Bergara HMR .308 Experience and Challenges

[jdbell2004]

TL;DR
My Bergara shoots FGMM 168gn comfortably under 1 MOA after warranty service by Bergara.
My handloads are consistently around 1.5" at 100 yards regardless of the seating depth.
Considering trying Sierra 168gn bullets and/or new dies
Looking for the community's insight and maybe some encouragement to keep at it

_____________
I have about 275 rounds down the tube of my newest rifle, the Bergara B14 HMR in .308. Aesthetically and ergonomically, it's an awesome rifle in my book. The trigger is light and crisp, the stock is firm with some heft, and the black cerakoted barrel and action look nice against the brown webbed stock. But I can't get her to shoot my handloads worth a damn.

I have a Vortex Venom 5-25x56 in Vortex PMR rings on a Talley base. All screws are torqued to spec and marked all to catch any backout. I shoot from either an Atlas V8 or a front bag with an Armageddon Gear squishy bag at the rear and typically off a bench. Both are exceptionally stable platforms for me. I'm cleaning lightly after each range visit, about 15-30 rounds, and have been scrubbing with a nylon brush and Hoppes 9 at about the 100-round mark after break-in.

I followed Bergara's break-in procedure and while I wasn't expecting the best groups, I was immediately disappointed in how she was grouping. Once break-in was complete, I went immediately into load development starting with a charge weight test. My go-to bullet has always been Hornady's BTHP Match as I've never failed to find an excellent load in my other rifles. Using this bullet in 168gn, Lapua brass, and CCI BR2 primers, seated to 2.800 COAL. I found two nodes and chose the faster of the two. 43.3gn Varget put me at 2630 fps. Groups again were not great but I attributed it to the awkwardness of having a Magnetospeed mounted on a Wiser Precision mount under the forearm.

Next I loaded 6 3 round sets at increasing seating depths starting at .020 off the lands (lands at 2.258" with Hornady BTHP Match 168gn) for a CBTO of 2.238" or a COAL of 2.857". I increased the seating depth by .005" for each set to a minimum CBTO of 2.213" or COAL of 2.832 (.045" off the lands). Groups were 1.5-2.1". At this point I thought I'd better try their recommended ammunition to see if I might have a warranty case.

I picked up a box of Federal GMM 168gn and got similar results, nothing meeting their 1 MOA guarantee. Now, some may ask, "Well, can you even shoot?" and I appreciate the question. I'm no professional marksman but I've been in the military for almost 20 years now qualifying expert regularly and get consistent ~.5 MOA groups with my RPR in 6.5cm (exceptional performing rifle by the way). I contacted Bergara, explaining all I had tried and they sent me a shipping label. I received the rifle back two weeks later with a little target card showing 3 shots at .861" and a work order showing a re-crowing and bolt lug lapping were performed.

Back to the range I went. I started with some Federal GMM 168s and was blown away, 3 shots in a neat little cloverleaf. I then loaded up some of my handloads from before I sent the rifle in and fired them to get the brass to start load development again. Groups were ugly again so I loaded up 3 more Federals and fired at the same target. Shot 2 in that group was a bit of a flier while the other two went almost exactly where the first 3 went. I left the range feeling like things were looking up!



Having already settled on the charge weight, I again ran the seating depth test the same as above. This is the best group I ended up with. Needless to say, I'm frustrated. I've since tried several other Hornady bullets and some Nosler RDF 168gn that I had sitting in the reloading room to see if there is ANY movement in the right direction. Not following any specific development process for these loads, just using mid-weight charges from the Hornady manual. While it feels like I'm just burning cash, I'm hoping getting some more lead down the barrel may help settle it in as well.



I'm considering trying a different bullet, starting with the Sierra Matchking 168 that seems to perform well in the Federal loads. I've also considered that my dies may be the issue. I'm using a used set - RCBS FL sizer and RCBS Matchmaster seater. Runout is on average .002" with an occasional round coming in at .005" but I was seeing similar runout in the Federal loads as well. Perhaps a Redding neck bushing sizing die (as I use for my 6.5) would help.

My reloading process is exactly the same as that for my 6.5 creedmoor and that rifle shoots lights out so, while anything is possible, at this time I don't think that is the cause of my problems.

I could really use some guidance from this community.

