Bolt locking up but I dont think it is pressure ?

[CZ550]

I have a 338 Lapua that has always had a little bit of stiff bolt lift but I thought it was because the brass had been fired to many times. When I bought the rifle it came with some brass that had been neck sized only. I bought some new Lapua brass and yesterday was the first day I fired any of that brass for the second time. I use Redding FL bushing dies and a Wilson case gauge to check shoulder bump. I locked the bolt up yesterday using my normal load of 92 grains of Retumbo, I had to use a hammer to get bolt open and the extractor failed to remove the case. Next I tried to lower the charge down to see if that helped with extraction and didn't really see an improvement until I got down to 86 grains wich is almost the recommended starting load but bolt still didn't open as smoothly as it should. I am bumping shoulders back as far as I can, using the Wilson case gauge I am a little below the lower step and cases seem to be just a little above upper step after firing. Rounds chamber easily before firing and primers look great. Why would I be having problems with even low charge weights.

The rifle is a 338 Lapua built by Kirby Allen
Bat Action.

 

[1000yardstare]

I am watching this thread with interest, not because I own a .338 Lapua, but because I see the same problem occuring with .338 Lapua shooters at our F Class practises. Now and then they have bolt lift problems and they don`t understand why. There was no problem the practise before or the practise after and they maintain they used the same load in all three practises.

I wasn`t standing at the reloading bench with them the night before so can only take their word on their loads. Perhaps the answers to this thread can enable me to advise .338 users next Summer as to the possible source of their difficulties.

 

[Shynloco]

Looks like you aren't alone. I've seen the same thing happen to two separate Savage .338's within the past few weeks at the range. If I were you, I'd call your rifle manufacturer to find out what is causing it since it seems to be happening to several rifles of that cailber.

 

[RonAKA]

May not apply in your case at all, but I have a Savage rimfire, that I experienced this issue with. It had nothing to do with the cartridge or chamber at all. Toward the back of the bolt is a steep ramp, that a pin slides up to cock the firing pin for the next round. At least in my Savage, this cocking takes place as you lift the bolt. The pin had severely galled due to lack of lubrication. Owner/operator problem. I like to keep my bolt clean with minimal lubrication, and over did it. Replaced the pin, and now I keep a light coat of an extreme pressure silicone grease on the pin and ramp.

In any case this is a low probability reason, but your post got my attention as you said you needed a hammer to open the bolt. That's exactly the way the Savage behaved.

 

[1000yardstare]

RonAKA.....excellent suggestion. The cocking cam at the rear of the bolt. Had an Anschutz .22 rimfire with the same problem. Galled surfaces. Had to be hammered open. Problem went away when lubed.

On my centrefire rifles, I lube the locking lug faces and cocking cam before every range session.

 

[7stubby]

Have a Weatherby Mark 5 in 7 WSM, bolt starting having heavy lift on cocking. Got some Pro Shot Pro Gold lube and problem fixed. $4.38 fixed my problems. A little lube goes a long way. :

 

[Neale]

high dollar fancy rifles and unaware of proper lubrication and maintenance......

 

[CZ550]

Nope I know how to lube a bolt and maintain my rifle, something else is going on and I think I may have found it. I thought that my sized brass was chambering easily but after further inspection I noticed that some of my once fired and sized brass had a little bit of resistance when closing the bolt, so I am thinking that I am not able to bump my shoulders back far enough with my curent setup. So I stoned my shellholder down several thousandths and it seemed to clear that condition up. But the shellholder broke out when I was trying to size some of my 5 times fired neck sized only brass. I am gonna maybe try to cut a few thou off of my die that seems like it would be a better way of doing it.

Anyone ???

 

[RonAKA]

CZ, I didn't think it was likely on a centerfire, but thought I would offer it. I fired thousands of rounds in my Savage, and pushed the limits, and was totally stumped when I could not lift the bolt with only this mickey mouse LR rimfire cartridge in the chamber. Hope you figure out the real issue.

My experience is that in 99% of the cases there is only one root cause, and when you find it, there is a big Ah Ha, I have it!

 

[mbp708]

Have you checked your case length or chamber length? Had a 6/284 Encore that was doing the same thing. Almost drove me crazy till I found out the chamber was cut short and pinching the neck on the cases.

 

[AndyTaber]

I had a similar experience with my Remington 700. I had installed an aftermarket firing pin assembly and after about 60-70 rounds through the rifle, the bolt started getting stiff until I too had to tap the bolt open with a mallet. I suspected a few of my loads may have been a little too hot. Turned out to be the firing pin cross pin was getting deformed - it was trying to look like a "w". I suspect they used an unhardened pin and it wasn't holding up. Replaced the pin with a Remington pin and problem gone.

 

[bozo699]

Have you checked your case length or chamber length? Had a 6/284 Encore that was doing the same thing. Almost drove me crazy till I found out the chamber was cut short and pinching the neck on the cases.

mbp708,
+ one on your post I had the same problem cz550 is having, came to the same conclusion he did, did the same as he did which helped. I was trimming my .300wm to specs, but the chamber was tight,trimmed a little more and problem went away.
Wayne.

 

[spdfreq]

i had the same problem with my 7mm stw took a while to find it but the barrel had a small crack in it back by the chamber and every it i touched it of the chamber would flex and the the brass would get stuck. might not be your trouble but i'm glad i found my trouble before things went really bad