question ?

D

Doug Casner

New member
Got me a .223 chambered Tikka. The Remington I bought wouldn't group. About 1.5 at a 100 was all I could get. Shot a couple of .5 groups with the Tikka none over an inch. Likes VV133 and Sierra 69 gr. BT match. My question. Ive read you cant shoot 5.56 IN A .223 chamber but you can shoot .223 in a 5.56 chamber. I had a couple you couldn't close the bolt on. Looked and they were military headstamp but they had been run through a .223 full length die though reloads. Will a full length .223 die change the specs on the 5.56 case to make it go in a .223 chamber? Is that why the bolt wouldn't close on the military case? Or was it because they were shot in a big chamber, AR15, and the full length sizing wouldn't bring em back. Ive never had a .223 chamber before always been 5.56. Thanks Doug
 
As I understand it, the 5.56 chamber has more freebore to keep the hotter pressures from spiking into dangerous ranges. Otherwise the chambers are the same. .223 chambers let the bullet get much closer to the land, too close for the hotter loaded 5.56 to deal with, particularly with the heavier bullets that put the ogive out much closer to being in direct contact with the rifling. So while shooting .223 in a 5.56 is safer, it might not be the best for accuracy. But a .223 chambered for accuracy, would put 5.56 pressures up into the range of not being real good on the rifle.
 
Thanks Stool and Vibe. I just got a set of .223 dies . Didn't get small base. I thought they were for autos. That old RCBS die sizes more than the die on my 550 Dillon. I guess the Tikka has a tight chamber. Makes sense cause it shoots good. Well thanks Doug
 
There is a difference in chambers between the 223 and 5.56 as well as the slight pressure difference.
The 223 is shorter throated and doesn't`t handle long bullets. The various newer manuals show two loads for these cartridges, the 223 usually stopping at the 69gr max weights and the 5.56 using heavier ones. Nosler as example stops at 64gr bullets in the 223 and Hornady quits with their 62gr bullet. Both have a separate 5.56 data chapter. Sierra uses all their bullet in one data compilation but uses a COAL of 2.550" for the heaviest wt. The SAAMI std for the 223 is 2.260" so you can see where a long throat is needed for these bullet weights.

I suspect the bullet is jamming the lands in your rifle and that is the cause of the chambering problems, could be wrong too...
 
Ill dig em outa the scrap and seat the bullet a little deeper and see if they'll go. Need to pull them down anyway. They might have gone if I would have got rough but I wasn't gonna stick one in the chamber. Thanks Guys, Doug
 
The better way

Is to measure the place where the bullet makes actual contact with the lands - rather than OAL. If Y'all have that covered I'm good.

Never was able to get the nomenclature straight concerning the difference there...don't think anybody else has either but could be wrong.
 
How 'bout this question...If I spec a .223 reamer with the same throat portion as a 5.56, what do I have?
 
mwezell said:
How 'bout this question...If I spec a .223 reamer with the same throat portion as a 5.56, what do I have?
Click to expand...


I think the Clymer website had a reamer print section where you could compare the two and answer that question.
 
You must log in or register to reply here.
Back
Top