.223 Rem Pressure Indicators

[Pooner_SW]

Afternoon All,

My Shooting Buddy has started to increase his charge on his .223 Rem and if it makes a difference he is firing a Remington 700. I think he is showing signs of over-pressure on his Once-Fired Lapua Cases. It may be false positives but if anyone who is an expert would like to comment on the below photo it would be most appreciated. He tells me the charge is within his Load-Data but very close to Max Charge

There looks like Ejector Wipe although it is present all the way around rather than just the Bolt Throw Movement, there also looks like there may possibly be Ejector Marks as well. 

He has the Ogive very close to his lands 

Any help or advice would be great.

[rem708]

interesting. Firstly I shoot a Rem 700 and the marks on the base are quite common from the ejector button as its very flat with sharp corners. If you look at the outer edge of the primer it is still nicely curved. Also if you look at the crater caused by the firing pin it curves inward. I would say the primer is NOT showing any signs of over pressure. When I have gone to the limit the primer outer edge squares off and the inner crater flattens out and metal flows backward down the firing pin hole in the bolt.

The action on the 700 is very strong and is the same profile as that of the 308. This increase in metal makes it very strong around the receiver for a 223.

I used to have the bullet just touching the lands and it does, without doubt. push the pressure up. Backing off even a few thou reduces that peak pressure.

I would suggest trying a different case manufacture but with the same load. You might find the brass reacts differently even though the internal dimensions may affect the pressure.

One question. Does the shot brass, once cooled, bind when re-chambered in the rifle?

Edited October 25, 2019 by rem708
wrong word

[Rewulf]

8 minutes ago, rem708 said:

One question. Does the shot brass, once cooled, bind when re-chambered in the rifle

This. 

I have the same rifle, you always know when you've pushed it, when it swells the bottom of the case. 

[Pooner_SW]

37 minutes ago, rem708 said:

interesting. Firstly I shoot a Rem 700 and the marks on the base are quite common from the extractor button as its very flat with sharp corners. If you look at the outer edge of the primer it is still nicely curved. Also if you look at the crater caused by the firing pin it curves inward. I would say the primer is NOT showing any signs of over pressure. When I have gone to the limit the primer outer edge squares off and the inner crater flattens out and metal flows backward down the firing pin hole in the bolt.

The action on the 700 is very strong and is the same profile as that of the 308. This increase in metal makes it very strong around the receiver for a 223.

I used to have the bullet just touching the lands and it does, without doubt. push the pressure up. Backing off even a few thou reduces that peak pressure.

I would suggest trying a different case manufacture but with the same load. You might find the brass reacts differently even though the internal dimensions may affect the pressure.

One question. Does the shot brass, once cooled, bind when re-chambered in the rifle?

Thanks for responding, 100% agree, no pressure signs on the primer, just lots of marks on the bottom of the case. He tells me the Bolt is quite resistant to close before firing on these particular rounds. He is going to try and re-chamber some brasss after work this evening and see if they are still chambering correctly. I know he also has some hornady brass so will see suggest he fires that with the same load for comparison.

32 minutes ago, Rewulf said:

This. 

I have the same rifle, you always know when you've pushed it, when it swells the bottom of the case. 

Fortunately, there is no swelling of the case. a bit more testing and development is required i think.

[Flyboy1950]

Agree with the previous comments, there dosn`t seem any over pressure signs on the case or primer. Does your pal full length resize or just neck size?

I would seat the bullet a bit deeper, that will help reduce the pressure and give the bullet a chance to jump into the rifling. Alter the depth seating to say  5 thou off the lands, then try 10 thou. See how he gets on.

Again as previously mentioned try changing the manufactured brass, they all have different internal volumes and so for the same weight of powder will show different results. I usually use ppu brass for my reloading. Interesting that with my CZ if I tried loading to the lands I could not get the 223 cartridge into the magazine, so I load to 2.20"COL which works just fine.

I have also found that loading a 50 grain bullet I can use Vit 140 powder with surprisingly good results. (Not normally used as it`s considered to slow a burn rate).

Careful with this reloading at home as it gets highly addictive.

Good luck.