Savage FTR .223 questions

[urbanrifleman]

Perhaps you should do some research on the 90 gr bullets. They can be made to shoot extremely well and tuning in competitive loads is not that difficult. The OP is interested in trying F-Class; more specifically, F-TR. The 80.5 is not the "default bullet" for shooting F-TR. Someone showing up to a 600 yd (or farther) F-TR match with 80.5s is going to be at a serious disadvantage to someone running the mighty 90 VLD, Berger 85.5s, Hornady 88s, or Sierra 90s/95s, if there's any wind at all. They'll be at even more of a disadvantage against F-TR shooters using a .308 Win with 200+ gr high BC bullets. I've done well with the 80.5s in 300 yd matches, but even at that distance the heavier, higher BC bullets are beneficial to shooting winning scores when the wind comes up. I've also scored for shooters that tried using 69 SMKs in both 300 and 600 yd F-TR matches. They fared poorly against shooters using heavier, higher BC bullets.

With the proper freebore, the 85, 88 and 90s are all outstanding on 223. Totally easy and forgiving.

If the freebore is appropriate.

 

[1911mag]

Perhaps you should do some research on the 90 gr bullets. They can be made to shoot extremely well and tuning in competitive loads is not that difficult. The OP is interested in trying F-Class; more specifically, F-TR. The 80.5 is not the "default bullet" for shooting F-TR. Someone showing up to a 600 yd (or farther) F-TR match with 80.5s is going to be at a serious disadvantage to someone running the mighty 90 VLD, Berger 85.5s, Hornady 88s, or Sierra 90s/95s, if there's any wind at all. They'll be at even more of a disadvantage against F-TR shooters using a .308 Win with 200+ gr high BC bullets. I've done well with the 80.5s in 300 yd matches, but even at that distance the heavier, higher BC bullets are beneficial to shooting winning scores when the wind comes up. I've also scored for shooters that tried using 69 SMKs in both 300 and 600 yd F-TR matches. They fared poorly against shooters using heavier, higher BC bullets.

Agree
The 80.5 does not show up as the FTR default choice of bullet. From what I have seen majority is 85.5 and 90’s.

 

[praveen]

For that rifle, 90 grains is the way to go.
Dave Kiff's ISSF Reamer - Use a T-handle and cut the throat long slowly. Cut-Measure-cut-measure. Its a 5-10 min job.
Once properly tuned, it would be hard to beat with any other bullet.

 

[dcali]

Do a little research on the 90 grain bullets. They are not viewed very favorably. The 80.5 Bergers are the default match 223 bullet. The 69SMK is also very good at shorter distances. JMO

This isn't my experience AT ALL. The 90s dominate .223 f class, and are incredibly easy to tune given a dedicated rifle.

 

[jnr88]

The Berger site twist calculate says the 90 is marginally stable with a 7 twist. YMMV

 

[Jeff Porter]

The Berger site twist calculate says the 90 is marginally stable with a 7 twist. YMMV

I am using them in a 7 twist Palma rifle with no issues.

 

[XTR]

I would write something about 90s, but the guys above covered it.

oh hell….

1. Get the right freebore
2. See 1. above, go no further until this is done.
3. use any brass and reliable primer
4. Load Varget at ~24.3gr plus or minus .2 (looking for high 2700s to low 2800s fps)
5. load 90VLD jammed 10, it may work better other ways, but it will work there.
5. Shoot Xs

I literally did exactly that for my 11 and 13 yr old sons to shoot mid range using a Savage with a 28” barrel and a chassis that I can shrink to fit them. Someone walked off the line and looked at me and said, “now my goal in life is to shoot better than a 13 yr old”.

Some folks including some of the above posters use H4895 and run a tad faster at the expense of brass life.

I’ve never used anything but a 1:7 and I’ve never taken my 223s past 600 yds. You’re stepping on them hard running 2900

 

[Ned Ludd]

The Berger site twist calculate says the 90 is marginally stable with a 7 twist. YMMV

Unfortunately, the language used in the output of the Berger Twist Rate Calculator can be somewhat...misleading. Here is the output for a 7-twist barrel for pointed 90 VLDs (estimated G7 BC = 0.290) using a muzzle velocity of 2825 fps, which is not unreasonable for a 30" barrel, an elevation of 1000 ft., and 70 degrees F temperature (i.e. a rather average set of environmental conditions):



Note that the predicted decrease in G7 BC is only 1% (i.e. a G7 BC of 0.290 for pointed 90 VLDs would be compromised by 1%, resulting in an effective G7 BC of 0.287). No one is going to even notice a decrease in BC of 1%, as the inherent BC variance within a single Lot# of bullets is greater than 1%. The decrease in G7 BC would be slightly greater at a lower elevation and/or temperature, or at a slower muzzle velocity. Nonetheless, the BC of the 90 VLD from a 7-twist barrel would still be approximately 20% greater than that of a pointed 80.5 Fullbore bullet. In terms of wind deflection, a 20% increase in BC is HUGE.

