Old vs. Modern 30-06 in Converted Mauser

I recently purchased a Colombian Mauser that has been converted from 7mm Mauser to 30-06 by the Colombian military in 1952. I know it is patterned after the type 98 Mauser and built by FN as a Model 24 or 30. I've never had a rifle this old before, so I am wondering if there are any differences in pressures or other safety concerns between the USGI 30-06 of 1952 and commercial 30-06 of now. Is it safe to use modern 30-06 in this rifle?

You'll have no problem at all firing modern .30-06 ammunition in a '98 Mauser action in good condition.

I'm another who would gleefully use the Mauser with current commercial .30-06 ammunition.

Just make sure the head space is correct, its a strong action.

There should be no difference old vs. new ammo. '06 ballistics have been the same since 1906. Headspace must be extremely excessive before it becomes a safety problem, not worth worrying about.

I made sure to have the chamber and bore checked out and no safety concerns were found! The main reason I was concerned about ammo is because the previous owner said he only used the same surplus ammo for M1 Garands. It is good to know there isn't a difference between old/surplus and modern commercial 30-06!

Tilheyra said:

I made sure to have the chamber and bore checked out and no safety concerns were found! The main reason I was concerned about ammo is because the previous owner said he only used the same surplus ammo for M1 Garands. It is good to know there isn't a difference between old/surplus and modern commercial 30-06!

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Not exactly, in an M1 it can make a difference. Apparently the bullet weight must be 147 to 165 and have a pressure curve similar to GI.

In a Garand the "pressure" cycles the action. In a bolt action there are no concerns.

The Garand requires a slower powder burn impulse, heavy bullets and quick burn powder bend the op rod.

Sorry, my last post was referring to a difference not being a concern in the Mauser. I didn't clearly note that.

But yes, it is good to know the M1 Garand needs specific ammo due to its design specifications. That is info that will be valuable if I have a Garand (I hope to have one in the future).

You will have no problem with a mauser
The issue is with the M1 Garand. Modern commercial ammo is too powerful and destroys the gas system, bent oprods and eroded ports. Back in the old days nobody cared because oprods were free with shipping and the supply was endless because out forebears are more like the grasshopper than the ant. I bet they think the 5$ g3 and 14$ Croatian magazines are endless too.

The Columbian contract FN built 98's are fine rifles.
They generally have a small notch in the top of the recv'r ring to allow the slightly longer 30-06 rd to load from stripped clips. Many also have a small relief cut on the ejection port at the front side to allow loaded rds to also be ejected w/o interference.

The Belgian Army contracted FN to build them M30 98 rifles in 30-06 in 51 and '52. They are pretty much the same rifle.
Belgium used them as a short term solution need for a service rifle till the FN49 got to them.

The 30-06 caliber because post WW2 UncleSam was handing out free GI Surplus ammo to make friends of everybody.

Good point to have the headspace checked, most real gunshops will have a set of 30-06 HS gauges and know how to use them.
Other than that the rifle in good condition is fine for any commercial or Military Surplus 30-06 rifle ammo.

Beware False Advice

In the Garand, we affectionately referred to as a "Pogo Stick", ya gotta use the medium fast powders: 4895, 4064. I ran thousands of such with Sierra 168's in the 90's in search of the coveted Distinguished pin. Not until 2002 with a M1A using 4895 did I acquire all the points needed to put the black rifles in their second place.

pantannojack said:

In the Garand, we affectionately referred to as a "Pogo Stick", ya gotta use the medium fast powders: 4895, 4064. I ran thousands of such with Sierra 168's in the 90's in search of the coveted Distinguished pin. Not until 2002 with a M1A using 4895 did I acquire all the points needed to put the black rifles in their second place.

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Getting distinguished with IMR of any type is impressive. The powder has too much tannin in it.

Many gas operated guns don't do well with commercial hunting ammo. It's not that the modern ammo is "too powerful", it's that hunting ammo is made for bolt guns and usually has a looooong pressure curve using a slowish powder. It feels easy on the shoulder and maximizes velocity. However, the maximum pressure is much the same as military ammo in that caliber.

Stick this ammo in a gas operated semi-auto and the pressure is still elevated in the case making it stick to the chamber sides while the gas driven mechanism is also trying to extract the case. Depending on the timing this can result in bent machinery (Garand) or case heads getting ripped off/broken extractors. This can even happen on rifles with adjustable gas systems like the FAL if you don't adjust it or run out of adjustment.

