Bullit OVERSIZE

[1jonzmith]

If I have a 308 barrel can I safely shoot 312 bullets? What about 309, 310 and 311? How would you expect the accuracy to be affected?

Thank you,

John

[ellobo]

I wouldnt use oversize bullets in any caliber. They will cause higher pressures that may be dangerous to you and your rifle.

El Lobo

[drybean]

lead bullets?
drybean

[Uncle Jack]

"Bullit OVERSIZE"

Oh, Hell.....I thought you were talking about one of my favorite old Steve McQueen movies.

uj

[Eric in NC]

"Bullit OVERSIZE"

Oh, ****.....I thought you were talking about one of my favorite old Steve McQueen movies.

uj

Steve must have been one heck of a driver for that little Mustang to keep up with that Hemi Charger!

[earl39]

"Bullit OVERSIZE"

Oh, ****.....I thought you were talking about one of my favorite old Steve McQueen movies.

uj

Steve must have been one heck of a driver for that little Mustang to keep up with that Hemi Charger!

He drove in more than one LaMans

[Eric in NC]

Yeah I know, but I also know they wired one of the four barrels on the Charger shut for the shoot.

Big Steve McCool fan (I ride a Triumph!) but I know the Hemi Charger would eat that Mustang up! (Not to mention they must have lost 26 hubcaps between them in that chase scene!).

[1jonzmith]

Can I shoot 310. 311 or 312 bullets in my 308? Bore has been carefully slugged.

Thanks,

John

[Eric in NC]

Cast lead with appropriate loads -maybe. Jacketed - not a good idea.

[GaCop]

Cast lead with appropriate loads -maybe. Jacketed - not a good idea.

Sound advice.........

[82boy]

1jonzmith
Please dont "double post" your questions, 1 post is all that is needed.
Thank you

[thomae]

John,
Here is a slightly expanded answer to your question. There is no simple answer, but hopefully the following will help you stay safe as you research this.

Accuracy? No way of knowing. Each barrel is finicky and prefers its own pet load(s).

I believe that a greater concern would be the additional pressure generated by trying to force that oversized projectile through your barrel.

That extra pressure might have a negligible effect, or it might overstress the receiver causing it to catastrophically fail.

What effect that extra pressure would have depends on too many factors to list here.
It depends on your loads, barrel, receiver, temperature, headspace, and I am sure many other factors.

Questions you should research would include but not be limited to:
What type of action do you have and how strong is your receiver?
Are you shooting hot loads (the latest 300 Super Duper Magnum Wildcat loaded to the max), or light loads (30 carbine plinking rounds)?
It all makes a difference.

Worst case scenario: Hot loads might blow up your gun, injuring or killing you. Light loads might allow the projectile to get stuck in the bore.

My own experience has been as follows: I have shot Russian ammo (nominally .311 bullets) through my savage factory 7.62x39 with a .308 bore. It seemed to function well and I carefully examined the brass (steel) for any pressure signs and found none that I could tell.

I also get better accuracy out of my Hammerli 32S&W Long target pistol using my reloads with .314 diameter lead wadcutters and shoot them through the .312 barrel. The .312 diameter bullets just don't perform as well for me.

However, that being said, It is my rifle, my pistol, my ammo, my level of experience (or inexperience), under my conditions.
Although it worked with me, it might not work so well for someone else under other conditions.
So, Since I don't know anything about you and your equipment, I would take the conservative route and agree with previous posters and would generally not recommend shooting oversized bullets through your barrel.

[earl39]

For the record there have been barrels either production or experimental that used a tapered bore to use a 311 bullet and squeeze it down to a 308. How well they work/worked i have no ideal but they have been made. I don't think the 311-308 was the only size they were tried in.

As to shooting a 311-312 bullet thru a 308 bore i have to agree that it is not a good ideal with jacketed bullets because of all the variables involved.

[Grit #1]

Lapua made/makes .3085 and .309 for use in the oversized bores that are normaly found on Garands, 03A3 and US Mod1917s. I have used both in all three. I have never tried an oversized bullet in a correctly sized barrel. I will tell you this. They shrink group sizes beyond 50% in both my Garand and US mod1917. The 03A3 is a Smith Corona with the proper High Standard barrel. It shoots any of the SMKs wonderfully.
Best regards,
Grit

[stangfish]

Yeah I know, but I also know they wired one of the four barrels on the Charger shut for the shoot.

