Can you "upsize" bullets a few thousandths easily

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[ARCHIVED THREAD] - Can you "upsize" bullets a few thousandths easily

Posted: 4/29/2021 3:04:56 PM EDT

I've seen where people take .311 bullets and put them through a lee sizing die to make them .308 diameter, is there a way to do the opposite?

I have a bunch of 308 size bullets and an ak. .311 bullets seem expensive. Yes I have the brass primers and powder already at pre panic prices. Just need a die set.

Thoughts?

Posted: 4/29/2021 3:08:23 PM EDT

[#1]

Knurl?

Posted: 4/29/2021 3:09:52 PM EDT

[#2]

Tap it with a hammer?

Posted: 4/29/2021 3:10:33 PM EDT

[#3]

Quoted:
I've seen where people take .311 bullets and put them through a lee sizing die to make them .308 diameter, is there a way to do the opposite?

I have a bunch of 308 size bullets and an ak. .311 bullets seem expensive. Yes I have the brass primers and powder already at pre panic prices. Just need a die set.

Thoughts?

View Quote

topologically speaking, yes - you can squash bullets down so they bulge in the middle a bit. No idea if there are actual dies designed to do so.

.308 will still engrave to a .311 bore, probably.

Posted: 4/29/2021 3:13:24 PM EDT

[#4]

I've used a swaging die w/ a flat nose punch, on some .452 cast bullets, to increase them to .454. But, I don't know how well this would work for rifle bullets, possibly the same.

Posted: 4/29/2021 3:15:13 PM EDT

[#5]

Sabot?

Posted: 4/29/2021 3:16:31 PM EDT

[#6]

The word you're looking for is "oblate".
It's what black powder bullets do when you shoot 'em (because they're soft).

Never heard of it done with regular bullets, but hey- where there's a will, there's a way.

Interested in answers...

ETA: powder coat? How much does that add? Maybe 2 coats? is that possible?

Posted: 4/29/2021 3:29:24 PM EDT

[#7]

What I have are hornady 150 fmj, that might change the answer

Thanks

Posted: 4/29/2021 3:39:48 PM EDT

[#8]

Have you tried any to see how they work?

Posted: 4/29/2021 4:08:54 PM EDT

[#9]

Quote History

Quoted:
Have you tried any to see how they work?

View Quote

Of course not

Posted: 4/29/2021 5:16:51 PM EDT

[#10]

Paper patch them?

Posted: 4/29/2021 7:43:36 PM EDT

[#11]

Someone mentioned doing this, but I can't find the post. I had never heard of it before. I've only swagged down from .311 to .308.

Edit: It might be easier to use a Faxon barrel that's a .308 bore assuming this is for a 7.62x39 or better yet find someone to trade bullets with.

Posted: 4/29/2021 7:59:09 PM EDT

[#12]

Bumping up cast bullets can be done, but with cast rifle bullets, precision is lost doing this. I have tried squishing some jacketed (soft pointed) bullets in the past, but uniformity goes to complete shit. They just don't expand in the same place each and every time. I also used a SACO bullet sizer with .312 dies and a good fitting nose punch to do this and I felt it was putting too much stress on the sizer. FMJ bullets would probably be even more difficult and give even worse results.

However, someone who has swaged jacketed bullets from scratch might have a workable solution.

Posted: 4/29/2021 9:54:24 PM EDT

[#13]

Quote History

Quoted:
Interested in answers...

ETA: powder coat? How much does that add? Maybe 2 coats? is that possible?

View Quote

Powder coating generally adds .002 to bullet diameter.

Posted: 4/29/2021 10:04:13 PM EDT

[#14]

The bore on a 7.62x39 is .300, so a .308 bullet is still a press fit through it.

I would wager a good deal of cheap 7.62 ammo is nowhere near .311”.

Posted: 4/29/2021 10:39:15 PM EDT

[#15]

Way back in the day, before there was plentiful and cheap surplus for Vietnam bring back SKSs 7.35 Italian was converted to 7.62x39mm. Case resized and trimmed and the .298-.299" projectiles were bumped up to .310-.311". Not sure how it was done though.

To OPs situation, firing .308" instead of .311" is more of an issue with the expander plug in your resizing die. I once measured a selection of foreign commercial and surplus x39 and it ranged from .309" to .312" with .310" being the most common. I would use the .308"s since it is an AK and not some precision instrument.

Posted: 4/30/2021 2:28:32 AM EDT

[#16]

I’ve powdercoated .308 jacketed bullets To move them up to .310-.312.

On average, 1 coat is .002”

Wish I had a high speed camera. I’ve found some powdercoat around the muzzle after firing. How much comes off?

Not worried about the powdercoat on the bullet after it leaves the bore, just want it to help engage the rifling while traveling down the bore.

Posted: 4/30/2021 2:45:53 AM EDT

[#17]

The Idahoan Show (YouTube) tried that a couple weeks ago.

Posted: 4/30/2021 2:01:13 PM EDT

[#18]

.308" bullets shoot fine through .311" bores. The gap between the bore and the bullet will only be .0015" when using the .308". The high pressure shock wave should expand any .308" flat based bullet's base to completely seal in the bore eliminating any blow buy.

