OCW - Already shoots sub-MOA with factory stuff.

[Yoshi]

My Savage Model 10PC (.308) shoots sub-MOA with FGMM. Is it worth it to find the OCW with respect to "tactical match" accuracy? Or, just try to match what the FGMM stats are?

 

[byf43]

While Federal GMM is the 'standard' by which all other ammo is measured, I like the challenge of working up a load that meets or exceeds that wonderful ammo!!!

While not a boltgun, my M1A will hold sub-MOA at 200 yards with Sierra 168 MK and W-748, and also with H-4895.
(The Sierra 165 GameKing bullet will hold that accuracy, too.)

 

[Bootknife]

Yes there is alot of satisfaction in Loading an accurate round for my Rifles,Rem 700,Savage 10 and M1A.

 

[E.Shell]

My Savage Model 10PC (.308) shoots sub-MOA with FGMM. Is it worth it to find the OCW with respect to "tactical match" accuracy? Or, just try to match what the FGMM stats are?

Trying to match FGMM is sort of misleading, since you really can only match the approximate performance with components we have available to us.

If you want a true match (approximate pressure curve/charge weight/muzzle velocity), RE-15 is the closest canister powder we have available and you'll likely end up at around 44 grains.

If you simply want to match performance (a 175 at 2,600 with minimal velocity variation), just find your OCW with either RE-15 or Varget. Varget is usually more consistent with regard to temperature change and is my own first choice.

You really cannot safely jump right to any given charge, so some careful testing is in order, no matter what you're after. The OCW method will show you both your maximum charges and your optimum points.

 

[Yoshi]

Trying to match FGMM is sort of misleading, since you really can only match the approximate performance with components we have available to us.

If you want a true match (approximate pressure curve/charge weight/muzzle velocity), RE-15 is the closest canister powder we have available and you'll likely end up at around 44 grains.

If you simply want to match performance (a 175 at 2,600 with minimal velocity variation), just find your OCW with either RE-15 or Varget. Varget is usually more consistent with regard to temperature change and is my own first choice.

You really cannot safely jump right to any given charge, so some careful testing is in order, no matter what you're after. The OCW method will show you both your maximum charges and your optimum points.

Thanks Ed! So, are max charges what we're looking for?

 

[Deep Creek Rock]

I think hes trying to tell you to work up your load. Start at the minimum charge weight in your load data, and work up in incriments - usally no more then .5 grain at a time.

Dont just start charging your cases at Max or near it. You need to start at starting charges, and monitor your cases for pressure signs or other problems that may occur.

 

[E.Shell]

Thanks Ed! So, are max charges what we're looking for?

Not "maximum", but very close. We are looking for a point at which combustion efficiency is at it's best, which can be recognized by reduced SD numbers, increased accuracy and reduced sensitivity to vertical dispersion.

Many people will just pick a load that is someplace above the "starting load" given by manuals if close range performance is acceptable. This is fine if we are close enough that velocity variations don't show on target, but as distances increase, the demand for consistent velocities does also. If you want consistent long range performance, you'll also want to get enough pressure to make ignition/combustion "crisp" and thus uniform.

I think hes trying to tell you to work up your load. Start at the minimum charge weight in your load data, and work up in incriments - usally no more then .5 grain at a time.

Dont just start charging your cases at Max or near it. You need to start at starting charges, and monitor your cases for pressure signs or other problems that may occur.

Yes, I am saying that we cannot just grab a load we would deem appropriate, or even a load used successfully by someone else without carefully working our way up to it.

 

[byf43]

...I am saying that we cannot just grab a load we would deem appropriate, or even a load used successfully by someone else without carefully working our way up to it.

Extremely well said!!!

 

[lensman]

Don't forget the shooter!

I've been reloading rifle ammo for over 20 years for both bolt guns and the AR platform.

I endorse all of the advice given in this thread but also want to note that, even when shooting from a bench rest, the shooter's technique is an important determinant in the results. Your performance with the factory ammo suggests that your technique must be pretty consistent. If you decide to explore handloading, keep up or improve the consistency of your shooting technique. It can do nothing but help your results.

