Sticky Bolt Ideas?

[ottobounds]

I need some of y'all experienced reloaders help: Trying to figure out why I'm getting a consistent sticky bolt (needs to be tapped up with the heel of my hand). Facts: 7PRC, Second firing of Peterson Brass, annealed, full length sized (Area 419 die), trimmed, 175ELDX, RL26 65gr (+/- 2968), 65.5gr (+/- 2990), and 66gr (+/- 3010). After finding lands, I targeted a .003 jump, then comparing that with SAAMI COAL of 3.340, I ended up needing to seat deeper to get closer to the SAAMI number and landed on a COAL of 3.3415. Hornady "Precision" Hunter COAL averaged +/- 3.2940. I have all of this in BTOL measurements but for the sake of discussion I thought the COAL number would be more valuable. The resized and loaded rounds chambered beautifully.

Hornady factory ammo extracts perfectly and runs in anywhere from the low 2880s to 2950s. No real consistency with the factory stuff.

During fire forming I got extractor marks on everything except the most mild loads. Even on hotter loads up to 67gr (3043 ave) the cases for the most part extracted okay but I didn't want to run that kind of velocity. Moved back down to the above loads for the second firing / nailing down my hunting load.

Anyway, I'm a more than a bit frustrated and it hurts burning through my RL-26 and still trying to find the happy place before Fall. Scratching my head and hoping its something simple that I am missing.

Thanks in advance.

 

[Phil Rizzo]

What kind of action?
Have you measured the web area of your fired cases vs sized?
How many shots since last cleaning?

 

[ottobounds]

Lone Peak Arms Fusion Ti (Rem 700) shot through a PR Carbon 24".

Web measurements:
Fired Brass: Hornady .5315
Peterson .5320
Unfired Brass: Hornady .5290
Peterson .5310

 

[Phil Rizzo]

PM sent

 

[ottobounds]

What kind of action?
Have you measured the web area of your fired cases vs sized?
How many shots since last cleaning?

Oh, and I clean after every range session.

 

[lancetkenyon]

Lone Peak Arms Fusion Ti

This is my guess.

I have two LPA Fuzion TIs. One has not had any issues, from moderate to hot loads.
The other gets sticky bolts seemingly early. I have had 3 barrels on it so far. And two different bolts, a mag bolt and standard bolt. Same issue. It can get frustrating. So I have just come to grips with the fact I have to run very moderate loads with it.

 

[VinceMule]

All of these sticky bolt issues is where the brass fired is very, very close in dimension to the chamber dimension.

You can sort this issue out in several aspects:
A. the brass was too large to begin with, and you may also see that the full-length sizer does not reduce the dia
very much if at all.
B. The chamber is smaller than it should be for the brass. Remember, that reamers do wear as a gunsmith uses them. Also, in Lance's case, perhaps the reamer picked up a chip and scored the chamber with no issues where the gunsmith "polished" out the imperfections. In that tight chamber, I would have the gunsmith take out .0015-.0020 using 320 wet sand/oil using a split dowel, shouldn't take more than 30 minutes.
C. IN some cases, the PRC rounds have a mismatch between reamers/brass/dies which is well documented as Lance has given his example. The new Brass dimension is of critical importance to consider, measured with a Micrometer to the .0001. Compare new brass size, fire-formed brass size, size after going through a full-length sizer.

In the end, you will come up with a dimension where the brass needs to be to fit your chamber with good extraction using peak pressure loads where the accuracy resides.

 

[Hugnot]

^ ^
This: "I got extractor marks on everything except the most mild loads." and this: "Hornady factory ammo extracts perfectly and runs in anywhere from the low 2880s to 2950s"

My guess is excessive pressures and excessive bolt thrust. Loads might be at 65K plus psi.

Look at fired brass under 10X to indicate annular chamber defects .

 

[WeiserBucks]

Ti actions will typically show pressure earlier vs SS and RE 26 does weird things in the summer heat.

 

[AIMBackcountry]

I'm not familiar with the action, but I had a 30 Nosler do the same thing. The chamber was fairly tight to begin with and would shave tiny slivers of brass on some reloads. I cleaned out the brass shavings from the chamber and didn't have anymore problems. It might be worth shining a light in the chamber and check for brass fillings.

 

[AkleyFan]

As suggested by VinceMule in item B, I believe your chamber may be on the small side in relation to your brass.

I took a 400 grit FlexHone, that is made for honing chambers, to a tight chambered 30-06 that had the same issues. I opened it up .0015" and that solved the sticky brass / heavy bolt lift problem - took a few minutes but that rifle runs perfectly now. I sprayed the hone with penetrating oil - my lubricant of choice for these types of operations. Keep us posted.

 

[Rosebud]

Try not cleaning between range sessions and let the rifle tell what pressure it likes, not what is done with a pressure barrel. Start backing off your load until it stops being sticky. Every rifle is different, including yours.

 

[Taylorbok]

My buddies 28 Nosler on a Cadex action is like this, I've chalked it up to that's all it will take. Load where it's not sticky and carry on with life

 

[VinceMule]

I took a 400 grit FlexHone, that is made for honing chambers, to a tight chambered 30-06 that had the same issues. I opened it up .0015" and that solved the sticky brass / heavy bolt lift problem - took a few minutes but that rifle runs perfectly now. I sprayed the hone with penetrating oil - my lubricant of choice for these types of operations. Keep us posted.

BINGO!!! WE HAVE A Winner!