Is the 5.45x39 a poorly engineered round?

[Richardito]

I shot a friends 5.45 rifle and I noticed a big amount of "keyhole" holes in my target. I asked him what was going on and he said "that happens sometimes". I just got a VEPR in this caliber. I wanted to get a 20" barrel rifle but I was only able to get a 16" one. I've read many stories in forums talking about issues with caliber. I read one that stated that, when cold, the rifle's accuracy is awful, but as it warms up the MOA gets smaller. That is exactly what I saw with my new VEPR! After about 15 rounds you could see the groupings get significantly tighter. There is also a slow motion video of Vickers firing an AK-74 and you can see the bullets roll as they come out of the barrel. I have a couple of theories/conclusions:

1. This is a very unstable round, who the heck tested it?
2. As the rounds warm the barrel the subsequent rounds loose less energy and gain more stability. That's why the grouping gets tighter.
3. This caliber is useless as a hunting round since you need accuracy on the first round.
4. This caliber is useless as a target or competition round.

I guess accuracy is not a real issue when firing a Krink full auto (and the barrel would get hot fast!). I thought that maybe the 20" barrel would be more accurate from round 1, but I have no data to prove or disprove my theory. Who out there has experience with this caliber/round and could chime in? I would love to get more data and theories about this.

 

[robertc1024]

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[Dawico]

I have no experience with that round but it sounds like a rifling twist rate issue.

Our military has done the same thing with our M16/ M4s by changing the twist rate over time. I expect us to make changes faster than ComBloc countries but maybe not.

You are dealing with surplus ammo and rifles.

Do you scrub your barrel in between every range trip? I have found a sparkling clean barrel shoots way worse than one with some fouling in it. This may not be the situation though, just curious.

 

[Richardito]

I have no experience with that round but it sounds like a rifling twist rate issue.

Our military has done the same thing with our M16/ M4s by changing the twist rate over time. I expect us to make changes faster than ComBloc countries but maybe not.

You are dealing with surplus ammo and rifles.

Do you scrub your barrel in between every range trip? I have found a sparkling clean barrel shoots way worse than one with some fouling in it. This may not be the situation though, just curious.

Not surplus, I'm dealing with a new VEPR which has a heavy duty new barrel and the ammo is Wolf.

 

[Richardito]

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No time to actually say anything useful?

 

[Dawico]

No time to actually say anything useful?

Maybe he decided it wasn't useful so he erased it. Users can't delete a post once posted, they can only delete the text at that point.

Don't take his delete as an insult to your situation.

 

[Dawico]

Not surplus, I'm dealing with a new VEPR which has a heavy duty new barrel and the ammo is Wolf.

Very strange then.

Sometimes imported steel case ammo is a hair on the light side. Velocity can help bullet stability.

My only guess would be chamber pressure is increased as it warms up and the ammo needs that little velocity boost to stabilize the bullet.

Again, very strange.

Have you tried different ammo? I would suggest lighter bullets or at least a different manufacturer to see if the situation improves or gets worse.

 

[Dawico]

Another thought would be something binding on the gun itself while cold. The heat from a few rounds firing is loosening it up.

Does the action move freely while cold? Any place you can see that is holding it up a little?

A little bad of grease somewhere may be the key to better cold bore shots.

 

[Richardito]

Very strange then.

Sometimes imported steel case ammo is a hair on the light side. Velocity can help bullet stability.

My only guess would be chamber pressure is increased as it warms up and the ammo needs that little velocity boost to stabilize the bullet.

Again, very strange.

Have you tried different ammo? I would suggest lighter bullets or at least a different manufacturer to see if the situation improves or gets worse.

Good point on the chamber pressure, it goes in hand with my "barrel warm up" theory. I only have Wolf ammo and it is the lightest with 55 grains.

 

[Richardito]

Another thought would be something binding on the gun itself while cold. The heat from a few rounds firing is loosening it up.

Does the action move freely while cold? Any place you can see that is holding it up a little?

A little bad of grease somewhere may be the key to better cold bore shots.

The VEPR is rock solid and the action is very smooth... I will lube it better the next time I go to the range and test that. Thanks for your ideas!

 

[Dawico]

Yes sir. Hope it helps.

That is a strange situation you have there.

 

[majormadmax]

I know Tantals Century built off kits had a problem for a while due to US-made barrel issues, but I have not heard the same from Veprs.

While more of a fan of the 7.62x39, I've shot the 5.45 and have never had a problem with it. I don't think it's the round, but the weapon you're using unless as noted, it's the particular brand of ammo.

 

[Eli]

If it's keyholing, it's most likely the result of a 5.56 barrel instead of 5.45 - that's what was wrong with the Tantals mentioned above. The 5.45 was designed to copy the effects of 5.56, but was more 'clean sheet' than 5.56 was.

Eli

 

[Saltyag2010]

Sounds like you have a bad rifle. I have 2 Adams arms 5.45 uppers and an AK74. Ak groups at 1" at 50yds and the ARs group around 2" at 50yds.

I only use milsurp ammo from the 80s.

 

[MTA]

Strange issue to be having with a VEPR. Their quality is top-notch. Might want to switch ammo brands to see if that helps.

 

[lmao]

I'd slug the barrel and mike (to the ten-thousandth) the bullets. also very carefully check the barrel throat. have you been shooting laquered ammo in it? Might have some bad fouling in front of the chamber

 

[ZX9RCAM]

So, I see he has been banned.

 

[majormadmax]

So, I see he has been banned.

Nevermind, now I see. Any idea what was the straw that broke the camel's back?

 

[ZX9RCAM]

Nevermind, now I see. Any idea what was the straw that broke the camel's back?

Not me, I just realized he had not posted anything and I started looking.

 

[ZX9RCAM]

It starts here...

https://www.texasguntalk.com/forums/showthread.php?t=79277&page=19&p=1599489&viewfull=1#post1599489