RAP bolt stuck

[FLshooter]

I just got a 6.5 Grendel RAP.Put over 100 rounds through it in three outings. First time was with the flimsy green stock that comes from the factory ,the last two times I?ve used my MDT chassis system .I did not work up any loads for it yet ,nor did I use factory ammo. I?ve been shooting my Hornady 123 g ELDM handloads. All the cases were trimmed and full length sized with a Forster sizing die on my Forster coax. I check random cases w/Wilson gauge.So,I am thinking,it is not the cases. Anyway,I loaded the rounds with 27.3 grains of H335.
The 6.5 Grendel RAP has been very impressive ,groups are good.I used an ASC 10rd mag.Feeds very well no jams of any kind.But the problem I had,was two times out of the hundred plus rounds I shot,the bolt locked up.And both happened today. First two outings no stuck bolt.it was not bad enough to where I needed to stick a rod or a dowel down the muzzle and mortar it out. I just had to keep trying to work the bolt B061B742-D67A-4F49-BDFB-0B1E59B564E4.jpegback ,eventually it worked itself free.
I looked at the fired case and it appears normal.No signs of high pressure. But in my mind that?s all I?m thinking it could be.Anytime I?ve had a bolt lock up and I both action rifle it was because I had loaded the round too hot. I had it done load development for this rifle yet, as I just got it. And I didn?t think that those rounds were very hot. I?ve shot them through my bodies are a P and through several of my A.R. 15 with no problems .
Still I can?t think of anything but high pressure that would cause a bowl to stick like that .I?m thinking that I will start load development 1.3 g lighter and work up .2g
As always I appreciate any input.
I inserted a picture of the two cases. Not sure that will help. But I?m sure that?s what most guys would want to see.

[Lemonaid]

A few things to check: Velocity, faster than normal?
OAL where bullets touch the lands, are the bullets seated so as to jam into the lands?
I noticed when I accidentally loaded a round meant for my AR grendel into my RAP that it was a lot harder to close the bolt. I full length resize everything grendel so you would think they would chamber fine in both firearms.
So if you are running brass in your RAP that had been fired in a different gun it may have some effect.
I switched to Lapua brass for the RAP and Hornady for the AR to make it easy to keep separate.
Last idea, My Rap's chamber is not very polished. I haven't had problems so I let it be. Something to check, a rough chamber makes it harder to extract.

[Javman]

By the looks of cartridge it seems you might have a rough spot in your chamber. Probably need to polish it a bit. Hope it's as simple as that.

[Klem]

Here's a thought and probably not the problem but shows how headspace is not as simple as the length from datum to base.

I once had a 338LM, a Rem X 'Special' (everything's 'special' in the gun industry). Basically a Rem700LA with beefed-up rail screws. The hand-loaded full length rounds went into the chamber fine but after firing the bolt was always sticky to open...even on the mildest work-loads. Turns out the whole chamber was flexing/expanding and then contracting to grip the empty case on firing. Remington stopped selling that line shortly after. In a fixed model like the Rem700 as the calibre gets bigger, there is less meat around the case to support the pressure. They cashed in on the new popularity of the 338L the cheapest way they could, just use an existing design.

Took us a while to figure it out, it was lateral headspace (measured by the diameter or how fat the cartridge is), not longitudinal headspace (measured by how long the cartridge is base-to-datum). All rifle gauge brands concentrate on longitudinal headspace and machine their diameters generously; to make sure everyone's fire-formed handloads will fit down to the datum. As I understand it, Sheridan machine their gauges with proper reamers so all axes are considered.

It could just be a tight chamber requiring more sizing.

[FLshooter]

I took the bolt out last night.Looked through it with bore light.The chamber didn’t look like it had a rough spot,it looked dirty ,maybe some kind of packing lube .Stuck a bore guide in and proceeded to run a brass brush through. Then I ran a little Hoppe’s cleaning solution and close to 40 patches through it till they came out clean.The barrel was filthy. I usually clean the barrel in a new rifle. I got lazy ,and I’ve also been leaving it in the back seat of my truck so I can shoot after work.I got to go back to my old routine.I usually run a nylon brush and patches through my rifles after every use.
Last night I hand loaded 50 rounds of 6.5 Grendel 123 grain Hornady ELDM 25.5g-26.7g. 10/ea in .3 g increments.Went to the club after work. 26.4 grains seems to be the winner. Almost a gr lighter than handloads I shot last time.Shot 50 rounds no bolt sticking problems.
I’m thinking that the reason my bolt stuck was too much chamber pressure from hot loads or dirty chamber.Either way it appears I solved the problem.

[AgedWarrior]

Reading the OP I was wondering if the new rifle got cleaned. New guns are typically needing cleaned in my experience; cleaned and lubed. I am glad the problem is solved.

[FLshooter]

Reading the OP I was wondering if the new rifle got cleaned. New guns are typically needing cleaned in my experience; cleaned and lubed. I am glad the problem is solved.

As posted,I did not clean it before shooting. Are usually do ,I got lazy. And I paid for it. Because now I don’t know exactly why it was sticking. I just know it was one of those two things.

[Rosecrans1]

And Ruger uses an oil that is very viscous in their barrels/chambers when shipped. (Plus the excessive light oil elsewhere in the bolt, trigger, action screws and under the rails).

[tdbru]

FLShooter,
this isn't the problem, and you found what the problem was, but on all bolt actions where the bolt lug raceway cutout area also has the front action screw into it (Rem 700, Win 70, etc.) if the front screw gets too long (various reasons), the bolt will hang up on the tip of the front action screw and the bolt won't go into or out of battery. now if the action screw is just shy of touching the bolt lug by fractions of a thousandth when cold, it is (remotely) possible that as you shoot and the bolt head gets warm and expands, it may expand just enough to catch the lug against the tip of the front action screw. probability of this situation is very remote. but none the less, this is a situation (front action screw getting far enough in to the bolt lug raceways cut out area and binding up the bolt) that needs checking once on any new or used rifle so you don't find it out, out in the field. use to occur sometimes with wood stocks and strong armed folks that made sure the action screws were "tight". eventually the wood would compress enough to allow the tip of the front action screw to penetrate into the bottom bolt lug raceway. and if you forgot to check before you headed out to hunt you were in for a bummer of a surprise. one thing about the original M98 design, Wby MkV, and Howa is that the front action screw goes into the front recoil lug so this cannot happen. i don't know how the front action screw on the 527 is located with respect to the action so this may be something to keep in mind or maybe not. as i mentioned, i'm glad you found that it was just a normal over pressure situation that is much easier to diagnose and correct.
-tdbru