Bolt lift 308 vs 6gt

[littlepod]

Swapped my action to a 6gt barrel today and noticed a heavier bolt lift when comparing it to how it functioned with my 308 barrel. Was wondering if that was to be expected. I'm guessing yes since the 6gt has more pressure?

Only thing I ever shot was 308 and 22lr so this is new to me.

Thanks.

 

[FatBoy]

Caliber makes no difference. Are you getting ejector flow or swiping on the case head?

 

[Kadams1563]

Pull the firing pin assembly and the ejector out of the bolt. See if the bolt closes with NO resistance and opens the same way. Brass might need to be resized smaller or bullet touching the lands.

I haven’t noticed any bolt lift difference from 6.5 cm to 6 GT but I’m using an impact.

 

[Changed]

Pull the firing pin assembly and the ejector out of the bolt. See if the bolt closes with NO resistance and opens the same way. Brass might need to be resized smaller or bullet touching the lands.

I haven’t noticed any bolt lift difference from 6.5 cm to 6 GT but I’m using an impact.

What kind of brass? My shooting partner experience issues with difficult bolt close/open due to the out of spec size of virgin brass.

 

[littlepod]

Bolt opens/closes without any problem. Cycled a few dozen rounds through my MDT 12-rounders. One of the MDT 12-rounders though I need to fix the feed lips (bought it used) and someone had mucked with them causing a weird taper at the front causing the round to spike. But in general feed, extract without any issues. No hitch at all.

This only happens on a fired round. I do notice this mark in the brass, looks like maybe a slight issue in the chamber, that needs to be fixed, maybe that little bump is causing the slight hitch on the extraction?

It's not a scratch, You can feel it noticebly when you run your thumb on it. Might be kind of hard to tell from the picture, but there's a line across the brass about 1/8" down from the bottom of the shoulder.

So the first part of the bolt lift is fine, I think that's cocking the trigger? Feels exactly the same as when I'm dry firing, or shooting my 308, then there's a bit of a hiccup, where I need to make sure I put more force up to get the bolt all the way before I pull back. I think that's the part that starts the extraction process.

 

[Changed]

A defect in the chamber will cause heavy bolt lift. I experienced this before. For the record this was a barrel cut by a very reputable smith.

Obviously the smith missed this in QC. He was easy to deal with and refunded my money.

 

[FatBoy]

If you have access to a borescope, check the chamber. You may be able to feel whatever is causing that with the tip of a dental cleaning tool, but be gentle. You don't want to scratch the chamber.

Is that ring raised or is it a groove?

 

[littlepod]

A defect in the chamber will cause heavy bolt lift. I experienced this before. For the record this was a barrel cut by a very reputable smith.

Obviously the smith missed this in QC. He was easy to deal with and refunded my money.

My bulge isn't that bad as your picture. My smith is dealing with it and cutting a new barrel right now. He could possibly hone it out, but that'll also widen the entire chamber specs by a little bit - so I think a new barrel, and maybe cut this one down to a 24".

I spoke to the smith and they said that the round I was running might be too hot. 2900fps 6GT lifts fine, but when he started pushing some hot rounds 105s at 3050, the lift was heavier.

I'm shooting Copper Creek's 105gr Berger Hybrid load, which they have listed at 3038 fps out of a 24" so I'm probably pushing close to 3060 out of a 26". So about 100fps hotter than the loads I'm seeing. Not sure why Clay's and Copper Creek run their ammo so hot if others are running it at Dasher speeds.

If you have access to a borescope, check the chamber. You may be able to feel whatever is causing that with the tip of a dental cleaning tool, but be gentle. You don't want to scratch the chamber.

Is that ring raised or is it a groove?

It is raised.

 

[Changed]

My bulge isn't that bad as your picture. My smith is dealing with it and cutting a new barrel right now. He could possibly hone it out, but that'll also widen the entire chamber specs by a little bit - so I think a new barrel, and maybe cut this one down to a 24".

I spoke to the smith and they said that the round I was running might be too hot. 2900fps 6GT lifts fine, but when he started pushing some hot rounds 105s at 3050, the lift was heavier.

I'm shooting Copper Creek's 105gr Berger Hybrid load, which they have listed at 3038 fps out of a 24" so I'm probably pushing close to 3060 out of a 26". So about 100fps hotter than the loads I'm seeing. Not sure why Clay's and Copper Creek run their ammo so hot if others are running it at Dasher speeds.



It is raised.