What you want to accomplish is labor intensive with zero hope of achieving any improvements in performance.

Posted: 4/30/2021 2:06:11 PM EDT

[#19]

Most (not all) 7.62x39mm die sets come with two expander balls. If yours does not, buy a .308 expander from the company that makes your dies. It should measure around .305" to .306" to hold a .308" bullet firmly enough not to require crimping.

You can spin polish any expander ball smaller if needed.

Posted: 5/1/2021 9:28:08 AM EDT

[#20]

Quote History

Quoted:
.308" bullets shoot fine through .311" bores. The gap between the bore and the bullet will only be .0015" when using the .308". The high pressure shock wave should expand any .308" flat based bullet's base to completely seal in the bore eliminating any blow buy.

What you want to accomplish is labor intensive with zero hope of achieving any improvements in performance.

View Quote

Even if it doesn’t seal completely, being jacketed the rifling will still grip the tougher copper jacket the OP is using. It will impart plenty of spin for stabilization. Cast lead bullets will certainly not enjoy the free gap.

case in point, plenty of Enfield military rifles had grooves ridiculously deep. 0.317-319 groove depth were not uncommon when .311 was spec. Our Krag rifles were just as off in the groove and sometimes in the bore (lands) as well.

Posted: 5/1/2021 2:28:34 PM EDT

[#21]

My experiance of shooting .308 bullets in an AK is that accuracy gets much worse.

As in patterns instead of groups.

Now that I powder coat my cast bullets, I make them the diameter I want.

Posted: 5/1/2021 3:07:16 PM EDT

[#22]

Never done it in Commie milsurps, but Enfield rifles shoot just fine with .308 bullets if the rifling is good.

Esp 147 gr FMJ bullet pulls. Give it a try before you start tapping rounds with a hammer.

Posted: 5/2/2021 8:23:56 AM EDT

[#23]

Quote History

Quoted:
Way back in the day, before there was plentiful and cheap surplus for Vietnam bring back SKSs 7.35 Italian was converted to 7.62x39mm. Case resized and trimmed and the .298-.299" projectiles were bumped up to .310-.311". Not sure how it was done though.

To OPs situation, firing .308" instead of .311" is more of an issue with the expander plug in your resizing die. I once measured a selection of foreign commercial and surplus x39 and it ranged from .309" to .312" with .310" being the most common. I would use the .308"s since it is an AK and not some precision instrument.

View Quote

It may be and probably will be wildly inaccurate though. In my own experience, I bought some wolf .303 and fired it through a No 4 Mk1 and I was getting 12 foot groups at 120 yards. Yes.12 FOOT GROUPS. Something had to be wrong, this rifle normally shoots 2 inches at 120 yards. Mic'd the bullets and found they were .308 from the factory. So I pulled those and loaded the Wolf brass with some .310 and got it back to 2 -3 inches. I was not happy with Wolf after that because I have 400 plus cartridges left that I still have to pull but at least I have a supply of brass and powder to use from it. I haven't tried the .308 pulled bullets yet but they do look good.

Posted: 5/2/2021 9:59:37 AM EDT

[#24]

A good first step would probably be for OP to clean the hell out of his barrel and slug it to determine his actual bore and groove dimensions. AKs are notorious for inconsistency. It's not really a flaw by any means, it's just outside its mission parameters.

Posted: 5/3/2021 12:17:31 AM EDT

[#25]

MG shooters used to 'bump-up' bulk, pulled .308" bullets for use in .303 and other similar sized MG barrels years ago. It requires specially made dies and (ideally) a swaging press. I would expect to pay big bucks for the dies (figure around $1K, and you probably won't be disappointed), and to have to wait 1-2 years to get them.

Posted: 5/4/2021 4:03:15 PM EDT

[#26]

Might be worth mic'ing the bore

There was a time when a lot of 7.62x39 guns had a .308 bore.

Posted: 5/6/2021 3:25:42 PM EDT

[#27]

If you will notice some of the loading manuals have loads for .308 projectiles in 7.62 x 39.

Posted: 5/8/2021 2:45:38 AM EDT

[#28]

Quote History

Quoted:
Most (not all) 7.62x39mm die sets come with two expander balls. If yours does not, buy a .308 expander from the company that makes your dies. It should measure around .305" to .306" to hold a .308" bullet firmly enough not to require crimping.

You can spin polish any expander ball smaller if needed.

View Quote

This is your answer, just put a 308 expander in your sizing die. They're only a few bucks by themselves.

My Lee set of dies came with a 311 and 308 expander.

Posted: 5/8/2021 9:45:55 PM EDT

[#29]

303 British has a larger land diameter than 308, but 7.62x54R and 7.62x39 both have the exact same 0.300" land diameter as 308.

Only the groove diameter is slightly larger and that shouldn't make a difference, especially with bullets heavier than 125 grains as the heavier bullets have a longer surface that is full diameter.

Use a 308 (0.307") expander for sizing cases for neck tension when seating 308 bullets.

[ARCHIVED THREAD] - Can you "upsize" bullets a few thousandths easily

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