Big Steve McCool fan (I ride a Triumph!) but I know the Hemi Charger would eat that Mustang up! (Not to mention they must have lost 26 hubcaps between them in that chase scene!).

......and a 13 speed gearbox.

[1jonzmith]

Thank you all very much. I believe I have my answer. Savage makes a 7.62 X 39 rifle that shoots .311 very well. More importantly, Savage doesn't emblazon the gun with warnings about using Russian 7.62 X 39.

But all the cautions and warnings are not lost on me, I assure you.

Thanks,

John

[Eric in NC]

Yes they make a 7.62x39 rifle that shoots .311 bullets well. That is because it HAS a .311 bore!

[thomae]

Yes they make a 7.62x39 rifle that shoots .311 bullets well. That is because it HAS a .311 bore!

When I called Savage and spoke with their tech folks, they told me the Model 10 FCM Scout in 7.62x39 had a .308 bore. To be honest, I have not slugged my barrel to confirm or deny this.

[Eric in NC]

Hmm - different from the info I got. If it does have a .308 then it probably has the long throat like a Ruger Mini-30. Not a great setup.

Anyhow - the 7.62x39 is a whole different animal than the 308 the OP was asking about. Still wouldn't go with 311 bullets in my 308 unless I had an oversized bore.

[1jonzmith]

Yes they make a 7.62x39 rifle that shoots .311 bullets well. That is because it HAS a .311 bore!

Eric,

Please refer to thomae pst that follows yours. I, like you seem to , want this to be cut and dried. After two days the bast I can say is it is controversial. If Savage makes a 308 bore that is chambered for the NATO round and has a chamber adapter to allow 7.62 X 39 to also be used (or vice versa).... seems to answer the question. Litigation would have long ago answered this question if the guns were blowing up.

One of the bottom lines here, as I see it is.... Many say this cannot be done safely and they base that on a lot of verified data. The problem is NO BODY EVER SAW ONE EXPLODE. Now that proves exactly nothing but it sure as heck begs the question. I am certainly not calling anyone wrong as there seems to be at least 5 sides to this issue. Wikapedia says the bullet and bore for the 7.62 is 312.

[1jonzmith]

Yes they make a 7.62x39 rifle that shoots .311 bullets well. That is because it HAS a .311 bore!

When I called Savage and spoke with their tech folks, they told me the Model 10 FCM Scout in 7.62x39 had a .308 bore. To be honest, I have not slugged my barrel to confirm or deny this.

Thank you Thomae,

You are at least the third person that has verified that about Savage and today I learned they have a cal adapter so it will shoot both rounds.

Please just stick a caliper into the muzzle (gently) and measure the groove and land diameter.

My Sierra rifle loading manual Fourth Edition, pp 385, says "rifles chambered for this round are readily available in two distinctly different bore sizes, 308 and the original 311.diameter. Reloading equip manufacturers recognized this and now supply their 7.62 X 39 dies with a expander ball for 308 and a separate one for 311."

This is the finale for me and I will order my chamber reamer for 7.62 X 39 with a 308 bore. Bet the barrel maker has a reamer on the shelf to handle it but I will do this more than once and I do have friends that will want to borrow it. Free bore and neck(unturned) diameter/clearance are now the questions to be answered. Reamer at Pac Tools always wants me to provide him with a unprimed round with the bullet of choice seated to the depth I want. S&B 123 grain SPBT gets the nod.

Thank you all. i will try to post a report on accuracy I get for the different diameter bullets. Not from the hospital, I hope. ??? ::) ;D

John

[thomae]

Yes they make a 7.62x39 rifle that shoots .311 bullets well. That is because it HAS a .311 bore!

When I called Savage and spoke with their tech folks, they told me the Model 10 FCM Scout in 7.62x39 had a .308 bore. To be honest, I have not slugged my barrel to confirm or deny this.

Thank you Thomae,

You are at least the third person that has verified that about Savage and today I learned they have a cal adapter so it will shoot both rounds.

