones a m96/38 but the Swede military did not distinguish between a converted M38 (almost always previously made by CG, but some were original by Mauser) and ones that were made from new by Husqvarna - from the book "The Crown Jewels", by Dana Jones.