I've had a remington sds tactical 308 with the 20" barrel for a year now. Mounted a vertex razor on it and shot sub groups with 165 and 169s. The hogue stock didnt fit me well, got a McMillan a5 stock with the adjustable rest, aluminum pillars installed, and a grayboe m5 bottom plate. It all mounted perfect and fit snug, took it back out, I'm around 3" to 4" groups. I've tried a few torque specs of 45in lbs, 55, and 65in lbs. This didnt help. Took it to a local gunsmith to check it out. He tried a different scope, did shave a bit off the bolt channel because it wasnt locking completely, and shot about the same groups. He can glass bed it, but he said it should still have shot better and doesnt think itll help much. Any thoughts on this other than calling mcmillan? I know the hogue stock hugged the barrel more and was torqued pretty hard from the factory where the a5 stock does not. But I can't think of anything else it may be other than that. Any thoughts?
Gunsmithing Wider groups after mcmillan upgrade
- Thread starter Jbdpayne
- Start date
Give McMillan a call. I'm sure they would be glad to help you ouy.
With the original stock are you saying you get 1 moa groups?
With the original stock are you saying you get 1 moa groups?
Yes I do have few simple but often overlooked items you can look into.
Be sure your magazine box floats and is not pinched or bound up between
The receiver and bottom metal, rifles tend to shoot like crap when bedded on their mag. Boxes. Do what it takes to alleviate that situation if it exists.
Be certain the recoil lug is not bottomed out in the lug pocket in the stock, if so you must establish tolerance at the bottom of the recoil lug so the screws will pull up to the bottom of the Receiver not the bottom of the recoil lug.
Be certain that no part of the trigger is in contact with either the stock or the trigger mortise thru the bottom metal. Again a pinch situation between the trigger and stock or bottom metal will cause problems.
Ensure the screw heads on your guard screws are in full contact of the circumference of each screw head in the screw counter bore. The wear marks in the screw counter bores will tell you how well those are pulling in under torque. Lapping the screw counter bores in the bottom metal can get you more and exact contact screws to bottom metal, important detail to maintain a torque setting shot to shot. Seems pretty but if all adds up to what amounts to a consistently accurate rifle, a good group every time not just every now and again. Be sure to clean all lapping compound out of the screw head counter bore if you go that route.
Had a kid in here the other day with a vanguard in 257 whby mag that was shooting 3 inch groups, every single item I just mentioned was in violation, with those items corrected and a trigger job. 45 minutes and a c-note he was shooting 3/8 sweet little clusters. Got him totally dialed on my on site private range.
Be sure your magazine box floats and is not pinched or bound up between
The receiver and bottom metal, rifles tend to shoot like crap when bedded on their mag. Boxes. Do what it takes to alleviate that situation if it exists.
Be certain the recoil lug is not bottomed out in the lug pocket in the stock, if so you must establish tolerance at the bottom of the recoil lug so the screws will pull up to the bottom of the Receiver not the bottom of the recoil lug.
Be certain that no part of the trigger is in contact with either the stock or the trigger mortise thru the bottom metal. Again a pinch situation between the trigger and stock or bottom metal will cause problems.
Ensure the screw heads on your guard screws are in full contact of the circumference of each screw head in the screw counter bore. The wear marks in the screw counter bores will tell you how well those are pulling in under torque. Lapping the screw counter bores in the bottom metal can get you more and exact contact screws to bottom metal, important detail to maintain a torque setting shot to shot. Seems pretty but if all adds up to what amounts to a consistently accurate rifle, a good group every time not just every now and again. Be sure to clean all lapping compound out of the screw head counter bore if you go that route.
Had a kid in here the other day with a vanguard in 257 whby mag that was shooting 3 inch groups, every single item I just mentioned was in violation, with those items corrected and a trigger job. 45 minutes and a c-note he was shooting 3/8 sweet little clusters. Got him totally dialed on my on site private range.
Try torquing it back in your old stock and shoot it . Wonder if your still having the same issue? Your mcmillian should be bedded anyway but agree it won't help much as far as accuracy goes. The barrel channel cut different wouldn't matter either S long as the barrel is still free floated .If that doesn't work call them . They are an awesome groupd of folks are very helpful with those kinda things.
It sounds like you have induced some stress on the action when you swapped stocks or there is a contact point in the barrel channel.
You can check a few things out first.
With the front action screw in try loosening and tightening the rear action screw while looking for any movement at the tang.
Check and make sure you have adequate barrel clearance in the forearm.
Check to make sure the back of the recoil lug is making square contact in the stock and also not contacting at the bottom before the receiver is flat.
You can check a few things out first.
With the front action screw in try loosening and tightening the rear action screw while looking for any movement at the tang.
Check and make sure you have adequate barrel clearance in the forearm.
Check to make sure the back of the recoil lug is making square contact in the stock and also not contacting at the bottom before the receiver is flat.
The lug mortise is always quite generous but to go from sub moa to spray and pray my money is on mag box. I also always dab some Prussian blue on the bolt handle and make sure it’s closing fully without touching the stock.
Not as big a problem with remmy actions but almost all the clones will have interference here with Bighorn being the worst offender.
Not as big a problem with remmy actions but almost all the clones will have interference here with Bighorn being the worst offender.
I’d also be willing to bet it wasn’t entirely free floated in that hogue and you were getting some dampening affect from the contact. Easily ascertained with some electrical tape and or business cards. Been more than one factory barrel that needed those speed bumps in the barrel channel.
I know it seems silly, but you are double sure you are using a INCH pound torque wrench? I made that mistake years ago and got 4" groups out of a sub minute 22-250.
Sorry for the late reply everyone. We moved into a newer home and it's been pretty busy unpacking. I was able to check out the lug and it looked good. I also was definitely using an in-lb torque wrench vs the ft-lb, but I'm going to try and get to the range here over the next couple weeks and try shimming that barrel. I wouldn't think a bull barrel would but I have had numerous people suggest the business cards. Going to see if thay tightens them up and report back!
Satterlee, if a stock has pillars do you recommend that the pillars are clean and free of paint or other coatings that stock manufacturers apply? For example, every Grayboe stock I've bought has had the pillars covered by paint and other material so much so that I've had to chip the material way to expose the bare aluminum. I'm not sure it makes a difference but I'd think that pillar on receiver and bottom metal contact would help consistency and accuracy.
Also, when you talk about the magazine box, do you mean the magazine itself or the bottom metal box that the magazine goes into contacting the receiver?
Also, when you talk about the magazine box, do you mean the magazine itself or the bottom metal box that the magazine goes into contacting the receiver?
Similar threads