There is nothing at all wrong with the 80.5 Fullbore bullet. In fact, it is an outstanding design. But for F-TR shooters using a .223 Rem that are already at a sizeable disadvantage against shooters using .308 Win rifles, the 85.5s/88s/90/95s are much better choices. As has been noted, an appropriate [long] freebore is necessary for the 85.5 to 95 gr bullets to obtain optimal performance. One could also use a slightly faster twist rate such as a 6.8- or 6.7-twist to obtain the full intrinsic BC, but a 7.0-twist will do the job and will generally cause a slightly lesser risk for jacket failure that a faster twist rate.

A few years ago, Bryan Litz advocated using a twist rate that would maintain a minimum gyroscopic coefficient (Sg) of 1.4 for a given bullet in order to obtain its full intrinsic BC. He later changed that to an Sg of 1.5 to get the full BC. I believe the manner in which the Berger Twist Rate Calculator designates Sgs between 1.0 and 1.5 as being "Marginal" can be misleading. In my hands, an Sg above 1.20-1.25 will result in gyroscopic stability as far as preventing obvious unstable bullet behavior such as oblong holes in the target, or even keyholing. In other words, the gyroscopic stability with an Sg greater than 1.20-1.25 in terms of obvious readouts such as oblong holes in the target or even keyholing is not "Marginal", but rather is just fine. It is true that a bullet fired from a slow twist rate barrel may behave as though its BC is lower than it actually is, but that is an effect that would largely manifest in terms of wind deflection and thus be much more difficult to readily observe than oblong holes in a target. For example, running bullets in a barrel twist rate that yields an Sg of ~1.3 will fly just fine to the target (i.e. they will be "stable", but they may be deflected a bit farther off line than might be expected based on the muzzle velocity and the manufacturer's BC value. Thus, "Marginal" is not a word I would choose for bullets having an Sg of perhaps 1.3 to 1.5. Sub-optimal, yes, but not "Marginal".

 

[jnr88]

Thanks Ned.

 

[dcali]

In addition to what Ned said, I have found calculators of all types to be a little bit conservative when it comes to predicting stability.

 

[Laurie]

A few years ago, Bryan Litz advocated using a twist rate that would maintain a minimum gyroscopic coefficient (Sg) of 1.4 for a given bullet in order to obtain its full intrinsic BC.

Litz/Berger use the MIllers Rules shortcut formulae to get their Sg values. Before Berger put its handy facility up online, people downloaded a little spreadsheet for the Millers calculations. For years and years, this stated that Sg 1.4 was the desirable value, and it was only when Bryan Litz started creating his range-tested bullet BCs database that he noticed BCs were slightly higher with a 1.5 Sg or better. So, as Ned says, 1.5 is optimal but not essential, and in many cases the calculated BC loss is so small that you'd be unlikely to ever notice it in actual shooting conditions. 1.5 probably helps produce optimal grouping too, but again the improvement over 1.4 is so small in most conditions, you'd probably shoot a barrel out acquiring enough groups to prove this assertion one way or the other.

In addition to what Ned said, I have found calculators of all types to be a little bit conservative when it comes to predicting stability.

Bryan Litz is the first to admit that whilst Millers Rules based calculators are an absolute godsend to shooters and bullet companies, the formulae employed take lots of shortcuts compared to doing the job fully, so the results are an approximation rather than spot on. This seems to often apply to HPBT match bullets with their airspace between the top of the lead core and the meplat giving a very light nose section. (Similarly, there seems to be an acceptance now that such calculators underestimate the Sg for 'plastic' tipped bullets which extend bullet overall length with a light material up front.)

My interest in this subject has increased massively recently as I had a top-quality .300 1 in 13" Palma blank I had kicking around spare chambered for .308 Win and put on a short-distance 'knockabout' range rifle. I now spend a fair bit of time calculating Sg values for the many odd & sods of .308 HPBT bullets I have spare and want to use up in this rifle. It'll be interesting to see how well (or otherwise) some shoot at modest MVs in this slow twist rate.

