M1 vs. M14 accuracy

[smle-man]

M1s can be made to shoot very accurately but it takes a lot of work to get there. Hanging the gas system at the end of the barrel does funny things for the harmonics of the barrel. The front handguard also causes issues and the long operating rod adds to the problem. Moving the gas system half way town the barrel helped a lot with the M14. According to an investigation conducted in the 60s by the government a lot of the accuracy problems with M14s was related to the M80 ball ammunition and not the rifles. The ammunition was inconsistant in both bullet diameter and powder charge. No big deal for an M60 MG but a real accuracy killer for the M14.

[kendog4570]

The other factor was the ammo. 7.26 Nato was supposedly more inherently accurate than the 06.

Why is that? I know that the match ammo of old used to be in the low 170grs, and both have .308" bullets. Likewise, modern match ammo seems to be 168grs, also with .308" bullets. If anything, the 30-06 with its larger case, shouldn't that have more oomph?

You probably know more about this than I do, so I'm all ears.

The original 30-06 chamber has a tapered leade, while the 308/7.62 was designed with a cylindrical leade, in the chamber throat. That is one factor leading to better inherent accuracy with the 308. There was greater than 50 years separating the development of the two cartridges. A few things were figured out in the mean time.

[Nodda Duma]

The only interesting rifles are accurate rifles. Most folks have been answering how accurate they are out of the box. I'd like to tender an answer to the question of how their potential accuracy compares.

There are two top-notch gunsmiths in the Ridgecrest, CA area. One is still a dealer, the other gunsmiths now only for close friends. One of them is an expert at accurizing and rebuilding M1A's, the other is an expert at accurizing and rebuilding M1 Garands. They both have been doing so for 30+ years. If you are from that area then you probably know who I'm referring to.

Seeing first-hand the results of both of their work, I'd say the differences between accuracy in the rifles are truly incomparable and leaves it up to the shooter to do his part.

There is a reason that both rifles still show up and win matches at Camp Perry.

[resident-shooter]

Like others have said, with good gun care and modern factory loaded match ammo the difference is negligible.

[slopoke]

I can shoot groups just a tad over 1" with my Scout and Loaded M1As with 168gn Hornady BTHP bullets and IMR-4895 powder.

[rojocorsa]

The original 30-06 chamber has a tapered leade, while the 308/7.62 was designed with a cylindrical leade, in the chamber throat. That is one factor leading to better inherent accuracy with the 308. There was greater than 50 years separating the development of the two cartridges. A few things were figured out in the mean time.

Excuse my ignorance, but what are these leades?

[kendog4570]

Excuse my ignorance, but what are these leades?

The portion of the chamber/barrel just after the neck and prior to the start of the rifling. Also called a freebore. I will try and post up an illustration later.
C E Harris had a great article in the Rifleman about 20 + years back that went into this in a lot of detail. He also was able to improve the performance of the 06 and 30-30 by modifying the leade to a cylinder.
For those who dont know who Ed Harris is, he has forgotten more about this stuff than most of us will ever know. You can still see his writings and he is very active in the Cast Bullet Association Forum.

[kendog4570]

The portion of the chamber/barrel just after the neck and prior to the start of the rifling. Also called a freebore. I will try and post up an illustration later.
C E Harris had a great article in the Rifleman about 20 + years back that went into this in a lot of detail. He also was able to improve the performance of the 06 and 30-30 by modifying the leade to a cylinder.
For those who dont know who Ed Harris is, he has forgotten more about this stuff than most of us will ever know. You can still see his writings and he is very active in the Cast Bullet Association Forum.

Here are some SAAMI chamber drawings that reflect the difference. The main point is just in front of the neck, the 308 has a section of same-diameter free bore, and the original 30-06 chamber design does not. This cylinder section is common in most new cartidges. It was found that by reaming out this area in the 30-06 with a throating tool, accuracy was improved.

308


30-06


Most, if not all, "match" reamers for 30-06 have this free bore section added to the original design.

[rojocorsa]

Thank you for your follow through with my question.

[kendog4570]

Thank you for your follow through with my question.

You're welcome. Were you able to make sense of the drawings? They give me a headache!

[Springfield45]

I would say they are both the same as far as accuracy.

[kendog4570]

I would say they are both the same as far as accuracy.

Across the course, a match conditioned M1 in 308 (or 7.62, whichever you prefer) usually will out-shoot the same gun in 30-06.
Based on my experience, I would say the average M14 (M1A) is slightly more accurate than a comparable M1. The OP wasn't asking about match guns, but it takes more effort to keep an M1 in match condition than an M14.

[rojocorsa]

You're welcome. Were you able to make sense of the drawings? They give me a headache!

Well, I knew what they were.

If it were up to me, I would have used different colors. I think the monochromatic thing it has going on is what makes it confusing.

[17+1]

Must be a bad one. My standard shoots 2-3 with GI ball, and 1-1.5 with my reloads.

+1

That sounds about right. I have some accurizing work done to mine and have gotten it to around 2 minutes give or take with surplus ball. Was able to come down below 2 but non consistently so it doesn't count. It started around 3 minutes with the same lot of M80 ball.

I have only shot about 30 of my reloads through it. Using M118 match brass, CCI primers, AA2520, 168 SMK's. I think the loads were a bit hot, I was getting pushed around comparable to factory M118.

M1 may be slightly easier to shoot accurately. Longer sight radius always helps me a ton.

[kendog4570]

Well, I knew what they were.

If it were up to me, I would have used different colors. I think the monochromatic thing it has going on is what makes it confusing.

Check them now.