Rem 721 30-06 Vertical stringing issues

[icentropy]

I purchased a Remington 721 from Born on date of 3/48 a few weeks ago.
Beautiful rifle, an AMAZING trigger, factory checkered stock, just a gem.

Trigger is so good in fact i can't imagine it's factory, must have had a very talented gunsmith work on it. I looks like it has a pressure bedded stock as it really doesn't look free-floating to me.

Chamber is very very tight, factory ammo fits perfectly, my resized brass barely fits.

Every indication points to a well made accurate rifle. So i purchased a new Buckmaster scope, mounted it and finally got a chance to take it out and see what it could do. It was a cold day and i started to sight it in. Left to right was easy. It's holding well under a 1" group at 100yards but verically it's stringing up to 3"! I've tried different ammo, and started working up some reloads and same exact issue. I did notice that the barrel on this rifle seems to heat up almost immediately. after 3 shots it's hot. Is there such a thing as a 1-2 shot rifle? Does it probably being pressure bedded mean that it needs to cool down completely after each shot? I've never had a rifle like this so I don't really know what to start looking into.

The only really weird thing i noticed is that when i had some time during the day to shoot some reloads i worked up it was probably 65-70F outside in the sun and it was touching bullet holes but i was only shooting 2 shots max then letting it rest. I worked up what i thought was a good starting load which did great in the warm day.

168gr Hornady HPBT Bullets
50gr Varget
3.300 COL

When i came back to it in the evening probably around 50F outside I made up 12 rds using the load above that did the best during the day and tried the same thing with 3-4 shot groups (sun was going down and i had to start hurrying) and the first shot went pretty well but the rest began stringing up/down. worst 3 shot group was 3" vertical string (1/2" horizontal string) at 100yards. But the average was a 2" vertical string with less than 3/4" horizontal spread.

Any ideas? I'm fairly new to reloading and target shooting in general so I have no idea if it's the rifle, the way i'm shooting it (bipod prone) or something like barrel heating up, outside temp,etc?

[Bhobbs]

It might be the stock flexing and pushing up on the barrel or stress in the barrel changing the POI when it heats up.

[ar15barrels]

Rem 721 30-06 Vertical stringing issues

1-2 shot accuracy is common in lightweight sporter barrels.
The accuracy of the first shot is what matters in hunting guns.

Target rifles have much heavier barrels to reduce thermal issues.

[icentropy]

1-2 shot accuracy is common in lightweight sporter barrels.
The accuracy of the first shot is what matters in hunting guns.

Target rifles have much heavier barrels to reduce thermal issues.

ahh, well that makes sense. I guess it's just gonna be a very very slow shooting gun if i want to keep the groups down. I have a gut feeling that this rifle is capable of being very accurate but was getting frustrated by the weird vertical stringing.

I'll wait for a sunny day and take my time. one shot every 30 minutes to see if that's really the culprit. I'm fine with a cold bore only hunting rifle as long as i can trust it's first shot will be where i want it. I've just never owned a rifle like that.

[Divernhunter]

Check the stock screws.
Sounds like pressure on the barrel.

[Fjold]

Cut a couple of strips out of an old credit card and put them under the action to lift it higher in the stock. This will reduce the pressure of the forearm on the barrel. Shoot it and see if this reduces the vertical stringing issue.

If it does, then remove the barreled action from the stock and take a rasp to the pressure point in the forearm. This is easily found by sliding a dollar bill between the barrel and the forearm until it catches. It is usually about 1" to 2" from the end of the forearm. Take a bit off at a time until you can slide a dollar bill between the barrel and the forearm with the action tight in the stock. Don't forget to reseal the rasped wood in the barrel channel with varnish/polyurethane.

[Knife Edge]

I have JB Weld / skim bedded a 30-06 and 338, both stock with HS stocks. In either case groups shrank to sub-MOA. The reality is the composite stocks, even the fiberglass ones flex a and the receiver contact points in stock form are minimal. Inconsistent contact between the receiver and stock will create unpredictable harmonics and throw shots.

First thing I would do is make sure the barrel is free floated and the screws through the bottom metal are tight, especially if your stock has aluminum bedding blocks.

[Knife Edge]

1-2 shot accuracy is common in lightweight sporter barrels.
The accuracy of the first shot is what matters in hunting guns.

Target rifles have much heavier barrels to reduce thermal issues.

Agree 100%. 2-3 shots IMO.

[kayaker]

I have a Ruger M77 ultralight .308 that had the same issue, it would string the shots out up and slightly to the right. If I fired 3 shots quickly there would be 6-8 inches from 1st shot to last.
I sent the barrel out to be cryogenicly tempered. This was about 20 years ago and it cost me $60.00 then plus shipping. The rifle has a very thin 16" barrel and now it still isn't as good as my Weatherby 30-06 but it's damn near as good. With factory ammo I can usually keep at least 1-1/2" groups at 100 yards, I shot a couple of sub 1" groups last time out.
I'm sure that there are a few companies. I'm not positive but I think this is the company that did my rifle.

http://www.300below.com/

[dfletcher]

I have a 721 in 300 H & H. The "bottom metal" is nothing more than a stamped piece of metal, probably more at home on a 22 LR than a centerfire rifle. It may be worthwhile to use metal pillers (pillars?) for the front & rear screws, provide a solid and repeatable setting front & back. Although the rifle looks untouched, whoever had it before me did that and free floated the barrel and the thing groups consistently.

[dpr]

Bed and float it and your problems will likely go away.