Is too much free bore my problem?

[birdiemc]

Ya know that aggravates the snot out of me, I do my best to measure everything to .001" I use torque wrenches, I try to go "by the book"....earlier this month was shooting with my brother in law, he been chasing the same accuracy issues with a Howa 1500 .308, but still in factory stock he "free floated" with a dremel, about 1/2" clearance under the barrel now. Had cheap gas station scope rings and a piece of plywood taped on with electrical tape for a cheek riser, redneck to the max. Well finally convinced him to at least put some talley rings on. He decides to bed the rings, did a good job but when he put it all back together put a couple screws in the wrong place, cross threaded one, stripped one out just totally fouled everything up he could, gorilla torque on everything and the SOB is now shooting better than ever. Yesterday he bought some factory 175 eld-x, shot a 6 round group, 1MOA....now that just drives me nuts, and the crazy thing about it, 3 shots touching, half inch right of that the other 3 are touching, probably bed that thing and put them through the same hole...

 

[RockyMtnMT]

We had a 308 win that did the same. Sounds like you have checked this but the issue was when action screws were tightened the bottom metal pressed the magazine shroud against the action. Shimmed the bottom metal out from the stock and cured it.

 

[birdiemc]

Got to shoot this morning. Loaded 6 rounds at 39.7, seated to .030 off lands. Shot two 3-shot groups at 100 yards, 1.5" and 2". But I noticed something, if I overlaid the 2, it ends up looking more like two 3/4" groups with one at 2 o'clock and the other at 7 o'clock. So it seems the stinging isn't quite random, I'm starting to wonder if I should bed the whole action, not supposed to have to in Magpul Hunter, but it's starting to look like a bedding issue from what I've read. I plan to pick up some factory ammo still and try out different weights, but Christmas Eve, might have to wait.

 

[RockyMtnMT]

I think you are on it now. Poor groups that show a pattern are something shifting back and forth or touching where there should not be.

 

[birdiemc]

Ok finally updating, I pulled my rifle apart and found a very small part where the bedding compound for the lug was contacting the receiver so cleaned that up as last hope before bedding the action. Bought some Federal gold medal 168 gr and 175 gr. Wind finally cooperated and got out there to shoot first thing this morning. With the 175 gr I shot 1 11/16" 3 shot group, 168 gr got 0.5" 3 shot group. And 1" 6 shot group. So conclusion is my gun likes 168 gr. Off to Angel Fire for a week of skiing now, so I'll play with it more when I get back, but just couldn't stand to leave not knowing. Thank you to everybody who offered up advice and opinions. I am finally happy with the way this rifle is shooting after owning it for over 2 years and wasting enough on the gun, parts and ammo that I could have just bought something that shot good from the start, lol.

 

[ShtrRdy]

Thanks for the update. My .308 loves the 168 hr FGMM too.

 

[tankgijohn72]

I have a Rem 700 .308 with factory 20" barrel 1:10 twist, been trying to get it to shoot decent for a couple years now. Out of the box it was 1.5-2 MOA. With or without suppressor, no difference in group size just slight shift in POI. Bedded Talley scope rings, torqued to recommended specs though dont recall now what that was. Lapped rings as they were showing limited contact. I thought maybe changing stocks would help so put it in a magpul hunter, groups opened up a bit and started throwing fliers 6" at 100yds. Pulled it apart checked contact with dykem found some problem areas around rear action screw and magazine, took care of them with a file, no contact on recoil lug except about .030 across the top edge so bedded the lug, still shooting over 2" at 100 yds. Tried different torques on action screws, 70 in/lbs finally brought it back down to where I began 1.5-2" at 100yds.
I finally got around to cracking open my hornady OAL comparator yesterday and found I have what I consider to be excessive free bore. I forgot to write down what it measured to the lands vs. a factory round but if I recall correctly it was about .210.
Today I seated everything to the max the magazine would allow and did write that measurement down, its .167 from the lands.
This is with a 220 gr ELD-X using varget 39.2-40.2 increasing in .2 increments
2240, 2272, 2275, 2285, 2302, 2337 checked using magnetospeed.
The accompanying groups with each load varied from 1.2-2", the tightest group was 39.8 and the POI shift from 39.6 to 39.8 was .143, not as good as .121 between first two charges, but looking at velocity, group size, and POI shift it seems 39.7 might be the ideal load.
Now back to the free bore problem, I'm already at max OAL for the magazine so trying to fine tune with seating depth seems a bit limited, and am I really going to be able to squeeze out an inch with seating depth?
I searched the history and found this thread below and see where many say this excessive free bore isnt necessarily a problem. So what are your thoughts?


https://www.longrangehunting.com/th...shot-out-rem-do-this-on-purpose.120193/page-2

I have a remington 700 SPS tac in .308 win. I load 168 hornady bthp match at 2.800". I have approximately 0.250" of freebore measured with the hornady oal gauge. It shoots lights out. You might consider changing bullets. Doesn't sound like your rifle likes the 220.

 

[dfanonymous]

OP did you pull the action out of the stock before you were aware of the accuracy issues?

 

[birdiemc]

OP did you pull the action out of the stock before you were aware of the accuracy issues?

Yes. I had accuracy issues with the original stock which is why I switched it to the Magpul hunter.

 

[dfanonymous]

Hmm. I've got the same rifle and in the same stock. Shoots sub moa with factory 178gr eldx (precision hunter) and even better with handloads. That being said, there seems to always be issues with remingtons quality control over the last years.

Anyways, I use threadtite on the action screws, I put my scope on right, I get rid of palalax swim, I keep the rifle level when shooting, I torque the action screws to to about 70 in lbs if I remember right, etc.
I DID try to do my reloads a couple thous of the lands (178 eld x handloads) and they were horrible compared to the factory ammo. I used something like 44gr of varget and I ended up seating the bullet down to the same depth as the factory and it was moa. I fine tuned from there. Most remingtons tend to have a decent amount of freebore so I wouldn't chalk it up to that. I'm almost positive it's a harmoic issue of a type

 

[birdiemc]

Well I have done too much to really say what finally got me to sub MOA with the 168 gr federal. Fortunately my dad bought the same rifle at the same time and it's only been fired enough to zero, dont remember what round I used. But I do remember the group size was unimpressive so I get to do it all over again. He had should surgery shortly after buying it and isnt up to shooting these days. I will say this, I'm going to start with the same 168 gr federal that finally grouped well in my rifle, then go from there with hand loads to see what i can do without changing anything at all about the rifle.

 

[Chase58]

Hey Birdiemc. I wanted to share with you something I happened across using the exact same rifle and stock you have. Not sure if you have resolve using the ELD-X 178gr. First off I am not a hunter but I have been getting into target shooting semi long range and ran across this thread so I signed up just so I could post up my lucky strike.
I was looking for some 178gr ELD-M bullets to try and was in Turners one day and just happened across the Hornaday ELD-X. That's all they had so I looked it up and saw the ballistic were better than the M's and picked them up. They shot TERRIBLE at mag length and I was pretty disappointed. I already had the load for the 178s but these were terrible. 4" plus at 100 yards. So stupid me knowing that a secant bullet is finicky on free bore seating to say the least. With all the freebore our rifles have, I could get to the lands with this bullet, but far from comfortable with not much bullet in the neck. So I moved it back to .050 off the lands....the LUCKY strike! 1/2" moa at 100yrds. And believe me when I say, for me that is good!

I am looking for a more temp insensitive powder right now as the RL-15 doesn't seem to like too much heat.

I know this is an older thread and hope this finds you. This will also be my 1000yd load. Hopefully at the end of this month I will put it to the test!