223 bolt gun and AR loads ?

[rebs]

I have read where guys have said you can load a little hotter for a bolt gun, is this true ?

 

[Larry Koch]

Now that's a loaded question. Maybe.

 

[Mark M.]

This is where an adjustable gas block on the AR would come in handy

 

[jepp2]

I have read where guys have said you can load a little hotter for a bolt gun, is this true ?

why not just rely on the actual test data?

 

[natdscott]

This is where an adjustable gas block on the AR would come in handy

Meh. Not as much as it might seem.

The AR15 DOES behave very well when it blows up though, so that's nice.

 

[Falfan2017]

Not that simple every chamber is different. Start low and slowly increase until you find what you want without being over pressure. Rarely is the hottest possible load going to be accurate or good for your brass.

 

[rebs]

I only asked because I didn't think it was completely true. I only use book data and find most accurate loads under max by anywhere from a grain to a grain and a half

 

[dcali]

If you stick to book loads, the data is what it is. In reality, with a well built custom match type rifle, yes, you can crank the pressure on a .223 bolt gun a little higher than you can in an AR.

Obligatory safety sermon:
As always, mileage may vary, and be safe. Max or slightly higher loads can be done safely if you know what you're doing, but can cause all manner of trouble (and danger) if you don't. If you don't know if you know enough, you don't. Stick to the book until you do.

 

[MGYSGT]

Most reloading books show two (2) sets of load data for .223 One for the AR and another for bolt guns. If you plan on switching back and forth with the same ammo, you will need to full length resize every time. AR brass tends to get longer as you use it.

 

[243winxb]

http://www.accuratepowder.com/load-data/ gives hotter Nato load data. NATO data should be used only in 5.56 chambers. Imo.

5.56 X 45MM NATO
CIP COMMERCIAL AND NATO/MIL SPECIFICATION (62,350 PSI)

SAAMI pressure for 223 Rem is 55,000 PSI . Its been said, the difference in measuring methods are the reason for the 7,350 PSI difference??

https://www.accurateshooter.com/cartridge-guides/223rem/ this is a great read on the difference in chambers and a lot more.

 

[Fotheringill]

As above, go by a manual or load data from powder manufacturer and start on the starting load. Why look for a problem?

 

[MislMan]

I believe using lower loads for an AR is based on the early unlocking and extraction process of the semi-auto firing cycle. For bolt rifles the bolt remains closed until a complete ignition/burn cycle has finished and can therefore retain more pressure more safely.

 

[Rsadams]

http://www.accuratepowder.com/load-data/ gives hotter Nato load data. NATO data should be used only in 5.56 chambers. Imo. SAAMI pressure for 223 Rem is 55,000 PSI . Its been said, the difference in measuring methods are the reason for the 7,350 PSI difference??

https://www.accurateshooter.com/cartridge-guides/223rem/ this is a great read on the difference in chambers and a lot more.

This is your answer... I would hope your AR has a 5.56 chamber , which should be stamped on the barrel... If not stay way away from 5.56 territory... Sit down and read this and understand the difference in the two Chambers and why the 5.56 can be loaded hotter... Also pay attention to what barrel length the data was recorded on , I have seen them as long as 24 inches for 5.56 and most ARs are between 16 and 20... Reading pressure signs on an AR is different than a bolt gun also.. Then you get into over gassed guns especially on the M4 which is very common , ejection patterns and what to look for and how to tune buffers and springs if it is...etc etc etc....

 

[butchlambert]

I will start on my TAC30 223-5.56 bolt rifle this weekend. I will be chambering the 12 twist barrel first and the 8 twist later. I borrowed a reamer from John Holiger that he spec'ed for a bolt gun and 52 grain bullets. I plan on using Robinett bullets in it.
I still need to find a quality used glass stock for a BDL SA Remington.

 

[urbanrifleman]

Auto guns are harder on the brass at hotter loads. You will lose primers on an AR15 where it will just squash them in a bolt gun.

 

[Zero333]

It's all about the freebore length and diameter.

Same load in 2 different chambers will generate different max pressure. What is safe in one could be too hot for the other.

A 223 chamber with very long freebore will handle all 556 loads with out breaking a sweat

Problem is SAAMI 223 chambers have short and tight freebore.

556 chambers (pretty much all AR-15's) have longer and wider freebore. Therefore 556 ammo is loaded slightly warmer.

5.56 NATO ammo shot in a SAAMI 223 chamber will generate higher max pressure than if it was shot in a 556 NATO chamber.

SAAMI 223 factory ammo shot in a 556nato chamber will generate less max pressure than if it was shot in a 223 SAAMI chamber.


But it doesn't mean 556 NATO shot in a 223 SAAMI chamber is unsafe. Only the ammo lot and firearm can dictate what is safe and unsafe.

I have a Rem.700 with a standard SAAMI 223 chamber and it fires m885 greet tip no problem and no hint of over pressure.

 

[Rustytigwire]

Compare sammi and gas gun C.O.A.L for more info.
So far under 60 gr has been the same what i have seen.
FYI no conclusion implied.
Tom

 

[Texas10]

5.56 is loaded higher in part because it's shot in a barrel with an extra long throat, which means more propellant escapes down the barrel before the bullet fully engraves and seals the barrel. That reduces max pressure attained. If you put that round in a bolt gun, especially a factory bolt gun that sometimes is produced with a too short or too tight chamber, and the bullet is seated into lands, you might experience an explosive disassembly on the firing line.

 

[_Raining]

I load my 223 bolt gun harder then my 223 AR, the (biggest) reason is the AR rounds need to fit in a mag and the bolt gun has a throat for the 80 VLDs that I single feed.