Load Development Question .308 - Fliers

[bulletpruf]

Rifle is R700, Faxon 22" M24 profile barrel, 1-10 twist, .090 freebore, Timney Elite Hunter Trigger set at 1.5#, Vortex 6x24, MDT field chassis. Shoots at/under 1 MOA at 100 yards with factory Federal GMM 168 gr SMK.

I'm working on ladder starting with 43.0 gr of Varget and going up to 46.0 gr, 168 gr SMK, Federal brass (annealed, deburred, chamfered, within spec on length), Federal 210 primers, COAL of 2.86", CBTO of 2.263" at .020" off the lands. Headspace checked with the LE Wilson gauge.

Shooting off a bench at an open range, 100 yards, 5 shot groups, cooling barrel in between shots. I'm starting with a fouled barrel. I do not have a chronograph.

This is my first attempt at reloading; I've been at it for a few weeks.

Every time I shoot 43.0 gr, I feel like I have made 5 good shots, but I inevitably have a flier that's about 1" away. I pull shots sometimes, but I don't think I pulled any of these. Any thoughts on whether this is indicative of a load that I should pursue or de-select? FYI - rifle shoots really well with 45.1 and 45.4 grains of Varget but I'm still intrigued by the tight 4 shots on 43.0.

 

[Coyotefurharvester]

Have you tested seating depth? Perhaps seating closer to suggested coal?

 

[bulletpruf]

Have you tested seating depth? Perhaps seating closer to suggested coal?

No, I have not done anything with seating depth yet. I was hoping to select a load before I start tweaking seating depth.

Thanks

 

[K22]

The parameters you mentioned sound spot on to me, i.e., fouled barrel, cool barrel shots, Varget powder, good trigger, etc. Although a 1 1/2 lbs. trigger would be too light for me.

In my experience, when I encountered flyers, it was due to one or more of the following:

1. Bedding and / or barrel in contact with forearm.

2. Barrel stripped of all copper taking several shots to re-establish consistent POI.

3. Shooter error which I should have listed first. With calibers such as the 308, with substantial recoil, consistent shoulder pressure and follow through is critical. It takes an experienced shooter not to flinch as the round count mounts on these 30 caliber rifles.

4. Wind and Mirage.

5. Failure to maintain a consistent position on the front and rear rest.

I can't remember a load issue creating "flyers". Large groups, yes, but not 4 tight shots then one significantly deviating from the others.

With the groups you posted, I would suspect something other than the load because of the 4 tight shots.

 

[DShortt]

What were the conditions? A half mph of wind at the wrong time can blow a bullet off nearly 1/2" at 100 yards.
Ask Eric Cortina if you don't believe me

 

[bulletpruf]

The parameters you mentioned sound spot on to me, i.e., fouled barrel, cool barrel shots, Varget powder, good trigger, etc. Although a 1 1/2 lbs. trigger would be too light for me.

In my experience, when I encountered flyers, it was due to one or more of the following:

1. Bedding and / or barrel in contact with forearm.

The MDT field chassis is supposed to be full floating up to and including an M24 barrel, but I can double check this.

2. Barrel stripped of all copper taking several shots to re-establish consistent POI.

Barrel has had a few hundred rounds through it. I cleaned it when it was new and have cleaned it once since then, but I haven not used anything more aggressive than Hoppes #9.

3. Shooter error which I should have listed first. With calibers such as the 308, with substantial recoil, consistent shoulder pressure and follow through is critical. It takes an experienced shooter not to flinch as the round count mounts on these 30 caliber rifles.

I'm a bigger guy at 6'4" and 235 lbs and I'm using a SilencerCo Scythe can, which reduced recoil, so it's really not noticeable.

I've been shooting for decades, but just military stuff and general hunting. This is my first time reloading and the first rifle that I've modified to be more accurate. I have been working on shoulder pressure but I really haven't spent any time working on follow through.

4. Wind and Mirage.

Wind is a possibility, but today I was shooting in a protected area. Would the mirage just be from a hot barrel or can? Or would 90 degree temps be enough?

5. Failure to maintain a consistent position on the front and rear rest.

This is a possibility. I'm waiting between shots so I have to get into position again each time.