 

[dcali]

Litz/Berger use the MIllers Rules shortcut formulae to get their Sg values. Before Berger put its handy facility up online, people downloaded a little spreadsheet for the Millers calculations. For years and years, this stated that Sg 1.4 was the desirable value, and it was only when Bryan Litz started creating his range-tested bullet BCs database that he noticed BCs were slightly higher with a 1.5 Sg or better. So, as Ned says, 1.5 is optimal but not essential, and in many cases the calculated BC loss is so small that you'd be unlikely to ever notice it in actual shooting conditions. 1.5 probably helps produce optimal grouping too, but again the improvement over 1.4 is so small in most conditions, you'd probably shoot a barrel out acquiring enough groups to prove this assertion one way or the other.



Bryan Litz is the first to admit that whilst Millers Rules based calculators are an absolute godsend to shooters and bullet companies, the formulae employed take lots of shortcuts compared to doing the job fully, so the results are an approximation rather than spot on. This seems to often apply to HPBT match bullets with their airspace between the top of the lead core and the meplat giving a very light nose section. (Similarly, there seems to be an acceptance now that such calculators underestimate the Sg for 'plastic' tipped bullets which extend bullet overall length with a light material up front.)

My interest in this subject has increased massively recently as I had a top-quality .300 1 in 13" Palma blank I had kicking around spare chambered for .308 Win and put on a short-distance 'knockabout' range rifle. I now spend a fair bit of time calculating Sg values for the many odd & sods of .308 HPBT bullets I have spare and want to use up in this rifle. It'll be interesting to see how well (or otherwise) some shoot at modest MVs in this slow twist rate.

I would argue that Bryan's choice of 1.5ish, or whatever gets max BC, is an arbitrary choice. Given his interests, I get why he would focus on that (and it certainly seems he's not wrong). But I think it's important to remind ourselves that BC is not the only factor, and sometimes chasing it can be counter productive.

On the Miller rule, which I have dug into extensively (I've gone and recreated the data for the majority or the bullets he used), and it's really remarkably (!!) good given the huge amount of simplification that went into it. That is, IF... you use bullets that look like the ones Don Miller used to make the rule - moderate weight boattail military designs, primarily. Miller really is a brilliant/convenient simplification.

How do I know it's good? Because I've also created software that calculates the full blown Sg number based on a bullet's detailed geometry. You have to painstakingly measure and input every dimension - ogive radius, meplat, jacket thickness, core height, etc. Surely this is the way, right?

I thought this would be helpful, but after running the software on a number of real life bullets, I realized that the difference between Miller and the full classical calculations was not worth fussing over. Typically, they're basically the same number. The difference between the calculations is generally less than the difference between the true stability and the calculations. For example, I ran some cases that predicted a 7.6 or 7.5 twist would be required for a bullet (depending on which method you use), but in reality, an 8 twist stabilized them just fine.

 

[Laurie]

For example, I ran some cases that predicted a 7.6 or 7.5 twist would be required for a bullet (depending on which method you use), but in reality, an 8 twist stabilized them just fine.

Of course, there are those on this forum that'll tell you the difference between 7.5 and 8 twist rates isn't at all marginal, rather a matter of [accuracy] life and death in such and such a set-up.

 

[Ned Ludd]

Of course, there are those on this forum that'll tell you the difference between 7.5 and 8 twist rates isn't at all marginal, rather a matter of [accuracy] life and death in such and such a set-up.

In some cases, they wouldn't be wrong. For example, I would never even consider running 88 ELDMs, 90 VLDs, or 95 SMKs out of a 7.5-twist barrel, even though that is within 0.5 of the 7.0-twist I know works well with these bullets. I think 0.5 twist rate can be a big deal, but that's only relative to the optimal twist rate. As long as the bullet remains in a reasonable Sg range, let's say something like 1.3+, changing the twist rate by 0.5 may not do much more than change the apparent BC and probably won't have a noticeably deleterious effect on stability. In contrast, a 0.5 twist rate change that drops the Sg down from "acceptable" (even if not "optimal") into the 1.1 to 1.15 range could easily start creating noticeable stability issues. That is basically the reason I find the word "Marginal" problematic with respect to its use on the Berger Twist Rate Calculator webpage, as it suggests that an Sg of 1.3, or even 1.4 is marginal, or close to the edge of stability, which isn't really true.

 

[Jeff Porter]

Thanks for all of the input. I will be renting the 4D throat reamer and slowly and judiciously, using copious amounts of cutting fluid and measuring often, attempt to lengthen the throat on this rifle to be close to what I have in my Palma rifle chamber for 88/90gr bullet CBTO.

