Rem700 300WM Troubleshooting

[WeiserBucks]

I hope you get to the bottom of it . My latest 300 WM shot both the 212 ELDX and 215 Hybrids with great accuracy using H1000 jumping about .045" due to mag length restrictions. Neither bullet seemed sensitive to powder charge or seating depth in my particular rifle, I simply reached max pressure and backed off accordingly.

 

[ShtrRdy]

If the rifle is set up with an internal box magazine, check to see if the box is binding between the action and the stock. There should be a little wiggle room.

What did the 'smith use for bedding compound?

I couldn't get the Nosler 190 gr LRAB to shoot in my 300 Win Mag either.

 

[WeiserBucks]

Did the gunsmith shoot the rifle to check function and accuracy? Pretty standard procedure.

 

[ShortMag3]

I'm newer to precision shooting than some and am having major stringing issues with a 300WM rifle built for me by a well known gunsmith in my area to use on a hunting trip that I was just barely able to "finish" in time to take. What I took with me had some issues that I needed resolved later, the trigger had a bind and I had set the torque value too high (65lbs I thought was standard but I should have had ~43lbs for this stock!).

Before I corrected the rifle, I expected no phenomenal results and was getting around .75" MOA with 200 grain ELDX @ 2850fps and 1.5" with both with 212 ELDX and 190 grain ABLR using fresh Nosler brass, CCI primers, and H1000. The 212 grain was stringing diagonally while the 190 grains were all over the place.

The other day, after filing out for the trigger and torqueing properly, I had time to develop loads for all 3 using reloader 26 and seating bullets again .03 off the lands in fresh brass and shot them in 3 shots groups. I had a primer dud on one of the 200 grain ELDX and, by the time I shot it, I didn't have enough light to chronograph it but the two shots were within half an inch of each other. The 190 grain was even worse than it had been, and the 212 grain @ 2900 fps shot another diagonal group but this time 3" long!

I've accepted the 190 grain ABLR won't perform in my gun but I would love to shoot the 212 ELDX and have hope for it. In my experience, dramatic stringing is normally caused by binds in the stock but is it possible the problem is elsewhere that would result in such a large string and what would your next step be? I havent been able to find any binds now and the 200 grains shot okay regardless of a known bind.

The rifle:

-Remington 700
-26" Douglas custom contour sporter bull barrel
-McMillan Game scout stock matched to the barrel
-Timney trigger
-VX6 optic
-Bedded, fire-lapped, and blue printed by the gunsmith

I noticed the action screw torque you had at 43 lbs. Torque with aluminum pillars should be 50 to 65 inch pounds. If you are using foot lbs it's way over tightened and creating stress on the action - recoil lug and barrel.

 

[EarlYoung]

Update:

I decided to leave the rifle with my dad because of my current work schedule. He too experienced the poor performance and went straight to work on it without the gunsmith. He cleaned out the brake and found that the bedding job looked nice but hated that the recoil lug was fully bedded from the beginning (gunsmith wanted to do it that way so I did) and somehow turned out to be around .002" too tight for the lug! He cut out the front and sides and read a lot of conflicting information regarding what the stock should be torqued at. On McMillan's site 40-45lbs, on a post by I think the owner of mcmillan on this site 45-50lbs, and elsewhere pillar bedding should be 50-55lbs. He settled on trying it at 48lbs based on what he read it wouldn't matter too much for overtightening them but it would matter undertightening them.

Build up image was after he worked on it using a Berger 215 grain hybrid, reloader 26, and seated at 3.570" which is just .010" short enough to fit the magazine and .047" off the lands. It's clocking around 2900 fps at what looks to me to be the right charge node, 73.4-73.6 grains. One casing of 73.8 showed light pressure signs and that's where he stopped.

He wanted to comment that every group he shot with this bullet and others had the first two closest, often touching, and the third was the worst. He thinks he's "wishing the shot in" due to his personal pressure of making it right for someone but is concerned there might still be something wrong because he doesn't do it often with other rifles.

For the lands, he did some testing before changing the stock and brake to find that moving the 212 grain ELDX went from 6" groups to 1" groups just by making them 0.010" longer. We are now firm believers in adjusting smaller amounts of COAL and hes gone back to all his rifles to experiment because of it. All buildup loads are scoring 1MOA or better after changes which is a great sign, the same 212 grain ELDX load was 3/4" on the last test.

 

[bigngreen]

I get quite a number of rifles in with accuracy issues for rebarreled that the previous smith did a poor job on the brake, a brake with burs or through hole out of concentricity will never shoot excellent!!
The recoil lug should be bedded tight in every are except the very bottom!!
Fire lapping is a tool of last resort for factory barrels!!

 

[EarlYoung]

Correction, meant from 3 MOA groups to around 0.8 MOA with the ELDX but he's going off memory there. I had a brain fart forgetting he shot at 200 yards that day because he had other rifles he was playing with and that the later test with the same 212 wasn't actually the same COAL so nevermind that. Second hand information sure does get screwed up easily if you dont write it down. I can't wait until I start getting enough free time to shoot it for myself now.

For some reason the forum isnt letting me edit my post right now

 

[EarlYoung]

I get quite a number of rifles in with accuracy issues for rebarreled that the previous smith did a poor job on the brake, a brake with burs or through hole out of concentricity will never shoot excellent!!
The recoil lug should be bedded tight in every are except the very bottom!!
Fire lapping is a tool of last resort for factory barrels!!

I believe the brake issues are now resolved but I'm sure they were a problem earlier.

As for the bedding, I realize I didn't mention that my father had cleared out below the lug as well. We've read that model 700s are often best bedded only at the rear of the lug and it has worked well for us in the past. Do you think the last shot of a group fliers might have to do with the current bedding and would you suggest trying to fully bed the lug again without the bottom this time if the fliers don't leave? I've heard of people shooting smaller calibers with heavy contour barrels benefiting occasionally from it but I'm still unsure if it's the right thing to do.

I wish he hadn't fire lapped it.

Also, I noticed some extreme growth on fired brass compared to other guns, 0.510 new at base to 0.5185 after fired and a shoulder growth length 0.019. Im not sure how concerned I should be about this.

 

[bigngreen]

You've got problem on every end of that thing, belted mags will blow out the shoulder and depending on the reamer manufacture it will vary just set the dies accordingly, the base growth is on the excessive side!
A round action needs the sides of the lug bedded tight, it's what takes the rotational torque, you don't want that transferring to the screws.

 

[Joefrazell]

You need to load up several charges with each bullet and powder. Start low aND work up in .5 gr. Increments. Some guns won't shoot a particular bullet or powder so remember that.

To be honest it sounds like a bedding issue because it's stringing. Is your barrel channel touching your barrel from recoil lug forward? I think it would.be very wise to take it back to the smith as 3" groups is not acceptable.

 

[WildRose]

I hope you get to the bottom of it . My latest 300 WM shot both the 212 ELDX and 215 Hybrids with great accuracy using H1000 jumping about .045" due to mag length restrictions. Neither bullet seemed sensitive to powder charge or seating depth in my particular rifle, I simply reached max pressure and backed off accordingly.

I had similar performance from both the .300wm and .300 with H1000, RL23, RL26 loading them the same way to mag length. Similar results in the 7mm STW and .260Rem with RL23 and RL19, again same "load to mag length" procedure.