Sticky bolt

[SST2500]

Ok. Here’s the problem. I have a 6mm BR Norma Rem 700 action with an MGM barrel. I shot the barrel after it came in and I had problems with heavy bolt lift at no where near max pressures or velocities. This is a Remage barrell set up. I am shooting 109 gr. Berger Targets. I am shooting these round thru Lapua twice fired brass with 28.3 gr. of H-4895 powder with an E-S of 4.0. I am getting approx. 2806 FPS with this load. I am not getting the type of accuracy I was expecting. The action has been blueprinted and the the receivery has been bedding .

 

[LHSmith]

So, you did not start with new brass for the new barrel? FL sizing?

 

[457ciSBC]

1. Are you FL sizing?
2. What are the chamber reamer specs?

 

[Drolds72]

All the lube off the brass before you fire it?
take a piece of brass fired in the new barrel and measure it for shoulder length and for base size at the .200 line. Compare the shoulder length on the fired to the unfired. Should be longer, not the same or shorter. Either you needed to size the 2x fired brass more for this chamber, or the die you are using is not sizing the base enough.

 

[Ccrider]

In addition to the things listed above, brass could be too long. Could be shoulder needs to be bumped back further.

 

[Link]

Remage / did you set it up with go - no go gages

 

[SST2500]

The brass has only been fired in this barrel, no other rifle. The barrel was installed with Go-No Go Gauges. The only cause I can come up with may be I am loading the bullets 0.012 into the lands. This may be increasing the pressure to the point I am getting sticky bolt lift. Almost all the loads listed on the 6mm BR page show to be loaded at this distance into the lands. I may have to try them just touching the lands and see if that cures the issue. I have shot Lapua factory ammo in the rifle with no issues. The brass is being resized and the shoulder bumped back 0.003. All the brass was trimmed after the first firing.

 

[LHSmith]

Always work up to any published load (other than reloading manual start loads).

 

[Dgd6mm]

What's your overall length your loading to?

 

[Eric Leonard]

If it’s a newer REM action the bolt handle cam extraction timing may be out of whack.

 

[David Milisock]

Ok. Here’s the problem. I have a 6mm BR Norma Rem 700 action with an MGM barrel. I shot the barrel after it came in and I had problems with heavy bolt lift at no where near max pressures or velocities. This is a Remage barrell set up. I am shooting 109 gr. Berger Targets. I am shooting these round thru Lapua twice fired brass with 28.3 gr. of H-4895 powder with an E-S of 4.0. I am getting approx. 2806 FPS with this load. I am not getting the type of accuracy I was expecting. The action has been blueprinted and the the receivery has been bedding .

So you have 3 problems, poor accuracy, low velocities and sticky bolt.

1. Check all case dimensions, a fired case and a resized case for proper specifications.

If the fired case specifications are correct.
2. Check the chamber for free bore.

If the resized case specifications are incorrect.
3. Take action to correct what ever the issue is.
check your procedures and your dies.

If the fired case is out of specifications
4. return the rifle to the gunsmith.

 

[dkhunt14]

The brass has only been fired in this barrel, no other rifle. The barrel was installed with Go-No Go Gauges. The only cause I can come up with may be I am loading the bullets 0.012 into the lands. This may be increasing the pressure to the point I am getting sticky bolt lift. Almost all the loads listed on the 6mm BR page show to be loaded at this distance into the lands. I may have to try them just touching the lands and see if that cures the issue. I have shot Lapua factory ammo in the rifle with no issues. The brass is being resized and the shoulder bumped back 0.003. All the brass was trimmed after the first firing.

.012 into the lands shouldn't be driving the pressure that high to get a sticky bolt. I would look for something else. I am not familiar with the Berger 109 but I bet it is long surface bearing bullet. Maybe not enough freebore in the barrel. That can drive pressure up by taking away capacity. You cant compare factory ammo to reloaded ammo because new cases are always smaller and not show pressure as good as already fired and reloaded cases. Sometimes it takes two or three firings till cases get expanded enough to get tight. Matt

 

[ttfreestyle]

Correct twist ?

 

[SST2500]

It’s a 1-7 twist barrel. I ran a load yesterday of 28.5 gr. of H-4895 in twice fired Lapua brass that was run through a full length case die and then neck sized. I was shooting Hornady 110gr. A-tips, 0.010 OFF the lands and getting a velocity of 2805 FPS with an SD of 5.0. I completely cleaned the barrel and chamber before shooting the rounds. I was still getting sticky extraction. This is NOT a hot load. From what I’ve seen, I should be able to run this up to possibly 2875 fps before I see pressure signs. As far as free bore goes, if you are jamming bullets into the lands, you have NO free bore at all. The sticky extraction occurs with the bullets jammed 0.012 or run 0.010 off the lands. It has to be something else causing the problem. Just can’t figure it out.

 

[Link]

REMAGE - Is it posable the barrel has moved back? Try your gages again . Maybe you should try a resize in a fl 30-06 die. I think it's like .0015 smaller at .2? I don't have time to look it up so.

;]

 

[Eric Leonard]

Is the bolt handle hard to lift or hard to pull back or both.

 

[SST2500]

The bolt handle is tight to lift but once it reaches the cam point, the round extracts fine.

 

[jelenko]

One of the remage barrels I had didn't have enough clearance for the muzzle side of the bolt locking lugs. I had to take a little material off the lugs.
The behavior was the same, 'stickly' lifting the handle, but easy pull back.

 

[SST2500]

Unusual but here’s the quirk. Originally, the action was an original Remington 700 factory action and I was having trouble with stiff bolt lift so I had the action blue printed by a gunsmith and after getting it back ( it appears the gunsmith did a good job) I installed the barrel and am still having the same the same stiff bolt lift issue. This is the most unusual problem I’ve come up against in my rifle assembly career.

 

[rocketron]

maybe give a 105 a try if you have any.