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Just picked up the new mini14 target can any one eplain to me the difference between .223 and 5.56*45 military surplus. can they be used interchangably. I have one guy at the gun shop say yes and another says absultly not.
 

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This is from Winchester's web site.

.223 Rem VS 5.56mm

Paul Nowak
5/4/2001
.223 Rem VS 5.56mm

There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.


The cartridge casings for both calibers have basically the same length and exterior dimensions.
The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.
The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.
The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.
You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.
Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.
The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.


Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges. Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy. However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.
 

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My shootin' buddy bought a Mini-target a few months ago. We ran it through the paces using the loads I worked up for my Rem 700. A 55 gr Nosler Ballistic Tip, R-P case, and 26.5 gr of Varget produced sub MOA 100 yard groups without touching the adjustable harmonic damper.

What Johngoboom said is absolutely true and don't let anyone tell you otherwise.
 

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Rugers are chambered for the GI 5.56 so you can shoot GI or commercial. Its the guns chambered for 223 that have to be careful.
 

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Cherokee, True for the Mini-14 and the Mini-14 Ranch but not the Mini-14 Target. It has a totally different barrel and a much tighter chamber than previous models. Using GI ammo would soon destroy the target grade accuracy in the Mini-Target model.
 

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Mini-14 Target

I purchased a Mini 14 Target and can not get the rifle to group...

I tried PMC 223 55gr Bronze ammo, all over the place, very inconsistent. I tried 40 rounds of PMC 55gr SS109 (green tip) ammo and I was able to get a group, but no where near what I have read from tests done on the rifle, about a 6" [email protected]

Thinking it was the scope, I changed out the scope three time... First scope was a Redfield 5 star 6-18x40, second scope was a Baush and Lomb 6-24x40, third scope was a Leupold 6.5-20 Mark IV... Guys it can't be the scope or mounts. Everything was checked and re-checked to 25 in-lbs, bore sighted and the rifle clean.

I broke the barrel in with 30 rounds and cleaned after every round. The rifle functions correctly but it won't group.

My next attempt will be to get match 223 and see what happens. But I'm guessing that it won't group based on the grouping that I'm getting with decent, not great ammo.

Just so you know, I will get 2 shots within a 1/4" of inch (first two), the next series of shots (3) will place any where from 2" to 8" away from the first two. So, I'm getting an 8" group at 100yds..........

The rifle has about 150 rounds of 223 through it and 40 rounds of 5.56, and like I said, the 5.56 will group better than the 223.

Do you think I damaged the chamber by firing the 5.56 ammo?
 

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parcours, Yes, there's a good chance your chamber has been damaged. I don't have a huge experience level with the target Mini but I do know they need quality ammo to get decent groups. The rate of fire is very critical in any rifle. The best "tool" is your hand placed on the barrel. If the barrel is too hot to leave your hand there, it's too hot to fire. Firing any rifle when the barrel is too hot can cause damage but usually once the barrel cools down, accuracy is restored.

Lots of people think you can do rapid fire with the Mini Target and expect it to group .... not so. If you allow a couple minutes in between shots, you should see decent groups.
 

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Iowegan, I'm very aware of the temp on the barrel and I never got the barrel hot enough to cause damage. I could always hold the barrel without any problems. I didn't purchase the rifle for rapid fire but rather for hunting.

I am worried about the bore. I did fire some SS109 5.56 just to see thinking that the chamber was the same as all other Mini's, shame on me...

Do you think that Ruger can look at this and see what's wrong?
 

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The bore is not the issue. It is the same for all .224" diameter bullets. The actual chamber and more specifically the chamber's throat is what catches hell when GI ammo is used. Hard to tell if you did any damage. Here's what I would do .... place the harmonic damper back in the factory position then test fire it with some decent quality ammo fired at a slow rate. Try 55 gr bullets, if it still doesn't group, I'd call Ruger to see if they can do anything about it.
 

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Well, I got match 223 77gr moly and WOW...

