90gr from 1/8 223

[Warren Dean]

I run Berger 82 BT Match around 2900 and they shoot little bitty bug holes in close and hold < 1/2 minute at 600. Savage Model 12 Palma, 1:7 factory barrel. Fun gun to shoot. 90s are too twitchy from what I have heard from many conversations with 223 f class shooters. When I first got it, Monte Milanuk suggested I try the 82s when I called him about possible loads for 90s. They shoot lights out when they are on but I always look for a load that isn't finicky....like seating depth, gun cleanliness, velocity change, etc. No thanks

 

[Ned Ludd]

Where can I find the 223 Rem ISSF reamer with .169 freebore?

http://pacifictoolandgauge.com/220-...lets.html?search_query=223+Rem+issf&results=1

 

[Kurt Blasser]

Can anyone of you that shoots the Berger 90 vld in the Kiff ISSF .169 freebore chamber give me a CBOT measurement and how that relates to the lands, eg -.020 off the lands etc. I’d like to make a dummy round to give to Kelbly’s for my new 223 barrel. Thanks!

 

[Ned Ludd]

Can anyone of you that shoots the Berger 90 vld in the Kiff ISSF .169 freebore chamber give me a CBOT measurement and how that relates to the lands, eg -.020 off the lands etc. I’d like to make a dummy round to give to Kelbly’s for my new 223 barrel. Thanks!

30" Bartlein 5R, 0.169" freebore cut with Kiff's 223 Rem ISSF reamer:

0 rounds fired, at "touching": COAL = 2.646"; CBTO (Hornady Caliper Insert) = 2.051"
414 rounds fired, at "touching": COAL = 2.649"; CBTO (Hornady Caliper Insert) = 2.054"
714 rounds fired, at "touching": COAL = 2.650"; CBTO (Hornady Caliper Insert) = 2.055"

Avg 90 VLD bullet OAL for these measurements = 1.247"

NOTE: the Hornady Caliper Insert has a smaller hole than do some other brands, therefore, the CBTO values obtained using one will be longer. Probably best to go off COAL measurement if the average length of your Lot of 90 VLDs is about the same.

 

[Kurt Blasser]

30" Bartlein 5R, 0.169" freebore cut with Kiff's 223 Rem ISSF reamer:

0 rounds fired, at "touching": COAL = 2.646"; CBTO (Hornady Caliper Insert) = 2.051"
414 rounds fired, at "touching": COAL = 2.649"; CBTO (Hornady Caliper Insert) = 2.054"
714 rounds fired, at "touching": COAL = 2.650"; CBTO (Hornady Caliper Insert) = 2.055"

Avg 90 VLD bullet OAL for these measurements = 1.247"

NOTE: the Hornady Caliper Insert has a smaller hole than do some other brands, therefore, the CBTO values obtained using one will be longer. Probably best to go off COAL measurement if the average length of your Lot of 90 VLDs is about the same.

Thanks! That gives me a good starting point. I also use the Hornady gauges.

 

[MGYSGT]

Tried a couple of 90's (Serria and Berg) in my 8 twist. Not so good. Switched to 80 VLD and presto, good groups. Of course we only have 300 yards to shoot here, but they held tight with a 200X17. Yea, I get excited and blow it every time.

 

[7Fingers]

7fingers - It is actually 0.269" freebore? Or is it 0.169", which is what is cut with PTG's 223 Rem ISSF reamer?

Beau - what's your point? On paper, a 6.8-twist barrel would be the minimum required for most .223 Rem shooters to fully stabilize the 90 VLDs. However, quite a few F-TR shooters using twist rates faster than 7 have experienced jacket failures during matches. A 7.0-twist is sufficient with the 90s in a .223 Rem to get the vast majority of the resistance to wind deflection they offer, while at the same time reducing the risk of a jacket failure and loss of 10 points, which pretty much puts you out of the running on a single shot. For others using cartridges with a little more horsepower, they might be able to go as low as 7.2-twist or so without giving up too much resistance to wind deflection. However, much slower of a twist than that and you'd be giving it up needlessly.

My mistake, free bore is .169 not .269

 

[Ned Ludd]

That's what I figured. What kind of velocities are you getting from the 28" barrel?

 

[Laurie]

NOTE: the Hornady Caliper Insert has a smaller hole than do some other brands, therefore, the CBTO values obtained using one will be longer. Probably best to go off COAL measurement if the average length of your Lot of 90 VLDs is about the same.

They've changed a bit over time too. I have one or two dupes going back to the days when I tried to batch bullets by using a pair to get approximate bearing surface lengths. I discovered the hard way that some newly bought examples were differently sized from the originals when I seated bullets wrongly. (Also, it'd affect the BS measurement depending on which insert was used on which end of the bullet.) I now stick to one insert for each calibre for all other jobs marking it up to ensure that it's the correct one of the pair.