• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

77 and 80’s with standard chamber

Bottom Fodder

Silver $$ Contributor
Is anybody running these in a standard SAAMI 223 (not match or Wylde) chamber bolt gun without extending the free bore
Thanks
 
Is anybody running these in a standard SAAMI 223 (not match or Wylde) chamber bolt gun without extending the free bore
Thanks

I use both Nosler 80s and Sierra 80s in a factory Tikka T3x Varmint with no alteration to the gun and plenty of accuracy.

Both loads seated at 2.450 OAL I believe.
 
I've loaded up the 80.5 Fullbore bullet for a custom .223 bolt rifle with a 26" barrel I had made as an F-TR practice rifle that was chambered with zero freebore. Due to the [relatively] short barrel and reduction in effective case volume (the boattail/bearing surface junction of the 80.5 was seated well below the neck/shoulder junction), I chose to use H322 powder, which is a bit faster than I would ordinarily select for a .224" bullet of >80 gr weight. It is certainly not an ideal situation to have to load heavy bullets that way, but it can also certainly be done. That particular load shoots very well. That rifle also shoots FGMM 77 commercial ammo extremely well.

How much effort you have to put into the load development may well depend on exactly how much freebore you have. As noted, that particular rifle/chamber has zero freebore. If it had had even .025" to .050" freebore, it would have been helpful and made the process easier. In that event, I likely would have gone with H4895 instead of H322 with the 80.5s. Nonetheless, it is certainly possible to do what you're asking, but you will need to select a powder fast enough to achieve the approximate velocity range you're after, and that also has sufficiently low bulk density (i.e. small kernels) to fit a sufficient amount of it in the case, if the effective internal case volume is reduced by the bullet boattail/bearing surface as it was for me. If you play around with it a bit, you ought to be able to find a combination that will work. FWIW - in my specific case with the zero freebore setup, the resulting loaded rounds were still too long to reliably feed from most magazines (~COAL = 2.345"). That didn't matter to me as F-TR is single-feed anyhow, but still is worth mentioning.

Another issue you might run into has to do with caliper inserts. With bullets seated very deep in the neck and a caliper insert with a hole just under bullet diameter, you might just observe extremely uniform seating depth, regardless of the seating die setting ;). In fact, it wouldn't surprise me if you measured round after round and came up with a base-to-ogive measurement of exactly 1.750". Ask me how I know this LOL. Turns out that with some bullets seated deep in the neck, the bullet ogive rifling contact point can actually be seated below the case mouth, such that a comparator insert with a hole very close to bullet diameter will actually seat on the case mouth, not the bullet ogive. Fortunately, it only took me about 8 or 10 loaded rounds to figure this out, whereupon I switched over to the Hornday comparator insert, which has a noticeably smaller hole and seat farther out on the bullet ogive.
 
Last edited:
I actually use the 80SMK in a 5.56 1:7 T/C Compass that is solid and factory stock internally

2.455" COAL
Oryx Chassis
WCC12 Brass
H322 21.5 Grains
CCI 400s
2679 FPS mean/ ES 11.91 FPS/ SD 4.85 FPS

and will regularly do .5-.6 MOA at 100 yards for 5 Groups of 5 - while I wait for my barrel to cool on my 6CM

It's a shooter in it's own right...Haven't taken it out past 500 yards but that is more due to running out of adjustment on the scope than anything else.
 
I run 77 SMKs and 77 NCCs in a 1:8" bolt-action SAAMI .223 Rem chamber cut with a Manson reamer. OAL at the lands very close to 2.280" I use them with Varget and it works pretty well. Certainly less than MOA, but I have not shot it at paper in a long, long while. It's worked well for me inside 600 yards on steel, until the wind blows.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
166,256
Messages
2,214,692
Members
79,487
Latest member
Aeronca
Back
Top