Mrnurse said:

The Garand requires a slower powder burn impulse, heavy bullets and quick burn powder bend the op rod.

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You remembered it backwards.

The Garand gas cylinder and it's gas port are located close to the muzzle and it's slow burning powders that will bend an op rod as those slower powders move the peak pressure farther down the bore and increase the gas port pressure.

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The production version of the Garand was designed around the 152 gr M2 ball round using what was essentially IMR 4895 and there's some history behind that.

The military started with the .30 M1906 ball round in 1906 using a 150 gr bullet and MR21 powder which was very similar to IMR 4198 which is a bit faster than IMR 4895.

In 1926, they developed the M1 ball round using a 174 gr bullet and IMR 1185 powder. The burn rate for IMR 1185 is estimated to be in between Reloader 12 and IMR 4320. For reference purposes IMR 4064 sits pretty much right in the middle of space between those two on a burn rate chart.

The logistics folks specified that existing stocks of M1906 be used first so the M1 ball ammo didn't come into common use until 1936. Given when the Garand was developed (and once the decision was made to stay with .30-06) the first 18,000 "gas trap" garands were designed for the M1 ball round.

When they started using M1 ball extensively in 1936 they quickly figured out the higher BC of the 174 gr bullet caused the round to exceed the safety limits on many of the Army's existing ranges.

Consequently, in 1937 they quickly developed the M2 ball round using a flat based 152 gr bullet and IMR 4895 powder. That was the round for which the millions of production Garands using the commonly known gas system were optimized.

Both M1 and M2 ball were used in the first few years of WWII and M1 Ball stayed in production into 1941 before all production transitioned to the M2 ball round. There were no observed issues using the M1 ball round in the Garand.

In 1956 when they began making National Match ammo again (it was discontinued in 1940) the M72 match ammo used a 173 grain projectile and IMR 4895 powder. That particular bullet was used due to its similarity with the bullet used in M1 ball, and it's reputation for accuracy in both the Springfield and the Garand.

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Now...despite that history and the similarity of IMR 1185 to IMR 4064 (i.e being a little slower burning than IMR 4895, but a lot faster than IMR 4831) there's a myth that M1 ball used IMR 4831. People have been bending op rods using slow powders like IMR 4831 in the Garand ever since. They usually don't realize it as the rifle still functions, but accuracy is adversely affected.

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Back when I shot national match with first a Garand and later an M1A, I used IMR 4895 in my Garand with 168 gr Sierras and surplus 173 gr FMJBT M72 projectiles. I could get them for $5 per box of 100 and they made great practice loads at the time 168 gr Sierra Match Kings cost around $14 to $15 per box of 100.

I used IMR 4064 in my M1A with those same bullets. The M1A uses a short stroke gas tappet and it's both closer to the chamber and more tolerant of excess port pressure.

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The takeaways here are:

1) If you are shooting a Garand, you need to stay with a powder with a burn rate very close to IMR 4895.

2) The slowest you should ever consider would be something around the IMR 4064 range.

3) IMR 4831 is way too slow for a Garand.

In terms of surplus gas operated arms, the FAL / L1A1 has a wonderful gas system adjustment feature and it'll eat just about any thing in .308 WIn / 7.62x51 NATO.

At the other extreme are the delayed blow back roller locked rifles like the HK 91, HK 93, the various CETME rifles and clones of all of the above. The rollers can be changed, but they are designed for a very specific recoil impulse (i.e. a specific bullet weight, and velocity that is also affected somewhat by powder charge weight). If you own one in 7.62x51 NATO you really need to keep the loads in the same ballpark as M80 ball (147 gr bullet at 2800 fps).

If you increase the recoil impulse, you start opening the action too soon, slide velocity is way too high, and you start throwing brass into the next county after ripping it out of the fluted chamber with really deep flutes still in case from being extracted while still under excessive pressure. If I had to guess, I'd say 3 out of every 4 owners of those rifles is clueless about this limitation, based on what I see at the range when they show up with one.

A long voyage around the world to answer the original question. A bolt action rifle will handle any .30-'06 ammunition, military or civilian.

I am happy to report that my Colombian Mauser had no safety issues with readily available commercial 30-06 ammo! I used Federal Power-Shok 150 grain Soft Point from my local Walmart. Thank you all for the help!

Now, I did have an interesting issue with light primer strikes, but I will create a new thread to discuss that.

IIRC, you can get adjustable plugs for Garands, but you have to calibrate each time you change ammo.