Please just stick a caliper into the muzzle (gently) and measure the groove and land diameter.

My Sierra rifle loading manual Fourth Edition, pp 385, says "rifles chambered for this round are readily available in two distinctly different bore sizes, 308 and the original 311.diameter. Reloading equip manufacturers recognized this and now supply their 7.62 X 39 dies with a expander ball for 308 and a separate one for 311."

This is the finale for me and I will order my chamber reamer for 7.62 X 39 with a 308 bore. Bet the barrel maker has a reamer on the shelf to handle it but I will do this more than once and I do have friends that will want to borrow it. Free bore and neck(unturned) diameter/clearance are now the questions to be answered. Reamer at Pac Tools always wants me to provide him with a unprimed round with the bullet of choice seated to the depth I want. S&B 123 grain SPBT gets the nod.

Thank you all. i will try to post a report on accuracy I get for the different diameter bullets. Not from the hospital, I hope. ??? ::) ;D

John

I'd like to make sure that we are talking about the same thing here.
I have a Savage rifle chambered in 7.62mmx39mm Russian. I believe it has a bore diameter of 308/1000 of an inch. It is not chambered for the .308 Winchester round. When I get around to slugging the barrel with one of my .314 lead pistol bullets, I'll confirm the diameter.

I own a set of Lee dies for 7.62x39. They have two expander rods, one for a .308" bore the other for a .311" bore.

Adapters are commercially available to shoot 7.62x39 rounds out of rifles chambered in .308 Winchester.

You are at least the third person that has verified that about Savage and today I learned they have a cal adapter so it will shoot both rounds.

The above sentence is confusing. What I verified is that my rifle, chambered for 7.62mmx39mm Russian, has a bore diameter of .308 inches.
I do not understand what you mean by "both rounds."

Other data to consider:
The difference in chamber length length between 7.62x39 and .308 is about 12 mm or 1/2". The adapter takes up this space, but that's a long way to jump before hitting the lands and grooves. This may or may not affect the accuracy of rounds shot from a rifle with an adapter. Don't know, never tried it.

The two rounds have different rim diameters .308Winchester and 30-06 Springfield are .473", 7.62mmx39mm Russian is = .447".

Now, before this thread spins out into the weeds, I am going to back up and specifically address the OPs original question:

If I have a 308 barrel can I safely shoot 312 bullets? What about 309, 310 and 311? How would you expect the accuracy to be affected?
Thank you,
John

1. Background: Some people have been successfully shooting .311 bullets in a .308 bore (specifically in rifles chambered for the 7.62mmx39mm Russian cartridge.)
2. From his question, I know nothing about what rifle or cartridge 1jonzmith wishes to use to shoot .312 bullets through a .308 bore. I also don't know what kind of bullets he would use. I don't know anything about his level of expertise, knowledge of reloading, internal issues, and a whole bunch of other issues that might affect the safety of what he wishes to attempt. Therefore, (and I am not putting him down or casting aspersions in his direction), although there may be some situations where it would be reasonably safe to shoot a specific oversized bullet through a .308 bored rifle, I take the high road and recommend that he DOES NOT shoot oversize bullets through his bore.
3. ...So my answer to the OP about shooting .312" bullets through a .308" bore: I would not recommend it.
4. ...as to .309", .310" and .311" bullets? Not enough information, so I would not recommend it.
5. ...as to accuracy? I don't know. Accuracy depends on so many more factors than bore and projectile diameter.

Sorry this is a long post, but I want to be as clear and specific as I can.

[Eric in NC]

You have a quote attributed to me that I did not say.

[thomae]

Eric,
Thanks for bringing that to my attention. I went back and corrected my post.
Sorry about that. I had edited out the extra stuff and cut and pasted incorrectly.

[1jonzmith]

Thomae,

You wrote:
"Adapters are commercially available to shoot 7.62x39 rounds out of rifles chambered in .308 Winchester."

That's what I meant by "both rounds" . I was quoting you.

I think your sharing that the die set comes with a 308 and 311 expander die, and others verifying that, as well as the advertisement of the die mfrs., I think this is settled. And, as always, advice to stick with the precise calibre is prudent and valid.

Thank you for all the info and your superb posts.

John