My uncle Dave who used to shoot at Perry’s pretty regularly asked me a question since I’m the ‘gun nut’ of the family (I also have the smallest collection).

He has a M1 in 308 he wants to get back to 3006,  am he get the chamber broached or does he need a new barrel?  I know 0 things about the M1, though I did inherit one.  His logic is that he’s sitting on a metric TON of 3006, probably 2 cubic yards of it.

Also please post Suggestions on places to get the changes done as needed.

I already told him to go do his homework in the twist & pressure issues he may have. My suggestions was to get it rebarrelled & sell me the 308 barrel I’m it now.

Rebarrel for ?$$$? or sell it and get a CMP Expert Grade in .30-06 for $1150.  I would not mess with reaming the chamber.  YMMV.

@flcracker

That’s my thought.  I know 0 about M1 other than piiiing when. You’re empty.  He wants to see if its doable even.

Just buy a .30-06 M1 barrel and send it and the gun to Countryside Gunsmithing in North Carolina

This.

@Jeremy2171

Make sure to ask him to install a vented gas plug while he has it.

Seriously though, besides his distain for vented gas plugs, he is knowledgeable on M1’s and has good reviews for fast turn around and good work. I would take a gamble with him if I did not have the tooling myself to rebarrel.

CMP and Fulton could also do it just fine.

Going to a 30-06 from a 308 requires either a new barrel, or setting the barrel back.  Setting the barrel back is a no go with the Garand, so you will need a new barrel.

Why not trade it for a 30-06 garand?

@JHMC79  I asked why not get another M1 & then you have both.  He doesn't want to go that option.  Though if the rebarrel labor cost & the new barrel cost are 50% of the cost of a new M1 he might.

A new barrel plus the labor to install it would be around $500

But not have it turned around in (usually) less than 2 weeks.

@FluffyTheCat I told him this & that it’s a great excuse for another gun.

I recently sent Fulton a WW2 Springfield receiver,a NOS 1955 barrel,NOS bolt and gas cyl  to barrel and headspace,had it back in less than 2 weeks.

I would just get an expert grade from the CMP and call it a day.

How many rounds through the .308? They usually last 4 - 5 thousand rounds. Most barrels were Douglas made decades ago. Definitely good barrels.

If the bore looks great he may get good results having it bedded again.

I started shooting service rifle matches in the early 1980's.

I barreled and built my own match rifles and reloaded my match ammunition.

Originally I used IMR-4895 powder for both 308 and 30-06.

My 308 Garands were more accurate than my 30-06 Garands, until I changed powders in 30-06 and that made them almost equal in accuracy.

A lot of people would say 308 was more accurate than 30-06.

308 has a different case taper than 30-06 and reaming to 30-06 might not be the best thing to do.

Also 308 Garands use a larger diameter gas port in the barrel than 30-06 Garands.

Match ammo in 1980's was usually either military surplus or hand loads, as commercial match ammo didn't really start showing up until around 1990 and it very expensive at that time.

I didn't have the Internet in 1980's and most all of my rifle building and reloading information came from old timers at the matches.

There is a reason the Navy team shot .308s, because they did tend to shoot better that the 06s.

I gotta ask though, what powder did you switch over to? I have an M1 I'd like to have built up into a Service Rifle, but I was going to convert it to .308. I'm all ears about the magic powder though.

Both IMR-4895 was position sensitive in 30-06.

IMR-4895 worked really well for me in 308, so I didn't mess with other powders in it.

The first switch I made in 30-06 was to IMR-4064 and this was just about perfect.

When Varget first came out in 1997 it wasn't very consistent.

A few later Varget turned out good with 168 grain bullets, but a bit touchy with 175 grain bullets.

IMR-4064 shot great with both 168 grain and 175 grain bullets.

Later Hornady told me that their most accurate 30-06 Garand load was 46.3 grains of VV N-135 with their 168 grain bullets.

That shot well.

Hornady told me that Varget was their second most accurate 30-06 Garand powder with their 168 grain bullets.

Before there were 175 grain MK bullets, some guys would use the old 180 grain MK bullets.

Those had the 190 grain MK boat tail and shot well.

Back then I stuck with 168 grain MK's.

When the 175 grain MK came out, the 180 grain MK switched to the 168 MK boat tail.

This was supposed to help it with slower 308 rifling, but made the 180 grain MK worse shooting than the 175 grain MK.

IMR-4064 seems the most forgiving in 30-06 Garand loads, with several bullet weights.

Accurate 4064 seems the same as IMR-4320, not like IMR-4064, neither in appearance, nor performance and looks like old IMR-4320.

When I first started match shooting, the old timers would say to avoid ball powders, as they were thought to foul the rifle more quickly than extruded powders.

How about this. You have an M1 in .30-06. He has 30-06 ammo. You buy .308 ammo and trade him round for round (maybe not two cubic yards to start with, just an ammo can or two).

Interesting, I wasn't aware of the position sensitivity with IMR 4895. I do have a jug of IMR 4064 that I'll try in my CMP Special.

I'm thinking I want to shoot the 135 Sierra at 200 and the 155s at 300 & 600. That being said, I have 190s and 180s that I could mess around with. I always had good luck with the newer 180s Sierras at 600 in my M1A. I'm surprised to hear that they didn't shoot all that well for you.

I legged out and made the P100 with an M14 back in the day, but I always thought the M1s were cool. Longer sight radius and more powder. I just never managed to get one built because I was too busy shooting ARs and then match rifles.