LM

 

[JamesBailey]

Personally, I would find a load with a 155gr bullet. I'd rather have the bullet going significantly faster than a 175gr SMK out of a 308. I'd give up the tad of BC to get them going flatter. Heck, if you shoot the new Berger Hybrid 155, you will actually have a higher BC than the 175 SMK. If you are interested in shooting the tactical matches around here - Mayberry, NH, Reade, Black Hat - you will not miss the heavier bullet but will pick up a lot of value from the flatter trajectory.

Would love to hear what Mr. Shell has to say on the 155 v 175 issue

 

[BenL]

Personally, I would find a load with a 155gr bullet. I'd rather have the bullet going significantly faster than a 175gr SMK out of a 308. I'd give up the tad of BC to get them going flatter. Heck, if you shoot the new Berger Hybrid 155, you will actually have a higher BC than the 175 SMK. If you are interested in shooting the tactical matches around here - Mayberry, NH, Reade, Black Hat - you will not miss the heavier bullet but will pick up a lot of value from the flatter trajectory.

Would love to hear what Mr. Shell has to say on the 155 v 175 issue

Interested, as well. I worked up a 175gr load that shoots well in my rifle and I shoot that for everything.

 

[Yoshi]

...
Would love to hear what Mr. Shell has to say on the 155 v 175 issue

Ditto! Haven't shot the 155's but have the 168's and 175's... But, I do remember that Ed said that I should prob shoot the 175's over anything else with respect to the .308. Don't recall if that was my specific requirements or rig though though.

 

[JamesBailey]

Well, the 175gr SMK is the best selling bullet in the world for a reason. Its the benchmark bullet. It has good characteristics on all fronts - fairly consistent pc to pc, lack of seating depth sensitivity, good down range terminal ballistics, OK form factor and sectional density producing a moderately good BC, good stability through sound barrier, fairly inexpensive. On balance, that is a good package.

I would say however that 308W cartridge doesn't offer enough punch to get the 175gr going at great MVs (>2800fps), meaning the projectile's trajectory is not as flat as it could be and it does give up some wind deflection as well. For F-class, no big deal, as the range and therefore the come-ups are always known. For tactical however, where ranges are not always known, or will change quickly, there are real downsides to a steep trajectory. This is where the 155gr comes in - and lots and lots of 308W shooters have moved to that weight class as there are really some great bullet choices there - Berger has half a dozen bullets at 155gr, Lapua makes one, Sierra's is pretty good, sure that Hornady has one, imagine that JLK and some of the custom guys are making one there too.

I don't have a coin in this discussion, as I don't have or reload anything in .30cal. I'm just an interested ballistician I do know that Ed was shooting 155grainers however; don't have a clue what his current thinking is, or what the MV difference he was getting between the 155 and the 175. Hopefully he will chime in...

 

[E.Shell]

...Would love to hear what Mr. Shell has to say on the 155 v 175 issue

I have not used the new Berger 155s.

In the context of the 155 Scenar vs the 175 SMK or 178 A-Max, it's a trade off based on priorities.

If we know how far the target is, a flat trajectory means nothing to our ability to hit it consistently. The real issue becomes the wind. If we don't know how far it is, the problem is a balance of both drop and deflection.

For unknown distance shooting, the advantage lies with the 155 Scenar over the 175/178 because it can be driven at higher speeds, yet enjoys a similar ballistic shape. If the Berger 155 has a better BC yet, than this becomes especially true.

At 2,850 or so, the 155 is up in the .260 velocity bracket, although we do give up a lot in BC (compared to 6.5s)and it soon falls behind again.

I'm not convinced the 155 is the best choice when we DO know the exact range, because we lose any advantage gained by a greater margin of ranging error and typically give up a little to wind deflection, especially as we get out further. It is very hard to make a light bullet deflect less than a heavy one, despite the BC similarities.

For best results at longer ranges at known distances, the heavier bullets reign because we don't care if they drop like rocks if they resist deflection better. You'll see proof of this on paper with the 1k F-Class and Match Rifle guys, who usually pick the heavier bullets for this reason.

Of course, everything above is predicated upon having similar accuracy with both bullets. If the accuracy advantage goes to either one, any theoretical benefits of the other mean nothing.

All things considered, the 175/178 grain bullets are not a bad place to start. I believe that Sierra MatchKings are more "forgiving" of less than optimum conditions, and thus are easier to manage, which is why I usually recommend them to new handloaders.