.223 Bolt Gun Bullet?

[Jeff Porter]

What's your barrel length? That's some good velocity for a charge weight below where a lot of people run 8202. I'm curios what the standard 23.2gr a lot of people shoot would chrono at.

Ryan - Mag length L-77's in a 26" 1:8 Kreiger bolt gun are 2900 ish with 23.2 of 8208, 205MAR primers in LC-4x fired brass for me.
H75's run a bit faster than SMK or L 77's in 20" SR with 23.2 8208 but have not run them in this rifle.

Kracken - I have found H75's and Nosler 77's like to jump and be seated deep, like 2.235" OAL in Wylde chambers... don't think that bullet needs to be out near the lands at all and using 8208/4895/RE-15 or Varget not losing much velo due to case capacity loss from deep bullet.

 

[searcher]

Ryan - Mag length L-77's in a 26" 1:8 Kreiger bolt gun are 2900 ish with 23.2 of 8208, 205MAR primers in LC-4x fired brass for me.
H75's run a bit faster than SMK or L 77's in 20" SR with 23.2 8208 but have not run them in this rifle.

Kracken - I have found H75's and Nosler 77's like to jump and be seated deep, like 2.235" OAL in Wylde chambers... don't think that bullet needs to be out near the lands at all and using 8208/4895/RE-15 or Varget not losing much velo due to case capacity loss from deep bullet.

I agree with the deep seating on the heavies. Those .223's develop the ring pretty quickly in my experience and worst performance will come when the bullets are just touching the ring - best to push them down past the ring. Not that it will get rid of the effects of the ring - but eliminates a lot of big fluctuation that comes with just touching, That seems to be why the heavies oftentimes shoot best seated deep and the lighter bullets shoot best when avoiding the ring area altogether. I think this also explains why factory ammo often shoots better with the heavies as opposed to reloading the same bullet after a few firings and trying to keep the same OAL

 

[Ned Ludd]

Comparing a loose 77 gr SMK to a commercial round loaded with the same bullet will illustrate just how deep bullets greater than about 70 gr weight are actually seated in factory .223 Rem loads. The boattail-bearing surface junction is seated way below the neck shoulder as illustrated by @afret above. Another way of saying the same thing would be to mention how short typical .223 Rem commercial rifle magazines are when feeding factory ammunition with 75-77 gr bullets. They only just barely fit/feed in some commonly-used magazines. Of course, the donut isn't a problem with commercial ammunition because no donut has yet formed in the virgin brass.

In the past, I have run Berger's 80.5 gr Fullbore bullet in a .223 Rem bolt rifle chambered with zero freebore; largely because I was able to figure out how to make it work and it was much easier and less expensive than sending the rifle off to be re-barreled. In fact, the boattail/bearing surface junction of the 80.5 bullet was seated stupidly far below the neck/shoulder junction. I could easily "feel" the donut/ring near the bottom of the neck every time a bullet was seated. Nonetheless, it worked, even after several firings. I did not notice any major detriment to precision caused by seating the bullets below the donut, and I shot that particular setup in 300 yd [F-TR] matches for a number of years and did quite well with it.

My take would be to load the 75s up and see how they shoot. If the brass is still virgin, fire a few cases until the donut forms and then try the 75s. If they shoot reasonably well and largely seem to be unaffected by the donut as in my case, I don't think you will have any trouble quickly forgetting about any problems the donut is supposed to cause. In contrast, if they don't shoot well, then you have your answer and should probably stick to the shorter 69s in that setup.

An intermediate approach might be to extend the rifle's freebore/throat out further so as to accomodate the longer 75 gr bullets and allow them to be seated above the donut. However, this may lead to issues being able to feed loaded rounds from a mag as they start to get pretty long (COL) very quickly. This issue can sometimes be addressed by using a different brand of magazine or by modifying and existing mag to feed much longer rounds, but may be a consideration for this approach, regardless.