150yds I got groups that you could cover with a dime (3 shot). These rifles are very temperamental when it comes to heating the barrel.

Three shots within 1 min would produce great groups. Went to 5 shots within the same time and I would get a flyer.

I'm not a moly guys, but this Black Hills match 77gr stuff is good.
 

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Great! Glad you found something that works and even more glad you didn't damage the chamber. Those heavy bullets won't hold stability beyond about 250 yards in your Mini. No problem if you don't plan to shoot long range stuff. If you do ... get some match grade 60 gr bullets. They will maintain stability to at least 600 yards .... probably longer but I never tried them beyond 600 yds.
 

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There's a gun show this weekend and I'm going to look for those 60-62gr match Black Hills ammo.

I was ready to send the thing back to Ruger, I'm glad I tried these heavier match bullets, I think I would have been embarrassed when Ruger sends the rifle back with a target that has all the holes touching.

You know, I'm not a moly fan, but these match moly loads shoot great!
 

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5.56 ammo

Now when you refer to 5.56 ammo damaging the barrel, you aren't reffering to resized ammo. I can take 5.56 and resize to a .223 and it's just fine correct?
 

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wpcexpert, While the 5.56 mm and .223 cartridges are very similar, they are not identical. Military cases are made from thicker brass than commercial cases, which reduces the powder capacity and increases chamber pressure. Test barrels made for 5.56 mm NATO measure chamber pressure at a the case mouth, as opposed to the SAAMI location (body). This accounts for upwards of 20,000 psi difference in pressure measurements. That means advertised pressure of 58,000 psi for 5.56 mm NATO, is around 78,000 psi when tested in a .223 Rem test barrel. Maybe that tells you why you should not shoot GI ammo in a chamber designed for 55,000 psi SAAMI commercial ammo.

Bottom line for handloaders, using military brass is plenty safe providing you back off the powder charge. Very few shooters own pressure testing equipment but most of us more serious handloaders do own chronographs. Here's the drill: you want to develop a load that will produce the same velocity as commercial factory ammo. Start a few grains lower than the "book load" and work up until you find the powder charge that produces the below velocities. Consider that a max load. You can run lighter loads, just don't load more powder than your "developed maximum".

For a 55 gr bullet, here's what the chronograph results should look like:
24" barrel, 3240 fps
22" barrel, 3200 fps
20" barrel, 3125 fps
18.5" barrel, 3075 fps
16.5" barrel, 3000 fps

If you increase the bullet weight, pressure also increases so to stay under max allowable pressure, you must lower the powder charge, which also lowers the muzzle velocity. If you have a particular bullet style and weight, I can run it through QuickLOAD for you and find the optimum velocity for your barrel length.
 

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Thanks

IOWEGAN,
Thanks for the pressure lesson. I didn't know the pressures were THAT great. But I did know there was a difference. I'd planned to start low. I'm thinking I'll keep the 5.56 for my AR. I'll just buy more brass for the Mini 14 Target. I'm working on some great loads for that. I'm planning on just loading some lower velocity plinking rounds for the AR. Thanks for the info.
 

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wpcexpert, Good idea. Even though the GI brass will work for commercial loads, it's nice to have both so you won't get confused and shoot the wrong ammo in your Mini-Target.
 

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Rugers are chambered for the GI 5.56 so you can shoot GI or commercial. Its the guns chambered for 223 that have to be careful.
Not all Rugers are chambered for 5.56. My 15 year old Mini-14 is stamped ".223". I have fired 5.56 from it before becoming aware of the difference, but will never do that again. :eek:
 

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my new mini handbook says 223 or 5.56, so what is the general consences on most acurate loads to use for targets ,varmits, etc.
 

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I just bought 1250 rounds of Winchester PSP 55 grain .223 ammo for 485.00 and I'm finding it extremely accurate!!

1.5 inch group at 100 yards without even touching the harmonic dampener yet!!
I'm thinking I'll get sub moa with this ammo!!

Keith
 
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