Now my eyes suck, but I have the money to play around with things.

So IMR 4064 is op rod friendly?

Yes, it is and is not position sensitive in 30-06.

4064 is a medium burn rate powder, it's listed in the Hornady Service Rifle reloading pamphlet and reloading manual for M1s and M14s. It's also listed in the John R Clark American Rifleman article Reloading for the M1 Rifle.

I shot a fair amount of it in M14s, I see no reason for it not to be op-rod friendly in an M1.

Nearly all powders are oprod friendly.

One of our Range Safety Officers, who’s also the Club’s resident Garand expert, says Varget is the best powder for M1s as long as the handloader follows the Hornady Serv. Rifle load data. He says Varget is op rod friendly and not sensitive to temperature variations or changes in positions.

Varget varies noticeably a bit from lot to lot.

Varget is good for 30-06 Garand loads with 155 and 168 grain bullets to full velocity, but with 175 grain bullets, the Varget Garand loads have to be a bit light, because Varget produces a lot of gas at the gas port for the chamber pressure.

IMR-4064 is extremely temperature stable.

I temperature tested it in the Arctic of Alaska and in the desert.

IMR-4895 had showed some changes at temperature extremes, but IMR-4064 did not.

You can get full factory ammo velocities with all bullet weights in 30-06 Garand loads with IMR-4064, without overgassing the Garand.

48.0 varget and 168/175 SMK is a near duplicate of M72 match and great accuracy.

The section of Hornady’s Serv. Rifle manual on M1 Garand load data specifies:

46.2 grns of Varget as the max load for 150-155grn bullets (FMJ and Match);

47.0 grns of Varget as the max load for 168grn Match bullets; and

46.4 grns of Varget as the max load for 178grn Match bullets.

Maybe 48.0 grns of Varget for a limited amount of shooting the 168grn bullets wouldn’t necessarily abuse the gas system or snap the op rod, but 48.0 grns is definitely over the recommended book max for the other bullet-weights.

Someone on the CMP forums did recommend 48.0 grns of Varget for shooting the 125grn bullets in matches but I haven’t had a chance to play with those yet.

The Hornady M1 Garand data is some of the only Garand data that measured gas port pressure.

Many years ago there was Garand data based on ejection pattern, compared to factory loaded military ammo.

I talked to somebody at Hornady soon after their Garand data came out.

First it was developed sometime earlier.

Around 1990-92 Winchester had change4d their primwers to be less slamfire sensitive, after service rifle match shooting really started becomong popular.

Ther earlier Winchester primers were prone to slamfires and the older Remington 9 1/2 primers were the slamfire safe primers.

Winchester changed their primers to be less sensitive and offered to swap their old primers with the newer primers to anybody that wanted the newer ones.

These primers were nickel plated and had three raised points on them (front edge or rear face).

I stuck to Remington 9 1/2 primers at the time, which were the mildest primers back trhen and compared to current CCI-200 primers.

Hornady then recommended Winchester primers for service rifle loading.

Around 2005 or so, Winchester (and others) switched to non-plated primers.

The Remington 9 1/2 primers became very hot for ball powder use.

Winchester stated that their new non-plated primers were made more sensitive, due to complaints of misfires, from light strikes and off-center strikes.

Even though Winchester changed their primers, Hornady continues to recommend Winchester primers for service rifle loading, based on previous data.

Hornady told me that their maximum loads aren't always maximum, but that either powder couldn't make the next velocity column without going overpressure at the chamber or the gas port, or the accuracy was not going well and they stopped loading a certain powder, or they ran out of powder and just quit there or for no reason at all and they broke for lunch or the end of the day and started with a different powder when they returned.

A lot of the data is good for Hornady cases, Winchester primers and the long Amax bullets.

In America Winchester sells magnum primers, but only has one production line of large rifle primers.

All Winchester primers are supposed to be Magnum rated, but the lots that measure at the hottest end of testing are sold in America as Magnum primers.

In other countries, Winchester doesn't market separate magnum primers, but states that all of their primers are magnum rated.

Varget wasn't imported to the US until 1997.

At that time, Varget could vary quite a bit from one can to the next, if they came from different lots.

Current Varget seems a bit better in that regard, but might be a bit slower than earlier Varget was.

For the chamber pressure produced, Varget makes more gas port pressure than a lot of other powders with similar burning rates.

For 30-06 Garand loads, the maximum chamber pressure is usually below maximum for other 30-06 loads, which can allow a window where Varget can generate some decent velocitty and not completely overgas the Garand, but it can be touchy loading in that window.

Hornady told me their most accurate 30-06 Garand powder was VV N-135 and Varget was their second most accurate.

IMR-4064 is way above IMR-4895 in accuracy.

The Sierra Match King hollow point bullets can take a bit more powder than the long Hornady Amax bullets, but not tremendously more.

For the 155 grain SMK I recommend the older, less pointy one, which is still produced and available.

The pointy one has to be seated deeper to fit and it is more sensitive to fast rifling twist rate of Garand barrels, as it is made for 14 inch rifling in very long Palma match barrels.

Hodgdon's service rifler data is just their regular data modified with a computer program and they didn't actually shoot those loads.

That's the reason you see a mix of CUP and PSI pressures in their, "new" service rifle data.

Hornady shows the same maximum load of H4895 for all three bullet weights in their Garand data.

With the heaviest bullet, that would be a very hot load.

It's not perfect, but some of their data can be useful.