Problem child of a rifle...(Cold Bore Question)

[Monttrap04]

I have a model 70 featherweight push feed that has been my meat and potatoes gun since I bought it new in the early 90's. Early on I always shot 165 grain factory core-lokts. When I began handloading for it 10 years or so ago I shot 165 Hornady Interlocks and 165 partitions. My handloads were fairly anemic but the rifle grouped adequate for my needs at the time (about 1-1.5"). With the rifle zeroed 2-3" high at 100 I killed truckloads of deer.

As I got more into shooting I was less happy with the performance of the rifle. I had it bedded, free-floated, and had a trigger job done. I began looking for a higher performing load and shot a variety of 165-180 grain projectiles with only average accuracy. Lots of groups around 1.5". I did notice lots of cold bore shots 1-2" higher than the rest of the group. In a rush last Fall I found what I thought was going to be my all-around load with a 150 TTSX going about 3000 fps with 3 shot groups in the 1-1.25" range. Plenty adequate for a big game rifle that I never plan to shoot much over 400 yards with. I settled on the charge pretty quickly and didn't do much follow up testing.

I didn't hunt with the rifle much and decided on the last weekend of the season to fill a doe tag with it. I held for the chest at maybe 125 yards and spined the deer.

I took it out Saturday to check zero and my cold bore shot went 6.5" above center. A good 3.5-4" above where it should have been. I adjusted the scope down and my shots with a warmer barrel were hitting below center at 100 yards. Unadjusted they would have been 2-3" high, right where I wanted them.

Looking back, even with my older loads, I have had several deer that were spined or missed completely on the first shot and then punched cleanly with the follow up. I always shrugged it off as poor shooting but I am rethinking that.

Any suggestions to reduce the spread between the cold bore and a warmer barrel?

Do I just sight the "group" dead on or just below at 100 and let the cold bore go 3" higher if it will do it consistently?

Do I try adding some fore end pressure to the stock and see if that quiets things down?

Is it time to rebarrel (I almost feel bad even doing that to the old girl)?

Guns flow through my house like water but this is not one that I ever plan to give up, except maybe to a grandkid. Way to much sentimental attachment. Every mark on that rifle is mine and probably 90% of my big game kills were with that gun. At the same time, I have gotten spoiled with accurate rifles and it drives me a little nuts having a rifle that I don't have much confidence it.

Any help is appreciated.

Thanks

 

[Rich Coyle]

tag

 

[Georgiashooter]

It seems like this started after the bedding job and floating barrel. Sounds like the floating caused it but it wouldn't hurt to check bedding as well.

I would first check the bedding and make sure there's no debris between action and bedding. Make sure trigger and bolt handle are clear of contact with stock. Next, install front action screw to around 45 lbs/in. Then install rear action screw and see if rear tang moves any. You can eyeball it or set up a dial indicator on barrel at tip of forearm to detect any significant movement. I like to see .001" or less to call it good.

If all that checks out, I would bed the barrel completely. That will usually calm a whippy barrel. After that take it out and shoot it, if it's not better, fold a business card and put under barrel just behind tip of forearm. Sometimes it helps, sometimes it doesn't. You can fold it again and try as well. If it gets better measure thickness of your pad and put you a glob of bedding compound in that same spot and work it down to same thickness as your pad after it sets up most of the way. The upward pressure should be @5 lbs, sometimes up to 10lbs pressure.

ETA: check the crown as well, or have a smith check and recut it if needed. I'm assuming the barrel is clean and not shot out with the above suggestions.

Richard

 

[Monttrap04]

Thanks for the suggestions!

I think the free floating has definitely made the situation worse. It is possibly exaggerated by the higher pressure loads I am now running (book max vs book min basically). Assuming it is bedded properly I will work on expirimenting with the fore end pressure as you mentioned. I have a Ruger Compact with a light barrel that got worse after floating and settled down with a business card wedged in the forearm.

 

[Greyfox]

i have owned FW Model 70's over the years and found that they generally shot better with fore end pressure on the barrel. I would however remove the existing pressure point in the fore-end and replace it with a 1" long section of epoxy bedding that encompassed the barrel to within 1/16" of the edge if the stock with pressure produced by the thickness of a matchbook cover. This gave better accuracy and 1st shot consistency over the sloppy job out of the factory.

 

[Jerry M]

The barrel has some use, is it clean? Also noted that you switched to a all copper bullet, again do you have a fowling problem, either copper or carbon?

 

[Frank in the Laurels]

Sometimes you just gotta let problem children go !!