Home Forums Hunting & Shooting Long Range Hunting Heavy bolt lift with very mild loads. No other signs of pressure. ???

I hit the range today with some 6.5x55

After purchasing some rounds through copper creek that were maxing out at around 2500 fps, I decided it was time to begin reloading to see what I could squeeze out of my T3 Swede.

I worked up some rounds with virgin Lapua Brass, Berger VLD Hunting (140 grain), and RL 22.

Unfortunately even with the mild loads I was getting heavy bolt lift after the rounds were fired.

No issues chambering unfired rounds, no issues re-chambering fired brass, no flattening of primer, no other signs of pressure.

The bolt while heavy was not extreme so I cautiously worked my way up from 43.5 to 45.75 grains. As you would expect velocity steadily increased from 2465 to 2578 with (average of 3 rounds for each load). Still there were no other signs of pressure other than the heavy bolt and the bolt did not get heavier as I proceeded.

I decided to not go any further without checking headspace with go-no-go. I will have to buy those to run them through the paces. Until then I am hoping someone can give me some insight as to what else may be causing the issue.

Like I said, no issues chambering unfired rounds. No issues chambering fired brass. Just the heavy bolt after firing.

I worked them up at 3.123 which is .005 off the lands.

The unfired cases are 2.157 and after being fired they are 2.153.

Other than headspace, are there other things I should be looking at/considering?

One more thing, the bolt lift is NOT heavy when chambering or ejecting loaded rounds. It is simply heavy AFTER being fired.

6.5x55 cartridge has a fair amount of taper
sounds like case setback against bolt face
clean chamber and loaded rounds with Acetone
report back

I cleaned with Hoppes #9 last week and this was the 1st range session since. I do have acetone on hand so may give that a second pass through the rifle and see if there is any difference

Grease the rear of the locking lugs as well as the extraction cam surface's. Muddy

RL22 is a slow burning double base powder. It is possible to get increased pressure with loads that are TOO LOW. You mentioned the bolt lift did not get heavier as you increased the charges. You also mentioned velocities of around 2500. I wouldn't be shocked if your hard bolt lift went away if you loaded to 2700 or so.

Buy some H4350. You should be able to get to 2700-2750 pretty easily.

Yes.

Try a burn rate that is more quicker'er.




Dave

I agree with them. Try H4350 and RL19. Either one should do well with the short barrel.

I'd guess none of the above. Pressure signs would show up if that was the issue. I don't think it's headspace either; it would show false pressure signs.

A rough chamber will cause heavy bolt lift at mild pressure. Dealt with that recently on a RAP in 6.5 Creed. That chamber had reamer marks that showed up on fired brass as shiny rings near the case web, and it only happened with one brand of brass, which must be a little softer. A little bit of careful lapping and polishing of the chamber fixed it, no more hard bolt lift with the same loads and components.

If you're not comfortable doing that yourself, don't take the risk, you can easily change headspace if you mess up. It's a relatively simple job for a decent gunsmith though. Bring him a few pieces of fired brass, the stuff that caused heavy bolt lift.

Yes, that is because you are cocking the spring on a fired round when you lift the bolt handle. Chamber an empty fired case, and pull the trigger. Now lift the bolt and see how the bolt feels...

Ok, so tonight I verified it is not a headspace issue (go/ no go)

I cleaned the bolt, the chamber as well as the lug recesses.

I then cleaned some brass of a few unfired rounds.

I greased the locking lugs and the extraction cam as well as the cocking cam.

I fired another round...same heavy lift.

when I got back I saw dogcatchers post and gave it a fire. Heavy lift after firing an empty round.

So the Copper Creek rounds did not give the hard lift symptom? Load some of that once fired brass with H4350 to mid-range level from your manual. Make sure you're not setting the shoulder back.

Bob

Bob, I did load some of the once fired copper creek brass (Hornady) and it gave me the same heavy lift (it did not give me the heavy lift the 1st fire)

note I loaded it with re 22 as I did not have any H4350 available.

DC223 has nailed it?

Dry fire it. Same "heavy lift" to work the bolt?

David

Look at the cam on the back of the bolt that cocks the firing pin, it may be rough, that would cause the fired bolt heavy lift you describe.

You should put a dab of grease on that cam, many people run it dry (not good). You can use a buffer wheel on a Dremel to polish the cam and reduce friction as well, but only polish it, then grease it up again.

Spot

Look at the cocking cam picture here - I forgot to mention you have to dissassemble the bolt to polish that cam.

http://www.accurateshooter.com/technical-articles/bolt-maintenance-methods-materials/

Hobnob and Canazes9, Yes DocCatcher was correct. Same heavy bolt after dry fire.

Sharpshooter, I found this very same article last night and greased the cocking cam but did not polish it. Believe it or not, I am one of the few without a dremmel. Looks like one may be in my near future. I will check to see if it is rough and if so it will be polished and regressed.

As I was taking a close look at everything late last night, I did find the ejector pin has a very small protrusion that is leaving a very small mark/scratch on the headstamp (regardless of if the round was fired or not) so that clearly needs to be smoothed out as well.

Last trip to the range I was pushing a Nosler 180 gr etip with 61 grs of RL 22 in my 30-06, first round the bolt seemed stiff. Checked the case and No sign of high pressure so I cleaned everything up and tried a second and again fired fine but stiff bolt raising and pull back.

I ran up to 62 grs of RL 22 (nosler book max) a few years back in the Tikka 30-06 I had at the time and there was no issues at all. This was all brass that had loaded serial time, thinking of loading up some NEW Nosler brass I have and working up from 58 gr this time.

Is RL 22 an issue?

Was the brass previously loaded for that rifle. If it wa loaded for another rifle, the base may be expanded a bit too much for your chamber??