I can't remember a load issue creating "flyers". Large groups, yes, but not 4 tight shots then one significantly deviating from the others.

Ok

With the groups you posted, I would suspect something other than the load because of the 4 tight shots.

Thanks

 

[Ccrider]

How consistent is your brass? How consistent are your billets? How consistent is your seating depth?

 

[bulletpruf]

What were the conditions? A half mph of wind at the wrong time can blow a bullet off nearly 1/2" at 100 yards.
Ask Eric Cortina if you don't believe me

These were 3 different sessions. Today the wind was negligible; the range is cut into the side of a hill, protected from the wind. Temps in the 80's climbing into the 90's.

There was virtually no wind on the 27th.

I don't have notes on wind on the 26th.

 

[bulletpruf]

How consistent is your brass?

All the brass has the same head stamp. All prepped the same way. It's not all trimmed to the minimum length of 2.005" but they're all between 2.005" and 2.015".

How consistent are your billets?

Very consistent; ogives all seem to be same spot with very little variation.

How consistent is your seating depth?

I'm shooting for 2.263" on the seating depth and I'm usually very close to this. However, I have had a few that were seated just a tad bit deep.

 

[DHD]

All shots suppressed? Any mirage boiling off of the suppressor?

Is there any consistency on which shot of the group goes "out"? What about the other groups with more powder? What do they look like?

When I run a test and am shooting 5 shots groups, I try to finish the test before I make any decisions (even though some groups are obviously not good).

Why are you waiting for the barrel to cool between shots? I personally will fire that 5 shot group before coming off of the gun unless there is an issue that makes me come off. Within reason, the barrel heat is not going to get so high on a 5 shot group to concern me. I suspect you are not being consistent behind the gun as I noted an infrared thermometer sitting there which you are checking temps between shots. Check your temps (if you feel you must) between groups, not shots.

I see nothing wrong with your recipe for loads as they fit in the easy button category for a 308. I would try to keep my case length tighter than .010" spread personally and I wouldn’t worry too much about measuring ogive length on Sierra SMK's. Yeah, they aren't perfect (who's bullets are?), but for what a 168 SMK is, it should be good enough to see .5" groups out of a decently built 308. Your numbers don't mean much to me as everyone's tools and the way they measure can be different. I will start with a tangent ogive bullet at .020" off jam for my barrels to begin. A SMK will usually not hate that measurement. Adjust from there assuming your magazine allows for a longer OAL.

That said, is 168 grain FGMM only shooting 1 MOA? I am not familiar with a Faxon barrel for a 700. Remage barrel, or did you have it fitted to your 700? A Remington 700 308 with a factory Varmint contour should do 3/4" out of the box with 168 FGMM.

 

[bulletpruf]

All shots suppressed?

Yes.

Any mirage boiling off of the suppressor?

I'm not noticing any.

Is there any consistency on which shot of the group goes "out"? What about the other groups with more powder? What do they look like?

I don't think there's any consistency with which shot is a flier.

I'm shooting decent groups with more powder; 44.2, 45.1, and 45.4 are my most promising, with sub-MOA for 5 shot groups at 100 yards, but nothing approaching .5 MOA like the 43.0 is, minus the fliers.

When I run a test and am shooting 5 shots groups, I try to finish the test before I make any decisions (even though some groups are obviously not good).

I do the same - I finish the 5 shot group each time. The pictures above with 43.0 are all 5 shot groups.

Why are you waiting for the barrel to cool between shots? I personally will fire that 5 shot group before coming off of the gun unless there is an issue that makes me come off. Within reason, the barrel heat is not going to get so high on a 5 shot group to concern me. I suspect you are not being consistent behind the gun as I noted an infrared thermometer sitting there which you are checking temps between shots. Check your temps (if you feel you must) between groups, not shots.

I have found that the groups really loosen up with a hot barrel, so I've been waiting 5 minutes in between shots. I'm in Texas and it's been in the 90's when I'm shooting, so it takes a while to cool down.

I could try waiting in between groups and not coming off the gun in between shots; I would not be surprised if my issues are caused by not being consistent behind the gun.