I would not accept a repaired barrel. I would demand a new barrel be cut.

 

[Petrov]

on my rem 700 after about 5k rounds the bolt handle where it cams off the reciver started to wear and peen over. 90% likely itots your dies but if its a rem 700 look at the bolt handle where it cams off the reciver

 

[littlepod]

This is a new Terminus Zeus action, about 50 rounds down it. New barrel. So I don't think it's anything wearing. This is Copper Creek loaded ammunition which I heard good things about.

Will send the barrel back to the smith and some ammo for them to check it out.

 

[FatBoy]

Have him check it. May just need to be set back 2-3 threads. Probably no big deal. I had an ecclusion open in a Wylde chamber a few years ago. Rifle functioned fine but the brass has a raised crescent about 30% around it. Started about 300 rounds in. He put a new barrel on and polished the ecclusion out of the old one. Still have them both. Got a backup I guess.

You're ring being all the way around, I would assume something cut a groove. No way to know if it was during the finish reaming or after, but it's a simple fix for someone who chambers barrels. Personally, I'd ask how much he needed to take off and if he can chase the threads and rechamber and I'd only loose about .25", I'd let him fix it.

Sucks dealing with this on a new rifle but shit happens. It's how people deal with it after the fact that really counts.

 

[littlepod]

Have him check it. May just need to be set back 2-3 threads. Probably no big deal. I had an ecclusion open in a Wylde chamber a few years ago. Rifle functioned fine but the brass has a raised crescent about 30% around it. Started about 300 rounds in. He put a new barrel on and polished the ecclusion out of the old one. Still have them both. Got a backup I guess.

You're ring being all the way around, I would assume something cut a groove. No way to know if it was during the finish reaming or after, but it's a simple fix for someone who chambers barrels. Personally, I'd ask how much he needed to take off and if he can chase the threads and rechamber and I'd only loose about .25", I'd let him fix it.

Sucks dealing with this on a new rifle but shit happens. It's how people deal with it after the fact that really counts.

Yep smith is great. I highly recommend them. They think something might've kicked up during the reaming that caused that to happen. They're going cut me a new barrel most likely, and might just chop this down to 24" and re-ream it and might be a backup barrel. They'll test fire it as they have an action like mine to mount it on and I'll send some of my ammo for them to look.

Thanks everyone for the tips and help.

 

[FatBoy]

Working with good people is always worth it.

 

[Snuby642]

Before shipping to smith and all that.

Have you tried any different ammo?

 

[littlepod]

Before shipping to smith and all that.

Have you tried any different ammo?

I don't handload so my choices are Copper Creek and Clay's right now. Copper Creek ammo was tested on this smith's barrels so it was tuned and made to shoot well on it. So I only purchased a few hundred rounds of Copper Creek. It shot great. First 5 shots were .7" and then the next group was .3" at 103 yards. I know it's not nearly enough for a break-in, just noticed the tight bolt lift and saw the brass. Before I keep shooting for $1.75 a round, might as well get the barrel taken care of.

 

[Snuby642]

I think you're rite. I was thinking more on the line of a production gun mentality.

I have had hassles with ammo company a scope company ect.

I got better customer service when I mounted the defective scope on 3 different ar's shot them and provided pictures.

The ammo from a small manufacturer was shot in three different guns and a reference group from different ammo provided resulted in imidiate resolution.

I just cut out as many variables as possible to smooth the process.

Hopefully your barrel is a quick fix.

 

[littlepod]

I think you're rite. I was thinking more on the line of a production gun mentality.

I have had hassles with ammo company a scope company ect.

I got better customer service when I mounted the defective scope on 3 different ar's shot them and provided pictures.

The ammo from a small manufacturer was shot in three different guns and a reference group from different ammo provided resulted in imidiate resolution.

I just cut out as many variables as possible to smooth the process.

Hopefully your barrel is a quick fix.

Thanks. Super happy with the smith as they didn't go and make me scout out more 6GT rifles and test the ammo. They just said send it back Unfortunately with the long weekend and vacations, I won't be able to get the barrel shipped until next Tuesday, so probably won't have a good answer until another week and a half or so.

 

[Snuby642]

I think that is a new world's record these days for a smith.

Sounds like the type of American craftsmen we all wish we knew.

Enjoy the weekend and plink some cheap rounds .

My son is returning from a 12 hr round trip drive with some varget he traded for.
Now I will be running the single stage and dillon for a week to catch up.