I will be playing with this Savage out to 600 with 80.5's for a few matches before the season ends then tackle the throat.

 

[Laurie]

as it suggests that an Sg of 1.3, or even 1.4 is marginal, or close to the edge of stability, which isn't really true.

I quite agree. I'd usually look for something a bit higher, say around the mid to high 1.3s as a minimum for short-range combinations. In the 13-twist 308 I mention in an earlier post, I'll push the Sg down a bit nearer your minimum with one combination as I have a few hundred old Lapua D46 rebated boat-tail 185s and equally stubby 185gn Scenars to use up.

Millers / Berger says Sg 1.32 on one 980 ft ASL range I shoot on, 1.28 on a lower lying one with a loss of 5% BC, which at 300 yards or less I'll never notice. It'll be interesting to see how they perform. (What many people don't know is that some years back before he did his stability vs BC work, Bryan Litz shot the then newly introduced and somewhat longer 185gn Berger BT Juggernaut in a 13 twist 308 Palma rifle under US Palma Rules with great success despite its 'marginal' stability, and at the time reckoned he'd rebarrel with a 12-twist when the 13 needed replacement, this being optimal. Now under his own 'rules', he'd need 11.7 or faster - although I've no idea where Bryan competed and the altitude of those ranges.)

 

[Laurie]

Thanks for all of the input. I will be renting the 4D throat reamer and slowly and judiciously, using copious amounts of cutting fluid and measuring often, attempt to lengthen the throat on this rifle to be close to what I have in my Palma rifle chamber for 88/90gr bullet CBTO.

I will be playing with this Savage out to 600 with 80.5's for a few matches before the season ends then tackle the throat.

Good luck. I have a friend who did just that with his 223 Savage factory BR rifle to shoot the since withdrawn 90gn Berger LRBT in UK 'BR Factory Rifle' class, mostly in 600 yards comps. It worked well, but being a scrupulously honest guy told the UK BR Association what he'd done. The throat extension was ruled as taking it out of factory spec and the rifle was reclassified 'Light Gun' putting him up against the out and out custom jobs. (Not an issue for you in F/TR of course.)

(Ill winds etc for me though in that when he sold the rifle and upgraded to a custom build, I acquired his stash of Berger 90gn LRBTs which were already as rare as hen's teeth several years ago and am still shooting them today.)

 

[marazzi59]

Looks like it's running well. You could purchase a ptg uni throater and then sell it to recoup most of your money. PM if you do buy/sell it. Or leave it alone and shoot

 

[Jeff Porter]

Thanks for all of the input. I will be renting the 4D throat reamer and slowly and judiciously, using copious amounts of cutting fluid and measuring often, attempt to lengthen the throat on this rifle to be close to what I have in my Palma rifle chamber for 88/90gr bullet CBTO.

I will be playing with this Savage out to 600 with 80.5's for a few matches before the season ends then tackle the throat.

Well … so much for slowly and judiciously. I rented the Uni throater from 4D rentals and started slowly with lots of cutting oil the I lost my mind and gave it about ten turns without measuring thinking I had the “stop” nuts set under my desired length …. Well knuckle head me had it set deeper than the target depth and I blew past my desired freebore by …. Let’s just say a bunch.

Feeling like a total dumbass I hardly slept that night. I was sure I would be sending the barrel in to be set back and have the chamber re-cut. The barrel was hammering with the 80.5’s with the short throat and I feared I “killed”it.

Then I figured I would try to use the 88ELDM as it has the longer bearing surface than the 90’s. I did a quick velocity and pressure work up using N135 as my supply of H4895 is down to the last jug. I found that I could get 2840fps with 23.7gr of the N135 and a CCI 450 in new Starline 5.56 brass. I loaded up 50 rounds at 0.005” jump.

That is … 2.175” base to ogive using my Hornady tool. Had about .200 above the boat tail in the neck. Yeah I went way deep.

I took them to the range and did a series of 3-5 shot tests having Scott shoot from the bipod at 100 yards. Following the Berger VLD jumps we saw that 0.090” was the best at that point. We then started moving from there and testing in smaller increments from there. We finished the test with 0.075” jump at 2.100 CBTO with my tools.
Scott shot this group of five doing a velocity check with some 205 MAR primers in the mix. Both 205 and 450 primers had SD of 4 for a 5 shot group.



Scott had it all warmed up so I squared up behind the rifle and shot this nugget. I’ll load up a couple of hundred of these and see if I can learn to shoot an FTR rig.

 

[Jeff Porter]

Seems to be in a good spot.