 

[Sandstorm]

Try the Lapua 155gr Scenar and go through
The whole solid load development for it before you quit. I think you should be able to find a happy place there. They shoot extremely well for me in my 12 twist Kreiger
Dont just throw a book charge together and call it good

 

[Jon08089]

Barnes 180 TSX work the best for mine. Hate using the bullet for target shooting, but it's the only bullet so far that gives me sub moa handloads.

N140 39.1gr CCI200 not done yet, need to see if I can push it a little faster than 2400fps

BTW, your not going to equal that 6.5CM ever with a factory barrel. Most of the time, there are always oddballs.

 

[Ned Ludd]

It sounds as though the FGMM 168s are shooting reasonably well after the work was done, so the good news is that you now know what the "easy" button is.

With regard to further load development, I would suggest also starting with the "easy" button, meaning a tangent ogive bullet that is known to be relatively forgiving with respect to seating depth. The SMK 168 and 175 certainly fit such a requirement. Whether you could effectively load using a heavier (longer) bullet such as the 185 Juggernaut will depend on the chamber/magazine specs.

If you decide to try one of these bullets, identifying an optimal charge weight shouldn't be much of an issue. Tuning the load in with seating depth is likely to be the most important aspect based on what you described above. I would suggest testing seating depth in .003" increments starting from about .003" off the lands. I gathered from your previous post that you started at .020" off, and it is possible, perhaps even likely, that there may be seating depth optima even closer to the lands than that. I might try a seating depth test of something like .003" off the lands to .030" off the lands to start. You could certainly do that initially using .005 increments, but eventually I would want to use a finer test increment than .005".

Finally, in a worst-case scenario, you may find the rifle simply does not produce much better than 1 MOA groups, or thereabouts. Certainly you hope this isn't the case, but even if it is, I suspect that having it re-barreled with a quality barrel at some point down the road might make a significant difference in terms of precision. Thus, even if you can't get it shooting as well as you'd like now, you can have fun with it and shoot out the barrel, and then think about having a new barrel cut and installed.

 

[Longrange57]

Agree with all the above. I have built several 308's thru the years and 155 Lapua and 185 Jugg never let me down. I believe your barrel is a 10 tw. should work great. Most of the time I'm touching or 3-5 thou off. Lapua brass and Varget always did the trick for me as well. I did have a short barrel rifle once that grouped better with 4064.
Don't give up on it....you will probably find what it likes!

 

[Jon08089]

Might try the 185 Juggs myself, cheaper option than the barnes TSX.

 

[Lone Hunter]

Have you bedded the rifle or was it bedded from factory? Have you checked torque values on stock and made sure everything is not touching that shouldn’t be? Like other posters have said try a different bullet/powder combo.

 

[Michshooter]

I’m new to reloading but did find a great load for mine.

48gr IMR 4064
150 sst
Seating depth is saami spec.

1/2 group in my .308 hmr

My rifle is very sensitive to seating depth

 

[jelenko]

Just to confirm, when you say you found a couple nodes -were they nodes from a charge weight 'ladder' or velocity nodes?

If they were velocity nodes, it's great evidence on how velocity nodes are not necessarily related to accuracy.

 

[3Sigma]

Why not chronograph the FGMM and try to replicate that? Matching muzzle velocity and seating depth... 168 or 175 Sierra MatchKings are pretty insensitive to seating depth, but you may be able to further refine it. Nedd's advice regarding tangent ogive bullets is spot on.

 

[HandgunHTR]

Just to confirm, when you say you found a couple nodes -were they nodes from a charge weight 'ladder' or velocity nodes?

If they were velocity nodes, it's great evidence on how velocity nodes are not necessarily related to accuracy.

I will echo the above. I have a 7-08AI that proves that out. With both my Varget and H4350 loads, the accuracy node is off of the velocity node by about 80FPS.

My guess is that is if you load up some ammo in .5 grain increments (5 rounds at each charge weight) up and down from your velocity node and shoot those for groups, you will find one that groups well. Play in .1 or .2 grain increments from that one and then you can start playing with seating depth to really dial it in. If you don't see any appreciable difference in groups using that method, then it is probably the gun.
It will eat up more components that way, but I would bet good money you will either find a combo that the gun likes or find out that it isn't going to shoot to your standards.