I see nothing wrong with your recipe for loads as they fit in the easy button category for a 308. That said, is 168 grain FGMM only shooting 1 MOA?

Last time I shot a 5 shot group with it, it was sub-MOA for 5 shots.

I am not familiar with a Faxon barrel for a 700. Remage barrel, or did you have it fitted to your 700? A Remington 700 with a factory Varmint contour should do 3/4" out of the box with 168 FGMM.

It's a Remage barrel, M24 profile.

 

[bulletpruf]

I see nothing wrong with your recipe for loads as they fit in the easy button category for a 308. I would try to keep my case length tighter than .010" spread personally and I wouldn’t worry too much about measuring ogive length on Sierra SMK's. Yeah, they aren't perfect (who's bullets are?), but for what a 168 SMK is, it should be good enough to see .5" groups out of a decently built 308. Your numbers don't mean much to me as everyone's tools and the way they measure can be different. I will start with a tangent ogive bullet at .020" off jam for my barrels to begin. A SMK will usually not hate that measurement. Adjust from there assuming your magazine allows for a longer OAL.

Tightening up the case length is easy enough. I can do that on my next batch of brass.

I'm using a Hornady comparator to check CBTO when I'm seating bullets; that's where I'm seeing a slight variation at times.

.020" off the lands is what I'm doing. I used the Hornady tool to measure find jam.

Thanks for the input.

 

[1holeaddict]

Is it always your last shot that is the flyer?

 

[tominboise]

Is it always your last shot that is the flyer?

This is what I was going to ask.

 

[bulletpruf]

Is it always your last shot that is the flyer?

No, I don't think so, but I'll pay closer attention next time.

 

[Ccrider]

Eliminate the pieces of brass that are giving you fliers.

 

[1holeaddict]

HAVE YOU MEASURED ALL YOUR FINISHED SEATING DEPTHS ON EVERY ROUND? ARE YOU GETTING INCONSISTENT SEATING DEPTHS ON FINISHED ROUNDS? IF SO CAN SOME OF THEM ACTUALLY BE JAMMED?

 

[Rick300]

This is what I was going to ask.

Me too!

 

[Doug Casner]

If your .020 off the lands I hope youve got an inline seater. Doug

 

[K22]

The MDT field chassis is supposed to be full floating up to and including an M24 barrel, but I can double check this.



Barrel has had a few hundred rounds through it. I cleaned it when it was new and have cleaned it once since then, but I haven not used anything more aggressive than Hoppes #9.



I'm a bigger guy at 6'4" and 235 lbs and I'm using a SilencerCo Scythe can, which reduced recoil, so it's really not noticeable.

I've been shooting for decades, but just military stuff and general hunting. This is my first time reloading and the first rifle that I've modified to be more accurate. I have been working on shoulder pressure but I really haven't spent any time working on follow through.



Wind is a possibility, but today I was shooting in a protected area. Would the mirage just be from a hot barrel or can? Or would 90 degree temps be enough?



This is a possibility. I'm waiting between shots so I have to get into position again each time.



Ok



Thanks

Sounds like you have most of the bases covered.

I know this is not popular in today's world, but I also only use Hoppes 9 and / or Shooter's Choice with a bronze brush and clean about every 50 or 60 round or so. All my rifles shoot to varmint level (1/2 to 5/8 moa) accuracy) if I do my part, wind and mirage notwithstanding. More importantly for a hunter, I do not have to fire fouling shots. My clean and cold bore shots are within my desired POI, an important consideration for a hunter because normally, it's the first shot that is the money shot.

I don't think mirage is an issue with the groups you posted since, at least in my experience, it produces the same effect on a string and usually high right or high left on a heavy boil. Wind is the real devil I deal with it since it swirls, change direction, and is variable at the places I shoot. Mirage boil and surrounding brush can help you see the wind effects. Wind flags are another aid. I've been shooting for about 60 years now and I have never quite mastered the wind issue.

I too am an experienced shooter, but I will and can, on occasion, push a shot and create a flyer from the other shots. Not necessarily saying this is an issue with you, but even experienced shooters are not immune to pulling a shot.

Best wishes in sorting this out.